Scholars@Duke
construction release_alert
The Scholars Team is working with OIT to resolve some issues with the Scholars search index
cancel
Ehsan Samei

Ehsan Samei

Professor in Radiology
Radiology
DUMC Box 2731, Durham, NC 27710
2424 Erwin Road, Suite 302, Ravin Advanced Imaging Labs, Durham, NC 27705

Selected Publications

The potential of photon-counting CT for the improved precision of lung nodule radiomics.

Journal Article Phys Med Biol · January 27, 2025 Objective.Lung nodule appearance may provide prognostic information, as the presence of spiculation increases the suspicion of a nodule being cancerous. Spiculations can be quantified using morphological radiomics features extracted from CT images. Radiomi ... Full text Link to item Cite

Photon-Counting CT Effects on Sensitivity for Liver Lesion Detection: A Reader Study Using Virtual Imaging.

Journal Article Radiology · January 2025 Background Detection of hepatic metastases at CT is a daily task in radiology departments that influences medical and surgical treatment strategies for oncology patients. Purpose To compare simulated photon-counting CT (PCCT) with energy-integrating detect ... Full text Link to item Cite

A Physics-Informed Deep Neural Network for Harmonization of CT Images.

Journal Article IEEE Trans Biomed Eng · December 2024 OBJECTIVE: Computed Tomography (CT) quantification is affected by the variability in image acquisition and rendition. This paper aimed to reduce this variability by harmonizing the images utilizing physics-based deep neural networks (DNNs). METHODS: An adv ... Full text Link to item Cite

A framework to model charge sharing and pulse pileup for virtual imaging trials of photon-counting CT.

Journal Article Phys Med Biol · November 6, 2024 Objective.This study describes the development, validation, and integration of a detector response model that accounts for the combined effects of x-ray crosstalk, charge sharing, and pulse pileup in photon-counting detectors.Approach.The x-ray photon tran ... Full text Link to item Cite

Preoperative planning for shoulder arthroplasty is feasible with computed tomography at lower-than-conventional radiation doses.

Journal Article J Shoulder Elbow Surg · October 21, 2024 BACKGROUND: Computed tomography (CT) offers a detailed assessment of the shoulder for preoperative shoulder arthroplasty planning; however, this technique exposes the patient to ionizing radiation. The purpose of this study was to prospectively evaluate th ... Full text Link to item Cite

Photon-counting computed tomography versus energy-integrating computed tomography for detection of small liver lesions: comparison using a virtual framework imaging.

Journal Article J Med Imaging (Bellingham) · September 2024 PURPOSE: Photon-counting computed tomography (PCCT) has the potential to provide superior image quality to energy-integrating CT (EICT). We objectively compare PCCT to EICT for liver lesion detection. APPROACH: Fifty anthropomorphic, computational phantoms ... Full text Link to item Cite

Development of a separability index for task specific characterization of spectral computed tomography.

Journal Article Phys Med · June 2024 PURPOSE: In this work, we define a signal detection based metrology to characterize the separability of two different multi-dimensional signals in spectral CT acquisitions. METHOD: Signal response was modelled as a random process with a deterministic signa ... Full text Link to item Cite

Influence of CT dose reduction on AI-driven malignancy estimation of incidental pulmonary nodules.

Journal Article Eur Radiol · May 2024 OBJECTIVES: The purpose of this study was to determine the influence of dose reduction on a commercially available lung cancer prediction convolutional neuronal network (LCP-CNN). METHODS: CT scans from a cohort provided by the local lung cancer center (n  ... Full text Link to item Cite

Protocol selection formalism for minimizing detectable differences in morphological radiomics features of lung lesions in repeated CT acquisitions.

Journal Article J Med Imaging (Bellingham) · March 2024 BACKGROUND: The accuracy of morphological radiomic features (MRFs) can be affected by various acquisition settings and imaging conditions. To ensure that clinically irrelevant changes do not reduce sensitivity to capture the radiomics changes between succe ... Full text Link to item Cite

A systematic task-based image quality assessment of photon-counting and energy integrating CT as a function of reconstruction kernel and phantom size.

Journal Article Med Phys · February 2024 BACKGROUND: Image quality of photon-counting and energy integrating CT scanners changes with object size, dose to the object, and kernel selection. PURPOSE: To comprehensively compare task-generic image quality of photon-counting CT (PCCT) and energy integ ... Full text Link to item Cite

Surface-based anthropomorphic bone structures for use in high-resolution simulated medical imaging.

Journal Article Phys Med Biol · December 28, 2023 Objective.Virtual imaging trials enable efficient assessment and optimization of medical image devices and techniques via simulation rather than physical studies. These studies require realistic, detailed ground-truth models or phantoms of the relevant ana ... Full text Link to item Cite

Unsupervised synthesis of realistic coronary artery X-ray angiogram.

Journal Article Int J Comput Assist Radiol Surg · December 2023 PURPOSE: Medical image analysis suffers from a sparsity of annotated data necessary in learning-based models. Cardiorespiratory simulators have been developed to counter the lack of data. However, the resulting data often lack realism. Hence, the proposed ... Full text Link to item Cite

Exploration of the pulse pileup effects in a clinical CdTe-based photon-counting computed tomography.

Journal Article Med Phys · November 2023 BACKGROUND: High tube current generates a high flux of x-rays to photon counting detectors (PCDs) that can potentially result in the piling up of pulses formed by concurrent photons, which can cause count loss and energy resolution degradation. PURPOSE: To ... Full text Link to item Cite

Pulsed wave Doppler ultrasound: Accuracy, variability, and impact of acquisition parameters on flow measurements.

Journal Article Med Phys · November 2023 BACKGROUND: Pulsed wave Doppler ultrasound is a useful modality for assessing vascular health as it quantifies blood flow characteristics. To facilitate accurate diagnosis, accuracy and consistency of this modality should be assessed through Doppler qualit ... Full text Link to item Cite

Coronary stenosis quantification in cardiac computed tomography angiography: multi-factorial optimization of image quality and radiation dose.

Journal Article J Med Imaging (Bellingham) · November 2023 BACKGROUND: The accuracy and variability of quantification in computed tomography angiography (CTA) are affected by the interplay of imaging parameters and patient attributes. The assessment of these combined effects has been an open engineering challenge. ... Full text Link to item Cite

Virtual monoenergetic imaging in photon-counting CT of the head and neck.

Journal Article Clin Imaging · October 2023 PURPOSE: Advantages of virtual monoenergetic images (VMI) have been reported for dual energy CT of the head and neck, and more recently VMIs derived from photon-counting (PCCT) angiography of the head and neck. We report image quality metrics of VMI in a P ... Full text Link to item Cite

Impact of the confluence of cardiac motion and high spatial resolution on performance of ECG-gated imaging with an investigational photon-counting CT system: A phantom study.

Journal Article Phys Med · October 2023 PURPOSE: Photon-counting CT (PCCT) has higher spatial resolution that conventional EID CT which improves imaging of stationary coronary plaques and stents.. In this work, we evaluated the relationship between higher spatial resolution and motion acquisitio ... Full text Link to item Cite

Quantitative performance of photon-counting CT at low dose: Virtual monochromatic imaging and iodine quantification.

Journal Article Med Phys · September 2023 BACKGROUND: Quantitative imaging techniques, such as virtual monochromatic imaging (VMI) and iodine quantification (IQ), have proven valuable diagnostic methods in several specific clinical tasks such as tumor and tissue differentiation. Recently, a new ge ... Full text Link to item Cite

Image quality of photon counting and energy integrating chest CT - Prospective head-to-head comparison on same patients.

Journal Article European journal of radiology · September 2023 PurposeTo prospectively compare the image quality of high-resolution, low-dose photon-counting detector CT (PCD-CT) with standard energy-integrating-detector CT (EID) on the same patients.MethodIRB-approved, prospective study; patients re ... Full text Open Access Cite

Exploratory analysis of mesenteric-portal axis CT radiomic features for survival prediction of patients with pancreatic ductal adenocarcinoma.

Journal Article Eur Radiol · August 2023 OBJECTIVE: To develop and evaluate task-based radiomic features extracted from the mesenteric-portal axis for prediction of survival and response to neoadjuvant therapy in patients with pancreatic ductal adenocarcinoma (PDAC). METHODS: Consecutive patients ... Full text Link to item Cite

A methodology for incorporating a photon-counting CT system into routine clinical use.

Journal Article J Appl Clin Med Phys · August 2023 Photon-counting computed tomography (PCCT) systems are increasingly available in the U.S. following Food and Drug Administration (FDA) approval of the first clinical PCCT system in Fall 2021. Consequently, there will be a need to incorporate PCCTs into exi ... Full text Link to item Cite

Comparative Risk Assessment of Clinical and Radiation Risk across a Cohort of Patient and Individualized Risk Optimization

Conference https://aapm.onlinelibrary.wiley.com/doi/epdf/10.1002/mp.16525 · July 23, 2023 Purpose Informed by a recent mathematical framework, we formulated an imaging strategy to balance interpretative performance-based clinical risk (i.e., false positive and false negative rates) and radiation risk as a risk-versus-risk assessment. The model ... Full text Open Access Link to item Cite

Development and Testing of a Clinical Tool to Predict and Optimize Liver Contrast-Enhanced CT Imaging

Conference https://aapm.onlinelibrary.wiley.com/doi/epdf/10.1002/mp.16525 · July 23, 2023 Achieving consistent and sufficient hepatic parenchyma contrast enhancement (HPCE) level can improve diagnostic performance and reduce enhancement variability; this raises the baseline image quality and optimize injection practices, both carries economic a ... Full text Open Access Link to item Cite

Accuracy of Noise Magnitude Measurements from Patient CT Images

Conference https://aapm.onlinelibrary.wiley.com/doi/epdf/10.1002/mp.16525 · July 23, 2023 Purpose Noise magnitude is a main CT image quality indicator. In vivo measurements emerged as a patient-specific methodology to assess and qualify CT noise, yet methods to do so vary. Current noise measurement methods in soft tissues and air surrounding t ... Full text Open Access Link to item Cite

Development and CT image-domain validation of a computational lung lesion model for use in virtual imaging trials.

Journal Article Med Phys · July 2023 PURPOSE: Computational abnormalities (e.g., lesion models) for use in medical imaging simulation studies are frequently generated using data collected from clinical images. Although this approach allows for highly-customizable lesion detectability studies ... Full text Link to item Cite

Exploiting the Potential of Photon-Counting CT in Abdominal Imaging.

Journal Article Invest Radiol · July 1, 2023 Photon-counting computed tomography (PCCT) imaging uses a new detector technology to provide added information beyond what can already be obtained with current CT and MR technologies. This review provides an overview of PCCT of the abdomen and focuses spec ... Full text Link to item Cite

High Spatial-Resolution Skull Base Imaging With Photon-Counting Computed Tomography and Energy-Integrating Computed Tomography: A Comparative Phantom Study.

Journal Article J Comput Assist Tomogr · July 2023 Photon-counting computed tomography (PCCT) offers better high-resolution and noise performance than energy integrating detector (EID) CT. In this work, we compared both technologies for imaging of the temporal bone and skull base. A clinical PCCT system an ... Full text Link to item Cite

Can Photon-Counting CT Improve Estimation Accuracy of Morphological Radiomics Features? A Simulation Study for Assessing the Quantitative Benefits from Improved Spatial Resolution in Deep Silicon-Based Photon-Counting CT.

Journal Article Acad Radiol · June 2023 RATIONALE AND OBJECTIVES: Deep silicon-based photon-counting CT (Si-PCCT) is an emerging detector technology that provides improved spatial resolution by virtue of its reduced pixel sizes. This article reports the outcomes of the first simulation study eva ... Full text Link to item Cite

AAPM President: 2023

Journal Article Medical Physics · June 1, 2023 Full text Cite

Emphysema Quantifications With CT Scan: Assessing the Effects of Acquisition Protocols and Imaging Parameters Using Virtual Imaging Trials.

Journal Article Chest · May 2023 BACKGROUND: CT scan has notable potential to quantify the severity and progression of emphysema in patients. Such quantification should ideally reflect the true attributes and pathologic conditions of subjects, not scanner parameters. To achieve such an ob ... Full text Link to item Cite

Liver fat quantification in photon counting CT in head to head comparison with clinical MRI - First experience.

Journal Article Eur J Radiol · April 2023 PURPOSE: To compare liver fat quantification between MRI and photon-counting CT (PCCT). METHOD: A cylindrical phantom with inserts containing six concentrations of oil (0, 10, 20, 30, 50 and 100%) and oil-iodine mixtures (0, 10, 20, 30 and 50% fat +3 mg/mL ... Full text Link to item Cite

Making CT Dose Monitoring Meaningful: Augmenting Dose with Imaging Quality.

Journal Article Tomography (Ann Arbor, Mich.) · April 2023 Due to the concerns about radiation dose associated with medical imaging, radiation dose monitoring systems (RDMSs) are now utilized by many radiology providers to collect, process, analyze, and manage radiation dose-related information. Currently, most co ... Full text Open Access Cite

Is it possible to use low-dose deep learning reconstruction for the detection of liver metastases on CT routinely?

Journal Article Eur Radiol · March 2023 OBJECTIVES: To compare the image quality and hepatic metastasis detection of low-dose deep learning image reconstruction (DLIR) with full-dose filtered back projection (FBP)/iterative reconstruction (IR). METHODS: A contrast-detail phantom consisting of lo ... Full text Link to item Cite

Harmonizing CT Images via Physics-based Deep Neural Networks.

Journal Article Proc SPIE Int Soc Opt Eng · February 2023 The rendition of medical images influences the accuracy and precision of quantifications. Image variations or biases make measuring imaging biomarkers challenging. The objective of this paper is to reduce the variability of computed tomography (CT) quantif ... Full text Link to item Cite

A systematic assessment of photon-counting CT for bone mineral density and microarchitecture quantifications.

Journal Article Proc SPIE Int Soc Opt Eng · February 2023 Photon-counting CT (PCCT) is an emerging imaging technology with potential improvements in quantification and rendition of micro-structures due to its smaller detector sizes. The aim of this study was to assess the performance of a new PCCT scanner (NAEOTO ... Link to item Cite

Development and Application of a Virtual Imaging Trial framework for Airway Quantifications via CT.

Journal Article Proc SPIE Int Soc Opt Eng · February 2023 Chronic obstructive pulmonary disease (COPD) is one of the top three causes of death worldwide, characterized by emphysema and bronchitis. Airway measurements reflect the severity of bronchitis and other airway-related diseases. Airway structures can be ob ... Full text Link to item Cite

Patient-specific Cardio-respiratory Motion Prediction in X-ray Angiography using LSTM Networks.

Journal Article Phys Med Biol · January 5, 2023 Objective.To develop a novel patient-specific cardio-respiratory motion prediction approach for X-ray angiography time series based on a simple long short-term memory (LSTM) model.Approach.The cardio-respiratory motion behavior in an X-ray image sequence w ... Full text Link to item Cite

Phase-contrast virtual chest radiography.

Journal Article Proc Natl Acad Sci U S A · January 3, 2023 Respiratory X-ray imaging enhanced by phase contrast has shown improved airway visualization in animal models. Limitations in current X-ray technology have nevertheless hindered clinical translation, leaving the potential clinical impact an open question. ... Full text Link to item Cite

Oncology-specific radiation dose and image noise reference levels in adult abdominal-pelvic CT.

Journal Article Clin Imaging · January 2023 OBJECTIVES: To provide our oncology-specific adult abdominal-pelvic CT reference levels for image noise and radiation dose from a high-volume, oncologic, tertiary referral center. METHODS: The portal venous phase abdomen-pelvis acquisition was assessed for ... Full text Link to item Cite

Coronary Artery Calcium Evaluation Using New Generation Photon-counting Computed Tomography Yields Lower Radiation Dose Compared With Standard Computed Tomography.

Journal Article J Thorac Imaging · January 1, 2023 Prospective head-to-head comparison of coronary calcium scores between standard computed tomography (CT) and photon-counting CT show no significant differences, while photon-counting CT administers substantially lower radiation dose. ... Full text Link to item Cite

CT-HARMONICA: physics-based CT harmonization for reliable lung density quantification

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2023 Pulmonary emphysema is a form of Chronic Obstructive Pulmonary Disease (COPD) and a chronic lung condition that results in a breakdown of alveoli walls. Quantitative Computed Tomography (CT) is increasingly used to assess the presence or progression of emp ... Full text Cite

Bone suppression technique for multidirectional dynamic chest radiography: A virtual imaging trial

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2023 Prediction of pleural invasion in lung cancer is crucial in planning appropriate operating procedures and can be assessed using dynamic chest radiography (DCR). However, this assessment is negatively affected by rib shadows in conventional images. The purp ... Full text Cite

Automatic quality control in computed tomography volumes segmentation using a small set of XCAT as reference images

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2023 Deep learning methods have performed superiorly to segment organs of interest from Computed Tomography images than traditional methods. However, the trained models do not generalize well at the inference phase, and manual validation and correction are not ... Full text Cite

Emphysema Score in CT for COPD Quantifications Using Artificial Intelligence Informed by Virtual Imaging Datasets

Conference AMERICAN JOURNAL OF RESPIRATORY AND CRITICAL CARE MEDICINE · 2023 Cite

Task-based validation and application of a scanner-specific CT simulator using an anthropomorphic phantom.

Journal Article Med Phys · December 2022 BACKGROUND: Quantitative analysis of computed tomography (CT) images traditionally utilizes real patient data that can pose challenges with replicability, efficiency, and radiation exposure. Instead, virtual imaging trials (VITs) can overcome these hurdles ... Full text Link to item Cite

A patient-informed approach to predict iodinated-contrast media enhancement in the liver.

Journal Article Eur J Radiol · November 2022 OBJECTIVE: To devise a patient-informed time series model that predicts liver contrast enhancement, by integrating clinical data and pharmacokinetics models, and to assess its feasibility to improve enhancement consistency in contrast-enhanced liver CT sca ... Full text Open Access Link to item Cite

Prospective Multireader Evaluation of Photon-counting CT for Multiple Myeloma Screening.

Journal Article Radiol Imaging Cancer · November 2022 Purpose To determine whether photon-counting CT (PCCT) acquisition of whole-body CT images provides similar quantitative image quality and reader satisfaction for multiple myeloma screening at lower radiation doses than does standard energy-integrating det ... Full text Link to item Cite

Dose coefficients for organ dosimetry in tomosynthesis imaging of adults and pediatrics across diverse protocols.

Journal Article Medical physics · August 2022 PurposeThe gold-standard method for estimation of patient-specific organ doses in digital tomosynthesis (DT) requires protocol-specific Monte Carlo (MC) simulations of radiation transport in anatomically accurate computational phantoms. Although a ... Full text Open Access Cite

Generative learning approach for radiation dose reduction in X-ray guided cardiac interventions.

Journal Article Med Phys · June 2022 BACKGROUND: Navigation guidance in cardiac interventions is provided by X-ray angiography. Cumulative radiation exposure is a serious concern for pediatric cardiac interventions. PURPOSE: A generative learning-based approach is proposed to predict X-ray an ... Full text Link to item Cite

Comparison of Simulated Low-Dose and Conventional-Dose CT for Preoperative Planning in Shoulder Arthroplasty.

Journal Article J Bone Joint Surg Am · June 1, 2022 BACKGROUND: Shoulder computed tomography (CT) is commonly utilized in preoperative planning for total shoulder arthroplasty. Conventional-dose shoulder CT may expose patients to more ionizing radiation than is necessary to provide high-quality images for t ... Full text Link to item Cite

Anatomically and physiologically informed computational model of hepatic contrast perfusion for virtual imaging trials.

Journal Article Med Phys · May 2022 PURPOSE: Virtual (in silico) imaging trials (VITs), involving computerized phantoms and models of the imaging process, provide a modern alternative to clinical imaging trials. VITs are faster, safer, and enable otherwise-impossible investigations. Current ... Full text Link to item Cite

Correction for Systematic Bias in Radiomics Measurements Due to Variation in Imaging Protocols.

Journal Article Acad Radiol · April 2022 RATIONALE AND OBJECTIVES: The accuracy of measured radiomics features is affected by CT imaging protocols. This study aims to ascertain if applying bias corrections can improve the classification performance of the radiomics features. MATERIALS AND METHODS ... Full text Link to item Cite

Reduced-Dose Deep Learning Reconstruction for Abdominal CT of Liver Metastases.

Journal Article Radiology · April 2022 Background Assessment of liver lesions is constrained as CT radiation doses are lowered; evidence suggests deep learning reconstructions mitigate such effects. Purpose To evaluate liver metastases and image quality between reduced-dose deep learning image ... Full text Link to item Cite

Technical note: Controlling the attenuation of 3D-printed physical phantoms for computed tomography with a single material.

Journal Article Med Phys · April 2022 PURPOSE: The purpose of this work was to characterize and improve the ability of fused filament fabrication to create anthropomorphic physical phantoms for CT research. Specifically, we sought to develop the ability to create multiple levels of X-ray atten ... Full text Link to item Cite

Quantitative analysis of changes in lung density by dynamic chest radiography in association with CT values: a virtual imaging study and initial clinical corroboration.

Journal Article Radiol Phys Technol · March 2022 Dynamic chest radiography (DCR) identifies pulmonary impairments as decreased changes in radiographic lung density during respiration (Δpixel values), but not as scaled/standardized computed tomography (CT) values. Quantitative analysis correlated with CT ... Full text Link to item Cite

A GPU-accelerated framework for individualized estimation of organ doses in digital tomosynthesis.

Journal Article Med Phys · February 2022 PURPOSE: Estimation of organ doses in digital tomosynthesis (DT) is challenging due to the lack of existing tools that accurately and flexibly model protocol- and view-specific collimations and motion trajectories of the source and detector for a variety o ... Full text Link to item Cite

Medical physics 3.0: A renewed model for practicing medical physics in clinical imaging.

Journal Article Phys Med · February 2022 Inspired by the principles of Medical Physics 3.0, this paper frames a new model of clinical physics practice, anchored to clinical realities, clinical priorities, and advanced physics. The model is based on the conviction that the physicist is vested with ... Full text Link to item Cite

Science and practice of imaging physics through 50 years of SPIE Medical Imaging conferences.

Journal Article J Med Imaging (Bellingham) · February 2022 Purpose: For 50 years now, SPIE Medical Imaging (MI) conferences have been the premier forum for disseminating and sharing new ideas, technologies, and concepts on the physics of MI. Approach: Our overarching objective is to demonstrate and highlight the m ... Full text Link to item Cite

SPIE Medical Imaging: Content within Context.

Journal Article J Med Imaging (Bellingham) · February 2022 The history of SPIE Medical Imaging and the legacy of its founders are part of our scientific heritage. ... Full text Link to item Cite

Classification of Multiple Diseases on Body CT Scans Using Weakly Supervised Deep Learning.

Journal Article Radiol Artif Intell · January 2022 PURPOSE: To design multidisease classifiers for body CT scans for three different organ systems using automatically extracted labels from radiology text reports. MATERIALS AND METHODS: This retrospective study included a total of 12 092 patients (mean age, ... Full text Link to item Cite

U.S. Diagnostic Reference Levels and Achievable Doses for 10 Pediatric CT Examinations.

Journal Article Radiology · January 2022 Background Diagnostic reference levels (DRLs) and achievable doses (ADs) were developed for the 10 most commonly performed pediatric CT examinations in the United States using the American College of Radiology Dose Index Registry. Purpose To develop robust ... Full text Link to item Cite

Key Performance Indicators for Quality Imaging Practice: Why, What, and How.

Journal Article J Am Coll Radiol · January 2022 A common trend across health care organizations is the development of key performance indicators (KPIs) for characterizing quality, identifying areas in need of change, and quantifying the impact of change. This article outlines a list of KPIs that can be ... Full text Link to item Cite

Medical Physics 3.0 and Its Relevance to Radiology.

Journal Article J Am Coll Radiol · January 2022 Medical Physics 3.0 is a grassroots movement within the medical physics community to re-envision a new commitment and engagement of physics in the care process. In this model, a physicist, present in either the clinic or the laboratory, is to practice phys ... Full text Link to item Cite

Corrections to "iPhantom: A Framework for Automated Creation of Individualized Computational Phantoms and its Application to CT Organ Dosimetry".

Journal Article IEEE J Biomed Health Inform · January 2022 In [1], the dose estimation accuracy using the alternative baseline method under modulated tube current was not correctly calculated due to an unintentional simulation error. ... Full text Link to item Cite

Comparing two different noise magnitude estimation methods in CT using virtual imaging trials

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2022 Several methods have been introduced over the years to measure CT image noise magnitudes in vivo applying different image segmentation strategies, HU thresholds, and regions of interests in which the noise is calculated. Therefore, it is impossible to dire ... Full text Open Access Cite

Inter- and intra-scan variability for lung imaging quantifications via CT.

Journal Article Proc SPIE Int Soc Opt Eng · 2022 CT imaging provides physicians valuable insights when diagnosing disease in a clinical setting. In order to provide an accurate diagnosis, is it important to have a high accuracy with controlled variability across CT scans from different scanners and imagi ... Full text Link to item Cite

Scanner-specific validation of a CT simulator using a COPD-emulated anthropomorphic phantom.

Journal Article Proc SPIE Int Soc Opt Eng · 2022 Traditional methods of quantitative analysis of CT images typically involve working with patient data, which is often expensive and limited in terms of ground truth. To counter these restrictions, quantitative assessments can instead be made through Virtua ... Full text Link to item Cite

Development and Clinical Applications of a Virtual Imaging Framework for Optimizing Photon-counting CT.

Journal Article Proc SPIE Int Soc Opt Eng · 2022 The purpose of this study was to develop a virtual imaging framework that simulates a new photon-counting CT (PCCT) system (NAEOTOM Alpha, Siemens). The PCCT simulator was built upon the DukeSim platform, which generates projection images of computational ... Full text Link to item Cite

Photon-counting CT versus conventional CT for COPD quantifications: intra-scanner optimization and inter-scanner assessments using virtual imaging trials.

Journal Article Proc SPIE Int Soc Opt Eng · 2022 Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory lung disease and a major cause of death and disability worldwide. Quantitative CT is a powerful tool to better understand the heterogeneity and severity of this disease. Quantitative CT ... Full text Link to item Cite

A truth-based primal-dual learning approach to reconstruct CT images utilizing the virtual imaging trial platform.

Journal Article Proc SPIE Int Soc Opt Eng · 2022 Inherent to Computed tomography (CT) is image reconstruction, constructing 3D voxel values from noisy projection data. Modeling this inverse operation is not straightforward. Given the ill-posed nature of inverse problem in CT reconstruction, data-driven m ... Full text Link to item Cite

Quality or quantity: toward a unified approach for multi-organ segmentation in body CT

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2022 Organ segmentation of medical images is a key step in virtual imaging trials. However, organ segmentation datasets are limited in in terms of quality (because labels cover only a few organs) and quantity (since case numbers are limited). In this study, we ... Full text Cite

Simulation of the combined effects of charge sharing and pulse pileup in photon-counting CT

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2022 Photon-counting CT (PCCT) is an emerging CT technology that uses photon-counting detectors (PCDs) to offer better spatial resolution, higher contrast, lower noise, and material-specific imaging as compared to conventional energy-integrating CT. To study th ... Full text Cite

Cardiac CT reconstruction for vendor-neutral virtual imaging trials

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2022 Cardiac CT imaging is invaluable in a variety of applications including non-invasive assessment of coronary artery calcifications, the ruling out of acute coronary artery syndrome, and the planning of valve replacement procedures. Newer applications includ ... Full text Cite

Optimization of imaging conditions in pediatric dynamic chest radiography: a virtual imaging trial

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2022 Ventilatory impairment is detected as decreased changes in lung density during respiration in dynamic chest radiography (DCR). The purpose of this study was to determine optimum imaging conditions in pediatric DCR through a virtual imaging trial (VIT). An ... Full text Cite

Virtual versus reality: external validation of COVID-19 classifiers using XCAT phantoms for chest radiography

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2022 Many published studies use deep learning models to predict COVID-19 from chest x-ray (CXR) images, often reporting high performances. However, the models do not generalize well on independent external testing. Common limitations include the lack of medical ... Full text Cite

Development and validation of a generic image-based noise addition software for simulating reduced dose computed tomography images using synthetic projections

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2022 The objective of this research was to develop and validate a computed tomography image-based noise addition tool for producing simulated reduced dose CT images by adding statistical noise to the images. The method relies only on an input CT series. It work ... Full text Cite

Virtual vs. reality: External validation of COVID-19 classifiers using XCAT phantoms for chest computed tomography

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2022 Research studies of artificial intelligence models in medical imaging have been hampered by poor generalization. This problem has been especially concerning over the last year with numerous applications of deep learning for COVID-19 diagnosis. Virtual imag ... Full text Cite

Optimization of imaging parameters of an investigational photon-counting CT prototype for lung lesion radiomics

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2022 The aim of this study was to evaluate and optimize the imaging parameters of a new dual-source photon-counting CT (PCCT) scanner (NAEOTOM Alpha, Siemens Healthineers) for lung lesion radiomics using virtual imaging trials. Virtual patients (XCAT phantoms) ... Full text Cite

Co-occurring diseases heavily influence the performance of weakly supervised learning models for classification of chest CT

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2022 Despite the potential of weakly supervised learning to automatically annotate massive amounts of data, little is known about its limitations for use in computer-aided diagnosis (CAD). For CT specifically, interpreting the performance of CAD algorithms can ... Full text Cite

Virtual Clinical Trials

Conference MEDICAL PHYSICS · 2022 Cite

Comparison of Low Dose Performance of Photon-Counting and Energy Integrating CT.

Journal Article Acad Radiol · December 2021 RATIONALE AND OBJECTIVES: The purpose of this study was to investigate the potential of photon-counting CT (PCCT) to improve quantitative image quality for low dose imaging compared to energy-integrating detector CT (EID CT). MATERIALS AND METHODS: An inve ... Full text Link to item Cite

CT Radiomic Features of Superior Mesenteric Artery Involvement in Pancreatic Ductal Adenocarcinoma: A Pilot Study.

Journal Article Radiology · December 2021 Background Current imaging methods for prediction of complete margin resection (R0) in patients with pancreatic ductal adenocarcinoma (PDAC) are not reliable. Purpose To investigate whether tumor-related and perivascular CT radiomic features improve preope ... Full text Open Access Link to item Cite

Development, validation, and relevance of in vivo low-contrast task transfer function to estimate detectability in clinical CT images.

Journal Article Med Phys · December 2021 PURPOSE: The current state-of-the-art calculation of detectability index (d') is largely phantom-based, with the latest being based on a hybrid phantom noise power spectrum (NPS) combined with patient-specific noise magnitude and high-contrast air-skin int ... Full text Link to item Cite

Patient Communication for Medical Physicists.

Journal Article J Am Coll Radiol · December 2021 Full text Link to item Cite

A mathematical framework to quantitatively balance clinical and radiation risk in Computed Tomography

Conference · December 1, 2021 Purpose: Risk in medical imaging is a combination of radiation risk and clinical risk, which is largely driven by the effective diagnosis. While radiation risk has traditionally been the main focus of Computed Tomography (CT) optimization, such a goal cann ... Open Access Cite

Organ-based and DLP-based effective dose as representations of radiation risk in a population of 8946 patients with cumulative effective dose greater than 100 mSv

Conference · December 1, 2021 Purpose. Recent studies have shown that it is not uncommon for a patient to undergo multiple CT exams resulting in high cumulative dose above 100 mSv, the radiation risk associated with which is not negligible. The purpose of this study was to compare the ... Open Access Cite

Quantification of Minimum Detectable Difference in Radiomics Features Across Lesions and CT Imaging Conditions.

Journal Article Acad Radiol · November 2021 RATIONALE AND OBJECTIVES: The 3-fold purpose of this study was to (1) develop a method to relate measured differences in radiomics features in different computed tomography (CT) scans to one another and to true feature differences; (2) quantify minimum det ... Full text Link to item Cite

Deep learning classification of COVID-19 in chest radiographs: performance and influence of supplemental training.

Journal Article Journal of medical imaging (Bellingham, Wash.) · November 2021 Purpose: Accurate classification of COVID-19 in chest radiographs is invaluable to hard-hit pandemic hot spots. Transfer learning techniques for images using well-known convolutional neural networks show promise in addressing this problem. These met ... Full text Open Access Cite

Design and implementation of a practical quality control program for dual-energy CT.

Journal Article J Appl Clin Med Phys · October 2021 A novel routine dual-energy computed tomography (DECT) quality control (QC) program was developed to address the current deficiency of routine QC for this technology. The dual-energy quality control (DEQC) program features (1) a practical phantom with clin ... Full text Link to item Cite

Evaluation of Coronary Plaques and Stents with Conventional and Photon-counting CT: Benefits of High-Resolution Photon-counting CT.

Journal Article Radiol Cardiothorac Imaging · October 2021 PURPOSE: To compare the performance of energy-integrating detector (EID) CT, photon-counting detector CT (PCCT), and high-resolution PCCT (HR-PCCT) for the visualization of coronary plaques and reduction of stent artifacts in a phantom model. MATERIALS AND ... Full text Link to item Cite

A scanner-specific framework for simulating CT images with tube current modulation.

Journal Article Phys Med Biol · September 13, 2021 Although tube current modulation (TCM) is routinely implemented in modern computed tomography (CT) scans, no existing CT simulator is capable of generating realistic images with TCM. The goal of this study was to develop such a framework to (1) facilitate ... Full text Link to item Cite

Comparison of 12 surrogates to characterize CT radiation risk across a clinical population.

Journal Article European radiology · September 2021 ObjectivesQuantifying radiation burden is essential for justification, optimization, and personalization of CT procedures and can be characterized by a variety of risk surrogates inducing different radiological risk reflections. This study compare ... Full text Open Access Cite

Variability in image quality and radiation dose within and across 97 medical facilities.

Journal Article J Med Imaging (Bellingham) · September 2021 Purpose: To characterize variability in image quality and radiation dose across a large cohort of computed tomography (CT) examinations and identify the scan factors with the highest influence on the observed variabilities. Approach: This retrospective ins ... Full text Link to item Cite

Development and validation of an automated methodology to assess perceptual in vivo noise texture in liver CT.

Journal Article J Med Imaging (Bellingham) · September 2021 Purpose: Developing, validating, and evaluating a method for measuring noise texture directly from patient liver CT images (i.e., in vivo). Approach: The method identifies target regions within patient scans that are least likely to have major contribution ... Full text Link to item Cite

iPhantom: A Framework for Automated Creation of Individualized Computational Phantoms and Its Application to CT Organ Dosimetry.

Journal Article IEEE J Biomed Health Inform · August 2021 OBJECTIVE: This study aims to develop and validate a novel framework, iPhantom, for automated creation of patient-specific phantoms or "digital-twins (DT)" using patient medical images. The framework is applied to assess radiation dose to radiosensitive or ... Full text Link to item Cite

Effect of deep learning image reconstruction in the prediction of resectability of pancreatic cancer: Diagnostic performance and reader confidence.

Journal Article Eur J Radiol · August 2021 OBJECTIVE: To assess the diagnostic performance and reader confidence in determining the resectability of pancreatic cancer at computed tomography (CT) using a new deep learning image reconstruction (DLIR) algorithm. METHODS: A retrospective review was con ... Full text Link to item Cite

A Clinically Driven Task-Based Comparison of Photon Counting and Conventional Energy Integrating CT for Soft Tissue, Vascular, and High-Resolution Tasks.

Journal Article IEEE Trans Radiat Plasma Med Sci · July 2021 Photon-counting CT detectors are the next step in advancing CT system development and will replace the current energy integrating detectors (EID) in CT systems in the near future. In this context, the performance of PCCT was compared to EID CT for three cl ... Full text Link to item Cite

Clinical concordance with Image Gently guidelines for pediatric computed tomography: a study across 663,417 CT scans at 53 clinical facilities.

Journal Article Pediatr Radiol · May 2021 BACKGROUND: Managing patient radiation dose in pediatric computed tomography (CT) examinations is essential. Some organizations, most notably Image Gently, have suggested techniques to lower dose to pediatric patients and mitigate risk while maintaining im ... Full text Link to item Cite

Minimum perceivable size difference: how well can radiologists visually detect a change in lung nodule size from CT images?

Journal Article Eur Radiol · April 2021 OBJECTIVE: The purpose of this study was to determine how well radiologists could visually detect a change in lung nodule size on the basis of visual image perception alone. SUBJECTS AND METHODS: Under IRB approval, 109 standard chest CT image series were ... Full text Link to item Cite

Assessment of pleural invasion and adhesion of lung tumors with dynamic chest radiography: A virtual clinical imaging study.

Journal Article Med Phys · April 2021 PURPOSE: Accurate preoperative assessment of tumor invasion/adhesion is crucial for planning appropriate operative procedures. Recent advances in digital radiography allow a motion analysis of lung tumors with dynamic chest radiography (DCR) with total exp ... Full text Link to item Cite

A GPU-accelerated framework for rapid estimation of scanner-specific scatter in CT for virtual imaging trials.

Journal Article Phys Med Biol · March 23, 2021 Virtual imaging trials (VITs), defined as the process of conducting clinical imaging trials using computer simulations, offer a time- and cost-effective alternative to traditional imaging trials for CT. The clinical potential of VITs hinges on the realism ... Full text Link to item Cite

Cell and extracellular matrix growth theory and its implications for tumorigenesis.

Journal Article Biosystems · March 2021 Cells associated with an abnormal (cancerous) growth exchange flows, morph freely and grow hand-in-glove with their immediate environment, the extracellular matrix (ECM). The cell structure experiences two mass flows in counterflow. Flowing into the struct ... Full text Open Access Link to item Cite

Review of Technical Advancements and Clinical Applications of Photon-counting Computed Tomography in Imaging of the Thorax.

Journal Article J Thorac Imaging · March 1, 2021 Photon-counting computed tomography (CT) is a developing technology that has the potential to address some limitations of CT imaging and bring about improvements and potentially new applications to this field. Photon-counting detectors have a fundamentally ... Full text Link to item Cite

Patient-Informed Organ Dose Estimation in Clinical CT: Implementation and Effective Dose Assessment in 1048 Clinical Patients.

Journal Article AJR. American journal of roentgenology · March 2021 OBJECTIVE. The purpose of this study is to comprehensively implement a patient-informed organ dose monitoring framework for clinical CT and compare the effective dose (ED) according to the patient-informed organ dose with ED according to the dose-le ... Full text Open Access Cite

Classification of COVID-19 in chest radiographs: assessing the impact of imaging parameters using clinical and simulated images

Journal Article Proc. SPIE 11597, Medical Imaging 2021: Computer-Aided Diagnosis, 115970A · February 15, 2021 As computer-aided diagnostics develop to address new challenges in medical imaging, including emerging diseases such as COVID-19, the initial development is hampered by availability of imaging data. Deep learning algorithms are particularly notorious for p ... Full text Open Access Link to item Cite

Estimation of in vivo noise in clinical CT images: comparison and validation of three different methods against ensemble noise gold-standard

Journal Article Proc. SPIE 11595, Medical Imaging 2021: Physics of Medical Imaging, 115952P · February 15, 2021 Image quality estimation is crucial in modern CT with noise magnitude playing a key role. Several methods have been proposed to estimate noise surrogates in vivo. This study aimed to ascertain the accuracy of three different noise-magnitude estimation meth ... Open Access Link to item Cite

Patient-based Performance Assessment for Pediatric Abdominal CT: An Automated Monitoring System Based on Lesion Detectability and Radiation Dose.

Journal Article Acad Radiol · February 2021 RATIONALE AND OBJECTIVE: To deploy an automated tool for evaluating pediatric body computed tomography (CT) performance utilizing metrics of radiation dose and image quality for the task of liver lesion detection. MATERIALS AND METHODS: This IRB approved r ... Full text Link to item Cite

Virtual Imaging Trials for Coronavirus Disease (COVID-19).

Journal Article AJR Am J Roentgenol · February 2021 OBJECTIVE. The virtual imaging trial is a unique framework that can greatly facilitate the assessment and optimization of imaging methods by emulating the imaging experiment using representative computational models of patients and validated imaging simula ... Full text Link to item Cite

Variability of quantitative measurements of metastatic liver lesions: a multi-radiation-dose-level and multi-reader comparison.

Journal Article Abdom Radiol (NY) · January 2021 PURPOSE: To evaluate the variability of quantitative measurements of metastatic liver lesions by using a multi-radiation-dose-level and multi-reader comparison. METHODS: Twenty-three study subjects (mean age, 60 years) with 39 liver lesions who underwent a ... Full text Link to item Cite

Task-dependent estimability index to assess the quality of cardiac computed tomography angiography for quantifying coronary stenosis.

Journal Article J Med Imaging (Bellingham) · January 2021 Purpose: Quantifying stenosis in cardiac computed tomography angiography (CTA) images remains a difficult task, as image noise and cardiac motion can degrade image quality and distort underlying anatomic information. The purpose of this study was to develo ... Full text Link to item Cite

A framework to simulate ct images with tube current modulation

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2021 Tube current modulation (TCM) is routinely implemented in clinical CT imaging. By modifying the x-ray tube current as a function of patient attenuation, image quality can be made more consistent and radiation dose can be better managed. Optimal TCM setting ... Full text Cite

An analysis of radiomics features in lung lesions in covid-19

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2021 Radiomic features extracted from CT imaging can be used to quantitively assess COVID-19. The objective of this work was to extract and analyze radiomics features in RT-PRC confirmed COVID-19 cases to identify relevant characteristics for COVID-19 diagnosis ... Full text Cite

An experimental evaluation of material separability in photon-counting ct

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2021 Signal separability is an important factor in the differentiation of materials in spectral computed tomography. In this work, we evaluated the separability of two such materials, iodine and gadolinium with k-edges of 33.1 keV and 50.2 keV, respectively, wi ... Full text Cite

A probabilistic conditional adversarial neural network to reduce imaging variation in radiography

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2021 Medical images can vary due to differences in imaging equipment and conditions. This variability negatively can impact the consistency and accuracy of diagnostic processes. Hence, it is critical to decrease the variability in image acquisition to achieve c ... Full text Cite

Copd quantifications via ct imaging: Ascertaining the effects of acquisition protocol using virtual imaging trial

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2021 COPD is the fourth leading cause of death in the United States. The structural and functional attributes of this disease can be assessed in vivo using computed tomography (CT). The value of quantitative CT has been demonstrated towards characterization and ... Full text Cite

Estimation of lung volume changes from frontal and lateral views of dynamic chest radiography using a convolutional neural network model: A computational phantom study

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2021 TWe aimed to estimate respiratory changes in lung volumes (i"lung volume) using frontal and lateral dynamic chest radiography (DCR) by employing a convolutional neural network (CNN) learning approach trained and tested using the four-dimensional (4D) exten ... Full text Cite

Multivariate snr in spectral computed tomography

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2021 In this work, we define a theoretical approach to characterizing the signal-to-noise ratio (SNR) of multi-channeled systems such as spectral computed tomography image series. Spectral image datasets encompass multiple near-simultaneous acquisitions that sh ... Full text Cite

Optimization of CT angiography using physiologically-informed computational plaques, dynamic XCAT phantoms, and physics-based CT simulation

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2021 Cardiovascular disease is a leading cause of death worldwide. Among all cardiovascular diseases, coronary artery disease (CAD) is a major contributor to mortality, accounting for approximately 10% of deaths per annum. Imaging techniques such as computed to ... Full text Cite

Multi-factorial optimization of imaging parameters for quantifying coronary stenosis in cardiac ct

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2021 The accuracy and variability of quantifications in Computed Tomography Angiography (CTA) are affected by imaging parameters and patient attributes. While patient attributes cannot usually be altered for a scan, imaging parameters can be optimized to improv ... Full text Cite

Correlation of respiratory changes in lung density on dynamic chest radiographs with changes in the ct value: A computational phantom study

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2021 Pulmonary impairments are observed as decreased changes in lung density during respiration on dynamic chest radiographs (DCR). To facilitate pulmonary function evaluation based on DCR, the present study was conducted to correlate respiratory changes in pix ... Full text Cite

IPhantom: An automated framework in generating personalized computational phantoms for organ-based radiation dosimetry

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2021 We propose an automated framework to generate 3D detailed person-specific computational phantoms directly from patient medical images. We investigate the feasibility of this framework in terms of accurately generating patient-specific phantoms and the clin ... Full text Cite

Automated patient-specific and organ-based image quality metrics on dual-energy ct datasets for large scale studies

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2021 The purpose of this study was to develop an automated patient-specific and organ-based image quality (IQ) assessment tool for dual energy (DE) computed tomography (CT) images for large scale clinical analysis. To demonstrate its utility, this tool was used ... Full text Cite

Effective Dose and Patient Dose

Conference MEDICAL PHYSICS · 2021 Cite

Justification of radiological procedures in COVID-19 pandemic based on radiation risk only

Conference · December 2, 2020 Purpose. Radiologic procedures are recommended based on benefit-to-risk justification. In X-ray imaging, while the benefit is often immediate for the patient, the associated radiation burden risk is a longer-term effect. Such a temporal gap can bias the ju ... Open Access Cite

Virtual Imaging Trials for Novel Coronavirus Disease (COVID-19)

Conference · December 2, 2020 PURPOSE Virtual imaging trial is a unique framework that can greatly facilitate the assessment and optimization of imaging, by emulating the experiments using representative models of patients and scanners. This study aimed to impalement and demonstrate a ... Cite

A comparison of COVID-19 and imaging radiation risk in clinical patient populations.

Journal Article Journal of radiological protection : official journal of the Society for Radiological Protection · November 2020 The outbreak of coronavirus SARS-COV2 affected more than 180 countries necessitating fast and accurate diagnostic tools. Reverse transcriptase polymerase chain reaction (RT-PCR) has been identified as a gold standard test with Chest CT and Chest Radiograph ... Full text Open Access Cite

Hallway Conversations in Physics.

Journal Article AJR Am J Roentgenol · November 2020 Full text Link to item Cite

Noise and spatial resolution properties of a commercially available deep learning-based CT reconstruction algorithm.

Journal Article Med Phys · September 2020 PURPOSE: To characterize the noise and spatial resolution properties of a commercially available deep learning-based computed tomography (CT) reconstruction algorithm. METHODS: Two phantom experiments were performed. The first used a multisized image quali ... Full text Link to item Cite

A database of 40 patient-based computational models for benchmarking organ dose estimates in CT.

Journal Article Medical physics · July 6, 2020 PURPOSE:Patient radiation burden in CT can best be characterized through risk estimates derived from organ doses. Organ doses can be estimated by Monte Carlo simulations of the CT procedures on computational phantoms assumed to emulate the patients. Howeve ... Full text Open Access Cite

Virtual clinical trials in medical imaging: a review.

Journal Article J Med Imaging (Bellingham) · July 2020 The accelerating complexity and variety of medical imaging devices and methods have outpaced the ability to evaluate and optimize their design and clinical use. This is a significant and increasing challenge for both scientific investigations and clinical ... Full text Link to item Cite

Virtual clinical trial for quantifying the effects of beam collimation and pitch on image quality in computed tomography.

Journal Article J Med Imaging (Bellingham) · July 2020 Purpose: To utilize a virtual clinical trial (VCT) construct to investigate the effects of beam collimation and pitch on image quality (IQ) in computed tomography (CT) under different respiratory and cardiac motion rates. Approach: A computational human mo ... Full text Link to item Cite

Virtual Clinical Trials: Why and What (Special Section Guest Editorial).

Journal Article J Med Imaging (Bellingham) · July 2020 The editorial introduces the S`pecial Section on Virtual Clinical Trials for Volume 7 Issue 4 of the Journal of Medical Imaging. ... Full text Link to item Cite

Clinical Decision Making in CT: Risk Assessment Comparison Across 12 Risk Metrics in Patient Populations

Conference Journal of Medical Physics · June 30, 2020 Purpose The Medical Physics 3.0 initiative aims to enhance direct physicist involvement in clinical decision making to improve patient care. In this involvement, it is crucial to achieve effective and patient-specific radiation risk assessment. CT risk cha ... Full text Open Access Cite

Correlation of Algorithmic and Visual Assessment of Lesion Detection in Clinical Images.

Journal Article Acad Radiol · June 2020 RATIONALE AND OBJECTIVES: Clinically-relevant quantitative measures of task-based image quality play key roles in effective optimization of medical imaging systems. Conventional phantom-based measures do not adequately reflect the real-world image quality ... Full text Link to item Cite

Automated quality control in nuclear medicine using the structured noise index.

Journal Article J Appl Clin Med Phys · April 2020 PURPOSE: Daily flood-field uniformity evaluation serves as the central element of nuclear medicine (NM) quality control (QC) programs. Uniformity images are traditionally analyzed using pixel value-based metrics, that is, integral uniformity (IU), which of ... Full text Open Access Link to item Cite

Patient-Informed and Physiology-Based Modelling of Hepatic Contrast Dynamics in Contrast-Enhanced CT Imaging

Journal Article · March 16, 2020 PURPOSE Iodinated contrast agents are commonly used in CT imaging to enhance tissue contrast. Consistency in contrast enhancement (CE) is critical in radiological diagnosis. Contrast material circulation in individual patients is affected by factors such a ... Open Access Cite

Technical Note: Validation of TG 233 phantom methodology to characterize noise and dose in patient CT data.

Journal Article Med Phys · February 10, 2020 PURPOSE: Phantoms are useful tools in diagnostic CT, but practical limitations reduce phantoms to being only a limited patient surrogate. Furthermore, a phantom with a single cross sectional area cannot be used to evaluate scanner performance in modern CT ... Full text Open Access Link to item Cite

Impact of Colorized Display of Mammograms on Lesion Detection.

Journal Article J Breast Imaging · February 4, 2020 OBJECTIVE: To assess the effect of the colorized display of digital mammograms on observer detection of subtle breast lesions. METHODS: Three separate observer studies compared detection performance using grayscale versus color display of 1) low-contrast m ... Full text Link to item Cite

Optimization of energy thresholds in photon-counting CT via a virtual clinical trial

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2020 In photon-counting CT, detector energy thresholds directly affect image quality attributes such as contrast and noise. The purpose of this study was to identify optimum energy thresholds using a comprehensive virtual clinical trial platform. The virtual tr ... Full text Cite

Virtual imaging trials: An emerging experimental paradigm in imaging research and practice

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2020 As medical imaging technologies continue to accelerate in complexity, application, and multiplicity of design choices and use features, they should ideally be evaluated and optimized through human clinical trials. However, such trials are often impossible ... Full text Cite

CT phantom with 3D anthropomorphic, contrast-enhanced texture

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2020 Physical phantoms with realistic anatomical texture and composition (including contrast media) are of high value and relevance in evaluating the performance of clinical computed tomography (CT) imaging systems. They can offer assessments of image quality i ... Full text Cite

Automatic phantom test pattern classification through transfer learning with deep neural networks

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2020 Imaging phantoms are test patterns used to measure image quality in computer tomography (CT) systems. A new phantom platform (Mercury Phantom, Gammex) provides test patterns for estimating the task transfer function (TTF) or noise power spectrum (NPF) and ... Full text Cite

A method to assess the performance and the relevance of segmentation in radiomic characterization

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2020 The quantification of radiomics features is impacted by a complex interplay of image quality and segmentation performance. To understand and optimize the process, it is highly beneficial to isolate the impact of each factor quantitatively. The purpose of t ... Full text Cite

In vivo noise texture estimation: Development and validation of an automated methodology

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2020 The purpose of this study was to develop, validate, and evaluate a method for measuring noise texture directly from patient CT images (i.e., “in vivo”). The method identifies target regions within patient scans which are least likely to have major contribu ... Full text Cite

Prediction of pleural invasion of lung cancer with dynamic chest radiography: A simulation study

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2020 We aimed to investigate the feasibility of predicting pleural invasion or adhesion of lung cancers with dynamic chest radiography (DCR), using a four-dimensional (4D) extended cardiac-torso (XCAT) computational phantom. An XCAT phantom of an adult man (50t ... Full text Cite

Modeling Patient-Informed Liver Contrast Perfusion in Contrast-enhanced Computed Tomography.

Journal Article J Comput Assist Tomogr · 2020 OBJECTIVE: To determine the correlation between patient attributes and contrast enhancement in liver parenchyma and demonstrate the potential for patient-informed prediction and optimization of contrast enhancement in liver imaging. METHODS: The study incl ... Full text Open Access Link to item Cite

Clinical Nuclear Imaging Physics: Current and Emerging Practice

Book · January 1, 2020 The evolution of new evaluation methodologies in the field of clinical nuclear medicine physics has recently become relatively stagnant, despite the availability of several new commercial offerings of nuclear imaging technologies and features in clinical p ... Full text Cite

CT Practice Monitoring

Chapter · December 16, 2019 This book is an ideal resource for practitioners of CT applications in medicine, including physicians, trainees, engineers, and scientists. This book offers a comprehensive and topical depiction of advances in CT imaging. ... Full text Cite

CT Practice Monitoring

Chapter · December 16, 2019 This book is an ideal resource for practitioners of CT applications in medicine, including physicians, trainees, engineers, and scientists. This book offers a comprehensive and topical depiction of advances in CT imaging. ... Link to item Cite

Total risk index: a mathematical model for decision making based on clinical and radiation risk assessment in CT

Conference · December 4, 2019 Purpose. Radiological risk is a combination of radiation and clinical risk (likelihood of not delivering a proper diagnosis), which together may be characterized as a total risk index (TRI). While many strategies have been developed to ascertain radiation ... Open Access Cite

Reproducibility of CT Radiomic Features within the Same Patient: Influence of Radiation Dose and CT Reconstruction Settings.

Journal Article Radiology · December 2019 Background Results of recent phantom studies show that variation in CT acquisition parameters and reconstruction techniques may make radiomic features largely nonreproduceable and of limited use for prognostic clinical studies. Purpose To investigate the e ... Full text Link to item Cite

A real-time Monte Carlo tool for individualized dose estimations in clinical CT.

Journal Article Phys Med Biol · November 4, 2019 The increasing awareness of the adverse effects associated with radiation exposure in computed tomography (CT) has necessesitated the quantification of dose delivered to patients for better risk assessment in the clinic. The current methods for dose quanti ... Full text Link to item Cite

Performance evaluation of computed tomography systems: Summary of AAPM Task Group 233.

Journal Article Med Phys · November 2019 BACKGROUND: The rapid development and complexity of new x-ray computed tomography (CT) technologies and the need for evidence-based optimization of image quality with respect to radiation and contrast media dose call for an updated approach towards CT perf ... Full text Link to item Cite

Organ doses from CT localizer radiographs: Development, validation, and application of a Monte Carlo estimation technique.

Journal Article Med Phys · November 2019 PURPOSE: The purpose of this study was to simulate and validate organ doses from different computed tomography (CT) localizer radiograph geometries using Monte Carlo methods for a population of patients. METHODS: A Monte Carlo method was developed to estim ... Full text Open Access Link to item Cite

Validation of algorithmic CT image quality metrics with preferences of radiologists.

Journal Article Med Phys · November 2019 PURPOSE: Automated assessment of perceptual image quality on clinical Computed Tomography (CT) data by computer algorithms has the potential to greatly facilitate data-driven monitoring and optimization of CT image acquisition protocols. The application of ... Full text Open Access Link to item Cite

Expanding the Concept of Diagnostic Reference Levels to Noise and Dose Reference Levels in CT.

Journal Article AJR. American journal of roentgenology · October 2019 OBJECTIVE. Diagnostic reference levels were developed as guidance for radiation dose in medical imaging and, by inference, diagnostic quality. The objective of this work was to expand the concept of diagnostic reference levels to explicitly include ... Full text Open Access Cite

A Simulation Paradigm for Evaluation of Subtle Liver Lesions at Pediatric CT: Performance and Confidence.

Journal Article Radiol Imaging Cancer · September 2019 PURPOSE: To create and validate a systematic observer performance platform for evaluation of simulated liver lesions at pediatric CT and to test this paradigm to measure the effect of radiation dose reduction on detection performance and reader confidence. ... Full text Link to item Cite

Development of a scanner-specific simulation framework for photon-counting computed tomography.

Journal Article Biomed Phys Eng Express · August 2019 The aim of this study was to develop and validate a simulation platform that generates photon-counting CT images of voxelized phantoms with detailed modeling of manufacturer-specific components including the geometry and physics of the x-ray source, source ... Full text Link to item Cite

Why physics in medicine?

Journal Article Phys Med · August 2019 Despite its crucial role in the development of new medical imaging technologies, in clinical practice, physics has primarily been involved in technical evaluation of technologies. However, this narrow role is no longer adequate. New trajectories in medicin ... Full text Link to item Cite

Evaluation of Simulated Lesions as Surrogates to Clinical Lesions for Thoracic CT Volumetry: The Results of an International Challenge.

Journal Article Acad Radiol · July 2019 RATIONALE AND OBJECTIVES: To evaluate a new approach to establish compliance of segmentation tools with the computed tomography volumetry profile of the Quantitative Imaging Biomarker Alliance (QIBA); and determine the statistical exchangeability between r ... Full text Link to item Cite

Systematic analysis of bias and variability of texture measurements in computed tomography.

Journal Article J Med Imaging (Bellingham) · July 2019 Texture is a key radiomics measurement for quantification of disease and disease progression. The sensitivity of the measurements to image acquisition, however, is uncertain. We assessed bias and variability of computed tomography (CT) texture feature meas ... Full text Link to item Cite

DukeSim: A Realistic, Rapid, and Scanner-Specific Simulation Framework in Computed Tomography.

Journal Article IEEE Trans Med Imaging · June 2019 The purpose of this study was to develop a CT simulation platform that is: 1) compatible with voxel-based computational phantoms; 2) capable of modeling the geometry and physics of commercial CT scanners; and 3) computationally efficient. Such a simulation ... Full text Link to item Cite

The Need for Practical and Accurate Measures of Value for Radiology.

Journal Article J Am Coll Radiol · June 2019 Radiologists play a critical role in helping the health care system achieve greater value. Unfortunately, today radiology is often judged by simple "checkbox" metrics, which neither directly reflect the value radiologists provide nor the outcomes they help ... Full text Link to item Cite

Improved Dose Estimates for Fluoroscopically Guided Lumbar Epidural Injections.

Journal Article Pain Med · May 1, 2019 OBJECTIVE: The goal of the study was to determine the potential impact of system inaccuracies and table attenuation on fluoroscope-reported dose values. DESIGN: An Institutional Review Board-approved study was conducted to collect detailed acquisition and ... Full text Link to item Cite

Can Realistic Liver Tissue Surrogates Accurately Quantify the Impact of Reduced-kV Imaging on Attenuation and Contrast of Parenchyma and Lesions?

Journal Article Acad Radiol · May 2019 RATIONALE AND OBJECTIVES: To assess if a liquid tissue surrogate for the liver (LTSL) can emulate contrast-enhanced liver parenchyma and lesions and quantify the impact of reduced-kV imaging as a function of lesion contrast, phase of enhancement, and phant ... Full text Link to item Cite

Virtual Unenhanced Images at Dual-Energy CT: Influence on Renal Lesion Characterization.

Journal Article Radiology · May 2019 Background Dual-energy (DE) CT allows reconstruction of virtual noncontrast (VNC) images from a single-phase contrast agent-enhanced examination, potentially reducing the need for multiphasic CT to characterize renal lesions. However, data regarding diagno ... Full text Link to item Cite

How accurate and precise are CT based measurements of iodine concentration? A comparison of the minimum detectable concentration difference among single source and dual source dual energy CT in a phantom study.

Journal Article Eur Radiol · April 2019 OBJECTIVES: To assess the impact of scan- and patient-related factors on the error and the minimum detectable difference in iodine concentration among different generations of single-source (SS) fast kV-switching and dual-source (DS) dual-energy CT (DECT). ... Full text Link to item Cite

Validation of lesion simulations in clinical CT data for anonymized chest and abdominal CT databases.

Journal Article Med Phys · April 2019 PURPOSE: To make available to the medical imaging community a computed tomography (CT) image database composed of hybrid datasets (patient CT images with digitally inserted anthropomorphic lesions) where lesion ground truth is known a priori. It is envisio ... Full text Link to item Cite

Three-dimensionally-printed anthropomorphic physical phantom for mammography and digital breast tomosynthesis with custom materials, lesions, and uniform quality control region.

Journal Article J Med Imaging (Bellingham) · April 2019 Anthropomorphic breast phantoms mimic patient anatomy in order to evaluate clinical mammography and digital breast tomosynthesis system performance. Our goal is to create a modular phantom with an anthropomorphic region to allow for improved lesion and cal ... Full text Link to item Cite

Design and fabrication of heterogeneous lung nodule phantoms for assessing the accuracy and variability of measured texture radiomics features in CT.

Journal Article J Med Imaging (Bellingham) · April 2019 We aimed to design and fabricate synthetic lung nodules with patient-informed internal heterogeneity to assess the variability and accuracy of measured texture features in CT. To that end, 190 lung nodules from a publicly available database of chest CT ima ... Full text Link to item Cite

Can Texture Analysis Be Used to Distinguish Benign From Malignant Adrenal Nodules on Unenhanced CT, Contrast-Enhanced CT, or In-Phase and Opposed-Phase MRI?

Journal Article AJR Am J Roentgenol · March 2019 OBJECTIVE: The purpose of this study is to determine whether second-order texture analysis can be used to distinguish lipid-poor adenomas from malignant adrenal nodules on unenhanced CT, contrast-enhanced CT (CECT), and chemical-shift MRI. MATERIALS AND ME ... Full text Link to item Cite

High-Pitch Wide-Coverage Fast-Kilovoltage-Switching Dual-Energy CT: Impact of Pitch on Noise, Spatial Resolution, and Iodine Quantification in a Phantom Study.

Journal Article AJR Am J Roentgenol · March 2019 OBJECTIVE: The purpose of this study was to assess the impact of high pitch values on image noise, spatial resolution, and iodine quantification in single-source wide-coverage fast-kilovoltage-switching dual-energy CT (DECT). MATERIALS AND METHODS: Two pha ... Full text Link to item Cite

Detection of Colorectal Hepatic Metastases Is Superior at Standard Radiation Dose CT versus Reduced Dose CT.

Journal Article Radiology · February 2019 Purpose To evaluate colorectal cancer hepatic metastasis detection and characterization between reduced radiation dose (RD) and standard dose (SD) contrast material-enhanced CT of the abdomen and to qualitatively compare between filtered back projection (F ... Full text Link to item Cite

Medical Physics 3.0: Ensuring Quality and Safety in Medical Imaging.

Journal Article Health Phys · February 2019 Medical imaging often involves radiation and thus radiation protection. Radiation protection in medicine is only one component of the broader calling of health care professionals: fostering human health. As such, radiation risk needs to be put into the con ... Full text Link to item Cite

Automated Early Identification of an Excessive Air-in-Oil X-ray Tube Artifact That Mimics Acute Cerebral Infarct.

Journal Article J Comput Assist Tomogr · 2019 PURPOSE: This study aimed to develop an automated, quantitative method to increase the likelihood of identifying and preventing such air-in-oil (AIO) artifact. METHODS: A 1-dimensional radial representation of the 2-dimensional noise power spectrum (NPS) w ... Full text Link to item Cite

Incorporation of the Living Heart Model into the 4D XCAT Phantom for Cardiac Imaging Research.

Journal Article IEEE Trans Radiat Plasma Med Sci · January 2019 The 4D extended cardiac-torso (XCAT) phantom has provided a valuable tool to study the effects of anatomy and motion on medical images, especially cardiac motion. One limitation of the XCAT was that it did not have a physiological basis which to realistica ... Full text Link to item Cite

Modeling "Textured" Bones in Virtual Human Phantoms.

Journal Article IEEE Trans Radiat Plasma Med Sci · January 2019 The purpose of this study was to develop detailed and realistic models of the cortical and trabecular bones in the spine, ribs, and sternum and incorporate them into the library of virtual human phantoms (XCAT). Cortical bone was modeled by 3D morphologica ... Full text Link to item Cite

A framework for realistic virtual clinical trials in photon counting computed tomography

Conference Medical Imaging 2019: Physics of Medical Imaging · 2019 Cite

Patient-informed and physiology-based modelling of contrast dynamics in cross-sectional imaging

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2019 Previous studies have shown that many factors including body habitus, sex, and age of the patient, as well as contrast injection protocol contribute to the variability in contrast-enhanced cross-sectional imaging (i.e., CT). We have previously developed a ... Full text Cite

Anatomically- and computationally-informed hepatic contrast perfusion simulations for use in virtual clinical trials

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2019 This study modeled a framework for virtual human liver phantoms, focusing primarily on the intricate vascular networks that comprise the liver. Large vasculature was segmented from clinical liver perfusion images to ascertain a general starting point for t ... Full text Cite

Systematic analysis of bias and variability of morphologic features for lung lesions in computed tomography.

Journal Article J Med Imaging (Bellingham) · January 2019 We propose to characterize the bias and variability of quantitative morphology features of lung lesions across a range of computed tomography (CT) imaging conditions. A total of 15 lung lesions were simulated (five in each of three spiculation classes: low ... Full text Link to item Cite

Using inkjet 3D printing to create contrast-enhanced textured physical phantoms for CT

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2019 Anthropomorphic phantoms can serve as anatomically structured tools for assessing clinical computed tomography (CT) imaging systems. The aim of this project is to create highly customized 3D inkjet-printed, contrast-enhanced physical liver phantoms for use ... Full text Cite

Deep learning of 3D computed tomography (CT) images for organ segmentation using 2D multi-channel SegNet model

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2019 Purpose To accurately segment organs from 3D CT image volumes using a 2D, multi-channel SegNet model consisting of a deep Convolutional Neural Network (CNN) encoder-decoder architecture. Method We trained a SegNet model on the extended cardiac-Torso (XCAT) ... Full text Cite

Utilizing deformable image registration to create new living human heart models for imaging simulation

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2019 The Living Heart Model (LHM) was developed as part of the Living Heart Project by Dassault Systemes to provide a numerical finite element (FE) model of the human heart that accurately reproduces the normal cardiac physiology. We previously incorporated the ... Full text Cite

Impact of energy threshold on material quantification of contrast agents in photon-counting CT

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2019 The purpose of this study was to examine the effect of energy threshold selection on the quantification of contrast agents in photon-counting CT (PCCT). A phantom was devised consisting of vials of iodine (4, 8, 16 mg/mL), gadolinium (4, 8, 16 mg/mL), and ... Full text Cite

Quantifying truth-based change in radiomics features between CT imaging conditions

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2019 The purpose of this study was to develop a method to ascertain the likelihood of actual change in radiomics features measured from pairs of sequentially acquired CT images under variable CT scan settings. Fifteen realistic computational lung nodule models ... Full text Cite

Modeling dynamic, nutrient-access-based lesion progression using stochastic processes

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2019 Simulation methods can be used to generate realistic, computational lesions for insertion into anatomical backgrounds for use in a virtual clinical trial framework. Typically, these simulation methods rely on clinical lesion images|with resolution many tim ... Full text Cite

Controlling the position-dependent contrast of 3D printed physical phantoms with a single material

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2019 Custom 3D printed physical phantoms are desired for testing the limits of medical imaging, and for providing patientspecific information. This work focuses on the development of low-cost, open source fused filament fabrication for printing of physical phan ... Full text Cite

Accuracy and variability of radiomics in photon-counting CT: Texture features and lung lesion morphology

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2019 The purpose of this study was to evaluate the potential of a prototype photon-counting CT system scanner to characterize liver texture and lung lesion morphology features. We utilized a multi-tiered phantom (Mercury Phantom 4.0) to characterize the noise p ... Full text Cite

Image quality in photon-counting CT images as a function of energy threshold

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2019 In this study, we examined image quality in photon-counting CT images due to variation in energy thresholds. Images of an ACR quality control phantom were acquired using a prototype photon-counting CT scanner with two variable energy thresholds. The lower ... Full text Cite

Dynamic chest radiography for pulmonary function diagnosis: A validation study using 4D extended cardiac-torso (XCAT) phantom

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2019 This study was performed to investigate the detection performance of trapped air in dynamic chest radiography using 4D extended cardiac-torso (XCAT) phantom with a user-defined ground truth. An XCAT phantom of an adult male (50th percentile in height and w ... Full text Cite

Cardiac CT estimability index: An ideal estimator in the presence of noise and motion

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2019 Estimating parameters of clinical significance, like coronary stenosis, accurately and precisely from cardiac CT images remains a difficult task as image noise and cardiac motion can degrade image quality and distort underlying anatomic information. The pu ... Full text Cite

CT-based quantification

Chapter · January 1, 2019 Image quantification is the extraction of quantitative measures from patient images and the relation of the quantitative measures to patient outcomes. For an image quantification to be most effective, it should meet four requirements of (1) relevance, (2) ... Full text Cite

CT performance optimization

Chapter · January 1, 2019 This chapter discusses the principles of optimization in CT imaging and how to target specific levels of image quality under the constraint of mitigating factors such as radiation dose. The goals are to (a) understand the theory behind imaging optimization ... Full text Cite

Preface

Book · January 1, 2019 Cite

Computed tomography: Approaches, applications, and operations

Book · January 1, 2019 Introduction This book offers a comprehensive and topical depiction of advances in CT imaging. CT has become a leading medical imaging modality, thanks to its superb spatial and temporal resolution to depict anatomical details. New advances have further ex ... Full text Cite

Hendee’s physics of medical imaging

Book · January 1, 2019 The extensively revised fifth edition of Hendee’s Medical Imaging Physics, offers a guide to the principles, technologies, and procedures of medical imaging. Comprehensive in scope, the text contains coverage of all aspects of image formation in modern med ... Full text Cite

The Handbook of Medical Image Perception and Techniques

Book · December 13, 2018 A state-of-the-art review of key topics in medical image perception science and practice, including associated techniques, illustrations and examples. This second edition contains extensive updates and substantial new content. ... Cite

Characterization of Radiation Risk across a Clinical CT Patient Population: Comparison across 12 Risks Metrics

Conference · November 27, 2018 PURPOSE Ascertaining radiological procedure radiation burden is essential for justification, optimization, and personalization of the procedure. While the exact radiation risk for an individual exam is unknowable, various risk-related figures have been use ... Cite

Effective Dose for Computed Tomography in Large, Clinical Populations

Conference · November 27, 2018 PURPOSE Effective dose can efficiently integrate multiple organ dose values into a singular scalar value of radiation dose. The effective dose can also be calculated using dose length product (DLP) to effective dose conversion coefficients. The purpose of ... Cite

A Data-Centric Strategy for Developing CT Dose and Noise Reference Levels from Clinical Patient Populations

Conference · November 27, 2018 PURPOSE To develop a data-centric strategy solution for developing CT dose and noise reference levels across large clinical patient populations and in CT scanners. METHOD AND MATERIALS This IRB-exempt study evaluated CT abdominopelvic (AP)-related examin ... Cite

CT Resolution, Noise, and Dose Reference Levels Across a Multi-Center Patient Population

Conference · November 26, 2018 PURPOSE The diagnostic reference level (DRL) is useful as a first-order tool to compare radiation exposures of one's imaging clinic against those of one's peers in computed tomography. Ria et al. have advocated for the addition of a Noise Reference Level ( ... Cite

A Novel Methodology for Automated Image Quality Assessment of Pediatric CT

Conference · November 25, 2018 PURPOSE To develop an effective and automated methodology for patient-specific image quality assessment of clinical pediatric body CT examinations. METHOD AND MATERIALS This IRB approved study evaluated 816 clinically performed (6/14-11/17), contrast-enh ... Cite

Beyond the DRL: Applying Automated Quality Metrics to Assess Pediatric CT Program Liver Lesion Detection Performance

Conference · November 25, 2018 PURPOSE To apply an automated program for evaluating pediatric body CT study quality which utilizes metrics of dose and image quality for optimization of liver lesion detection. METHOD AND MATERIALS With IRB approval, 880 clinical contrast-enhanced abdom ... Cite

3D task-transfer function representation of the signal transfer properties of low-contrast lesions in FBP- and iterative-reconstructed CT.

Journal Article Med Phys · November 2018 PURPOSE: The purpose of this study was to investigate how accurately the task-transfer function (TTF) models the signal transfer properties of low-contrast features in a non-linear commercial CT system. METHODS: A cylindrical phantom containing 24 anthropo ... Full text Link to item Cite

Medical Physics 3.0, physics for every patient.

Journal Article J Appl Clin Med Phys · November 2018 Full text Link to item Cite

Dependency of prescribed CT dose on table height, patient size, and localizer acquisition for one clinical MDCT.

Journal Article Phys Med · November 2018 PURPOSE: The purpose of this study was to quantify the effect that table height, patient size, and localizer acquisition order may have on AEC prescribed dose. METHOD AND MATERIALS: Three phantoms were used for this study: the Mercury Phantom, acrylic shee ... Full text Link to item Cite

Automated quality control assessment of clinical chest images.

Journal Article Med Phys · October 2018 PURPOSE: The purpose of this study was to determine whether a proposed suite of objective image quality metrics for digital chest radiographs is useful for monitoring image quality in a clinical setting unique from the one where the metrics were developed. ... Full text Link to item Cite

Local complexity metrics to quantify the effect of anatomical noise on detectability of lung nodules in chest CT imaging.

Journal Article J Med Imaging (Bellingham) · October 2018 The purpose of this study is to (1) develop metrics to characterize the regional anatomical complexity of the lungs, and (2) relate these metrics with lung nodule detection in chest CT. A free-scrolling reader-study with virtually inserted nodules (13 radi ... Full text Link to item Cite

Medical imaging dose optimisation from ground up: expert opinion of an international summit.

Journal Article J Radiol Prot · September 2018 As in any medical intervention, there is either a known or an anticipated benefit to the patient from undergoing a medical imaging procedure. This benefit is generally significant, as demonstrated by the manner in which medical imaging has transformed clin ... Full text Link to item Cite

Medical physics 3.0 versus 1.0: A case study in digital radiography quality control.

Journal Article J Appl Clin Med Phys · September 2018 PURPOSE: The study illustrates how a renewed approach to medical physics, Medical Physics 3.0 (MP3.0), can identify performance decrement of digital radiography (DR) systems when conventional Medical Physics 1.0 (MP1.0) methods fail. METHODS: MP1.0 tests i ... Full text Link to item Cite

Redefining and reinvigorating the role of physics in clinical medicine: A Report from the AAPM Medical Physics 3.0 Ad Hoc Committee.

Journal Article Med Phys · July 10, 2018 Derived from 2 yr of deliberations and community engagement, Medical Physics 3.0 (MP3.0) is an effort commissioned by the American Association of Physicists in Medicine (AAPM) to devise a framework of strategies by which medical physicists can maintain and ... Full text Link to item Cite

Estimating detectability index in vivo: development and validation of an automated methodology.

Journal Article J Med Imaging (Bellingham) · July 2018 This study's purpose was to develop and validate a method to estimate patient-specific detectability indices directly from patients' CT images (i.e., in vivo). The method extracts noise power spectrum (NPS) and modulation transfer function (MTF) resolution ... Full text Link to item Cite

Estimability index for volume quantification of homogeneous spherical lesions in computed tomography.

Journal Article J Med Imaging (Bellingham) · July 2018 Volume of lung nodules is an important biomarker, quantifiable from computed tomography (CT) images. The usefulness of volume quantification, however, depends on the precision of quantification. Experimental assessment of precision is time consuming. A mat ... Full text Link to item Cite

Inter-laboratory comparison of channelized hotelling observer computation.

Journal Article Med Phys · July 2018 PURPOSE: The task-based assessment of image quality using model observers is increasingly used for the assessment of different imaging modalities. However, the performance computation of model observers needs standardization as well as a well-established t ... Full text Link to item Cite

Why Physics in Medicine?

Journal Article J Am Coll Radiol · July 2018 Despite its crucial role in the development of new medical imaging technologies, in clinical practice, physics has primarily been involved in the technical evaluation of technologies. However, this narrow role is no longer adequate. New trajectories in med ... Full text Link to item Cite

Interchangeability between real and three-dimensional simulated lung tumors in computed tomography: an interalgorithm volumetry study.

Journal Article J Med Imaging (Bellingham) · July 2018 Using hybrid datasets consisting of patient-derived computed tomography (CT) images with digitally inserted computational tumors, we establish volumetric interchangeability between real and computational lung tumors in CT. Pathologically-confirmed malignan ... Full text Link to item Cite

A Third-Generation Adaptive Statistical Iterative Reconstruction Technique: Phantom Study of Image Noise, Spatial Resolution, Lesion Detectability, and Dose Reduction Potential.

Journal Article AJR Am J Roentgenol · June 2018 OBJECTIVE: The purpose of this study was to assess image noise, spatial resolution, lesion detectability, and the dose reduction potential of a proprietary third-generation adaptive statistical iterative reconstruction (ASIR-V) technique. MATERIALS AND MET ... Full text Link to item Cite

Role of the Diagnostic Physicist

Conference MEDICAL PHYSICS · June 1, 2018 Link to item Cite

Application of the 4-D XCAT Phantoms in Biomedical Imaging and Beyond.

Journal Article IEEE Trans Med Imaging · March 2018 The four-dimensional (4-D) eXtended CArdiac-Torso (XCAT) series of phantoms was developed to provide accurate computerized models of the human anatomy and physiology. The XCAT series encompasses a vast population of phantoms of varying ages from newborn to ... Full text Link to item Cite

Modeling Lung Architecture in the XCAT Series of Phantoms: Physiologically Based Airways, Arteries and Veins.

Journal Article IEEE Trans Med Imaging · March 2018 The purpose of this paper was to extend the extended cardiac-torso (XCAT) series of computational phantoms to include a detailed lung architecture including airways and pulmonary vasculature. Eleven XCAT phantoms of varying anatomy were used in this paper. ... Full text Link to item Cite

Report of AAPM Task Group 162: Software for planar image quality metrology.

Journal Article Med Phys · February 2018 PURPOSE: The AAPM Task Group 162 aimed to provide a standardized approach for the assessment of image quality in planar imaging systems. This report offers a description of the approach as well as the details of the resultant software bundle to measure det ... Full text Link to item Cite

Clinically Acceptable Optimized Dose Reduction in Computed Tomographic Imaging of Necrotizing Pancreatitis Using a Noise Addition Software Tool.

Journal Article J Comput Assist Tomogr · 2018 OBJECTIVE: This study aimed to determine potential radiation dose reduction of contrast-enhanced computed tomography (CECT) for imaging necrotizing pancreatitis (NP) using a noise addition tool. METHODS: Eighty-four patients were identified with at least 1 ... Full text Link to item Cite

Quantification of uncertainty in the assessment of coronary plaque in CCTA through a dynamic cardiac phantom and 3D-printed plaque model.

Journal Article J Med Imaging (Bellingham) · January 2018 The purpose of this study was to develop a dynamic physical cardiac phantom with a realistic coronary plaque to investigate stenosis measurement accuracy under clinically relevant heart-rates. The coronary plaque model (5 mm diameter, 50% stenosis, and 32  ... Full text Link to item Cite

3D printed anthropomorphic physical phantom for mammography and DBT with high contrast custom materials, lesions, and uniform chest wall region

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2018 Anthropomorphic breast phantoms mimic anatomy to evaluate the performance of clinical mammography and digital breast tomosynthesis (DBT) systems. Our goal is to make a phantom that mimics clinically relevant appearance of a patient to allow for improved im ... Full text Cite

From patient-informed to patient-specific organ dose estimation in clinical computed tomography

Conference Medical Imaging 2018: Physics of Medical Imaging · 2018 Cite

Virtual clinical trial in action: Textured XCAT phantoms and scanner-specific CT simulator to characterize noise across CT reconstruction algorithms

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2018 Although non-linear CT systems offer improved image quality over conventional linear systems, they disrupt certain assumptions of the dependency of noise and resolution on radiation dose that are true of linear systems. As such, simplistic phantoms do not ... Full text Cite

A rapid GPU-based Monte-Carlo simulation tool for individualized dose estimations in CT

Conference Medical Imaging 2018: Physics of Medical Imaging · 2018 Cite

Development of a fast, voxel-based, and scanner-specific CT simulator for image-quality-based virtual clinical trials

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2018 This study aimed to develop a simulation framework to synthesize accurate and scanner-specific Computed Tomography (CT) images of voxel-based computational phantoms. Two phantoms were used in the simulations, a geometry-based Mercury phantom and a "texture ... Full text Cite

How reliable are texture measurements?

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2018 The purpose of this study was to assess the bias (objectivity) and variability (robustness) of computed tomography (CT) texture features (internal heterogeneities) across a series of image acquisition settings and reconstruction algorithms. We simulated a ... Full text Cite

Realistic lesion simulation: Application of hyperelastic deformation to lesion-local environment in lung CT

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2018 Lesion simulation programs can be used to insert realistic, generated lesions into anatomical images for further study. Most lesion simulation programs rely on insertion of a mask within an otherwise unchangeable, i.e., static surrounding - in reality, les ... Full text Cite

Bias and variability in morphology features of lung lesions across CT imaging conditions

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2018 CT imaging method can influence radiomic features. The purpose of this study was to characterize the intra-protocol and inter-protocol variability and bias of quantitative morphology features of lung lesions across a range of CT imaging conditions. A total ... Full text Cite

Can a 3D task transfer function accurately represent the signal transfer properties of low-contrast lesions in non-linear CT systems?

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2018 The purpose of this study was to investigate how accurately the task-transfer function (TTF) models the signal transfer properties of low-contrast features in a non-linear CT system. A cylindrical phantom containing 24 anthropomorphic liver lesions (modele ... Full text Cite

Variability of stenosis characterization: Impact of coronary vessel motion in cardiac CT

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2018 Despite much advancement, quantitative optimization of cardiac CT has remained an elusive challenge. The purpose of this study was to quantify the stenosis measurement variability introduced by the relative motion of coronary vessels in cardiac CT. Even wi ... Full text Cite

THE HANDBOOK OF MEDICAL IMAGE PERCEPTION AND TECHNIQUES: Second Edition

Book · January 1, 2018 A state-of-the-art review of key topics in medical image perception science and practice, including associated techniques, illustrations and examples. This second edition contains extensive updates and substantial new content. Written by key figures in the ... Full text Cite

Medical Image Perception

Chapter · January 1, 2018 Full text Cite

Radiation risk index for pediatric CT: a patient-derived metric.

Journal Article Pediatr Radiol · December 2017 BACKGROUND: There is a benefit in characterizing radiation-induced cancer risk in pediatric chest and abdominopelvic CT: a singular metric that represents the whole-body radiation burden while also accounting for age, gender and organ sensitivity. OBJECTIV ... Full text Link to item Cite

Quantifying quality: correlation phantom and clinical scan CT noise levels to contruct a Quality Reference Level

Conference · November 26, 2017 Conclusion This study represents a proof of concept method to develop and refine a Noise Reference Level for a given protocol and scanner. This represents a first step in establishing an automated Performance Reference Level for a given scan protocol that ... Cite

Organ Dose Estimation in CT through Voxelized Phantoms and Monte Carlo Methods: Impact of Wrong Patient-Phantom Matching

Conference · November 26, 2017 PURPOSE The aim of this study was to assess the impact on organ dose estimation for Body CT examinations when the patient is matched to the wrong virtual phantom. METHODS AND MATERIALS Patient-specific organ dosimetry is estimated using a Monte Carlo fram ... Cite

Optimizing window settings for improved presentation of virtual monoenergetic images in dual-energy computed tomography.

Journal Article Med Phys · November 2017 PURPOSE: Dual-energy computed tomography virtual monoenergetic imaging (VMI) at 40 keV exhibits superior contrast-to-noise ratio (CNR), although practicing radiologists do not consistently prefer it over VMI at 70 keV due to high perceivable noise. We hypo ... Full text Link to item Cite

A method for characterizing and matching CT image quality across CT scanners from different manufacturers.

Journal Article Med Phys · November 2017 PURPOSE: The purpose of this study was to quantitatively characterize the fundamental aspects of image quality (IQ) associated with different computed tomography (CT) reconstruction algorithms, the resolution, noise texture, noise magnitude per dose, and u ... Full text Link to item Cite

Awareness of medical radiation exposure among patients: A patient survey as a first step for effective communication of ionizing radiation risks.

Journal Article Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB) · November 2017 IntroductionThe European Directive 2013/59/EURATOM requires patient radiation dose information to be included in the medical report of radiological procedures. To provide effective communication to the patient, it is necessary to first assess the ... Full text Open Access Cite

Effect of Radiation Dose Reduction and Reconstruction Algorithm on Image Noise, Contrast, Resolution, and Detectability of Subtle Hypoattenuating Liver Lesions at Multidetector CT: Filtered Back Projection versus a Commercial Model-based Iterative Reconstruction Algorithm.

Journal Article Radiology · September 2017 Purpose To determine the effect of radiation dose and iterative reconstruction (IR) on noise, contrast, resolution, and observer-based detectability of subtle hypoattenuating liver lesions and to estimate the dose reduction potential of the IR algorithm in ... Full text Link to item Cite

Patient-specific quantification of image quality: An automated technique for measuring the distribution of organ Hounsfield units in clinical chest CT images.

Journal Article Med Phys · September 2017 PURPOSE: To develop and validate an automated technique for measuring organ Hounsfield units (HUs) in clinical chest CT images. MATERIALS AND METHODS: An automated computer algorithm was developed to measure the distribution of HUs inside four major organs ... Full text Link to item Cite

Techniques for virtual lung nodule insertion: volumetric and morphometric comparison of projection-based and image-based methods for quantitative CT.

Journal Article Phys Med Biol · August 22, 2017 Virtual nodule insertion paves the way towards the development of standardized databases of hybrid CT images with known lesions. The purpose of this study was to assess three methods (an established and two newly developed techniques) for inserting virtual ... Full text Link to item Cite

Size-based quality-informed framework for quantitative optimization of pediatric CT.

Journal Article J Med Imaging (Bellingham) · July 2017 The purpose of this study was to formulate a systematic, evidence-based method to relate quantitative diagnostic performance to radiation dose, enabling a multidimensional system to optimize computed tomography imaging across pediatric populations. Based o ... Full text Link to item Cite

Breast dose reduction with organ-based, wide-angle tube current modulated CT.

Journal Article J Med Imaging (Bellingham) · July 2017 This study aimed to estimate the organ dose reduction potential for organ-dose-based tube current modulated (ODM) thoracic computed tomography (CT) with a wide dose reduction arc. Twenty-one computational anthropomorphic phantoms (XCAT) were used to create ... Full text Link to item Cite

Organ dose variability and trends in tomosynthesis and radiography.

Journal Article J Med Imaging (Bellingham) · July 2017 The purpose of this study was to investigate relationships between patient attributes and organ dose for a population of computational phantoms for 20 tomosynthesis and radiography protocols. Organ dose was estimated from 54 adult computational phantoms (a ... Full text Link to item Cite

Patient dose monitoring and the use of diagnostic reference levels for the optimization of protection in medical imaging: current status and challenges worldwide.

Journal Article J Med Imaging (Bellingham) · July 2017 Optimization is one of the key concepts of radiation protection in medical imaging. In practice, it involves compromising between the image quality and dose to the patient; the dose should not be higher than necessary to achieve an image quality (or diagno ... Full text Link to item Cite

Special Section Guest Editorial: Visions of Safety: Perspectives on Radiation Exposure and Risk in Medical Imaging.

Journal Article J Med Imaging (Bellingham) · July 2017 This guest editorial introduces the special section on Visions of Safety: Perspectives on Radiation Exposure and Risk in Medical Imaging. ... Full text Link to item Cite

Robustness and Accuracy of An Automated Solution for Measuring Image Noise, Spatial Resolution, Contrast, and Dose in Clinical CT Images: Efforts Towards Patient-Specific Quantifications of CT Image Quality and Radiation Dose

Conference Medical Physics · June 30, 2017 Purpose: To develop a robust and accurate automated solution for measuring image noise, spatial resolution, contrast, and radiation dose using clinical patient CT images. Methods: An automated infrastructure has been developed to measure the image quality ... Cite

Image Quality Monitoring: Variability in Contrast Enhancement Across a Clinical Population

Conference Medical Physics · June 30, 2017 Purpose: Iodinated contrast agents are commonly used in computed tomography (CT) to delineate vasculature and blood perfusion by enhancement of Hounsfield unit values. Contrast-enhancement is affected by anatomical and physiological factors, and varies acr ... Cite

Organ Dose Estimation for CT Localizer Images

Conference Medical Physics · June 30, 2017 Purpose: Current radiation dose estimation for CT localizer exams report a single CTDIvol value. Localizer exams with the same CTDIvol can be acquired as AP, PA, or lateral geometries, each of which carry different radiation burdens. The Purpose of this st ... Cite

From DRL to NRL: A First Step Toward Quality-Based Reference Level

Conference Medical Physics · June 30, 2017 Purpose: Radiologic procedures are optimized based on a benefit-to-risk. However, risk has been the primary focus of radiology optimization and dose monitoring. Such programs are typically based on the concept of Diagnostic Reference Level (DRL). The term ... Cite

The Effect of Contrast Material on Radiation Dose at CT: Part I. Incorporation of Contrast Material Dynamics in Anthropomorphic Phantoms.

Journal Article Radiology · June 2017 Purpose To develop a method to incorporate the propagation of contrast material into computational anthropomorphic phantoms for estimation of organ dose at computed tomography (CT). Materials and Methods A patient-specific physiologically based pharmacokin ... Full text Link to item Cite

Image noise and dose performance across a clinical population: Patient size adaptation as a metric of CT performance.

Journal Article Medical physics · June 2017 PurposeModern CT systems adjust X-ray flux accommodating for patient size to achieve certain image noise values. The effectiveness of this adaptation is an important aspect of CT performance and should ideally be characterized in the context of re ... Full text Open Access Cite

The Effect of Contrast Material on Radiation Dose at CT: Part II. A Systematic Evaluation across 58 Patient Models.

Journal Article Radiology · June 2017 Purpose To estimate the radiation dose as a result of contrast medium administration in a typical abdominal computed tomographic (CT) examination across a library of contrast material-enhanced computational patient models. Materials and Methods In part II ... Full text Link to item Cite

Variability in Radiation Dose From Repeat Identical CT Examinations: Longitudinal Analysis of 2851 Patients Undergoing 12,635 Thoracoabdominal CT Scans in an Academic Health System.

Journal Article AJR Am J Roentgenol · June 2017 OBJECTIVE: The purpose of this study was to conduct longitudinal analyses of radiation dose data from adult patients undergoing clinically indicated, repeat identical thoracoabdominal CT examinations. MATERIALS AND METHODS: Radiation dose data were electro ... Full text Link to item Cite

Medical Physics 3.0 in Practice

Conference MEDICAL PHYSICS · June 1, 2017 Link to item Cite

Organ Dose Estimation for CT Localizer Images

Conference MEDICAL PHYSICS · June 1, 2017 Link to item Cite

Medical Physics 3.0 in Design

Conference MEDICAL PHYSICS · June 1, 2017 Link to item Cite

Dual-Source Single-Energy Multidetector CT Used to Obtain Multiple Radiation Exposure Levels within the Same Patient: Phantom Development and Clinical Validation.

Journal Article Radiology · May 2017 Purpose To develop, in a phantom environment, a method to obtain multidetector computed tomographic (CT) data sets at multiple radiation exposure levels within the same patient and to validate its use for potential dose reduction by using different image r ... Full text Link to item Cite

Size-specific optimization of CT protocols based on minimum detectability.

Journal Article Med Phys · April 2017 PURPOSE: To develop a comprehensive model of task-based performance of CT across a broad library of CT protocols, so that radiation dose and image quality can be optimized within a large multivendor clinical facility. METHODS: Eighty adult CT protocols fro ... Full text Link to item Cite

Adaptability index: quantifying CT tube current modulation performance from dose and quality informatics

Journal Article Proc. SPIE 10132, Medical Imaging 2017: Physics of Medical Imaging, 101322N (March 9, 2017) · March 9, 2017 The balance between risk and benefit in modern CT scanners is governed by the automatic adaptation mechanisms that adjust x-ray flux for accommodating patient size to achieve certain image noise values. The effectiveness of this adaptation is an important ... Full text Open Access Link to item Cite

CT breast dose reduction with the use of breast positioning and organ-based tube current modulation.

Journal Article Med Phys · February 2017 PURPOSE: This study aimed to investigate the breast dose reduction potential of a breast-positioning (BP) technique for thoracic CT examinations with organ-based tube current modulation (OTCM). METHODS: This study included 13 female anthropomorphic computa ... Full text Link to item Cite

Hallway Conversations in Physics.

Journal Article AJR Am J Roentgenol · January 2017 Full text Link to item Cite

Automated, patient-specific estimation of regional imparted energy and dose from tube current modulated computed tomography exams across 13 protocols.

Journal Article J Med Imaging (Bellingham) · January 2017 Currently, computed tomography (CT) dosimetry relies on surrogates for dose, such as CT dose index and size-specific dose estimates, rather than dose per se. Organ dose is considered as the gold standard for radiation dosimetry. However, organ dose estimat ... Full text Link to item Cite

Accuracy assessment and characterization of x-ray coded aperture coherent scatter spectral imaging for breast cancer classification.

Journal Article J Med Imaging (Bellingham) · January 2017 Although transmission-based x-ray imaging is the most commonly used imaging approach for breast cancer detection, it exhibits false negative rates higher than 15%. To improve cancer detection accuracy, x-ray coherent scatter computed tomography (CSCT) has ... Full text Link to item Cite

Third generation anthropomorphic physical phantom for mammography and DBT: Incorporating voxelized 3D printing and uniform chest wall QC region

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2017 Physical breast phantoms provide a standard method to test, optimize, and develop clinical mammography systems, including new digital breast tomosynthesis (DBT) systems. In previous work, we produced an anthropomorphic phantom based on 500x500x500 μm breas ... Full text Cite

An atlas-based organ dose estimator for tomosynthesis and radiography

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2017 The purpose of this study was to provide patient-specific organ dose estimation based on an atlas of human models for twenty tomosynthesis and radiography protocols. The study utilized a library of 54 adult computational phantoms (age: 18-78 years, weight ... Full text Cite

Estimation of breast dose reduction potential for organ-based tube current modulated CT with wide dose reduction arc

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2017 This study aimed to estimate the organ dose reduction potential for organ-dose-based tube current modulated (ODM) thoracic CT with wide dose reduction arc. Twenty-one computational anthropomorphic phantoms (XCAT, age range: 27- 75 years, weight range: 52.0 ... Full text Cite

Airways, vasculature, and interstitial tissue: Anatomically informed computational modeling of human lungs for virtual clinical trials

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2017 This study aimed to model virtual human lung phantoms including both non-parenchymal and parenchymal structures. Initial branches of the non-parenchymal structures (airways, arteries, and veins) were segmented from anatomical data in each lobe separately. ... Full text Cite

Accuracy and variability of texture-based radiomics features of lung lesions across CT imaging conditions

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2017 Texture analysis for lung lesions is sensitive to changing imaging conditions but these effects are not well understood, in part, due to a lack of ground-truth phantoms with realistic textures. The purpose of this study was to explore the accuracy and vari ... Full text Cite

Development of local complexity metrics to quantify the effect of anatomical noise on detectability of lung nodules in chest CT imaging

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2017 The purpose of this study was to develop metrics of local anatomical complexity and compare them with detectability of lung nodules in CT. Data were drawn retrospectively from a published perception experiment in which detectability was assessed in cases e ... Full text Cite

Quantification of the uncertainty in coronary CTA plaque measurements using dynamic cardiac phantom and 3D-printed plaque models

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2017 The purpose of this study was to quantify the accuracy of coronary computed tomography angiography (CTA) stenosis measurements using newly developed physical coronary plaque models attached to a base dynamic cardiac phantom (Shelley Medical DHP-01). Corona ... Full text Cite

Improved virtual cardiac phantom with variable diastolic filling rates and coronary artery velocities

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2017 To facilitate studies of measurement uncertainty in computed tomography angiography (CTA), we investigated the cardiac motion profile and resulting coronary artery motion utilizing innovative dynamic virtual and physical phantoms. The four-chamber cardiac ... Full text Cite

In-vivo detectability index: Development and validation of an automated methodology

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2017 The purpose of this study was to develop and validate a method to estimate patient-specific detectability indices directly from patients' CT images (i.e., "in vivo"). The method works by automatically extracting noise (NPS) and resolution (MTF) properties ... Full text Cite

Comparison of effects of dose on image quality in digital breast tomosynthesis across multiple vendors

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2017 In traditional radiography and computed tomography (CT), contrast is an important measure of image quality that, in theory, does not vary with dose. While increasing dose may increase the overall contrast-to-noise ratio (CNR), the contrast in an image shou ... Full text Cite

Inter-algorithm lesion volumetry comparison of real and 3D simulated lung lesions in CT

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2017 The purpose of this study was to establish volumetric exchangeability between real and computational lung lesions in CT. We compared the overall relative volume estimation performance of segmentation tools when used to measure real lesions in actual patien ... Full text Cite

Comparison of low-contrast detectability between two CT reconstruction algorithms using voxel-based 3D printed textured phantoms.

Journal Article Med Phys · December 2016 PURPOSE: To use novel voxel-based 3D printed textured phantoms in order to compare low-contrast detectability between two reconstruction algorithms, FBP (filtered-backprojection) and SAFIRE (sinogram affirmed iterative reconstruction) and determine what im ... Full text Link to item Cite

Estimation of Radiation Dose in CT Based on Projection Data.

Journal Article J Digit Imaging · October 2016 Managing and optimizing radiation dose has become a core problem for the CT community. As a fundamental step for dose optimization, accurate and computationally efficient dose estimates are crucial. The purpose of this study was to devise a computationally ... Full text Link to item Cite

Patient-specific quantification of image quality: An automated method for measuring spatial resolution in clinical CT images.

Journal Article Med Phys · October 2016 PURPOSE: To develop and validate an automated technique for evaluating the spatial resolution characteristics of clinical computed tomography (CT) images. METHODS: Twenty one chest and abdominopelvic clinical CT datasets were examined in this study. An alg ... Full text Link to item Cite

Assessing task performance in FFDM, DBT, and synthetic mammography using uniform and anthropomorphic physical phantoms.

Journal Article Med Phys · October 2016 PURPOSE: The purpose of this study is to quantify the differences in detectability between full field digital mammography (FFDM), digital breast tomosynthesis (DBT), and synthetic mammography (SM) for challenging, low contrast signals, in the context of bo ... Full text Link to item Cite

Technical Note: Gray tracking in medical color displays-A report of Task Group 196.

Journal Article Med Phys · July 2016 PURPOSE: The authors discuss measurement methods and instrumentation useful for the characterization of the gray tracking performance of medical color monitors for diagnostic applications. The authors define gray tracking as the variability in the chromati ... Full text Link to item Cite

Development and validation of a segmentation-free polyenergetic algorithm for dynamic perfusion computed tomography.

Journal Article J Med Imaging (Bellingham) · July 2016 Dynamic perfusion imaging can provide the morphologic details of the scanned organs as well as the dynamic information of blood perfusion. However, due to the polyenergetic property of the x-ray spectra, beam hardening effect results in undesirable artifac ... Full text Link to item Cite

Impact of breast structure on lesion detection in breast tomosynthesis, a simulation study.

Journal Article J Med Imaging (Bellingham) · July 2016 This study aims to characterize the effect of background tissue density and heterogeneity on the detection of irregular masses in breast tomosynthesis, while demonstrating the capability of the sophisticated tools that can be used in the design, implementa ... Full text Link to item Cite

Correlation between human detection accuracy and observer model-based image quality metrics in computed tomography.

Journal Article J Med Imaging (Bellingham) · July 2016 The purpose of this study was to compare computed tomography (CT) low-contrast detectability from human readers with observer model-based surrogates of image quality. A phantom with a range of low-contrast signals (five contrasts, three sizes) was imaged o ... Full text Link to item Cite

Variability in CT scanning over-range across clinical operation

Conference Medical physics · June 30, 2016 Cite

Effect of a Noise-Optimized Second-Generation Monoenergetic Algorithm on Image Noise and Conspicuity of Hypervascular Liver Tumors: An In Vitro and In Vivo Study.

Journal Article AJR Am J Roentgenol · June 2016 OBJECTIVE: The purpose of this study is to investigate whether the reduction in noise using a second-generation monoenergetic algorithm can improve the conspicuity of hypervascular liver tumors on dual-energy CT (DECT) images of the liver. MATERIALS AND ME ... Full text Link to item Cite

SU-G-206-13: Validating Dose Split: A Method to Image the Same Patient at Multiple Doses with a Single CT Acquisition.

Journal Article Med Phys · June 2016 PURPOSE: Dose optimization studies in CT have a need for images acquired at multiple dose levels. This presents ethical and logistical challenges for performing such research with human subjects. As a result, most studies rely on phantom data. The purpose ... Full text Link to item Cite

SU-F-R-11: Designing Quality and Safety Informatics Through Implementation of a CT Radiation Dose Monitoring Program.

Journal Article Med Phys · June 2016 PURPOSE: Recent legislative and accreditation requirements have driven rapid development and implementation of CT radiation dose monitoring solutions. Institutions must determine how to improve quality, safety, and consistency of their clinical performance ... Full text Link to item Cite

TU-FG-209-07: Medical Physics 1.0 Versus Medical Physics 2.0: A Case Study.

Conference Med Phys · June 2016 PURPOSE: To illustrate how performance analytics can identify performance decrement in digital radiography systems. METHODS: Subsequent to a radiologist's image quality complaint, four different advanced methods contributed to root cause analysis. Our syst ... Full text Link to item Cite

TH-CD-207B-04: Is TTF a True Representation of the Sharpness Property of a Non-Linear CT System?

Journal Article Med Phys · June 2016 PURPOSE: To investigate if the task-transfer-function (TTF) accurately models the transfer properties of a CT system for lung nodule imaging. METHODS: An anthropomorphic lung phantom was imaged using a standard chest protocol on a clinical CT scanner with ... Full text Link to item Cite

TH-CD-207B-02: An Automated Technique to Measure Spatial Resolution in Clinical CT Images: Application to Patient Data.

Journal Article Med Phys · June 2016 PURPOSE: To evaluate an automated technique for measuring spatial resolution across a database of clinical CT exams. METHODS: A fully automated algorithm was developed to extract a CT resolution index (RI) analogous to the modulation transfer function from ... Full text Link to item Cite

SU-F-I-45: An Automated Technique to Measure Image Contrast in Clinical CT Images.

Journal Article Med Phys · June 2016 PURPOSE: To develop and validate an automated technique for measuring image contrast in chest computed tomography (CT) exams. METHODS: An automated computer algorithm was developed to measure the distribution of Hounsfield units (HUs) inside four major org ... Full text Link to item Cite

TU-H-207A-05: Automated Early Identification of An Excessive Air-In-Oil X-Ray Tube Artifact That Mimics Acute Cerebral Infarct.

Journal Article Med Phys · June 2016 PURPOSE: There is an infrequent but serious CT artifact that occurs when there is too much air in the cooling oil of an x-ray tube. This artifact manifests as patchy hypodensities and mimics acute cerebral infarct. Routine quality control testing is unlike ... Full text Link to item Cite

TU-H-207A-09: An Automated Technique for Estimating Patient-Specific Regional Imparted Energy and Dose From TCM CT Exams Across 13 Protocols.

Journal Article Med Phys · June 2016 PURPOSE: To develop an automated technique for estimating patient-specific regional imparted energy and dose from tube current modulated (TCM) computed tomography (CT) exams across a diverse set of head and body protocols. METHODS: A library of 58 adult co ... Full text Link to item Cite

TU-D-207A-02: Quantitative Assessment of CT Systems with Iterative Image Reconstruction Algorithms.

Journal Article Med Phys · June 2016 In recent several years, motivated by the need to reduce radiation doses in CT exams, all of the major CT manufacturers have commercialized different iterative image reconstruction techniques and these innovative techniques were used in clinical routines w ... Full text Link to item Cite

TU-FG-209-06: Quantitative Evaluation of the Temporal Performance of Clinical Fluoroscopic Imaging Systems: The Temporal Modulation Transfer Function (TMTF).

Journal Article Med Phys · June 2016 PURPOSE: Measure the temporal modulation transfer function (TMTF) of clinical fluoroscopic flat panel imaging systems in order to accurately quantify their performance for temporally sensitive clinical tasks. METHODS: Copper blades (0.76 mm thick, 6 cm rad ... Full text Link to item Cite

TU-H-206-01: An Automated Approach for Identifying Geometric Distortions in Gamma Cameras.

Journal Article Med Phys · June 2016 PURPOSE: To develop a clinically-deployable, automated process for detecting artifacts in routine nuclear medicine (NM) quality assurance (QA) bar phantom images. METHODS: An artifact detection algorithm was created to analyze bar phantom images as part of ... Full text Link to item Cite

WE-B-BRC-03: Risk in the Context of Medical Imaging.

Journal Article Med Phys · June 2016 Prospective quality management techniques, long used by engineering and industry, have become a growing aspect of efforts to improve quality management and safety in healthcare. These techniques are of particular interest to medical physics as scope and co ... Full text Link to item Cite

TH-AB-207A-01: Contrast-Enhanced CT: Correlation of Radiation Dose and Biological Effect.

Journal Article Med Phys · June 2016 PURPOSE: The potential risk from CT is generally characterized in terms of radiation dose. The presence of iodinated-contrast medium increases radiation dose. However, it is unclear how much of this increase is biologically relevant. The purpose of this st ... Full text Link to item Cite

Convolution-based estimation of organ dose in tube current modulated CT.

Journal Article Phys Med Biol · May 21, 2016 Estimating organ dose for clinical patients requires accurate modeling of the patient anatomy and the dose field of the CT exam. The modeling of patient anatomy can be achieved using a library of representative computational phantoms (Samei et al 2014 Pedi ... Full text Link to item Cite

How does c-view image quality compare with conventional 2D FFDM?

Journal Article Med Phys · May 2016 PURPOSE: The FDA approved the use of digital breast tomosynthesis (DBT) in 2011 as an adjunct to 2D full field digital mammography (FFDM) with the constraint that all DBT acquisitions must be paired with a 2D image to assure adequate interpretative informa ... Full text Link to item Cite

Finite-element modeling of compression and gravity on a population of breast phantoms for multimodality imaging simulation.

Journal Article Med Phys · May 2016 PURPOSE: The authors are developing a series of computational breast phantoms based on breast CT data for imaging research. In this work, the authors develop a program that will allow a user to alter the phantoms to simulate the effect of gravity and compr ... Full text Link to item Cite

Quantitative Features of Liver Lesions, Lung Nodules, and Renal Stones at Multi-Detector Row CT Examinations: Dependency on Radiation Dose and Reconstruction Algorithm.

Journal Article Radiology · April 2016 PURPOSE: To determine if radiation dose and reconstruction algorithm affect the computer-based extraction and analysis of quantitative imaging features in lung nodules, liver lesions, and renal stones at multi-detector row computed tomography (CT). MATERIA ... Full text Link to item Cite

A quantitative metrology for performance characterization of five breast tomosynthesis systems based on an anthropomorphic phantom.

Journal Article Med Phys · April 2016 PURPOSE: In medical imaging systems, proper rendition of anatomy is essential in discerning normal tissue from disease. Currently, digital breast tomosynthesis (DBT) systems are evaluated using subjective evaluation of lesion visibility in uniform phantoms ... Full text Link to item Cite

Effects of automatic tube potential selection on radiation dose index, image quality, and lesion detectability in pediatric abdominopelvic CT and CTA: a phantom study.

Journal Article Eur Radiol · January 2016 OBJECTIVES: To assess the effect of automatic tube potential selection (ATPS) on radiation dose, image quality, and lesion detectability in paediatric abdominopelvic CT and CT angiography (CTA). METHODS: A paediatric modular phantom with contrast inserts w ... Full text Link to item Cite

Population of 224 realistic human subject-based computational breast phantoms.

Journal Article Med Phys · January 2016 PURPOSE: To create a database of highly realistic and anatomically variable 3D virtual breast phantoms based on dedicated breast computed tomography (bCT) data. METHODS: A tissue classification and segmentation algorithm was used to create realistic and de ... Full text Link to item Cite

Accurate assessment and prediction of noise in clinical CT images.

Journal Article Med Phys · January 2016 PURPOSE: The objectives of this study were (a) to devise a technique for measuring quantum noise in clinical body computed tomography (CT) images and (b) to develop a model for predicting that noise with high accuracy. METHODS: The study included 83 clinic ... Full text Link to item Cite

Determination of contrast media administration to achieve a targeted contrast enhancement in computed tomography.

Journal Article J Med Imaging (Bellingham) · January 2016 Contrast enhancement is a key component of computed tomography (CT) imaging and offers opportunities for optimization. The design and optimization of techniques, however, require orchestration with the scan parameters and, further, a methodology to relate ... Full text Link to item Cite

Design and implementation of coded aperture coherent scatter spectral imaging of cancerous and healthy breast tissue samples.

Journal Article J Med Imaging (Bellingham) · January 2016 A scatter imaging technique for the differentiation of cancerous and healthy breast tissue in a heterogeneous sample is introduced in this work. Such a technique has potential utility in intraoperative margin assessment during lumpectomy procedures. In thi ... Full text Link to item Cite

Design, fabrication, and implementation of voxel-based 3D printed textured phantoms for task-based image quality assessment in CT

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2016 In x-ray computed tomography (CT), task-based image quality studies are typically performed using uniform background phantoms with low-contrast signals. Such studies may have limited clinical relevancy for modern non-linear CT systems due to possible influ ... Full text Cite

Second generation anthropomorphic physical phantom for mammography and DBT: Incorporating voxelized 3D printing and inkjet printing of iodinated lesion inserts

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2016 Physical phantoms are needed for the evaluation and optimization of new digital breast tomosynthesis (DBT) systems. Previously, we developed an anthropomorphic phantom based on human subject breast CT data and fabricated using commercial 3D printing. We no ... Full text Cite

Coded aperture coherent scatter imaging for breast cancer detection: A Monte Carlo evaluation

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2016 It is known that conventional x-ray imaging provides a maximum contrast between cancerous and healthy fibroglandular breast tissues of 3% based on their linear x-ray attenuation coefficients at 17.5 keV, whereas coherent scatter signal provides a maximum c ... Full text Cite

Comparison of model and human observer performance in FFDM, DBT, and synthetic mammography

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2016 Reader studies are important in assessing breast imaging systems. The purpose of this work was to assess task-based performance of full field digital mammography (FFDM), digital breast tomosynthesis (DBT), and synthetic mammography (SM) using different pha ... Full text Cite

A technique for multi-dimensional optimization of radiation dose, contrast dose, and image quality in CT imaging

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2016 The purpose of this study was to substantiate the interdependency of image quality, radiation dose, and contrast material dose in CT towards the patient-specific optimization of the imaging protocols. The study deployed two phantom platforms. First, a vari ... Full text Cite

Organ dose conversion coefficients for tube current modulated CT protocols for an adult population

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2016 In computed tomography (CT), patient-specific organ dose can be estimated using pre-calculated organ dose conversion coefficients (organ dose normalized by CTDIvol, h factor) database, taking into account patient size and scan coverage. The conversion coef ... Full text Cite

An automated technique for estimating patient-specific regional imparted energy and dose in TCM CT exams

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2016 Currently computed tomography (CT) dosimetry relies on CT dose index (CTDI) and size specific dose estimates (SSDE). Organ dose is a better metric of radiation burden. However, organ dose estimation requires precise knowledge of organ locations. Regional i ... Full text Cite

Estimation of breast dose saving potential using a breast positioning technique for organ-based tube current modulated CT

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2016 In thoracic CT, organ-based tube current modulation (OTCM) reduces breast dose by lowering the tube current in the 120° anterior dose reduction zone of patients. However, in practice the breasts usually expand to an angle larger than the dose reduction zon ... Full text Cite

Development of a Hausdorff distance based 3D quantification technique to evaluate the CT imaging system impact on depiction of lesion morphology

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2016 The purpose of this study was to develop a 3D quantification technique to assess the impact of imaging system on depiction of lesion morphology. Regional Hausdorff Distance (RHD) was computed from two 3D volumes: virtual mesh models of synthetic nodules or ... Full text Cite

Development and comparison of projection and image space 3D nodule insertion techniques

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2016 This study aimed to develop and compare two methods of inserting computerized virtual lesions into CT datasets. 24 physical (synthetic) nodules of three sizes and four morphologies were inserted into an anthropomorphic chest phantom (LUNGMAN, KYOTO KAGAKU) ... Full text Cite

Synthesized interstitial lung texture for use in anthropomorphic computational phantoms

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2016 A realistic model of the anatomical texture from the pulmonary interstitium was developed with the goal of extending the capability of anthropomorphic computational phantoms (e.g., XCAT, Duke University), allowing for more accurate image quality assessment ... Full text Cite

Evaluation of Low-Contrast Detectability of Iterative Reconstruction across Multiple Institutions, CT Scanner Manufacturers, and Radiation Exposure Levels.

Journal Article Radiology · October 2015 PURPOSE: To compare image resolution from iterative reconstruction with resolution from filtered back projection for low-contrast objects on phantom computed tomographic (CT) images across vendors and exposure levels. MATERIALS AND METHODS: Randomized repe ... Full text Link to item Cite

Monte Carlo reference data sets for imaging research: Executive summary of the report of AAPM Research Committee Task Group 195.

Journal Article Med Phys · October 2015 The use of Monte Carlo simulations in diagnostic medical imaging research is widespread due to its flexibility and ability to estimate quantities that are challenging to measure empirically. However, any new Monte Carlo simulation code needs to be validate ... Full text Link to item Cite

Volumetric x-ray coherent scatter imaging of cancer in resected breast tissue: a Monte Carlo study using virtual anthropomorphic phantoms.

Journal Article Phys Med Biol · August 21, 2015 Breast cancer patients undergoing surgery often choose to have a breast conserving surgery (BCS) instead of mastectomy for removal of only the breast tumor. If post-surgical analysis such as histological assessment of the resected tumor reveals insufficien ... Full text Link to item Cite

Characteristic image quality of a third generation dual-source MDCT scanner: Noise, resolution, and detectability.

Journal Article Med Phys · August 2015 PURPOSE: The purpose of this work was to assess the inherent image quality characteristics of a new multidetector computed tomography system in terms of noise, resolution, and detectability index as a function of image acquisition and reconstruction for a ... Full text Link to item Cite

The development of a population of 4D pediatric XCAT phantoms for imaging research and optimization.

Journal Article Med Phys · August 2015 PURPOSE: We previously developed a set of highly detailed 4D reference pediatric extended cardiac-torso (XCAT) phantoms at ages of newborn, 1, 5, 10, and 15 yr with organ and tissue masses matched to ICRP Publication 89 values. In this work, we extended th ... Full text Link to item Cite

A Case for Wide-Angle Breast Tomosynthesis.

Journal Article Acad Radiol · July 2015 RATIONALES AND OBJECTIVES: Conventional mammography is largely limited by superimposed anatomy. Digital breast tomosynthesis (DBT) and computed tomography (CT) alleviate this limitation but with added out-of-plane artifacts or limited chest wall coverage. ... Full text Link to item Cite

Automated Technique to Measure Noise in Clinical CT Examinations.

Journal Article AJR Am J Roentgenol · July 2015 OBJECTIVE: The purpose of this study was to develop and validate an automated method to measure noise in clinical CT examinations. MATERIALS AND METHODS: An automated algorithm was developed to measure noise in CT images. To assess its validity, the global ... Full text Link to item Cite

Development of realistic physical breast phantoms matched to virtual breast phantoms based on human subject data.

Journal Article Med Phys · July 2015 PURPOSE: Physical phantoms are essential for the development, optimization, and evaluation of x-ray breast imaging systems. Recognizing the major effect of anatomy on image quality and clinical performance, such phantoms should ideally reflect the three-di ... Full text Link to item Cite

An Improved Index of Image Quality for Task-based Performance of CT Iterative Reconstruction across Three Commercial Implementations.

Journal Article Radiology · June 2015 PURPOSE: To develop and validate a metric of computed tomographic (CT) image quality that incorporates the noise texture and resolution properties of an image. MATERIALS AND METHODS: Images of the American College of Radiology CT quality assurance phantom ... Full text Link to item Cite

Diagnostic Performance of an Advanced Modeled Iterative Reconstruction Algorithm for Low-Contrast Detectability with a Third-Generation Dual-Source Multidetector CT Scanner: Potential for Radiation Dose Reduction in a Multireader Study.

Journal Article Radiology · June 2015 PURPOSE: To assess the effect of radiation dose reduction on low-contrast detectability by using an advanced modeled iterative reconstruction (ADMIRE; Siemens Healthcare, Forchheim, Germany) algorithm in a contrast-detail phantom with a third-generation du ... Full text Link to item Cite

TH-EF-BRA-07: A Reference Organ Dose Database for Body CT Examination Based On AAPM 246.

Journal Article Med Phys · June 2015 PURPOSE: This study aims to establish a reference organ dose database for clinical body CT based on detailed modeling of patient anatomy and irradiation condition. METHODS: Clinical CT images of 40 adult patients (age range: 18-78 y.o., 22 male, 18 female) ... Full text Link to item Cite

TH-AB-201-12: A Consumer Report for Mobile Digital Radiography: A Holistic Comparative Evaluation Across Four Systems.

Journal Article Med Phys · June 2015 PURPOSE: To provide a template for the comprehensive clinical evaluation of new imaging technologies with initial application to mobile digital radiography (DR). METHODS: Four mobile DR devices (GE Optima XR220amx+Flashpad; Carestream DRX Revolution+DRX-1C ... Full text Link to item Cite

WE-G-204-09: Medical Physics 2.0 in Practice: Automated QC Assessment of Clinical Chest Images.

Journal Article Med Phys · June 2015 PURPOSE: To determine whether a proposed suite of objective image quality metrics for digital chest radiographs is useful for monitoring image quality in our clinical operation. METHODS: Seventeen gridless AP Chest radiographs from a GE Optima portable dig ... Full text Link to item Cite

WE-G-204-07: Automated Characterization of Perceptual Quality of Clinical Chest Radiographs: Improvements in Lung, Spine, and Hardware Detection.

Journal Article Med Phys · June 2015 PURPOSE: To develop and validate more robust methods for automated lung, spine, and hardware detection in AP/PA chest images. This work is part of a continuing effort to automatically characterize the perceptual image quality of clinical radiographs. [Y. L ... Full text Link to item Cite

MO-F-CAMPUS-I-03: GPU Accelerated Monte Carlo Technique for Fast Concurrent Image and Dose Simulation.

Journal Article Med Phys · June 2015 PURPOSE: To develop an accurate and fast Monte Carlo (MC) method of simulating CT that is capable of correlating dose with image quality using voxelized phantoms. METHODS: A realistic voxelized phantom based on patient CT data, XCAT, was used with a GPU ac ... Full text Link to item Cite

TU-CD-207-08: Intrinsic Image Quality Comparison of Synthesized 2-D and FFDM Images.

Journal Article Med Phys · June 2015 PURPOSE: With the combined interest of managing patient dose, maintaining or improving image quality, and maintaining or improving the diagnostic utility of mammographic data, this study aims to compare the intrinsic image quality of Hologic's synthesized ... Full text Link to item Cite

TU-G-204-04: A Unified Strategy for Bi-Factorial Optimization of Radiation Dose and Contrast Dose in CT Imaging.

Conference Med Phys · June 2015 PURPOSE: To substantiate the interdependency of contrast dose, radiation dose, and image quality in CT towards the patient- specific optimization of the imaging protocols METHODS: The study deployed two phantom platforms. A variable sized (12, 18, 23, 30, ... Full text Link to item Cite

Prospective estimation of organ dose in CT under tube current modulation.

Journal Article Med Phys · April 2015 PURPOSE: Computed tomography (CT) has been widely used worldwide as a tool for medical diagnosis and imaging. However, despite its significant clinical benefits, CT radiation dose at the population level has become a subject of public attention and concern ... Full text Link to item Cite

Implementation of the ACR Dose Index Registry.

Journal Article J Am Coll Radiol · March 2015 Full text Link to item Cite

Assessment of the dose reduction potential of a model-based iterative reconstruction algorithm using a task-based performance metrology.

Journal Article Med Phys · January 2015 PURPOSE: Different computed tomography (CT) reconstruction techniques offer different image quality attributes of resolution and noise, challenging the ability to compare their dose reduction potential against each other. The purpose of this study was to e ... Full text Link to item Cite

A multireader diagnostic performance study of low-contrast detectability on a third-generation dual-source CT scanner: Filtered back projection versus advanced modeled iterative reconstruction

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2015 The purpose of this work was to compare CT low-contrast detectability between two reconstruction algorithms, filtered back-projection (FBP) and advanced modeled iterative reconstruction (ADMIRE). A phantom was designed with a range of low-contrast circular ... Full text Cite

What observer models best reflect low-contrast detectability in CT?

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2015 The purpose of this work was to compare CT low-contrast detectability as measured via human perception experiments with observer model surrogates of image quality measured directly from the images. A phantom was designed with a range of low-contrast circul ... Full text Cite

The impact of breast structure on lesion detection in breast tomosynthesis

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2015 Virtual clinical trials (VCT) can be carefully designed to inform, orient, or potentially replace clinical trials. The focus of this study was to demonstrate the capability of the sophisticated tools that can be used in the design, implementation, and perf ... Full text Cite

Experimental implementation of coded aperture coherent scatter spectral imaging of cancerous and healthy breast tissue samples

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2015 A fast and accurate scatter imaging technique to differentiate cancerous and healthy breast tissue is introduced in this work. Such a technique would have wide-ranging clinical applications from intra-operative margin assessment to breast cancer screening. ... Full text Cite

A quantitative metrology for performance characterization of breast tomosynthesis systems based on an anthropomorphic phantom

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2015 Purpose: Common methods for assessing image quality of digital breast tomosynthesis (DBT) devices currently utilize simplified or otherwise unrealistic phantoms, which use inserts in a uniform background and gauge performance based on a subjective evaluati ... Full text Cite

Determination of contrast media administration to achieve a targeted contrast enhancement in CT

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2015 Contrast enhancement is a key component of CT imaging and offer opportunities for optimization. The design and optimization of new techniques however requires orchestration with the scan parameters and further a methodology to relate contrast enhancement a ... Full text Cite

Convolution-based estimation of organ dose in tube current modulated CT

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2015 Among the various metrics that quantify radiation dose in computed tomography (CT), organ dose is one of the most representative quantities reflecting patient-specific radiation burden.1 Accurate estimation of organ dose requires one to effectively model t ... Full text Cite

Dual-energy MDCT in hypervascular liver tumors: effect of body size on selection of the optimal monochromatic energy level.

Journal Article AJR Am J Roentgenol · December 2014 OBJECTIVE: The purpose of this article is to investigate the effect of body size on the selection of optimal monochromatic energy level for maximizing the conspicuity of hypervascular liver tumors during late hepatic arterial phase using dual-energy MDCT. ... Full text Link to item Cite

Evaluating iterative reconstruction performance in computed tomography.

Journal Article Med Phys · December 2014 PURPOSE: Iterative reconstruction (IR) offers notable advantages in computed tomography (CT). However, its performance characterization is complicated by its potentially nonlinear behavior, impacting performance in terms of specific tasks. This study aimed ... Full text Link to item Cite

Organ localization: toward prospective patient-specific organ dosimetry in computed tomography.

Journal Article Med Phys · December 2014 PURPOSE: With increased focus on radiation dose from medical imaging, prospective radiation dose estimates are becoming increasingly desired. Using available populations of adult and pediatric patient phantoms, radiation dose calculations can be catalogued ... Full text Link to item Cite

A generic framework to simulate realistic lung, liver and renal pathologies in CT imaging.

Journal Article Phys Med Biol · November 7, 2014 Realistic three-dimensional (3D) mathematical models of subtle lesions are essential for many computed tomography (CT) studies focused on performance evaluation and optimization. In this paper, we develop a generic mathematical framework that describes the ... Full text Link to item Cite

Automated characterization of perceptual quality of clinical chest radiographs: validation and calibration to observer preference.

Journal Article Med Phys · November 2014 PURPOSE: The authors previously proposed an image-based technique [Y. Lin et al. Med. Phys. 39, 7019-7031 (2012)] to assess the perceptual quality of clinical chest radiographs. In this study, an observer study was designed and conducted to validate the ou ... Full text Link to item Cite

Determining organ dose: the holy grail.

Journal Article Pediatr Radiol · October 2014 Among the various metrics to quantify CT radiation dose, organ dose is generally regarded as one of the best to reflect patient radiation burden. Organ dose is dependent on two main factors, namely patient anatomy and irradiation field. An accurate estimat ... Full text Link to item Cite

Pros and cons of organ shielding for CT imaging.

Journal Article Pediatr Radiol · October 2014 With the increased importance of CT radiation dose to health care providers, patients and the general public, there is an increased responsibility to minimize patient dose effectively. Bismuth shields offer a simple strategy to reduce dose to certain anter ... Full text Link to item Cite

An X-ray scatter system for material identification in cluttered objects: A Monte Carlo simulation study

Journal Article Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms · September 15, 2014 The analysis of X-ray scatter patterns has been demonstrated as an effective method of identifying specific materials in mixed object environments, for both biological and non-biological applications. Here we describe an X-ray scatter imaging system for ma ... Full text Cite

Impact of dual-energy multi-detector row CT with virtual monochromatic imaging on renal cyst pseudoenhancement: in vitro and in vivo study.

Journal Article Radiology · September 2014 PURPOSE: To investigate whether dual-energy multi-detector row computed tomography (CT) with virtual monochromatic imaging can overcome renal cyst pseudoenhancement in a phantom experiment and a clinical study. MATERIALS AND METHODS: This retrospective sin ... Full text Link to item Cite

Quantum noise properties of CT images with anatomical textured backgrounds across reconstruction algorithms: FBP and SAFIRE.

Journal Article Med Phys · September 2014 PURPOSE: Quantum noise properties of CT images are generally assessed using simple geometric phantoms with uniform backgrounds. Such phantoms may be inadequate when assessing nonlinear reconstruction or postprocessing algorithms. The purpose of this study ... Full text Link to item Cite

The impact on CT dose of the variability in tube current modulation technology: a theoretical investigation.

Journal Article Phys Med Biol · August 21, 2014 Body CT scans are routinely performed using tube-current-modulation (TCM) technology. There is notable variability across CT manufacturers in terms of how TCM technology is implemented. Some manufacturers aim to provide uniform image noise across body regi ... Full text Link to item Cite

Dose index analytics: more than a low number.

Journal Article J Am Coll Radiol · August 2014 Full text Link to item Cite

Model-based CT performance assessment and optimization for iodinated and noniodinated imaging tasks as a function of kVp and body size.

Journal Article Med Phys · August 2014 PURPOSE: The goal of this study was to assess the comparative performance of iterative reconstruction in space (IRIS) and filtered back projection (FBP) reconstruction algorithms in terms of image quality and dose across kVps and phantom sizes. METHODS: Th ... Full text Link to item Cite

Development and application of a suite of 4-D virtual breast phantoms for optimization and evaluation of breast imaging systems.

Journal Article IEEE Trans Med Imaging · July 2014 Mammography is currently the most widely utilized tool for detection and diagnosis of breast cancer. However, in women with dense breast tissue, tissue overlap may obscure lesions. Digital breast tomosynthesis can reduce tissue overlap. Furthermore, imagin ... Full text Link to item Cite

Patient-based estimation of organ dose for a population of 58 adult patients across 13 protocol categories.

Journal Article Med Phys · July 2014 PURPOSE: This study aimed to provide a comprehensive patient-specific organ dose estimation across a multiplicity of computed tomography (CT) examination protocols. METHODS: A validated Monte Carlo program was employed to model a common CT system (LightSpe ... Full text Link to item Cite

Assessment of volumetric noise and resolution performance for linear and nonlinear CT reconstruction methods.

Journal Article Med Phys · July 2014 PURPOSE: For nonlinear iterative image reconstructions (IR), the computed tomography (CT) noise and resolution properties can depend on the specific imaging conditions, such as lesion contrast and image noise level. Therefore, it is imperative to develop a ... Full text Link to item Cite

An angle-dependent estimation of CT x-ray spectrum from rotational transmission measurements.

Journal Article Med Phys · June 2014 PURPOSE: Computed tomography (CT) performance as well as dose and image quality is directly affected by the x-ray spectrum. However, the current assessment approaches of the CT x-ray spectrum require costly measurement equipment and complicated operational ... Full text Link to item Cite

WE-D-18A-02: Performance Evaluation of Automatic Exposure Control (AEC) Across 12 Clinical CT Systems.

Journal Article Med Phys · June 2014 PURPOSE: Automatic exposure control (AEC) is not typically evaluated or monitored in CT quality assurance programs. The purpose of this study was to develop/evaluate a new AEC testing platform for the clinical physics program at our institution, and charac ... Full text Link to item Cite

SU-E-I-94: Automated Image Quality Assessment of Radiographic Systems Using An Anthropomorphic Phantom.

Conference Med Phys · June 2014 PURPOSE: In a large, academic medical center, consistent radiographic imaging performance is difficult to routinely monitor and maintain, especially for a fleet consisting of multiple vendors, models, software versions, and numerous imaging protocols. Thus ... Full text Link to item Cite

SU-C-9A-02: Structured Noise Index as An Automated Quality Control for Nuclear Medicine: A Two Year Experience.

Journal Article Med Phys · June 2014 PURPOSE: Flood-field uniformity evaluation is an essential element in the assessment of nuclear medicine (NM) gamma cameras. It serves as the central element of the quality control (QC) program, acquired and analyzed on a daily basis prior to clinical imag ... Full text Link to item Cite

SU-F-18C-07: Automated CT QC Program with Analytics, Archival, and Notification Capabilities.

Journal Article Med Phys · June 2014 PURPOSE: Tracking metrics over time is a well-established means of establishing a quality control program. The number of metrics followed and testing frequency is limited by available resources. Automating the image analysis and data archival of a QC progr ... Full text Link to item Cite

TH-E-9A-01: Medical Physics 1.0 to 2.0, Session 4: Computed Tomography, Ultrasound and Nuclear Medicine.

Journal Article Med Phys · June 2014 Medical Physics 2.0 is a bold vision for an existential transition of clinical imaging physics in face of the new realities of value-based and evidencebased medicine, comparative effectiveness, and meaningful use. It speaks to how clinical imaging physics ... Full text Link to item Cite

TU-C-18C-01: Medical Physics 1.0 to 2.0: Introduction and Panel Discussion.

Journal Article Med Phys · June 2014 Medical Physics 2.0, a new frontier in clinical imaging physics: Diagnostic imaging has always been a technological highlight of modern medicine. Imaging systems, with their ever-expanding advancement in terms of technology and application, increasingly re ... Full text Link to item Cite

TH-C-18A-06: Combined CT Image Quality and Radiation Dose Monitoring Program Based On Patient Data to Assess Consistency of Clinical Imaging Across Scanner Models.

Journal Article Med Phys · June 2014 PURPOSE: One of the principal challenges of clinical imaging is to achieve an ideal balance between image quality and radiation dose across multiple CT models. The number of scanners and protocols at large medical centers necessitates an automated quality ... Full text Link to item Cite

SU-C-12A-03: The Impact of Contrast Medium On Radiation Dose in CT: A Systematic Evaluation Across 58 Patient Models.

Journal Article Med Phys · June 2014 PURPOSE: To assess the effect of contrast medium on radiation dose as a function of time via Monte Carlo simulation from the liver CT scan across a library of 5D XCAT models METHODS: A validated Monte Carlo simulation package (PENELOPE) was employed to mod ... Full text Link to item Cite

MO-C-18A-01: Advances in Model-Based 3D Image Reconstruction.

Journal Article Med Phys · June 2014 Recent years have seen the emergence of CT image reconstruction techniques that exploit physical models of the imaging system, photon statistics, and even the patient to achieve improved 3D image quality and/or reduction of radiation dose. With numerous ad ... Full text Link to item Cite

SU-E-I-91: Reproducibility in Prescribed Dose in AEC CT Scans Due to Table Height, Patient Size, and Localizer Acquisition Order.

Journal Article Med Phys · June 2014 PURPOSE: In CT scanners, the automatic exposure control (AEC) tube current prescription depends on the acquired prescan localizer image(s). The purpose of this study was to quantify the effect that table height, patient size, and localizer acquisition orde ... Full text Link to item Cite

MO-E-17A-02: Incorporation of Contrast Medium Dynamics in Anthropomorphic Phantoms: The Advent of 5D XCAT Models.

Journal Article Med Phys · June 2014 PURPOSE: To develop a unique method to incorporate the dynamics of contrast-medium propagation into the anthropomorphic phantom, to generate a five-dimensional (5D) patient model for multimodality imaging studies. METHODS: A compartmental model of blood ci ... Full text Link to item Cite

MO-C-18C-01: Radiation Risks at Level of Few CT Scans: How Real?- Science to Practice.

Journal Article Med Phys · June 2014 There are controversies surrounding radiation effects in human population in the range of radiation doses encountered by patients resulting from one to several CT scans. While it is understandable why the effects from low levels of diagnostic radiation are ... Full text Link to item Cite

SU-F-18C-01: Minimum Detectability Analysis for Comprehensive Sized Based Optimization of Image Quality and Radiation Dose Across CT Protocols.

Journal Article Med Phys · June 2014 PURPOSE: This work involved a comprehensive modeling of task-based performance of CT across a wide range of protocols. The approach was used for optimization and consistency of dose and image quality within a large multi-vendor clinical facility. METHODS: ... Full text Link to item Cite

Task-based strategy for optimized contrast enhanced breast imaging: analysis of six imaging techniques for mammography and tomosynthesis.

Conference Med Phys · June 2014 PURPOSE: The use of contrast agents in breast imaging has the capability of enhancing nodule detectability and providing physiological information. Accordingly, there has been a growing trend toward using iodine as a contrast medium in digital mammography ... Full text Link to item Cite

A fast poly-energetic iterative FBP algorithm.

Journal Article Phys Med Biol · April 7, 2014 The beam hardening (BH) effect can influence medical interpretations in two notable ways. First, high attenuation materials, such as bones, can induce strong artifacts, which severely deteriorate the image quality. Second, voxel values can significantly de ... Full text Link to item Cite

A set of 4D pediatric XCAT reference phantoms for multimodality research.

Journal Article Med Phys · March 2014 PURPOSE: The authors previously developed an adult population of 4D extended cardiac-torso (XCAT) phantoms for multimodality imaging research. In this work, the authors develop a reference set of 4D pediatric XCAT phantoms consisting of male and female ana ... Full text Link to item Cite

Comparison of patient specific dose metrics between chest radiography, tomosynthesis, and CT for adult patients of wide ranging body habitus.

Journal Article Med Phys · February 2014 PURPOSE: Given the radiation concerns inherent to the x-ray modalities, accurately estimating the radiation doses that patients receive during different imaging modalities is crucial. This study estimated organ doses, effective doses, and risk indices for ... Full text Link to item Cite

An efficient polyenergetic SART (pSART) reconstruction algorithm for quantitative myocardial CT perfusion.

Journal Article Med Phys · February 2014 PURPOSE: In quantitative myocardial CT perfusion imaging, beam hardening effect due to dense bone and high concentration iodinated contrast agent can result in visible artifacts and inaccurate CT numbers. In this paper, an efficient polyenergetic Simultane ... Full text Link to item Cite

Pediatric chest and abdominopelvic CT: organ dose estimation based on 42 patient models.

Journal Article Radiology · February 2014 PURPOSE: To estimate organ dose from pediatric chest and abdominopelvic computed tomography (CT) examinations and evaluate the dependency of organ dose coefficients on patient size and CT scanner models. MATERIALS AND METHODS: The institutional review boar ... Full text Link to item Cite

Population of 100 realistic, patient-based computerized breast phantoms for multi-modality imaging research

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2014 Breast imaging is an important area of research with many new Techniques being investigated To further reduce The morbidity and mortality of breast cancer Through early detection. Computerized phantoms can provide an essential Tool To quantitatively compar ... Full text Cite

X-ray coherent scatter imaging for surgical margin detection: A Monte Carlo study

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2014 Instead of having the entire breast removed (a mastectomy), breast cancer patients often receive a breast con-serving surgery (BCS) for removal of only the breast tumor. If post-surgery analysis reveals ta missed margin around the tumor tissue excised thro ... Full text Cite

A second generation of physical anthropomorphic 3D breast phantoms based on human subject data

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2014 Previous fabrication of anthropomorphic breast phantoms has demonstrated Their viability as a model for 2D (mammography) and 3D (tomosynthesis) breast imaging systems. Further development of These models will be essential for The evaluation of breast x-ray ... Full text Cite

A task-based comparison of two reconstruction algorithms for digital breast tomosynthesis

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2014 Digital breast tomosynthesis (DBT) generates 3-D reconstructions of the breast by taking X-Ray projections at various angles around the breast. DBT improves cancer detection as it minimizes tissue overlap that is present in traditional 2-D mammography. In ... Full text Cite

Validation of an image-based technique to assess the perceptual quality of clinical chest radiographs with an observer study

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2014 We previously proposed a novel image-based quality assessment technique1 to assess the perceptual quality of clinical chest radiographs. In this paper, an observer study was designed and conducted to systematically validate this technique. Ten metrics were ... Full text Cite

Design of anthropomorphic Textured phantoms for CT performance evaluation

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2014 Commercially available computed Tomography (CT) Technologies such as iterative reconstruction (IR) have The potential To enable reduced patient doses while maintaining diagnostic image quality. However, systematically determining safe dose reduction levels ... Full text Cite

The development of a population of 4D pediatric XCAT phantoms for CT imaging research and optimization

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2014 With The increased use of CT examinations, The associated radiation dose has become a large concern, especially for pediatrics. Much research has focused on reducing radiation dose Through new scanning and reconstruction methods. Computational phantoms pro ... Full text Cite

Prospective optimization of CT under Tube current modulation: I. organ dose

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2014 In an environment in which computed Tomography (CT) has become an indispensable diagnostic Tool employed with great frequency, dose concerns at The population level have become a subject of public attention. In That regard, optimizing radiation dose has be ... Full text Cite

Prospective optimization of CT under tube current modulation: II. image quality

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2014 Despite the significant clinical benefits of computed tomography (CT) in providing diagnostic information for a broad range of diseases, concerns have been raised regarding the potential cancer risk induced by CT radiation exposure. In that regard, optimiz ... Full text Cite

A refined methodology for modeling volume quantification performance in CT

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2014 The utility of CT lung nodule volume quantification technique depends on the precision of the quantification. To enable the evaluation of quantification precision, we previously developed a mathematical model that related precision to image resolution and ... Full text Cite

Improved nuclear medicine uniformity assessment with noise texture analysis.

Journal Article J Nucl Med · January 2014 UNLABELLED: Because γ cameras are generally susceptible to environmental conditions and system vulnerabilities, they require routine evaluation of uniformity performance. The metrics for such evaluations are commonly pixel value-based. Although these metri ... Full text Link to item Cite

Dose coefficients in pediatric and adult abdominopelvic CT based on 100 patient models.

Journal Article Phys Med Biol · December 21, 2013 Recent studies have shown the feasibility of estimating patient dose from a CT exam using CTDI(vol)-normalized-organ dose (denoted as h), DLP-normalized-effective dose (denoted as k), and DLP-normalized-risk index (denoted as q). However, previous studies ... Full text Link to item Cite

Clinical impact of an adaptive statistical iterative reconstruction algorithm for detection of hypervascular liver tumours using a low tube voltage, high tube current MDCT technique.

Journal Article Eur Radiol · December 2013 OBJECTIVES: To investigate the impact of an adaptive statistical iterative reconstruction (ASiR) algorithm on diagnostic accuracy and confidence for the diagnosis of hypervascular liver tumours, as well as the reader's perception of image quality, using a ... Full text Link to item Cite

Volumetric quantification of lung nodules in CT with iterative reconstruction (ASiR and MBIR).

Journal Article Med Phys · November 2013 PURPOSE: Volume quantifications of lung nodules with multidetector computed tomography (CT) images provide useful information for monitoring nodule developments. The accuracy and precision of the volume quantification, however, can be impacted by imaging a ... Full text Link to item Cite

Estimation of radiation exposure for brain perfusion CT: standard protocol compared with deviations in protocol.

Journal Article AJR Am J Roentgenol · November 2013 OBJECTIVE: The purpose of this study was to measure the organ doses and estimate the effective dose for the standard brain perfusion CT protocol and erroneous protocols. MATERIALS AND METHODS: An anthropomorphic phantom with metal oxide semiconductor field ... Full text Link to item Cite

Digital breast tomosynthesis: A concise overview

Journal Article Imaging in Medicine · October 1, 2013 The proven limited sensitivity of mammography, due to tissue superposition in a 2D image, has motivated the development of alternative 3D imaging systems with minimal ionizing exposure and relatively low cost. The advent of digital detectors facilitated th ... Full text Cite

Comparison of conventional and simulated reduced-tube current MDCT for evaluation of suspected appendicitis in the pediatric population.

Journal Article AJR Am J Roentgenol · September 2013 OBJECTIVE: The purpose of this study was to compare CT with conventional and simulated reduced-tube current in the evaluation for acute appendicitis in children. MATERIALS AND METHODS: Validated noise-addition (tube current-reduction) software was used to ... Full text Link to item Cite

Effective DQE (eDQE) for monoscopic and stereoscopic chest radiography imaging systems with the incorporation of anatomical noise.

Journal Article Med Phys · September 2013 PURPOSE: Stereoscopic chest biplane correlation imaging (stereo∕BCI) has been proposed as an alternative modality to single view chest x-ray (CXR). The metrics effective modulation transfer function (eMTF), effective normalized noise power spectrum (eNNPS) ... Full text Link to item Cite

DQE of wireless digital detectors: comparative performance with differing filtration schemes.

Journal Article Med Phys · August 2013 Featured Publication PURPOSE: Wireless flat panel detectors are gaining increased usage in portable medical imaging. Two such detectors were evaluated and compared with a conventional flat-panel detector using the formalism of the International Electrotechnical Commission (IEC ... Full text Link to item Cite

Monte-Carlo simulations of a coded-aperture X-ray scatter imaging system for molecular imaging

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 3, 2013 In this work, we demonstrate the ability to determine the material composition of a sample by measuring coherent scatter diffraction patterns generated using a coded-aperture x-ray scatter imaging (CAXSI) system. Most materials are known to exhibit unique ... Full text Cite

Estimating breast density with dual energy mammography: A simple model based on calibration phantoms

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 3, 2013 Dual energy digital mammography has been used to suppress specific breast tissue, primarily for the purpose of iodine contrast-enhanced imaging. Another application of dual energy digital mammography is to estimate breast density, as defined by the fractio ... Full text Cite

Organ dose in chest CT: Effect of modulation scheme on estimation accuracy

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 3, 2013 The purpose of this study was to evaluate how different implementations of the tube current modulation (TCM) technology affect organ dose conversion factors in chest CT and how organ dose can be accurately estimated for various modulation schemes. Computat ... Full text Cite

Comparative dosimetry of radiography, tomosynthesis, and CT for chest imaging across 59 adult patients

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 3, 2013 There are three main x-ray based modalities for imaging the thorax: radiography, tomosynthesis, and CT. CT provides perhaps the highest level of feature resolution but at notably higher radiation dose. To implement the ALARA (as low as reasonable achievabl ... Full text Cite

Projection-based dose metric: Accuracy testing and applications for CT design

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 3, 2013 The purpose of this study was to develop and validate a projection-based dose metric that enables computationally efficient dose estimation. The two physical quantities determining dose, absorbed energy and mass, were estimated in projection space. The abs ... Full text Cite

Development of a phantom-based methodology for the assessment of quantification performance in CT

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 3, 2013 The quantification of lung nodule volume from CT images provides valuable information for cancer diagnosis and staging. However, the usefulness of quantification depends on its precision. Direct assessment of the volume quantification precision involves mu ... Full text Cite

Are uniform phantoms sufficient to characterize the performance of iterative reconstruction in CT?

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 3, 2013 The evaluation of dose reduction potential from iterative reconstruction (IR) algorithms is an area of ongoing research in CT. The non-linearity of IR algorithms poses challenges to using traditional image quality metrics. Past attempts to evaluate iterati ... Full text Cite

Simulation of anatomical texture in voxelized XCAT phantoms

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 3, 2013 While great advances are made toward making highly realistic, surface models of the human anatomy, very little has been done to fill these bounded surfaces with models of anatomical texture. We propose a method whereby realistic anatomically-based computed ... Full text Cite

WE-C-103-06: An Automated CT Quality Control Program.

Journal Article Med Phys · June 2013 PURPOSE: Daily image quality assessment is an essential part of a rigorous quality control program. Time constraints; however, make it difficult to fully analyze image quality daily. Therefore, the goal of this work was to develop a robust automated CT qua ... Full text Link to item Cite

MO-A-141-01: Memorial to Fearghus O' tFoghludha - Memorial Lecture.

Journal Article Med Phys · June 2013 Medical Physics community lost one of its prominent members, Fearghus O' tFoghludha, in July 2012. Fearghus O' tFoghludha was the editor of Medical Physics from 1985 to 1987 and the President of the AAPM from 1971 to 1972. Born in 1927 in Dublin, Fearghus ... Full text Link to item Cite

MO-D-141-10: Development of 4D XCAT Pediatric Reference Phantoms for Multi-Modality Imaging Research and Optimization.

Journal Article Med Phys · June 2013 PURPOSE: A set of 4D Extended Cardiac-Torso (XCAT) pediatric reference phantoms were created for multimodality imaging research, which have highly detailed whole-body anatomies, including cardiac and respiratory functions. Models were created for newborn, ... Full text Link to item Cite

The effect of dose heterogeneity on radiation risk in medical imaging.

Journal Article Radiat Prot Dosimetry · June 2013 Featured Publication The current estimations of risk associated with medical imaging procedures rely on assessing the organ dose via direct measurements or simulation. The dose to each organ is assumed to be homogeneous. To take into account the differences in radiation sensit ... Full text Link to item Cite

Precision of iodine quantification in hepatic CT: effects of iterative reconstruction with various imaging parameters.

Journal Article AJR Am J Roentgenol · May 2013 Featured Publication OBJECTIVE: The objective of this study was to evaluate the feasibility of using iterative reconstructions in hepatic CT to improve the precision of Hounsfield unit quantification, which is the degree to which repeated measurements under unchanged condition ... Full text Link to item Cite

Population of anatomically variable 4D XCAT adult phantoms for imaging research and optimization.

Journal Article Med Phys · April 2013 Featured Publication PURPOSE: The authors previously developed the 4D extended cardiac-torso (XCAT) phantom for multimodality imaging research. The XCAT consisted of highly detailed whole-body models for the standard male and female adult, including the cardiac and respiratory ... Full text Link to item Cite

Assessment of multi-directional MTF for breast tomosynthesis.

Journal Article Phys Med Biol · March 7, 2013 A method was developed to assess the multi-directional modulation transfer function (MTF) of breast tomosynthesis imaging systems using a sphere phantom. The method was initially developed based on a simulation dataset. Projections were simulated for a uni ... Full text Link to item Cite

A methodology for image quality evaluation of advanced CT systems.

Journal Article Med Phys · March 2013 Featured Publication PURPOSE: This work involved the development of a phantom-based method to quantify the performance of tube current modulation and iterative reconstruction in modern computed tomography (CT) systems. The quantification included resolution, HU accuracy, noise ... Full text Link to item Cite

Relating noise to image quality indicators in CT examinations with tube current modulation.

Journal Article AJR Am J Roentgenol · March 2013 Featured Publication OBJECTIVE: Modern CT systems use surrogates of noise-noise index (NI) and quality reference effective tube current-time product (Q)-to infer the quality of images acquired using tube current modulation. This study aimed to determine the relationship betwee ... Full text Link to item Cite

Preliminary evaluation of biplane correlation (BCI) stereographic imaging for lung nodule detection.

Journal Article J Digit Imaging · February 2013 A biplane correlation (BCI) imaging system obtains images that can be viewed in stereo, thereby minimizing overlapping structures. This study investigated whether using stereoscopic visualization provides superior lung nodule detection compared to standard ... Full text Link to item Cite

TU‐C‐103‐07: Prospective Estimation of Diagnostic Performance and Radiation Dose for Individual CT Scans

Conference Medical Physics · January 1, 2013 Purpose: Te prespectively determine size‐and task‐based image quality indices and te quantify the relatienship between image quality and radiatien dese as a patient‐specific basis fer abdeminepelvic CT scans. Methods: Medel ebserver metric ef detectability ... Full text Cite

TU‐C‐103‐01: A Framework for 3D Modeling of Anthropomorphic Lesions in CT

Conference Medical Physics · January 1, 2013 Purpose: Realistic three‐dimensional mathematical models of subtle lesions are essential for many CT studies focused on performance evaluation and optimization. The purpose of this work was to develop and apply a generic framework for creating such models ... Full text Cite

TU‐C‐103‐10: An Automated Technique to Measure CT Noise in Patient Images

Conference Medical Physics · January 1, 2013 Purpose: Phantoms are routinely used for image quality assessment of CT scanners. The image quality in phantom images, however, may not be representative of the image quality in patient images due to differences in physical composition and scan parameters. ... Full text Cite

Evaluation of two objective methods to optimize kVp and personnel exposure using a digital indirect flat panel detector and simulated veterinary patients.

Journal Article Vet Radiol Ultrasound · 2013 Featured Publication It is important to optimize digital radiographic technique settings for small animal imaging in order to maximize image quality while minimizing radiation exposure to personnel. The purpose of this study was to evaluate two objective methods for determinin ... Full text Link to item Cite

Development of matched virtual and physical breast phantoms based on patient data

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · 2013 Physical phantoms are essential for the development, optimization, and clinical evaluation of x-ray systems. These phantoms are used for various tests such as quality assurance testing, system characterization, reconstruction evaluation, and dosimetry. The ... Full text Cite

Effects of protocol and obesity on dose conversion factors in adult body CT.

Journal Article Med Phys · November 2012 Featured Publication PURPOSE: In computed tomography (CT), organ dose, effective dose, and risk index can be estimated from volume-weighted CT dose index (CTDI(vol)) or dose-length product (DLP) using conversion coefficients. Studies have investigated how these coefficients va ... Full text Link to item Cite

An image-based technique to assess the perceptual quality of clinical chest radiographs.

Journal Article Med Phys · November 2012 PURPOSE: Current clinical image quality assessment techniques mainly analyze image quality for the imaging system in terms of factors such as the capture system modulation transfer function, noise power spectrum, detective quantum efficiency, and the expos ... Full text Link to item Cite

Automated size-specific CT dose monitoring program: assessing variability in CT dose.

Journal Article Med Phys · November 2012 Featured Publication PURPOSE: The potential health risks associated with low levels of ionizing radiation have created a movement in the radiology community to optimize computed tomography (CT) imaging protocols to use the lowest radiation dose possible without compromising th ... Full text Link to item Cite

Quantitative comparison of noise texture across CT scanners from different manufacturers.

Journal Article Med Phys · October 2012 Featured Publication PURPOSE: To quantitatively compare noise texture across computed tomography (CT) scanners from different manufacturers using the noise power spectrum (NPS). METHODS: The American College of Radiology CT accreditation phantom (Gammex 464, Gammex, Inc., Midd ... Full text Link to item Cite

Application of a dynamic 4D anthropomorphic breast phantom in contrast-based imaging system optimization: Dual-energy or temporal subtraction?

Journal Article Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) · August 15, 2012 We previously developed a dynamic 4D anthropomorphic breast phantom, which can be used to optimize contrast-based breast imaging systems, accounting for patient variability and contrast kinetics [1]. In this study we aim to compare the performance of contr ... Full text Cite

Radiation dose reduction in abdominal computed tomography during the late hepatic arterial phase using a model-based iterative reconstruction algorithm: how low can we go?

Journal Article Invest Radiol · August 2012 OBJECTIVE: The aim of this study was to compare the image quality of abdominal computed tomography scans in an anthropomorphic phantom acquired at different radiation dose levels where each raw data set is reconstructed with both a standard convolution fil ... Full text Link to item Cite

The effects of ambient lighting in chest radiology reading rooms.

Journal Article J Digit Imaging · August 2012 Featured Publication Under typical dark chest radiography reading room conditions, a radiologist's pupils contract and dilate as their visual focus intermittently shifts between the high luminance monitor and the darker background wall, resulting in increased visual fatigue an ... Full text Link to item Cite

Achieving routine submillisievert CT scanning: report from the summit on management of radiation dose in CT.

Journal Article Radiology · August 2012 Featured Publication This Special Report presents the consensus of the Summit on Management of Radiation Dose in Computed Tomography (CT) (held in February 2011), which brought together participants from academia, clinical practice, industry, and regulatory and funding agencie ... Full text Link to item Cite

Pencil beam coded aperture x-ray scatter imaging

Journal Article Optics Express · July 16, 2012 We use coded aperture x-ray scatter imaging to interrogate scattering targets with a pencil beam. Observations from a single x-ray exposure of a flat-panel scintillation detector are used to simultaneously determine the along-beam positions and momentum tr ... Full text Cite

Towards task-based assessment of CT performance: System and object MTF across different reconstruction algorithms.

Journal Article Med Phys · July 2012 Featured Publication PURPOSE: To investigate a measurement method for evaluating the resolution properties of CT imaging systems across reconstruction algorithms, dose, and contrast. METHODS: An algorithm was developed to extract the task-based modulation transfer function (MT ... Full text Link to item Cite

SU-D-217A-03: Nuclear Medicine Uniformity Assessment Using 2D Noise Power Spectrum.

Journal Article Med Phys · June 2012 PURPOSE: Nuclear medicine quality control programs require daily evaluation for the presence of potential non-uniformities by commonly utilizing a traditional pixel value-based assessment (Integral CFOVUniformity). While this method effectively captures re ... Full text Link to item Cite

SU-E-I-47: Comparison of Risks for Two Medical Imaging Procedures.

Journal Article Med Phys · June 2012 PURPOSE: Radiologists may need to decide which type of image procedure is most appropriate for a particular patient. One factor relevant in making this decision is the relative risk of secondary cancers due to each relevant procedure. Differences in the ri ... Full text Link to item Cite

MO-D-BRA-01: Limits of Dose Reduction in CT: Where are They and How Will We Know When We Get There?

Journal Article Med Phys · June 2012 UNLABELLED: Radiation Dose continues to be a concern with respect to all diagnostic imaging using ionizing radiation, but especially so with CT imaging. We have always known how to reduce radiation dose in CT - for example, simply turning down the system o ... Full text Link to item Cite

TU-F-217A-01: Informatics 2: Dose Monitoring.

Journal Article Med Phys · June 2012 UNLABELLED: Public concern over radiation from medical imaging is now higher than ever before and hospitals are being placed under increased scrutiny to ensure that their patients do not receive radiation overdoses. California already requires that there i ... Full text Link to item Cite

SU-E-I-77: X-Ray Coherent Scatter Diffraction Pattern Modeling in GEANT4.

Journal Article Med Phys · June 2012 PURPOSE: To model X-ray coherent scatter diffraction patterns in GEANT4 for simulating experiments involving material detection through diffraction pattern measurement. Although coherent scatter cross-sections are modeled accurately in GEANT4, diffraction ... Full text Link to item Cite

Organ doses, effective doses, and risk indices in adult CT: comparison of four types of reference phantoms across different examination protocols.

Journal Article Med Phys · June 2012 PURPOSE: Radiation exposure from computed tomography (CT) to the public has increased the concern among radiation protection professionals. Being able to accurately assess the radiation dose patients receive during CT procedures is a crucial step in the ma ... Full text Link to item Cite

Development of a dynamic 4D anthropomorphic breast phantom for contrast-based breast imaging

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · May 4, 2012 Mammography is currently the most widely accepted tool for detection and diagnosis of breast cancer. However, the sensitivity of mammography is reduced in women with dense breast tissue due to tissue overlap, which may obscure lesions. Digital breast tomos ... Full text Cite

Series of 4D adult XCAT phantoms for imaging research and dosimetry

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · May 4, 2012 Computerized phantoms are finding an increasingly important role in medical imaging research. With the ability to simulate various imaging conditions, they offer a practical means with which to quantitatively evaluate and improve imaging devices and techni ... Full text Cite

Patient- and cohort-specific dose and risk estimation for abdominopelvic CT: A study based on 100 patients

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · May 4, 2012 The purpose of this work was twofold: (a) to estimate patient- and cohort-specific radiation dose and cancer risk index for abdominopelvic computer tomography (CT) scans; (b) to evaluate the effects of patient anatomical characteristics (size, age, and gen ... Full text Cite

3D biopsy for tomosynthesis: Simulation of prior information based reconstruction for dose and artifact reduction

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · May 4, 2012 Accurately targeting of small lesions for success is crucial in breast biopsy. In this paper, we proposed a new 3D tomobased biopsy, which is characterized in being more accurate, easier to perform, lower in dose, and free of metal artifact. In the scout p ... Full text Cite

Relevance of MTF and NPS in quantitative CT: Towards developing a predictable model of quantitative performance

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · May 4, 2012 The quantification of lung nodule volume based on CT images provides valuable information for disease diagnosis and staging. However, the precision of the quantification is protocol, system, and technique dependent and needs to be evaluated for each specif ... Full text Cite

CT performance as a variable function of resolution, noise, and task property for iterative reconstructions

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · May 4, 2012 The increasing availability of iterative reconstruction (IR) algorithms on clinical scanners is creating a demand for effectively and efficiently evaluating imaging performance and potential dose reduction. In this study, the location- and task-specific ev ... Full text Cite

A computerized scheme for lung nodule detection in multiprojection chest radiography.

Journal Article Med Phys · April 2012 PURPOSE: Our previous study indicated that multiprojection chest radiography could significantly improve radiologists' performance for lung nodule detection in clinical practice. In this study, the authors further verify that multiprojection chest radiogra ... Full text Link to item Cite

Quantitative CT: technique dependence of volume estimation on pulmonary nodules.

Journal Article Phys Med Biol · March 7, 2012 Featured Publication Current estimation of lung nodule size typically relies on uni- or bi-dimensional techniques. While new three-dimensional volume estimation techniques using MDCT have improved size estimation of nodules with irregular shapes, the effect of acquisition and ... Full text Link to item Cite

Plate-specific gain map correction for the improvement of detective quantum efficiency in computed radiography.

Journal Article Med Phys · March 2012 PURPOSE: The purpose of this work is to improve the noise power spectrum (NPS), and thus the detective quantum efficiency (DQE), of computed radiography (CR) images by correcting for spatial gain variations specific to individual imaging plates. CR devices ... Full text Link to item Cite

Biplane correlation imaging: a feasibility study based on phantom and human data.

Journal Article J Digit Imaging · February 2012 Featured Publication The objective of this study was to implement and evaluate the performance of a biplane correlation imaging (BCI) technique aimed to reduce the effect of anatomic noise and improve the detection of lung nodules in chest radiographs. Seventy-one low-dose pos ... Full text Link to item Cite

Gray-scale inversion radiographic display for the detection of pulmonary nodules on chest radiographs.

Journal Article Clin Imaging · 2012 The purpose of this study was to investigate gray-scale inversion in nodule detection on chest radiography. Simulated nodules were superimposed randomly onto normal chest radiographs. Six radiologists interpreted 144 chest radiographs during three reading ... Full text Link to item Cite

The tenuous state of clinical medical physics in diagnostic imaging.

Journal Article Med Phys · December 2011 Featured Publication Full text Link to item Cite

Effect of gadolinium chelate contrast agents on diffusion weighted MR imaging of the liver, spleen, pancreas and kidney at 3 T.

Journal Article Eur J Radiol · November 2011 Featured Publication PURPOSE: To retrospectively test the null hypotheses that the qualitative appearance of DWI and the signal intensity values in DWI and corresponding ADC values of the liver, spleen, pancreas and kidneys are identical before and after the administration of ... Full text Link to item Cite

Synthetic positron emission tomography-computed tomography images for use in perceptual studies.

Journal Article Semin Nucl Med · November 2011 Featured Publication To better understand fundamental issues, perception studies of the fusion display would best be performed with a panel of lesions of variable location, size, intensity, and background. There are compelling reasons to use synthetic images that contain artif ... Full text Link to item Cite

Dual-energy contrast-enhanced breast tomosynthesis: optimization of beam quality for dose and image quality.

Journal Article Phys Med Biol · October 7, 2011 Featured Publication Dual-energy contrast-enhanced breast tomosynthesis is a promising technique to obtain three-dimensional functional information from the breast with high resolution and speed. To optimize this new method, this study searched for the beam quality that maximi ... Full text Link to item Cite

Effective dose efficiency: an application-specific metric of quality and dose for digital radiography.

Journal Article Phys Med Biol · August 21, 2011 Featured Publication The detective quantum efficiency (DQE) and the effective DQE (eDQE) are relevant metrics of image quality for digital radiography detectors and systems, respectively. The current study further extends the eDQE methodology to technique optimization using a ... Full text Link to item Cite

Patient-specific radiation dose and cancer risk for pediatric chest CT.

Journal Article Radiology · June 2011 Featured Publication PURPOSE: To estimate patient-specific radiation dose and cancer risk for pediatric chest computed tomography (CT) and to evaluate factors affecting dose and risk, including patient size, patient age, and scanning parameters. MATERIALS AND METHODS: The inst ... Full text Link to item Cite

A patient image-based technique to assess the image quality of clinical chest radiographs

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · May 13, 2011 Current clinical image quality assessment techniques mainly analyze image quality for the imaging system in terms of factors such as the capture system DQE and MTF, the exposure technique, and the particular image processing method and processing parameter ... Full text Cite

The feasibility of universal DLP-to-risk conversion coefficients for body CT protocols

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · May 13, 2011 The effective dose associated with computed tomography (CT) examinations is often estimated from dose-length product (DLP) using scanner-independent conversion coefficients. Such conversion coefficients are available for a small number of examinations, eac ... Full text Cite

A new iodinated liver phantom for the quantitative evaluation of advanced CT acquisition and reconstruction techniques

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · May 13, 2011 An iodinated liver phantom is needed for liver CT related studies, such as the quantification of lesion contrast. Prior studies simulated iodinated hepatic lesions with tubes of iodine solution, which involved complications associated with the setup, diffe ... Full text Cite

3D task-based performance assessment metrics for optimization of performance and dose in breast tomosynthesis

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · May 13, 2011 This study aimed to investigate a method for empirically evaluating 3D imaging task performance of breast tomosynthesis imaging systems. A simulation and experimental approach was used to develop a robust method for performance assessment. To identify a me ... Full text Cite

Predictive models for observer performance in CT: Applications in protocol optimization

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · May 13, 2011 The relationship between theoretical descriptions of imaging performance (Fourier-based) and the performance of real human observers was investigated for detection tasks in multi-slice CT. The detectability index for the Fisher-Hotelling model observer and ... Full text Cite

An anthropomorphic breast model for breast imaging simulation and optimization.

Journal Article Acad Radiol · May 2011 Featured Publication RATIONALE AND OBJECTIVES: Optimization studies for x-ray-based breast imaging systems using computer simulation can greatly benefit from a phantom capable of modeling varying anatomical variability across different patients. This study aimed to develop a t ... Full text Link to item Cite

Lung nodule detection in pediatric chest CT: quantitative relationship between image quality and radiologist performance.

Journal Article Med Phys · May 2011 Featured Publication PURPOSE: To determine the quantitative relationship between image quality and radiologist performance in detecting small lung nodules in pediatric CT. METHODS: The study included clinical chest CT images of 30 pediatric patients (0-16 years) scanned at tub ... Full text Link to item Cite

Comparative performance of multiview stereoscopic and mammographic display modalities for breast lesion detection.

Journal Article Med Phys · April 2011 Featured Publication PURPOSE: Mammography is known to be one of the most difficult radiographic exams to interpret. Mammography has important limitations, including the superposition of normal tissue that can obscure a mass, chance alignment of normal tissue to mimic a true le ... Full text Link to item Cite

Computed tomography dose index and dose length product for cone-beam CT: Monte Carlo simulations.

Journal Article J Appl Clin Med Phys · January 19, 2011 Dosimetry in kilovoltage cone beam computed tomography (CBCT) is a challenge due to the limitation of physical measurements. To address this, we used a Monte Carlo (MC) method to estimate the CT dose index (CTDI) and the dose length product (DLP) for a com ... Full text Open Access Link to item Cite

SU‐C‐220‐01: Comparative MTF and DQE Performance of Wireless Digital Image Receptors

Conference Medical Physics · January 1, 2011 Purpose: Two new wireless digital receptors were evaluated and compared with a conventional flat‐panel using the International Electrotechnical Commission formalism (IEC 62220‐1) for measuring modulation transfer function (MTF), noise power spectrum (NPS), ... Full text Cite

WE‐G‐110‐03: Directional MTF Measurement of Tomosynthesis Images Using a Cone‐Based Technique

Conference Medical Physics · January 1, 2011 Purpose: To develop a cone‐based modulation transfer function (MTF) measurement technique for tomosynthesis using a sphere phantom. Methods: Projections were simulated for a voxelized breast phantom with 12 mm sphere inserts using a fluence modeled from 28 ... Full text Cite

TH‐A‐214‐03: Automated Patient‐Specific CT Dose Monitoring System: Assessing Variability in CT Dose

Conference Medical Physics · January 1, 2011 Purpose: To develop an automated patient‐specific radiation dose monitoring system for CT capable of assessing variability in CT dose delivered to individual patients. Methods: CT image data were sent from PACS to a secure dosimetry server. The dose report ... Full text Cite

TH‐A‐214‐02: Organ Dose, Effective Dose, and Dose Conversion Coefficients in Adult CT: Comparison of Mathematical, XCAT, and ICRP Reference Phantoms

Conference Medical Physics · January 1, 2011 Purpose: To compare organ dose, effective dose, and dose conversion coefficients in adult CT estimated using three types of reference phantoms: (1) hermaphrodite mathematical phantom employed by the imPACT CT dose calculator, (2) reference male and female ... Full text Cite

WE‐G‐110‐06: Introduction to the AAPM Task Group No. 195 ‐ Monte Carlo Reference Data Sets for Imaging Research

Conference Medical Physics · January 1, 2011 Purpose: To develop reference data sets of common Monte Carlo simulations in medical imaging research for use by researchers who are learning how to implement Monte Carlo simulations or needing to validate their own Monte Carlo simulations. Methods: Comple ... Full text Cite

TU‐C‐110‐01: Patient Dose in CT: Calculating Patient Specific Doses in CT(Joint with Education)

Conference Medical Physics · January 1, 2011 In light of recent events involving dose to patients undergoing CT exams, many efforts to record patient dose have been initiated. Many national and international groups (FDA, NIBIB, ACR, IAEA, and NIH intramural programs) have called for recording “dose”, ... Full text Cite

TU‐A‐110‐01: Resolution in Digital Radiography

Conference Medical Physics · January 1, 2011 Full text Cite

SU‐D‐301‐06: Impact of Non‐Stationarity in Breast Tomosynthesis on Task‐Based Imaging Performance

Conference Medical Physics · January 1, 2011 Purpose: Reconstructed tomosynthesis data is known to exhibit non‐stationarity, (i.e., the pixel mean and standard deviation depends on location), which is expected to impact our ability to accurately assess imaging performance. The purpose of this study w ... Full text Cite

WE‐C‐110‐08: A Novel Phantom for CT Performance Assessment: Towards a Task‐Based Measure of Image Quality

Conference Medical Physics · January 1, 2011 Purpose: The advent of CT iterative reconstructions in the clinic has posed an increasing challenge on the community in our ability to assess image quality due to increased non‐stationarity and non‐linearity of reconstructed images. The purpose of this stu ... Full text Cite

Patient-specific radiation dose and cancer risk estimation in CT: part II. Application to patients.

Journal Article Med Phys · January 2011 Featured Publication PURPOSE: Current methods for estimating and reporting radiation dose from CT examinations are largely patient-generic; the body size and hence dose variation from patient to patient is not reflected. Furthermore, the current protocol designs rely on dose a ... Full text Link to item Cite

Patient-specific radiation dose and cancer risk estimation in CT: part I. development and validation of a Monte Carlo program.

Journal Article Med Phys · January 2011 Featured Publication PURPOSE: Radiation-dose awareness and optimization in CT can greatly benefit from a dose-reporting system that provides dose and risk estimates specific to each patient and each CT examination. As the first step toward patient-specific dose and risk estima ... Full text Link to item Cite

Computed tomography dose index and dose length product for cone-beam CT: Monte Carlo simulations of a commercial system

Journal Article Journal of Applied Clinical Medical Physics · January 1, 2011 Dosimetry in kilovoltage cone beam computed tomography (CBCT) is a challenge due to the limitation of physical measurements. To address this, we used a Monte Carlo (MC) method to estimate the CT dose index (CTDI) and the dose length product (DLP) for a com ... Full text Cite

Quantitative breast tomosynthesis: from detectability to estimability.

Journal Article Med Phys · December 2010 Featured Publication PURPOSE: This work aimed to extend Fourier-based imaging metrics for modeling and predicting quantitative imaging performance. The new methodology was applied to the platform of breast tomosynthesis for investigating the influence of acquisition parameters ... Full text Link to item Cite

Patient-specific radiation dose and cancer risk estimation in pediatric chest CT: A study in 30 patients

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · December 1, 2010 Radiation-dose awareness and optimization in CT can greatly benefit from a dose- reporting system that provides radiation dose and cancer risk estimates specific to each patient and each CT examination. Recently, we reported a method for estimating patient ... Full text Cite

Quantitative CT: Technique dependency of volume assessment for pulmonary nodules

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · December 1, 2010 Current lung nodule size assessment methods typically rely on one-dimensional estimation of lesions. While new 3D volume assessment techniques using MSCT scan data have enabled improved estimation of lesion size, the effect of acquisition and reconstructio ... Full text Cite

The myth of mean dose as a surrogate for radiation risk?

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · December 1, 2010 The current estimations of risk associated with medical imaging procedures rely on assessing the organ dose via direct measurements or simulation. Each organ dose is assumed to be homogeneous, a representative sample or mean of which is weighted by a corre ... Full text Cite

Towards an international consensus strategy for periodic quality control of digital breast tomosynthesis systems

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · December 1, 2010 As a collaborative effort between scientists affiliated with the American Association of Physicists in Medicine (AAPM) and the European reference center for breast cancer screening and diagnosis (EUREF), the Working Group on Phantoms for Breast Imaging (WG ... Full text Cite

Extending the detectability index to quantitative imaging performance: Applications in tomosynthesis and CT

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · December 1, 2010 This study aimed to extend Fourier-based imaging metrics for the modeling of quantitative imaging performance. Breast tomosynthesis was used as a platform for investigating acquisition and processing parameters (e.g., acquisition angle and dose) that can s ... Full text Cite

Wide-angle breast tomosynthesis: Initial comparative evaluation

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · December 1, 2010 Conventional mammography is largely limited by superimposed anatomy which is alleviated by breast tomosynthesis and CT. Limited acquisition in tomosynthesis can result in significant out of plane artifacts while large angular acquisition span in CT can lim ... Full text Cite

Detection of pancreatic tumors, image quality, and radiation dose during the pancreatic parenchymal phase: effect of a low-tube-voltage, high-tube-current CT technique--preliminary results.

Journal Article Radiology · August 2010 Featured Publication PURPOSE: To intraindividually compare a low-tube-voltage (80 kVp), high-tube-current (675 mA) computed tomographic (CT) technique with a high-tube-voltage (140 kVp) CT protocol for the detection of pancreatic tumors, image quality, and radiation dose durin ... Full text Link to item Cite

Constancy checking of digital breast tomosynthesis systems

Journal Article Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) · July 21, 2010 As the number of installed digital breast tomosynthesis (DBT) systems increases, the need for quality control routines rises. Current work reports on our initial experience with a newly developed method for the analysis of DBT acquisitions of a homogenous ... Full text Cite

Kilovoltage cone-beam CT: comparative dose and image quality evaluations in partial and full-angle scan protocols.

Journal Article Med Phys · July 2010 PURPOSE: To assess imaging dose of partial and full-angle kilovoltage CBCT scan protocols and to evaluate image quality for each protocol. METHODS: The authors obtained the CT dose index (CTDI) of the kilovoltage CBCT protocols in an on-board imager by ion ... Full text Link to item Cite

Quantitative imaging in breast tomosynthesis and CT: Comparison of detection and estimation task performance.

Journal Article Med Phys · June 2010 Featured Publication PURPOSE: This work investigates a framework for modeling volumetric breast imaging to compare detection and estimation task performance and optimize quantitative breast imaging. METHODS: Volumetric reconstructions of a breast phantom, which incorporated el ... Full text Link to item Cite

The quantitative potential for breast tomosynthesis imaging.

Journal Article Med Phys · March 2010 Featured Publication PURPOSE: Due to its limited angular scan range, breast tomosynthesis has lower resolution in the depth direction, which may limit its accuracy in quantifying tissue density. This study assesses the quantitative potential of breast tomosynthesis using relat ... Full text Link to item Cite

A technique optimization protocol and the potential for dose reduction in digital mammography.

Journal Article Med Phys · March 2010 Featured Publication Digital mammography requires revisiting techniques that have been optimized for prior screen/film mammography systems. The objective of the study was to determine optimized radiographic technique for a digital mammography system and demonstrate the potenti ... Full text Link to item Cite

Generalized "satisfaction of search": adverse influences on dual-target search accuracy.

Journal Article J Exp Psychol Appl · March 2010 Featured Publication The successful detection of a target in a radiological search can reduce the detectability of a second target, a phenomenon termed satisfaction of search (SOS). Given the potential consequences, here we investigate the generality of SOS with the goal of si ... Full text Link to item Cite

SU‐GG‐I‐14: A Method to Estimate Cone‐Beam CT Dose Index and Cone‐Beam Dose Length Product

Conference Medical Physics · January 1, 2010 Purpose: To characterize the cone‐beam CTDI (CBCTDI) and cone‐beam dose length product (CBDLP) by Monte Carlo (MC) technique. Method and Materials: An extended CT head phantom (60cm long) and an extended CT body phantom (90cm long) were created in our BEAM ... Full text Cite

SU‐GG‐I‐57: Dose and Image Quality Evaluation for Partial and Full‐Angle Kilovoltage Cone‐Beam CT Protocols

Conference Medical Physics · January 1, 2010 Purpose: To assess imaging dose of partial and full‐angle CBCT scan protocols, and to evaluate their image quality. Method and Materials: The CTDI of the six new CBCT protocols for Varian OBI were obtained by ion chamber (IC) measurements and Monte Carlo ( ... Full text Cite

MO‐B‐201C‐01: Color Monitors for Medical Workstations

Conference Medical Physics · January 1, 2010 Business class monitors are now widely used to display radiologic images for primary interpretation and for secondary display in the health enterprise. This course will review the technology and performance available in current products and discuss the inc ... Full text Cite

Low-tube-voltage, high-tube-current multidetector abdominal CT: improved image quality and decreased radiation dose with adaptive statistical iterative reconstruction algorithm--initial clinical experience.

Journal Article Radiology · January 2010 Featured Publication PURPOSE: To investigate whether an adaptive statistical iterative reconstruction (ASIR) algorithm improves the image quality at low-tube-voltage (80-kVp), high-tube-current (675-mA) multidetector abdominal computed tomography (CT) during the late hepatic a ... Full text Link to item Cite

Micro-CT imaging of breast tumors in rodents using a liposomal, nanoparticle contrast agent

Journal Article International Journal of Nanomedicine · November 2009 Full text Cite

Optimized image acquisition for breast tomosynthesis in projection and reconstruction space.

Journal Article Med Phys · November 2009 Featured Publication Breast tomosynthesis has been an exciting new development in the field of breast imaging. While the diagnostic improvement via tomosynthesis is notable, the full potential of tomosynthesis has not yet been realized. This may be attributed to the dependency ... Full text Link to item Cite

Effective DQE (eDQE) and speed of digital radiographic systems: an experimental methodology.

Journal Article Med Phys · August 2009 Featured Publication Prior studies on performance evaluation of digital radiographic systems have primarily focused on the assessment of the detector performance alone. However, the clinical performance of such systems is also substantially impacted by magnification, focal spo ... Full text Link to item Cite

An exposure indicator for digital radiography: AAPM Task Group 116 (executive summary).

Journal Article Med Phys · July 2009 Featured Publication Digital radiographic imaging systems, such as those using photostimulable storage phosphor, amorphous selenium, amorphous silicon, CCD, and MOSFET technology, can produce adequate image quality over a much broader range of exposure levels than that of scre ... Full text Link to item Cite

Pediatric MDCT: towards assessing the diagnostic influence of dose reduction on the detection of small lung nodules.

Journal Article Acad Radiol · July 2009 Featured Publication RATIONALE AND OBJECTIVES: The purpose of this study was to evaluate the effect of reduced tube current (dose) on lung nodule detection in pediatric multidetector array computed tomography (MDCT). MATERIALS AND METHODS: The study included normal clinical ch ... Full text Link to item Cite

Contrast detail curves in head ct examinations

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 22, 2009 The purpose of this study was to generate contrast detail (CD) curves for low contrast mass lesions embedded in images obtained in head and neck CT examinations. Axial head and neck CT slice images were randomly chosen from patients at five different level ... Full text Cite

Patient specific computerized phantoms to estimate dose in pediatric CT

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 16, 2009 We create a series of detailed computerized phantoms to estimate patient organ and effective dose in pediatric CT and investigate techniques for efficiently creating patient-specific phantoms based on imaging data. The initial anatomy of each phantom was p ... Full text Cite

Extension of DQE to include scatter, grid, magnification, and focal spot blur: A new experimental technique and metric

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 15, 2009 In digital radiography, conventional DQE evaluations are performed under idealized conditions that do not reflect typical clinical operating conditions. For this reason, we have developed and evaluated an experimental methodology for measuring the effectiv ... Full text Cite

Patient-specific dose estimation for pediatric abdomen-pelvisCT

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 15, 2009 The purpose of this study is to develop a method for estimating patient-specific dose from abdomen-pelvis CT examinations and to investigate dose variation across patients in the same weight group. Our study consisted of seven pediatric patients in the sam ... Full text Cite

Optimized lesion detection in breast tomosynthesis

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 15, 2009 While diagnostic improvement via breast tomosynthesis has been notable, the full potential of tomosynthesis has not yet been realized. This is because of the complex task of optimizing multiple parameters that constitute image acquisition and thus affect t ... Full text Cite

The effect of dose reductions on lesion detection in head CT

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 15, 2009 The purpose of this study was to quantitatively evaluate the effect of reducing radiation dose (i.e., mAs) on lesion detection in head CT examinations. We used a simulation package (Syngo Explorer) to reconstruct 5-mm thick CT images of the brain of one pa ... Full text Cite

Use of effective detective quantum efficiency to optimise radiographic exposures for chest imaging with computed radiography

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 15, 2009 The purpose of the work was to test if effective detective quantum efficiency (eDQE) could be useful for optimisation of radiographic factors for computed radiography (CR) for adult chest examinations. The eDQE was therefore measured across a range of kilo ... Full text Cite

Can compression be reduced for breast tomosynthesis? Monte carlo study on mass and microcalcification conspicuity in tomosynthesis.

Journal Article Radiology · June 2009 Featured Publication PURPOSE: To assess, in a voxelized anthropomorphic breast phantom, how the conspicuity of breast masses and microcalcifications may be affected by applying reduced breast compression in tomosynthesis. MATERIALS AND METHODS: A breast tomosynthesis system wa ... Full text Link to item Cite

Hypervascular liver tumors: low tube voltage, high tube current multidetector CT during late hepatic arterial phase for detection--initial clinical experience.

Journal Article Radiology · June 2009 Featured Publication PURPOSE: To intraindividually compare a low tube voltage (80 kVp), high tube current computed tomographic (CT) technique with a standard CT protocol (140 kVp) in terms of image quality, radiation dose, and detection of malignant hypervascular liver tumors ... Full text Link to item Cite

Three-dimensional simulation of lung nodules for paediatric multidetector array CT.

Journal Article Br J Radiol · May 2009 Featured Publication The purpose of this study was to develop and validate a technique for three-dimensional (3D) modelling of small lung nodules on paediatric multidetector array computed tomography (MDCT) images. Clinical images were selected from 21 patients (<18 years old) ... Full text Link to item Cite

Probing and preventing quantum dot-induced cytotoxicity with multimodal alpha-lipoic acid in multiple dimensions of the peripheral nervous system.

Journal Article Nanomedicine (Lond) · April 2009 AIM: Toxicity of nanoparticles developed for biomedical applications is extensively debated as no uniform guidelines are available for studying nanomaterial safety, resulting in conflicting data obtained from different cell types. This study demonstrates t ... Full text Link to item Cite

Towards optimized acquisition scheme for multiprojection correlation imaging of breast cancer.

Journal Article Acad Radiol · April 2009 Featured Publication RATIONALE AND OBJECTIVES: Correlation imaging (CI) is a form of multiprojection imaging in which multiple images of a patient are acquired from slightly different angles. Information from these images is combined to make the final diagnosis. A critical fac ... Full text Link to item Cite

The influence of increased ambient lighting on mass detection in mammograms.

Journal Article Acad Radiol · March 2009 Featured Publication RATIONALE AND OBJECTIVES: Recent research has provided evidence that in reading rooms equipped with liquid crystal displays (LCDs), a measured increase of ambient lighting may improve clinicians' detection performance. In agreement with this research, the ... Full text Link to item Cite

Comparison of patient size-based methods for estimating quantum noise in CT images of the lung.

Journal Article Med Phys · February 2009 Featured Publication The authors explored four methods for estimating quantum noise in CT images of the lung, each based on a different definition of patient size (water-equivalent diameter) and the relationship between noise and diameter determined in water phantoms. The accu ... Full text Link to item Cite

Mass detection on mammograms: influence of signal shape uncertainty on human and model observers.

Journal Article J Opt Soc Am A Opt Image Sci Vis · February 2009 Featured Publication We studied the influence of signal variability on human and model observers for detection tasks with realistic simulated masses superimposed on real patient mammographic backgrounds and synthesized mammographic backgrounds (clustered lumpy backgrounds, CLB ... Full text Link to item Cite

Design and Development of a New Multi-Projection X-Ray System for Chest Imaging.

Journal Article IEEE Trans Nucl Sci · February 2009 Overlapping anatomical structures may confound the detection of abnormal pathology, including lung nodules, in conventional single-projection chest radiography. To minimize this fundamental limiting factor, a dedicated digital multi-projection system for c ... Full text Link to item Cite

MO‐FF‐A4‐01: Evaluation of Background Trend Correction Technique in Breast Tomosynthesis Quantitation

Conference Medical Physics · January 1, 2009 Purpose: The main shortcoming of breast tomosynthesis (tomo) imaging when compared to CT is poor resolution in the depth direction and the associated difficulty in quantifying tissue density. This study will assess the quantitative potential of breast tomo ... Full text Cite

SU‐FF‐I‐109: Quantitative Breast Tomosynthesis: Development of An Estimation Performance Metric and Optimization Framework

Conference Medical Physics · January 1, 2009 Purpose: To develop performance metrics for estimation tasks and employ the framework to optimize breast tomosynthesis systems for quantitative imaging purposes. Method and Materials: A maximum likelihood (ML) estimator was derived in terms of the noise po ... Full text Cite

Micro-CT imaging of breast tumors in rodents using a liposomal, nanoparticle contrast agent.

Journal Article Int J Nanomedicine · 2009 Featured Publication A long circulating liposomal, nanoscale blood pool agent encapsulating traditional iodinated contrast agent (65 mg I/mL) was used for micro-computed tomography (CT) imaging of rats implanted with R3230AC mammary carcinoma. Three-dimensional vascular archit ... Open Access Link to item Cite

Patient-specific dose estimation for pediatric chest CT.

Journal Article Med Phys · December 2008 Featured Publication Current methods for organ and effective dose estimations in pediatric CT are largely patient generic. Physical phantoms and computer models have only been developed for standard/limited patient sizes at discrete ages (e.g., 0, 1, 5, 10, 15 years old) and d ... Full text Link to item Cite

Detector or system? Extending the concept of detective quantum efficiency to characterize the performance of digital radiographic imaging systems.

Journal Article Radiology · December 2008 Featured Publication PURPOSE: To develop an experimental method for measuring the effective detective quantum efficiency (eDQE) of digital radiographic imaging systems and evaluate its use in select imaging systems. MATERIALS AND METHODS: A geometric phantom emulating the atte ... Full text Link to item Cite

The effect of breast compression on mass conspicuity in digital mammography.

Journal Article Med Phys · October 2008 Featured Publication This study analyzed how the inherent quality of diagnostic information in digital mammography could be affected by breast compression. A digital mammography system was modeled using a Monte Carlo algorithm based on the Penelope program, which has been succ ... Full text Link to item Cite

Multi-projection correlation imaging as a new diagnostic tool for improved breast cancer detection

Conference Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) · September 9, 2008 Multi-projection imaging technique offers an advantage over single projection imaging techniques in rendering pathology that may be surrounded by a complex cloud of anatomical structures. The process of harnessing the geometrical and statistical dependence ... Full text Cite

Knowledge transfer across breast cancer screening modalities: A pilot study using an information-theoretic CADe system for mass detection

Conference Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) · September 9, 2008 We have performed a series of experiments to assess whether a featureless, knowledge-based CADe system that relies on information theoretic principles is capable of transferring knowledge across cases acquired with different imaging modalities. Typical fea ... Full text Cite

Assessment of low energies and slice depth in the quantification of breast tomosynthesis

Conference Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) · September 9, 2008 This study attempts to assess the quantitative potential of breast tomosynthesis imaging. Tomosynthesis might be a feasible replacement for digital mammography, so it is worthwhile to consider whether it can be quantitative like computed tomography (CT), w ... Full text Cite

Breast mass detection under increased ambient lighting

Journal Article Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) · September 9, 2008 Under typical dark conditions found in mammography reading rooms, a reader's pupils will contract and dilate as the visual focus moves between the high luminance display and the darker background wall, potentially resulting in visual fatigue and degraded d ... Full text Cite

Automated breast mass detection in 3D reconstructed tomosynthesis volumes: a featureless approach.

Journal Article Med Phys · August 2008 Featured Publication The purpose of this study was to propose and implement a computer aided detection (CADe) tool for breast tomosynthesis. This task was accomplished in two stages-a highly sensitive mass detector followed by a false positive (FP) reduction stage. Breast tomo ... Full text Link to item Cite

Inter-reader variability in Alternate Forced Choice studies

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 23, 2008 In this study, we investigated differences in detection performance for twelve observers who each generated a CT contrast detail curve. An anthropomorphic newborn phantom's abdomen was imaged using a GE Light Speed CT scanner (4-slice). Alternate Forced Ch ... Full text Cite

Reconstruction filters and contrast detail curves in CT

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 18, 2008 In this study, we investigated the effect of CT reconstruction filters in abdominal CT images of a male anthropomorphic phantom. A GE Light Speed CT 4-slice scanner was used to scan the abdomen of an adult Rando phantom. Cross sectional images of the phant ... Full text Cite

Mass detection on mammograms: Signal variations and performance changes for human and model observers

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 18, 2008 We studied the influence of signal variability on human and model observer performances for a detection task with mammographic backgrounds and computer generated clustered lumpy backgrounds (CLB). We used synthetic yet realistic masses and backgrounds that ... Full text Cite

Optimized acquisition scheme for multi-projection correlation imaging of breast cancer

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 2, 2008 We are reporting the optimized acquisition scheme of multi-projection breast Correlation Imaging (CI) technique, which was pioneered in our lab at Duke University. CI is similar to tomosynthesis in its image acquisition scheme. However, instead of analyzin ... Full text Cite

Computer aided detection of breast masses in tomosynthesis reconstructed volumes using information-theoretic similarity measures

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 2, 2008 The purpose of this project is to study two Computer Aided Detection (CADe) systems for breast masses for digital tomosynthesis using reconstructed slices. This study used eighty human subject cases collected as part of on-going clinical trials at Duke Uni ... Full text Cite

Introduction to grayscale calibration and related aspects of medical imaging grade liquid crystal displays.

Journal Article J Digit Imaging · June 2008 Featured Publication Consistent presentation of digital radiographic images at all locations within a medical center can help ensure a high level of patient care. Currently, liquid crystal displays (LCDs) are the electronic display technology of choice for viewing medical imag ... Full text Link to item Cite

Object detectability at increased ambient lighting conditions.

Journal Article Med Phys · June 2008 Featured Publication Under typical dark conditions encountered in diagnostic reading rooms, a reader's pupils will contract and dilate as the visual focus intermittently shifts between the high luminance display and the darker background wall, resulting in increased visual fat ... Full text Link to item Cite

Optimization of exposure parameters in full field digital mammography.

Journal Article Med Phys · June 2008 Featured Publication Optimization of exposure parameters (target, filter, and kVp) in digital mammography necessitates maximization of the image signal-to-noise ratio (SNR), while simultaneously minimizing patient dose. The goal of this study is to compare, for each of the maj ... Full text Link to item Cite

Utility of a prototype liposomal contrast agent for x-ray imaging of breast cancer: A proof of concept using micro-CT in small animals

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · May 14, 2008 Imaging tumor angiogenesis in small animals is extremely challenging due to the size of the tumor vessels. Consequently, both dedicated small animal imaging systems and specialized intravascular contrast agents are required. The goal of this study was to i ... Full text Cite

Optimization of dual energy contrast enhanced breast tomosynthesis for improved mammographic lesion detection and diagnosis

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · May 14, 2008 Dual-energy contrast-enhanced breast tomosynthesis has been proposed as a technique to improve the detection of early-stage cancer in young, high-risk women. This study focused on optimizing this technique using computer simulations. The computer simulatio ... Full text Cite

Towards assessing the diagnostic influence of dose reduction in pediatric CT: A study based on simulated lung nodules

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · May 14, 2008 The purpose of this study is to evaluate the effect of reduced tube current, as a surrogate for radiation dose, on lung nodule detection in pediatric chest multi-detector CT (MDCT). Normal chest MDCT images of 13 patients aged 1 to 7 years old were used as ... Full text Cite

Toward quantification of breast tomosynthesis imaging

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · May 14, 2008 Due to the high prevalence of breast cancer among women, much is being done to detect breast cancer earlier and more accurately. In current clinical practice, the most widely-used mode of breast imaging is mammography. Its main advantages are high sensitiv ... Full text Cite

The effect of increased ambient lighting on detection accuracy in uniform and anatomical backgrounds

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · May 7, 2008 Under typical dark conditions found in reading rooms, a reader's pupils will contract and dilate as the visual focus intermittently shifts between the high luminance monitor and the darker background wall, resulting in increased visual fatigue and the degr ... Full text Cite

A comparative contrast-detail study of five medical displays.

Journal Article Med Phys · April 2008 Featured Publication The objective of this study was to compare the contrast-detail performance of five different commercial liquid crystal displays (LCDs) to other LCD and cathode-ray tube (CRT) displays for medical applications. A contrast-detail phantom, supplemented with 5 ... Full text Link to item Cite

A mathematical model platform for optimizing a multiprojection breast imaging system.

Journal Article Med Phys · April 2008 Featured Publication Multiprojection imaging is a technique in which a plurality of digital radiographic images of the same patient are acquired within a short interval of time from slightly different angles. Information from each image is combined to determine the final diagn ... Full text Link to item Cite

Hypervascular liver tumors: low tube voltage, high tube current multi-detector row CT for enhanced detection--phantom study.

Journal Article Radiology · January 2008 Featured Publication PURPOSE: To prospectively evaluate, for the depiction of simulated hypervascular liver lesions in a phantom, the effect of a low tube voltage, high tube current computed tomographic (CT) technique on image noise, contrast-to-noise ratio (CNR), lesion consp ... Full text Link to item Cite

Design of a new multi-projection imaging system for chest radiography

Journal Article IEEE Nuclear Science Symposium Conference Record · December 1, 2007 Overlapping anatomical structures may confound detection of lung nodules in conventional projection chest radiography. To alleviate the visual clutter due to overlying anatomy, a dedicated digital multi-projection system for chest imaging was recently deve ... Full text Cite

An Anger-Camera Study of Scatter Effects in Single-photon-Emission Imaging With Flat-Panel Detectors

Conference International Journal of Radiation Oncology*Biology*Physics · November 2007 Full text Cite

Initial human subject results for breast Bi-plane correlation imaging technique

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · October 18, 2007 Computer aided detection (CADe) systems often present multiple false-positives per image in projection mammography due to overlapping anatomy. To reduce the number of such false-positives, we propose performing CADe on image pairs acquired using a bi-plane ... Full text Cite

A contrast-detail comparison of computed mammotomography and digital mammography

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · October 16, 2007 We use a contrast-detail observer study to compare performance of a novel 3D computed mammotomography (CmT) system with a commercially developed full-field digital mammography (FFDM) system. A contrast-detail phantom comprised of uniform acrylic spheres of ... Full text Cite

Effect of increased ambient lighting on detectability - A psychophysical study

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · October 15, 2007 Last year in this conference, we presented a theoretical analysis of how ambient lighting in dark reading rooms could be moderately increased without compromising the interpretation of images displayed on LCDs.' Based on that analysis, in this paper we pre ... Full text Cite

A mathematical model approach towards combining information from multiple image projections of the same patient

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · October 15, 2007 The purpose of this study was to, i) use a mathematical observer model to combine information obtained from multiple angular projections of the same breast to determine the overall detectability of a simulated lesion in a multi-projection breast imaging sy ... Full text Cite

Methodology of NEQ (f) analysis for optimization and comparison of digital breast tomosynthesis acquisition techniques and reconstruction algorithms

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · October 15, 2007 As a new three-dimensional imaging technique, digital breast tomosynthesis allows the reconstruction of an arbitrary set of planes in the breast from a limited-angle series of projection images. Though several tomosynthesis algorithms have been proposed, n ... Full text Cite

Experimental benchmarking of a Monte Carlo dose simulation code for pediatric CT

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · October 15, 2007 In recent years, there has been a desire to reduce CT radiation dose to children because of their susceptibility and prolonged risk for cancer induction. Concerns arise, however, as to the impact of dose reduction on image quality and thus potentially on d ... Full text Cite

Visual image quality metrics for optimization of breast tomosynthesis acquisition technique

Conference Progress in Biomedical Optics and Imaging - Proceedings of SPIE · October 15, 2007 Breast tomosynthesis is currently an investigational imaging technique requiring optimization of its many combinations of data acquisition and image reconstruction parameters for optimum clinical use. In this study, the effects of several acquisition param ... Full text Cite

Validation of software for QC assessment of MTF and NPS

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · October 15, 2007 Modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE) are widely accepted measures of digital radiographic system performance. However the implementation of these measurement methodologies has been limited t ... Full text Cite

Does image quality matter? Impact of resolution and noise on mammographic task performance.

Journal Article Med Phys · October 2007 Featured Publication The purpose of this study was to examine the effects of different resolution and noise levels on task performance in digital mammography. This study created an image set with images at three different resolution levels, corresponding to three digital displ ... Full text Link to item Cite

Effect of dose reduction on the detection of mammographic lesions: a mathematical observer model analysis.

Journal Article Med Phys · August 2007 Featured Publication The effect of reduction in dose levels normally used in mammographic screening procedures on the detection of breast lesions were analyzed. Four types of breast lesions were simulated and inserted into clinically-acquired digital mammograms. Dose reduction ... Full text Link to item Cite

Assessment of detective quantum efficiency: intercomparison of a recently introduced international standard with prior methods.

Journal Article Radiology · June 2007 Featured Publication PURPOSE: To prospectively evaluate the recently introduced international standard method for measurement of the detective quantum efficiency (DQE) of digital radiography systems, in comparison with representative prior methods. MATERIALS AND METHODS: A rec ... Full text Link to item Cite

Digital mammography: comparative performance of color LCD and monochrome CRT displays.

Journal Article Acad Radiol · May 2007 Featured Publication RATIONALE AND OBJECTIVES: To evaluate the comparative performance of high-fidelity liquid crystal display (LCD) and cathode ray tube (CRT) devices for mammography applications, and to assess the impact of LCD viewing angle on detection accuracy. MATERIALS ... Full text Link to item Cite

Digital mammography: effects of reduced radiation dose on diagnostic performance.

Journal Article Radiology · May 2007 Featured Publication PURPOSE: To experimentally determine the relationship between radiation dose and observer accuracy in the detection and discrimination of simulated lesions for digital mammography. MATERIALS AND METHODS: This HIPAA-compliant study received institutional re ... Full text Link to item Cite

Multiprojection correlation imaging for improved detection of pulmonary nodules.

Journal Article AJR Am J Roentgenol · May 2007 Featured Publication OBJECTIVE: The purpose of this study was the development and preliminary evaluation of multiprojection correlation imaging with 3D computer-aided detection (CAD) on chest radiographs for cost- and dose-effective improvement of early detection of pulmonary ... Full text Link to item Cite

Tomographic digital subtraction angiography for lung perfusion estimation in rodents.

Journal Article Med Phys · May 2007 Featured Publication In vivo measurements of perfusion present a challenge to existing small animal imaging techniques such as magnetic resonance microscopy, micro computed tomography, micro positron emission tomography, and microSPECT, due to combined requirements for high sp ... Full text Link to item Cite

Dose dependence of mass and microcalcification detection in digital mammography: free response human observer studies.

Journal Article Med Phys · February 2007 Featured Publication The purpose of this study was to evaluate the effect of dose reduction in digital mammography on the detection of two lesion types-malignant masses and clusters of microcalcifications. Two free-response observer studies were performed-one for each lesion t ... Full text Link to item Cite

TU‐EE‐A4‐06: Experimental Evaluation of Effective Detective Quantum Efficiency for Digital Radiographic Imaging Systems

Journal Article Medical Physics · January 1, 2007 Purpose: To develop and evaluate an experimental methodology for measuring the effective detective quantum efficiency (eDQE) of digital radiographic systems which reflects the actual signal‐to‐noise performance of the system per unit exposure. Method and M ... Full text Cite

Ambient illumination revisited: a new adaptation-based approach for optimizing medical imaging reading environments.

Journal Article Med Phys · January 2007 Featured Publication Ambient lighting in soft-copy reading rooms is currently kept at low values to preserve contrast rendition in the dark regions of a medical image. Low illuminance levels, however, create inadequate viewing conditions and may also cause eye strain. This eye ... Full text Link to item Cite

MO‐D‐L100F‐03: New Developments in Digital Breast Tomosynthesis

Conference Medical Physics · January 1, 2007 Digital tomosynthesis is one of the most exciting recent developments in breast imaging. By modifying existing full field digital mammography systems, one can achieve this type of limited‐angle cone‐beam CT imaging which produces 3D slice images of the bre ... Full text Cite

TU‐E‐L100E‐01: Image Quality Measurement Workshop

Conference Medical Physics · January 1, 2007 Achieving a high level of image quality is a notable goal of any medical imaging system. Over decades, there has been much research about the techniques for the assessment of image quality and the clinical relevance of its quantitative values. This worksho ... Full text Cite

TU‐B‐M100J‐01: Optimizing Mammography Image Quality and Dose: X‐Ray Spectrum and Exposure Parameter Selection

Conference Medical Physics · January 1, 2007 Optimization of exposure parameters (target, filter, and kVp) in digital mammography necessitates maximization of the image signal‐to‐noise ratio (SNR), while simultaneously minimizing patient dose. The goal of this talk is to compare, for each of the majo ... Full text Cite

TH‐D‐M100F‐01: An Evaluation of Noise in Radiotracer Emission Imaging Using Flat‐Panel Detectors

Conference Medical Physics · January 1, 2007 Purpose: Single Photon Emission Computed Tomography (SPECT) onboard radiation therapy machines could enable the use of functional and molecular imaging in guiding the therapy beam and in monitoring disease. Costs and spatial constraints of onboard SPECT mi ... Full text Cite

SU‐FF‐I‐28: Evaluation of a Noise Addition Software for Simulating Low Dose MDCT Images

Conference Medical Physics · January 1, 2007 Purpose: To evaluate the utility of a noise addition software in simulating realistic MDCT images at reduced radiation dose levels. Methods and Materials: The utility of the software in simulating realistic low dose CT images was evaluated using a water ph ... Full text Cite

Improving mammographic decision accuracy by incorporating observer ratings with interpretation time.

Journal Article Br J Radiol · December 2006 Featured Publication Mammography is currently the most established technique for the early detection of breast cancer. However, mammography would benefit from further improvements as it does produce some errors, such as not finding all early-stage cancers. The objectives of th ... Full text Link to item Cite

Recent advances in chest radiography.

Journal Article Radiology · December 2006 Featured Publication There have been many remarkable advances in conventional thoracic imaging over the past decade. Perhaps the most remarkable is the rapid conversion from film-based to digital radiographic systems. Computed radiography is now the preferred imaging modality ... Full text Link to item Cite

Invited paper: Displaying your health: An overview of medical display research

Journal Article Proceedings of the Third Americas Display Engineering and Applications Conference, ADEAC 2006 · December 1, 2006 Medical imaging has been moving from analog technologies (such as x-ray film) to digital ones in recent years. The quality of a digital image depends on the quality of the detector equipment used to capture the image, image processing applied to the image, ... Cite

Optimized radiographic spectra for small animal digital subtraction angiography.

Journal Article Med Phys · November 2006 Featured Publication The increasing use of small animals in basic research has spurred interest in new imaging methodologies. Digital subtraction angiography (DSA) offers a particularly appealing approach to functional imaging in the small animal. This study examines the optim ... Full text Link to item Cite

Comparison of LCD and CRT displays based on efficacy for digital mammography.

Journal Article Acad Radiol · November 2006 Featured Publication RATIONALE AND OBJECTIVES: To compare two display technologies, cathode ray tube (CRT) and liquid crystal display (LCD), in terms of diagnostic accuracy for several common clinical tasks in digital mammography. MATERIALS AND METHODS: Simulated masses and mi ... Full text Link to item Cite

1032

Conference International Journal of Radiation Oncology*Biology*Physics · November 2006 Full text Cite

In-field assessment of display resolution and noise: Performance evaluation of a commercial measurement system

Journal Article Journal of the Society for Information Display · October 1, 2006 Two key metrics of image quality for high-fidelity displays, including medical displays, are resolution and noise. Until now, these properties have been primarily measured in laboratory settings. For the first time, a system consisting of a CCD camera and ... Full text Cite

A photographic technique for assessing the viewing-angle performance of liquid-crystal displays

Journal Article Journal of the Society for Information Display · October 1, 2006 Liquid-crystal displays (LCDs) have notable variation in luminance and perceived contrast as a function of the angle from which they are viewed. Though this is an important performance issue for LCDs, most evaluation techniques for assessing this variation ... Full text Cite

In-field evaluation of the modulation transfer function and the signal-to-noise ratio of electronic-display devices

Journal Article Journal of the Society for Information Display · October 1, 2006 This paper describes a charged-coupled device (CCD) camera, which was developed for in-field evaluation of the image quality of electronic-display devices [such as cathode-ray tubes (CRTs) and liquid-crystal displays (LCDs)] used for medical applications. ... Full text Cite

Visual assessment of angular response in medical liquid crystal displays.

Journal Article J Digit Imaging · September 2006 Featured Publication In spite of having non-Lambertian emission, displays based on liquid crystal technology are becoming popular for medical diagnostic work stations. For all liquid crystal displays (LCDs), the contrast performance varies with viewing direction. Accurate meas ... Full text Link to item Cite

Digital mammography image quality: image display.

Journal Article J Am Coll Radiol · August 2006 Featured Publication This paper on digital mammography image display is 1 of 3 papers written as part of an intersociety effort to establish image quality standards for digital mammography. The information included in this paper is intended to support the development of an Ame ... Full text Link to item Cite

Simulation of mammographic lesions.

Journal Article Acad Radiol · July 2006 Featured Publication RATIONALE AND OBJECTIVES: This study presents a method for generating breast masses and microcalcifications in mammography via simulation. This simulation method allows for the creation of large image datasets with particular lesions, which may serve as a ... Full text Link to item Cite

A novel method to characterize the MTF in 3D for computed mammotomography

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 30, 2006 A novel phantom has been developed to measure the modulation transfer function (MTF) in 3D for x-ray computed tomography. The phantom consists of three tungsten wires, positioned nearly orthogonal to each other. Simultaneous measurements of the MTF are tak ... Full text Cite

A Monte Carlo investigation on the impact of scattered radiation on mammographic resolution and noise

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 30, 2006 Scattered radiation plays a significant role in mammographic imaging, with scatter fractions over 50% for larger, denser breasts. For screen-film systems, scatter primarily affects the image contrast, reducing the conspicuity of subtle lesions. While digit ... Full text Cite

The impact of angular separation on the performance of biplane correlation imaging for lung nodule detection

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 30, 2006 In this paper, we evaluate the performance of biplane correlation imaging (BCI) using a set of off-angle projections acquired from an anthropomorphic chest phantom. BCI reduces the effect of anatomical noise, which would otherwise impact the detection subt ... Full text Cite

Performance evaluation of a commercial system for quantitative measurement of display resolution

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 30, 2006 One of the key metrics that carry information about image quality of medical displays is resolution. Until now, this property has been quantitatively assessed in laboratory settings. For the first time, a device consisting of a CCD camera and analysis soft ... Full text Cite

A method for reduction of eye fatigue by optimizing the ambient light conditions in radiology reading rooms

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 30, 2006 Ambient lighting in soft-copy reading rooms are currently kept at low values to preserve contrast rendition in the dark regions of a medical image. Low illuminance levels, however, create inadequate viewing conditions and may also cause eye-strain. This ey ... Full text Cite

X-ray tube voltage and image quality in adult and pediatric CT

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 30, 2006 The purpose of this study was to investigate how tissue x-ray attenuation coefficients, and their uncertainties, vary with x-ray tube voltage in different sized patients. Anthropomorphic phantoms (newborn, 10 year old, adult) were scanned a GE LightSpeed s ... Full text Cite

Biplane correlation imaging for lung nodule detection: Initial human subject results

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 22, 2006 In this paper, we present performance of biplane correlation imaging (BCI) on set of chest x-ray projections of human data. BCI significantly minimizes the number of false positives (FPs) when used in conjunction with computer aided detection (CAD) by elim ... Full text Cite

Potential for lower absorbed dose in digital mammography: A JAFROC experiment using clinical hybrid images with simulated dose reduction

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 22, 2006 To determine how image quality linked to tumor detection is affected by reducing the absorbed dose to 50% and 30% of the clinical levels represented by an average glandular dose (AGO) level of 1.3 mGy for a standard breast according to European guidelines. ... Full text Cite

Analyzing the Effect of dose reduction on the detection of mammographic lesions using mathematical observer models

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 22, 2006 The purpose of this study was to determine the effect of dose reduction on the detectability of breast lesions in mammograms. Mammograms with dose levels corresponding to 50% and 25% of the original clinically-relevant exposure levels were simulated. Detec ... Full text Cite

Contrast-detail analysis of three flat panel detectors for digital radiography.

Journal Article Med Phys · June 2006 Featured Publication In this paper we performed a contrast detail analysis of three commercially available flat panel detectors, two based on the indirect detection mechanism (GE Revolution XQ/i, system A, and Trixell/Philips Pixium 4600, system B) and one based on the direct ... Full text Link to item Cite

Intercomparison of methods for image quality characterization. II. Noise power spectrum.

Journal Article Med Phys · May 2006 Featured Publication Second in a two-part series comparing measurement techniques for the assessment of basic image quality metrics in digital radiography, in this paper we focus on the measurement of the image noise power spectrum (NPS). Three methods were considered: (1) a m ... Full text Link to item Cite

Intercomparison of methods for image quality characterization. I. Modulation transfer function.

Journal Article Med Phys · May 2006 Featured Publication The modulation transfer function (MTF) and the noise power spectrum (NPS) are widely recognized as the most relevant metrics of resolution and noise performance in radiographic imaging. These quantities have commonly been measured using various techniques, ... Full text Link to item Cite

Imaging properties of digital magnification radiography.

Journal Article Med Phys · April 2006 Featured Publication Flat panel detectors exhibit improved signal-to-noise ratio (SNR) and display capabilities compared to film. This improvement necessitates a new evaluation of optimal geometry for conventional projection imaging applications such as digital projection mamm ... Full text Link to item Cite

Viewing angle performance of medical liquid crystal displays.

Journal Article Med Phys · March 2006 Featured Publication Cathode-ray tube (CRT) and liquid crystal display (LCD) are currently two main technologies for displaying medical images. LCDs possess a number of advantages, but their performance varies as a function of viewing angle. Our purpose in this study was to ch ... Full text Link to item Cite

Simulation of liver lesions for pediatric CT.

Journal Article Radiology · February 2006 Featured Publication PURPOSE: To develop and validate a technique based on characteristics of real lesions for simulating realistic small liver lesions on pediatric computed tomographic (CT) images. MATERIALS AND METHODS: The institutional review board provided exempt status f ... Full text Link to item Cite

Resolution and noise measurements of five CRT and LCD medical displays.

Journal Article Med Phys · February 2006 Featured Publication The performance of soft-copy displays plays a significant role in the overall image quality of a digital radiographic system. In this work, we discuss methods to characterize the resolution and noise of both cathode ray tube (CRT) and liquid crystal displa ... Full text Link to item Cite

Analysis of a novel offset cone-beam computed mammotomography system geometry for accomodating various breast sizes.

Journal Article Phys Med · 2006 Featured Publication We evaluate a newly developed dedicated cone-beam transmission computed mammotomography (CmT) system configuration using an optimized quasi-monochromatic cone beam technique for attenuation correction of SPECT in a planned dual-modality emission and transm ... Full text Link to item Cite

Beam optimization for digital mammography - II

Journal Article Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) · January 1, 2006 Optimization of acquisition technique factors (target, filter, and kVp) in digital mammography is required for maximization of the image SNR, while minimizing patient dose. The goal of this study is to compare, for each of the major commercially available ... Full text Cite

Geometrical repeatability and motion blur analysis of a new multi-projection X-ray imaging system

Journal Article IEEE Nuclear Science Symposium Conference Record · January 1, 2006 We report on the reproducibility and tests for possible motion blur artifacts of a new high frame-rate prototype x-ray multi-projection system recently installed in the Radiology Department of Duke University. The system, which has a translating x-ray tube ... Full text Cite

Why Medical Image Perception?

Journal Article Journal of the American College of Radiology · January 1, 2006 Full text Cite

SU‐FF‐I‐48: Assessment of Detective Quantum Efficiency: Inter‐Comparison of IEC 62220‐1 with Representative Prior Methods

Conference Medical Physics · January 1, 2006 Purpose: To evaluate a new international standard method for the measurement of detective quantum efficiency (DQE) of digital radiography systems in comparison with representative prior methods. Methods and Materials: Three DQE evaluation methods were cons ... Full text Cite

MO‐E‐230C‐00: Display Evaluation Demonstration Workshop: Part II

Conference Medical Physics · January 1, 2006 Participants: J Charette, Barcoview, LLC; E Samei, Duke University; N Hashimoto, Eizo Nanao; K Compton, National Display Systems; A Abileah, Planar Systems; D Sorensen, Richardson Electronics / Image Systems; C Lipfert, Scanditronix Wellhofer GmbH; M Haseg ... Full text Cite

TH‐C‐330A‐02: Does Image Quality Impact Mammographic Accuracy?

Conference Medical Physics · January 1, 2006 Purpose: To assess the impact of resolution and noise on observer performance in detecting and classifying breast masses and microcalcifications in x‐ray mammography. Method and Materials: Simulated breast masses and microcalcifications were inserted into ... Full text Cite

MO‐D‐230C‐01: Evaluation of Medical Displays

Conference Medical Physics · January 1, 2006 Participants: J Charette, Barcoview, LLC; E Samei, Duke University; N Hashimoto, Eizo Nanao; K Compton, National Display Systems; A Abileah, Planar Systems; D Sorensen, Richardson Electronics / Image Systems; C Lipfert, Scanditronix Wellhofer GmbH; M Haseg ... Full text Cite

The nature of the digital image

Conference SPECIFICATIONS PERFORMANCE EVALUATION AND QUALITY ASSURANCE OF RADIOGRAPHIC AND FLUOROSCOPIC SYSTEMS IN THE DIGITAL ERA · January 1, 2006 Link to item Cite

TU‐FF‐A3‐02: Preliminary Investigations Into Combined CT/SPECT Imaging Onboard Therapy Machines

Conference Medical Physics · January 1, 2006 Purpose: Functional and molecular (F&M) imaging onboard radiation therapy machines would allow for targeting of functional tumor volume, and avoiding of healthy tissue, by guiding and modifying radiation beams, in the treatment room, based on real‐time F&M ... Full text Cite

Studying the effect of physics-based-enhancement on LCDs (IBM's 9.2 MP) and CRTs (Barco's 5 MP) on X=ray Mammograms acquired using Full Field Digital Mammography and Ultrasound (FFDMUS) System

Journal Article SID Conference Record of the International Display Research Conference · December 1, 2005 The latest technological changes In diagnostic radiology are fast replacing the conventional cathode ray tube (CRT) displays with liquid crystal displays (LCDs). Even though LCDs offer considerable advantages over conventional CRTs, the pixelated pattern o ... Cite

A study of CRT (5-Mpixel) vs. LCD (9-Mpixel) displays for breast lesion detection in full-field digital mammography and ultrasound (FFDMUS) data sets via image-enhancement algorithms

Journal Article Digest of Technical Papers - SID International Symposium · December 1, 2005 The latest technological changes are fast replacing the conventional cathode ray tube (CRT) displays with liquid crystal displays (LCDs). It is thus important to understand and evaluate them. The novelty of our evaluation strategy comes from the usage of c ... Full text Cite

MTF and NPS study of high-resolution LCDs and CRTs for mammography

Journal Article Digest of Technical Papers - SID International Symposium · December 1, 2005 This paper presents a closer look on the link between the physical parameters (MTF and NPS) that characterize the performance of a liquid crystal display (LCD) and the architecture that generates the images. Understanding the major architectural difference ... Full text Cite

Initial study of quasi-monochromatic x-ray beam performance for x-ray computed mammotomography

Journal Article IEEE Transactions on Nuclear Science · October 1, 2005 We evaluate the feasibility, benefits, and operating parameters of a quasimonochromatic beam for a newly developed x-ray cone beam computed mammotomography application. The value of a near monochromatic x-ray source for fully 3D dedicated mammotomography i ... Full text Cite

Effect of display resolution on the detection of mammographie lesions

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · September 19, 2005 For diagnosis of breast cancer by mammography, the mammograms must be viewed by a radiologist. The purpose of this study was to determine the effect of display resolution on the specific clinical task of detection of breast lesions by a human observer. Usi ... Full text Cite

Detector evaluation of a prototype amorphous selenium-based full field digital mammography system

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · August 25, 2005 This study evaluated the physical performance of a selenium-based direct full-field digital mammography prototype detector (Siemens Mammomat Novation DR), including the pixel value vs. exposure linearity, the modulation transfer function (MTF), the normali ... Full text Cite

Design and development of a fully-3D dedicated x-ray computed mammotomography system

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · August 25, 2005 Our effort to implement a volumetric x-ray computed mammotomography (CmT) system dedicated to imaging breast disease comprises: demonstrated development of a quasi-monochromatic x-ray beam providing minimal dose and other optimal imaging figures of merit; ... Full text Cite

Physical evaluation of a high frame rate, extended dynamic range flat panel detector for real-time cone beam computed tomography applications

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · August 25, 2005 The use of flat panel detectors in computed tomography (CT) systems can improve resolution, reduce system cost, and add operational flexibility by combining fluoroscopy and radiography applications within CT systems. However, some prior studies have sugges ... Full text Cite

Photographic measurement of the effects of viewing angle on the luminance and contrast of liquid crystal displays

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · August 16, 2005 An actively cooled charge couple device detector in combination with a 4 mm focal length lens (camera) was used to evaluate the luminance and perceived contrast properties of a liquid crystal display (LCD). The circular field of view (FOV) of the camera oc ... Full text Cite

Comparison of edge analysis techniques for the determination of the MTF of digital radiographic systems.

Journal Article Phys Med Biol · August 7, 2005 Featured Publication The modulation transfer function (MTF) is well established as a metric to characterize the resolution performance of a digital radiographic system. Implemented by various laboratories, the edge technique is currently the most widespread approach to measure ... Full text Link to item Cite

Measurement of the detective quantum efficiency in digital detectors consistent with the IEC 62220-1 standard: Practical considerations regarding the choice of filter material.

Journal Article Med Phys · July 2005 Featured Publication As part of a larger evaluation we attempted to measure the detective quantum efficiency (DQE) of an amorphous silicon flat-panel detector using the method described in the International Electrotechnical Commission standard 62220-1 published in October 2003 ... Full text Link to item Cite

Comparative scatter and dose performance of slot-scan and full-field digital chest radiography systems.

Journal Article Radiology · June 2005 Featured Publication PURPOSE: To evaluate the scatter, dose, and effective detective quantum efficiency (DQE) performance of a slot-scan digital chest radiography system compared with that of a full-field digital radiography system. MATERIALS AND METHODS: Scatter fraction of a ... Full text Link to item Cite

Assessment of display performance for medical imaging systems: executive summary of AAPM TG18 report.

Journal Article Med Phys · April 2005 Featured Publication Digital imaging provides an effective means to electronically acquire, archive, distribute, and view medical images. Medical imaging display stations are an integral part of these operations. Therefore, it is vitally important to assure that electronic dis ... Full text Link to item Cite

Physical characterization of a prototype selenium-based full field digital mammography detector.

Journal Article Med Phys · February 2005 Featured Publication The purpose of this study was to measure experimentally the physical performance of a prototype mammographic imager based on a direct detection, flat-panel array design employing an amorphous selenium converter with 70 microm pixels. The system was charact ... Full text Link to item Cite

AAPM/RSNA physics tutorial for residents: technological and psychophysical considerations for digital mammographic displays.

Journal Article Radiographics · 2005 Featured Publication Digital mammography is gradually replacing screen-film analog mammography, a transition driven by a desire to improve the efficiency and possibly the quality of the interpretation of mammograms. Digital mammography involves the use of electronic display de ... Full text Link to item Cite

A framework for optimising the radiographic technique in digital X-ray imaging.

Journal Article Radiat Prot Dosimetry · 2005 Featured Publication The transition to digital radiology has provided new opportunities for improved image quality, made possible by the superior detective quantum efficiency and post-processing capabilities of new imaging systems, and advanced imaging applications, made possi ... Full text Link to item Cite

WE‐E‐I‐609‐01: Advances In Perception & Visualization

Conference Medical Physics · January 1, 2005 Perceptual & Cognitive Mechanisms in the Interpretation of Medical Images — E. Krupinski Optimizing Image Quality for Softcopy Reading — E. Samei Modeling the human visual system for medical image interpretation — M. Eckstein This symposium brings together ... Full text Cite

MO‐E‐W‐608‐01: Display Evaluation Demonstration Workshop

Conference Medical Physics · January 1, 2005 The AAPM TG18 is a new initiative aimed to provide standard guidelines and procedures for acceptance testing and quality control of electronic display devices for medical applications. The recommendations, based on the newly‐designed TG18 test patterns, in ... Full text Cite

MO‐D‐W‐608‐01: Display Evaluation Demonstration Workshop

Conference Medical Physics · January 1, 2005 The AAPM TG18 is a new initiative aimed to provide standard guidelines and procedures for acceptance testing and quality control of electronic display devices for medical applications. The recommendations, based on the newly‐designed TG18 test patterns, in ... Full text Cite

New DICOM elements promise better image quality

Journal Article Diagnostic Imaging Online · December 2004 Link to item Cite

Toward clinically relevant standardization of image quality.

Journal Article J Digit Imaging · December 2004 Featured Publication In recent years, notable progress has been made on standardization of medical image presentations in the definition and implementation of the Digital Imaging and Communications in Medicine (DICOM) Grayscale Standard Display Function (GSDF). In parallel, th ... Full text Link to item Cite

The effect of viewing angle response on DICOM compliance of liquid crystal displays

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · December 1, 2004 Cathode-ray tube (CRT) and liquid crystal display (LCD) are currently two main technologies for displaying medical images. LCDs possess a number of advantages, but their performance varies as a function of viewing angle. The purpose of this study was to de ... Full text Cite

Characterization of breast masses for simulation purposes

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · December 1, 2004 Simulation of radiographic lesions is an important prerequisite for several research applications in medical imaging, including hardware and software design and optimization. For mammography, breast masses are an important class of lesions to be considered ... Full text Cite

Liquid-crystal displays for medical imaging: A discussion of monochrome versus color

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · October 27, 2004 A common view is that color displays cannot match the performance of monochrome displays, normally used for diagnostic x-ray imaging. This view is based largely on historical experience with cathode-ray tube (CRT) displays, and does not apply in the same w ... Full text Cite

Luminance and contrast performance of liquid crystal displays for mammographic applications.

Journal Article Technol Cancer Res Treat · October 2004 Featured Publication Liquid crystal displays (LCDs) are gradually replacing cathode-ray tubes (CRTs) as the primary means of electronic display of digital radiographs. The transition from CRT to LCD is fueled by advantages of the LCD technology such as enhanced maximum luminan ... Full text Link to item Cite

Fundamental imaging characteristics of a slot-scan digital chest radiographic system.

Journal Article Med Phys · September 2004 Featured Publication Our purpose in this study was to evaluate the fundamental image quality characteristics of a new slot-scan digital chest radiography system (ThoraScan, Delft Imaging Systems/Nucletron, Veenendaal, The Netherlands). The linearity of the system was measured ... Full text Link to item Cite

Determination of the detective quantum efficiency of a digital x-ray detector: comparison of three evaluations using a common image data set.

Journal Article Med Phys · August 2004 Featured Publication The detective quantum efficiency (DQE) of an x-ray digital imaging detector was determined independently by the three participants of this study, using the same data set consisting of edge and flat field images. The aim was to assess the possible variation ... Full text Link to item Cite

Development of an optimal X-ray beam for dual-mode emission and transmission mammotomography

Journal Article Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment · July 11, 2004 The development of an optimal x-ray beam for dual-mode emission and transmission mammotomography for evaluation of breast lesions is discussed. The idealized operating parameters for the quasi-monochromatic beam were determined by evaluating a beam hardeni ... Full text Cite

Measurements of an optimized beam for x-ray computed mammotomography

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · July 5, 2004 Simulation results from previous studies indicate that a quasi-monochromatic x-ray beam can be produced using a newly developed beam filtration technique. This technique utilizes heavy filtration with novel high Z filter materials having k-edges just above ... Full text Cite

Assessment of flat panel LCD primary class display performance based on AAPM TG 18 acceptance protocol.

Journal Article Med Phys · July 2004 Featured Publication The image display is an important component of the Picture Archiving and Communication System (PACS) and of digital imaging in general. In this paper, we assess the display performance of 32 different flat panel LCD devices, in terms of their reflection, l ... Full text Link to item Cite

TG18 display evaluation demonstration workshop

Journal Article MEDICAL PHYSICS · June 1, 2004 Link to item Cite

TG18 display evaluation demonstration workshop

Journal Article MEDICAL PHYSICS · June 1, 2004 Link to item Cite

From physics to medicine - Introduction

Journal Article MEDICAL PHYSICS · June 1, 2004 Link to item Cite

Impact of resolution and noise characteristics of digital radiographic detectors on the detectability of lung nodules.

Journal Article Med Phys · June 2004 Featured Publication One of the unanswered questions in digital radiography is the connection between physical image quality metrics and clinical detection performance. In this paper, we examine the impact of two physical metrics, resolution and noise, on the detectability of ... Full text Link to item Cite

Simulation study of a quasi-monochromatic beam for x-ray computed mammotomography.

Journal Article Med Phys · April 2004 Featured Publication The purpose of this simulation study was to evaluate the feasibility, benefits, and potential operating parameters of a quasi-monochromatic beam from a tungsten-target x-ray source yielding projection images. The application is intended for newly developed ... Full text Link to item Cite

AAPM/RSNA tutorial on equipment selection: PACS equipment overview: general guidelines for purchasing and acceptance testing of PACS equipment.

Journal Article Radiographics · 2004 Featured Publication A picture archiving and communication system (PACS) is a comprehensive computer system that is responsible for the electronic storage and distribution of medical images in the medical enterprise. The system is highly integrated with digital acquisition and ... Full text Link to item Cite

Initial study of quasi-monochromatic X-ray beam performance for X-ray computed mammotomography

Journal Article IEEE Nuclear Science Symposium Conference Record · December 1, 2003 We evaluate the feasibility, benefits, and operating parameters of a quasi-monochromatic beam for a newly developed X-ray cone beam computed mammotomography application. The value of a near monochromatic X-ray source for a fully 3D tomography application i ... Cite

Sonography of fetal choroid plexus cysts: detection depends on cyst size and gestational age.

Journal Article J Ultrasound Med · November 2003 Featured Publication OBJECTIVE: To establish diagnostic criteria for the diagnosis of fetal choroid plexus cysts across gestation. METHODS: Prenatal sonographic images of 166 fetuses without choroid plexus cysts were prospectively collected from 13 weeks to term. Texture chara ... Full text Link to item Cite

A method for modifying the image quality parameters of digital radiographic images.

Journal Article Med Phys · November 2003 Featured Publication A new computer simulation approach is presented that is capable of modeling several varieties of digital radiographic systems by their image quality characteristics. In this approach, the resolution and noise characteristics of ideal supersampled input ima ... Full text Link to item Cite

Optimizing beam quality for X-ray computed mammotomography

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · September 15, 2003 The purpose of this study was to determine the optimum beam quality in terms of kVp and filtration for a tungsten-target x-ray source for a newly developed cone beam computed mammotomography application. The optimized beam is expected to yield enhanced ima ... Full text Cite

Bi-plane correlation imaging for improved detection of lung nodules

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · September 15, 2003 Bi-plane correlation imaging (BCI) is a new imaging approach that utilizes angular information from a bi-plane digital acquisition in conjunction with computer assisted detection (CAD) to reduce the degrading influence of anatomical noise in the detection ... Full text Cite

Impact of resolution and noise characteristics of digital radiographic detectors on the detectability of lung nodules

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · September 15, 2003 The current system performance metrics for Digital Radiographic detectors describe physical parameters, such as resolution (Modulation Transfer Function), noise (Noise Power Spectrum) and efficiency (Detective Quantum Efficiency). However, little has been ... Full text Cite

Fast search and localization algorithm based on human visual perception modeling: An application for fast localization of structures in mammograms

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · September 12, 2003 A computer algorithm for fast identification and localization of structures of interest in images is presented. The algorithm is based on the analysis of a reduced set of image neighborhoods selected randomly by a constrained sampling of an associated imag ... Full text Cite

Clinical verification of TG18 methodology for display quality evaluation

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · August 22, 2003 The American Association of Physicists in Medicine Task Group 18 (TG18) has recently developed guidelines for objective performance evaluation of medical displays. This paper reports on the first multi-institutional trial focusing on the implementation and ... Full text Cite

Subtle lung nodules: influence of local anatomic variations on detection.

Journal Article Radiology · July 2003 Featured Publication PURPOSE: To assess the influence of local anatomic noise on the detection of subtle lung nodules depicted on chest radiographs. MATERIALS AND METHODS: Six 8 x 8-cm lung regions were extracted from digital chest radiographs obtained in healthy subjects. Sim ... Full text Link to item Cite

Image quality in two phosphor-based flat panel digital radiographic detectors.

Journal Article Med Phys · July 2003 Featured Publication Two general types of phosphor screens are currently used in indirect digital radiographic systems: structured phosphor screens and turbid phosphor screens. The purpose of the study was to experimentally compare the image quality characteristics of two flat ... Full text Link to item Cite

TG18 display evaluation

Journal Article MEDICAL PHYSICS · June 1, 2003 Link to item Cite

Digital mammography displays

Journal Article MEDICAL PHYSICS · June 1, 2003 Link to item Cite

An experimental comparison of detector performance for direct and indirect digital radiography systems.

Journal Article Med Phys · April 2003 Featured Publication Current flat-panel detectors either directly convert x-ray energy to electronic charge or use indirect conversion with an intermediate optical process. The purpose of this work was to compare direct and indirect detectors in terms of their modulation trans ... Full text Link to item Cite

Evaluation of a flat panel digital radiographic system for low-dose portable imaging of neonates.

Journal Article Med Phys · April 2003 Featured Publication The purpose of this study was to evaluate the clinical utility of an investigational flat-panel digital radiography system for low-dose portable neonatal imaging. Thirty image-pairs from neonatal intensive care unit patients were acquired with a commercial ... Full text Link to item Cite

Chest radiography: optimization of X-ray spectrum for cesium iodide-amorphous silicon flat-panel detector.

Journal Article Radiology · January 2003 Featured Publication PURPOSE: To ascertain the optimum x-ray spectrum for chest radiography with a cesium iodide-amorphous silicon flat-panel detector. MATERIALS AND METHODS: End points for optimization included the ratio of tissue contrast to bone contrast and a figure of mer ... Full text Link to item Cite

Simulation study of quasi-monochromatic X-ray beam performance for X-ray computed mammotomography given various breast compositions and lesion sizes

Journal Article IEEE Nuclear Science Symposium Conference Record · January 1, 2003 A quasi-monochromatic X-ray computed mammo-tomograph (XCT) system is under development. The importance of a near-monochromatic x-ray beam is that tissues of close attenuation coefficients are expected to be more easily separable compared with those from a ... Full text Cite

Perceptual assessment of soft-copy display quality

Journal Article MEDICAL PHYSICS · June 1, 2002 Link to item Cite

An experimental comparison of detector performance for computed radiography systems.

Journal Article Med Phys · April 2002 Featured Publication The intrinsic resolution, noise, and signal-to-noise transfer characteristics of five commercial digital computed radiography (CR) systems were compared using identical experimental methods. The reader/screen combinations evaluated were Agfa ADC-Compact/MD ... Full text Link to item Cite

CR performance evaluation

Journal Article Advance · January 2002 Cite

PACS acceptance Testing

Journal Article Advance · May 2001 Cite

Evaluation of a quality control phantom for digital chest radiography

Journal Article Journal of Applied Clinical Medical Physics · March 2001 Rationale and Objectives: To examine the effectiveness and suitability of a quality control (QC) phantom for a routine QC program in digital radiography. Materials and Methods: The chest phantom ... Full text Cite

Performance evaluation of computed radiography systems.

Journal Article Med Phys · March 2001 Featured Publication Recommended methods to test the performance of computed radiography (CR) digital radiographic systems have been recently developed by the AAPM Task Group No. 10. Included are tests for dark noise, uniformity, exposure response, laser beam function, spatial ... Full text Link to item Cite

DQE of direct and indirect digital radiographic systems

Journal Article Proceedings of SPIE- The International Society for Optical Engineering · January 1, 2001 Current flat-panel detectors either directly convert x-ray energy to electronic charge or use indirect conversion with an intermediate optical process. The purpose of this work was to compare direct and indirect detectors in terms of their modulation trans ... Full text Cite

Evaluation of a quality control phantom for digital chest radiography.

Journal Article J Appl Clin Med Phys · 2001 Featured Publication RATIONALE AND OBJECTIVES: To examine the effectiveness and suitability of a quality control (QC) phantom for a routine QC program in digital radiography. MATERIALS AND METHODS: The chest phantom consists of copper and aluminum cutouts arranged to resemble ... Full text Link to item Cite

Optimal display processing for digital radiography

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · January 1, 2001 Display processing is used to transform digital radiography raw data in log-signal units to display values for presentation using a workstation or film printer. Radiographic appearance with respect to subject latitude and detail contrast varies significant ... Full text Cite

Objective performance evaluation of medical image displays: A preliminary report of the AAPM TG18

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · January 1, 2001 Recent advances in electronic imaging have led to an increased utilization of soft-copy displays for presentation and diagnostic interpretation of medical images in clinical settings. Because of the fundamental importance of display quality in the overall ... Full text Cite

A method for in-field evaluation of the modulation transfer function of electronic display devices

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · January 1, 2001 Electronic medical display devices require routine monitoring of their resolution characteristics. This paper introduces a methodology for the assessment of resolution (MTF) characteristics of display devices using a photographic-grade CCD camera, and repo ... Full text Cite

Health physics consequences of out-patient treatment of non-Hodgkin's lymphoma with 131I-radiolabeled anti-B1 antibody.

Journal Article Health Phys · November 2000 Featured Publication The Medical University of South Carolina is currently participating in clinical trials of 131I radiolabeled Anti-B1 antibody for treatment of Non-Hodgkin's lymphoma. Under current South Carolina Department of Health and Environmental Control regulatory gui ... Full text Link to item Cite

Numerical simulation of a TLD pulsed laser-heating scheme for determination of shallow dose and deep dose in low-LET radiation fields.

Journal Article Appl Radiat Isot · June 2000 Featured Publication A new method is described to determine the depth-dose distribution in low-LET radiation fields using a thick thermoluminescent dosimeter (TLD) with a pulsed laser-heating scheme to obtain TL glow output. The computational simulation entails heat conduction ... Full text Link to item Cite

Use of Wiener filtering in the measurement of the two-dimensional modulation transfer function

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · January 1, 2000 This paper presents a new method for the measurement of modulation transfer function (MTF) using Wiener filtering. The method, unlike conventional methods using slit or edge devices, allows the direct determination of the MTF in all directions at one step. ... Full text Cite

Detection of subtle lung nodules: relative influence of quantum and anatomic noise on chest radiographs.

Journal Article Radiology · December 1999 Featured Publication PURPOSE: To assess the relative influence of quantum mottle and structured lung patterns (anatomic noise) on the detection of subtle lung nodules on chest radiographs. MATERIALS AND METHODS: Sixty 8 x 8-cm lung pattern images were extracted from digital ch ... Full text Link to item Cite

Experimental comparison of noise and resolution for 2k and 4k storage phosphor radiography systems.

Journal Article Med Phys · August 1999 Featured Publication The purpose of this study was to compare the image quality for a digital storage phosphor system using 1760 x 2140 (2k) and 3520 x 4280 (4k) image arrays. Measurements were made on a chest radiography system (Fuji FCR-9501) with special provisions to be op ... Full text Link to item Cite

The radiologist's workbench - Critical features for image review and reporting

Conference PRACTICAL DIGITAL IMAGING AND PACS · 1999 Cite

Chest radiographic image quality: comparison of asymmetric screen-film, digital storage phosphor, and digital selenium drum systems--preliminary study.

Journal Article Radiographics · 1998 Featured Publication Conventional screen-film radiography does not display all regions of the thorax satisfactorily. Three chest radiographic techniques display both the lung and the mediastinum with good contrast. These techniques are asymmetric screen-film (ASF), digital sto ... Full text Link to item Cite

A method for measuring the presampled MTF of digital radiographic systems using an edge test device.

Journal Article Med Phys · January 1998 Featured Publication The modulation transfer function (MTF) of radiographic systems is frequently evaluated by measuring the system's line spread function (LSF) using narrow slits. The slit method requires precise fabrication and alignment of a slit and high radiation exposure ... Full text Link to item Cite

The effect of local background anatomical patterns on the detection of subtle lung nodules in chest radiographs

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · January 1, 1998 Anatomical noise in chest radiography, created by the projection of anatomical features in the thorax such as ribs and pulmonary vessels, greatly influences the detection of subtle lung nodules in chest radiographs. Detection may be hindered by 1) the "glo ... Full text Cite

The performance of digital x-ray imaging systems in detection of subtle lung nodules

Journal Article Medical Physics · January 1, 1998 Subtle lung nodules (SLNs) are lesions that are commonly missed in radiologic examinations of the chest. This thesis explores three factors that influence the detection of these lesions: contrast-diameter characteristics of SLNs, physical performance of th ... Full text Cite

Physical measures of image quality in photostimulable phosphor radiographic systems

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · December 1, 1997 The purpose of this study was to critically assess and compare the intrinsic resolution, noise, and signal-to-noise transfer characteristics of two modern digital photostimulable phosphor (PSP) radiographic systems. Two commercial PSP systems were evaluate ... Full text Cite

Simulation of subtle lung nodules in projection chest radiography.

Journal Article Radiology · January 1997 Featured Publication PURPOSE: To measure the radiologic characteristics of subtle lung nodules and develop nodule phantoms that simulate these characteristics. MATERIALS AND METHODS: From a database of chest radiographs, 16 radiographs that showed confirmed subtle lung nodules ... Full text Link to item Cite

An atlas of selected beta-ray spectra and depth-dose distributions in lithium fluoride and soft tissue generated by a fast Monte Carlo-based sampling method

Journal Article Radiation Physics and Chemistry · December 1, 1996 A method to generate depth-dose distributions due to beta radiation in LiF and soft tissue is proposed. In this method, the EGS4 Monte Carlo radiation transport code is initially used to generate a library of monoenergetic electron depth-dose distributions ... Full text Cite

Performance of low-voltage phosphors in emissive flat panel displays for radiologic applications

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · December 1, 1996 To date, the lack of adequate electronic display devices has been the primary factor limiting the use of digital radiographic images. Flat panel display technology using field emissive cathodes in microvacuum cells has emerged as a potential solution. Howe ... Full text Cite

Comparison of observer performance for real and simulated nodules in chest radiography

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · January 1, 1996 Observer performance studies are frequently performed to evaluate and compare various radiographic techniques with regard to detection of subtle lung nodules using simulated nodules. The fidelity of the simulated nodules and their equivalency to the real l ... Cite

A limited bibliography of the Federal Government-funded human radiation experiments.

Journal Article Health Phys · December 1995 Featured Publication From the early 1940's thousands of U.S. citizens have been the subjects of federally supported scientific experiments that involved the administration of ionizing radiation or radioactive substances. Recently, many questions have been raised regarding the ... Full text Link to item Cite

Sensitivity of a mixed field dosimetry algorithm to uncertainties in thermoluminescent element readings.

Journal Article Health Phys · March 1995 Featured Publication An error analysis of the effects of the algorithms used to resolve the deep and shallow dose components for mixed fields from multi-element thermoluminescent (TLD) badge systems was undertaken for a commonly used system. Errors were introduced independentl ... Full text Link to item Cite

Numerical modelling of a new method for determination of shallow dose and deep dose in low let radiation fields

Journal Article Radiation Protection Dosimetry · January 1, 1995 This study introduces a new TLD reading technique to be adopted for low LET radiation field dosimetry capable of shallow and deep dose measurements which utilises simultaneously obtained integrated glow values from two sides of a hot gas-heated TLD slab. T ... Cite

Impact of variations in physical parameters on glow curves for planchet heating of TL dosimeters

Journal Article Nuclear Inst. and Methods in Physics Research, A · December 30, 1994 This study consists of a theoretical analysis of the directional planchet heating of Thermoluminescent Dosimeters (TLD) with an emphasis on influence of radiation field type, TL material properties, and heating scheme parameters on the resulting glow curve ... Full text Cite

A preliminary study on Halley's comet

Journal Article Iranian Journal of Physics · 1986 Cite

Halley: results of recent investigations

Journal Article Iranian Journal of Physics · 1986 Cite