Scholars@Duke
Ehsan Samei

Ehsan Samei

Reed and Martha Rice Distinguished Professor of Radiology
Radiology
DUMC Box 2731, Durham, NC 27710
ORCID iDhttps://orcid.org/0000-0001-7451-3309
2424 Erwin Road, Suite 302, Ravin Advanced Imaging Labs, Durham, NC 27705

Scholarly Works - Conferences

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

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

Conference AMERICAN JOURNAL OF RESPIRATORY AND CRITICAL CARE MEDICINE · May 1, 2023 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

Virtual Clinical Trials

Conference MEDICAL PHYSICS · June 2022 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

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

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

Effective Dose and Patient Dose

Conference MEDICAL PHYSICS · June 2021 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

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

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

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 (50< ... Full text 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

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

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

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

Role of the Diagnostic Physicist

Conference MEDICAL PHYSICS · June 1, 2018 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

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

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

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

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

SU-F-I-48: Variability in CT Scanning Over-Range Across Clinical Operation.

Conference Med Phys · June 2016 PURPOSE: Inconsistency in the scan range for a given protocol can be a source of variability in patient dose. The purpose of this study was to determine the variability in the over-scan length in clinical CT operation for chest and abdominopelvic (A&P) pro ... 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

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 conv ... 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

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

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

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

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

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

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

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

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

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

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

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

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 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

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

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

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

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

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

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

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

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

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

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

1032

Conference International Journal of Radiation Oncology*Biology*Physics · November 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

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