Ehsan Abadi

Journal article Phys Med · August 2026 PURPOSE: The purpose of this study was to demonstrate the use of integrated PET/CT virtual imaging trials (VITs) for evaluating PET/CT acquisition protocols and clinically relevant sources of PET quantification variability under controlled, repeatable cond ... Full text Link to item Cite

Proton therapy range uncertainty reduction using vendor-agnostic tissue characterization on a virtual photon-counting CT head scan.

Journal article Med Phys · May 2026 BACKGROUND: Photon-counting CT (PCCT) is the latest technology enabling imaging with reduced noise and inherent spectral separation, with the potential to directly calculate a more accurate tissue stopping power from spectral data. This potential benefit i ... Full text Link to item Cite

Optimizing energy settings in CdTe, CZT, and Si photon-counting CT for material separation and detection.

Journal article Phys Med Biol · April 8, 2026 Objective. The performance of photon-counting CT (PCCT) depends on how detector energy thresholds or bins (collectively referred to as energy settings) are defined. This study aimed to identify optimal energy settings for various PCCT technologies to enhan ... Full text Link to item Cite

Precise Lung Density Quantification with a Physics-based CT Harmonizer.

Journal article Radiol Cardiothorac Imaging · April 2026 Purpose To develop a physics-based image harmonization method that transforms images into a reference quality index of noise, spatial resolution, and lung volume and to evaluate its performance for improving reproducibility of lung density measurement. Mat ... Full text Link to item Cite

Truth-based physics informed estimation of material composition in spectral CT in terms of density and effective atomic number.

Journal article Phys Med Biol · February 13, 2026 Objective.Spectral computed tomography (CT) data from photon-counting CT (PCCT) enables material decomposition. Mechanistic approaches such as maximum likelihood estimation are noise sensitive. Deep learning alternatives mitigate this issue, but their accu ... Full text Link to item Cite

Virtual Imaging-Guided Harmonization of Chest X-rays Using a Generative Adversarial Neural Network.

Journal article IEEE Trans Biomed Eng · January 26, 2026 OBJECTIVE: To reduce variability in chest radiography (CXR) from acquisition and post-processing, and assess whether harmonization improves image quality and down-stream diagnostic performance. METHODS: A generative adversarial network (GAN) was trained ex ... Full text Link to item Cite

Airway quantifications of bronchitis patients with photon-counting and energy-integrating computed tomography.

Journal article J Med Imaging (Bellingham) · January 2026 PURPOSE: Accurate airway measurement is critical for bronchitis quantification with computed tomography (CT), yet optimal protocols and the added value of photon-counting CT (PCCT) over energy-integrating CT (EICT) for reducing bias remain unclear. We quan ... Full text Link to item Cite

Utility of the virtual imaging trials methodology for objective characterization of AI systems and training data.

Journal article J Med Imaging (Bellingham) · January 2026 PURPOSE: The credibility of artificial intelligence (AI) models for medical imaging continues to be a challenge, affected by the diversity of models, the data used to train the models, and the applicability of their combination to produce reproducible resu ... Full text Link to item Cite

Development of a customizable model for spectral photon-counting detector CT.

Journal article Med Phys · December 2025 BACKGROUND: Photon-counting detector CT (PCD-CT) is a new CT technology that offers enhanced spatial and spectral imaging performances. As a new technology, conditioning and qualifying its precise performance can benefit from a comprehensive framework to e ... Full text Link to item Cite

Reproducibility of lung density quantification across photon-counting and conventional energy-integrating CT: a comparative study.

Journal article Br J Radiol · November 1, 2025 OBJECTIVES: To evaluate how photon-counting CT (PCCT) reproducibly quantifies lung density compared to conventional CT (energy-integrating CT or EICT) and assess the relevance of image quality. METHODS: In this retrospective analysis of a prospective study ... Full text Link to item Cite

Sensitivity analysis of key CT simulation parameters and their impact on quality of virtual images.

Journal article Med Phys · November 2025 BACKGROUND: Trials of medical imaging systems using clinical cases are often impractical motivating the use of virtual imaging trials (VITs). To emulate reality, VITs need models of imaging systems, whose realism depends on simulation parameter choice. PUR ... Full text Link to item Cite

Evaluation of unified harmonization of CT images across multiple tasks: A step towards AI generalizability.

Journal article Med Phys · November 2025 BACKGROUND: In medical imaging, harmonization is pivotal for mitigating variability stemming from diverse imaging devices and protocols. Virtual imaging trials (VITs) can provide a way to simulate diverse imaging conditions in silico and thus provide a uni ... Full text Link to item Cite

Comparison of quantitative lung measures in low dose energy-integrating detector and photon-counting detector chest CT with an anthropomorphic phantom.

Journal article Biomed Phys Eng Express · October 30, 2025 Photon-counting detector (PCD) computed tomography (CT) promises improved resolution and contrast at reduced x-ray dose compared to energy-integrating detector (EID) CT. Our objective is to determine the parameters that achieve robust accuracy of quantitat ... Full text Link to item Cite

An end-to-end CT simulation framework with graphical user interface and sample scanner models.

Journal article Med Phys · October 2025 BACKGROUND: Virtual imaging trials (VIT) facilitate medical imaging experimentation through computational models of patients and scanning equipment. For broad adoption across the medical imaging community, VIT tools should not only be accurate but also rob ... Full text Link to item Cite

Liver fat quantification using deep silicon photon-counting CT: an in silico imaging study.

Journal article Radiol Adv · September 2025 BACKGROUND: Accurate liver fat quantification is essential for early diagnosis and effective management of fatty liver disease. PURPOSE: To investigate the potential clinical utility of a deep silicon-based photon-counting CT (dSi-PCCT), currently in devel ... Full text Link to item Cite

Development of a deep learning based approach for multi-material decomposition in spectral CT: a proof of principle in silico study.

Journal article Sci Rep · August 6, 2025 Conventional approaches to material decomposition in spectral CT face challenges related to precise algorithm calibration across imaged conditions and low signal quality caused by variable object size and reduced dose. In this proof-of-principle study, a d ... Full text Link to item Cite

Effects of Intra-patient Lung Volume Variability on CT-Based Emphysema Quantification: A Virtual Imaging Study.

Journal article Acad Radiol · August 2025 BACKGROUND: While CT scans can non-invasively diagnose and quantify emphysema, its consistency can be impacted by the variability in the patient's lung volume during the acquisition. Studies to evaluate and mitigate this variability requires imaging of pat ... Full text Link to item Cite

XCAT 3.0: A comprehensive library of personalized digital twins derived from CT scans.

Journal article Med Image Anal · July 2025 Virtual Imaging Trials (VIT) offer a cost-effective and scalable approach for evaluating medical imaging technologies. Computational phantoms, which mimic real patient anatomy and physiology, play a central role in VITs. However, the current libraries of c ... Full text Open Access Link to item Cite

Iodine quantification performance with deep silicon-based Photon-Counting CT: A virtual imaging trial study.

Journal article Phys Med · July 2025 PURPOSE: This study investigates the imaging performance of a deep silicon-based photon-counting CT (Si-PCCT) in quantifying iodine contrast through a virtual imaging trial (VIT). METHODS: We developed a VIT framework using Si-PCCT simulator and benchmarke ... Full text Link to item Cite

Library of realistic 4D digital beating heart models based on patient CT data.

Journal article Med Phys · July 2025 BACKGROUND: The prevalence of cardiovascular disease (CVD) has risen alongside new medical imaging technologies designed for its diagnosis and treatment. Computational phantoms play a crucial role in imaging research, supporting applications ranging from b ... Full text Link to item Cite

A Multidimensional Diagnostic Approach for Chronic Obstructive Pulmonary Disease.

Journal article JAMA · June 24, 2025 IMPORTANCE: Individuals at risk for chronic obstructive pulmonary disease (COPD) but without spirometric airflow obstruction can have respiratory symptoms and structural lung disease on chest computed tomography. Current guidelines recommend COPD diagnosti ... Full text Link to item Cite

Container applications for the development and integration of virtual imaging platforms.

Journal article Med Phys · June 2025 BACKGROUND: Virtual imaging trials (VIT) have made significant advancements through the development of realistic human anatomy models, scanner-specific simulations, and virtual image interpretation. To promote VIT widespread adoption in the medical imaging ... Full text Link to item Cite

In silico modeling of a clinical photon-counting CT system: Verification and validation.

Journal article Med Phys · June 2025 BACKGROUND: Computed tomography (CT) is rapidly advancing with the recent FDA clearance of photon-counting CT (PCCT) systems for clinical use. New technologies are best evaluated using physical phantoms or patient images. However, both methods have their d ... Full text Link to item Cite

Virtual Lung Screening Trial (VLST): An In Silico Study Inspired by the National Lung Screening Trial for Lung Cancer Detection.

Journal article ArXiv · April 4, 2025 Clinical imaging trials play a crucial role in advancing medical innovation but are often costly, inefficient, and ethically constrained. Virtual Imaging Trials (VITs) present a solution by simulating clinical trial components in a controlled, risk-free en ... Link to item Cite

AAPM Truth-based CT (TrueCT) reconstruction grand challenge.

Journal article Med Phys · April 2025 BACKGROUND: This Special Report summarizes the 2022, AAPM grand challenge on Truth-based CT image reconstruction. PURPOSE: To provide an objective framework for evaluating CT reconstruction methods using virtual imaging resources consisting of a library of ... Full text Open Access Link to item Cite

Development and Clinical Evaluation of a Contrast Optimizer for Contrast-Enhanced CT Imaging of the Liver.

Journal article J Comput Assist Tomogr · March 2025 OBJECTIVE: Patient characteristics, iodine injection, and scanning parameters can impact the quality and consistency of contrast enhancement of hepatic parenchyma in CT imaging. Improving the consistency and adequacy of contrast enhancement can enhance dia ... Full text Open Access Link to item Cite

Virtual imaging trials in medicine: A brief takeaway of the lessons from the first international summit.

Journal article Med Phys · March 2025 BACKGROUND: The rapid advancement of medical technologies presents significant challenges for researchers and practitioners. While traditional clinical trials remain the gold standard, they are often limited by high costs, lengthy durations, and ethical co ... Full text Open Access Link to item Cite

Black-box Optimization of CT Acquisition and Reconstruction Parameters: A Reinforcement Learning Approach.

Journal article Proc SPIE Int Soc Opt Eng · February 2025 Protocol optimization is critical in Computed Tomography (CT) for achieving desired diagnostic image quality while minimizing radiation dose. Due to the inter-effect of influencing CT parameters, traditional optimization methods rely on the testing of exha ... Full text Link to item Cite

Quantitative Accuracy of CT Protocols for Cross-sectional and Longitudinal Assessment of COPD: A Virtual Imaging Study.

Journal article Proc SPIE Int Soc Opt Eng · February 2025 Chronic obstructive pulmonary disease (COPD), encompassing chronic bronchitis and emphysema, requires precise quantification through CT imaging to accurately assess disease severity and progression. However, inconsistencies in imaging protocols often lead ... Full text Link to item Cite

Intra- and inter-scanner CT variability and their impact on diagnostic tasks.

Journal article Proc SPIE Int Soc Opt Eng · February 2025 The increased development and production of Computed Tomography (CT) scanner technology has expanded patient access to advanced and affordable medical imaging technologies but has also introduced sources of variability in the clinical imaging landscape, wh ... Full text Link to item Cite

The Role of Harmonization: A Systematic Analysis of Various Task-based Scenarios.

Journal article Proc SPIE Int Soc Opt Eng · February 2025 In medical imaging, harmonization plays a crucial role in reducing variability arising from diverse imaging devices and protocols. Patient images obtained under different computed tomography (CT) scan conditions may show varying performance when analyzed u ... Full text Link to item Cite

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

Technology Characterization Through Diverse Evaluation Methodologies: Application to Thoracic Imaging in Photon-Counting Computed Tomography.

Journal article J Comput Assist Tomogr · January 2025 OBJECTIVE: Different methods can be used to condition imaging systems for clinical use. The purpose of this study was to assess how these methods complement one another in evaluating a system for clinical integration of an emerging technology, photon-count ... Full text Open Access 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

Impact of image formation factors on material discrimination in spectral CT.

Journal article Phys Med Biol · December 24, 2024 Objective.The accuracy of material decomposition in spectral computed tomography (CT) depends on the information quality captured in image acquisition, a factor that cannot be adequately assessed using conventional image quality metrologies due to the mult ... Full text Link to item Cite

Optimization of abdominal CT based on a model of total risk minimization by putting radiation risk in perspective with imaging benefit.

Journal article Commun Med (Lond) · December 19, 2024 BACKGROUND: Risk-versus-benefit optimization required a quantitative comparison of the two. The latter, directly related to effective diagnosis, can be associated to clinical risk. While many strategies have been developed to ascertain radiation risk, ther ... Full text Open Access 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

Toward widespread use of virtual trials in medical imaging innovation and regulatory science.

Journal article Med Phys · December 2024 The rapid advancement in the field of medical imaging presents a challenge in keeping up to date with the necessary objective evaluations and optimizations for safe and effective use in clinical settings. These evaluations are traditionally done using clin ... 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

Estimation of threshold thickness of residual normal tissue in lung dysfunction detectable by dynamic chest radiography: A virtual imaging trial.

Journal article Med Phys · September 2024 BACKGROUND: Dynamic chest radiography (DCR) is a recently developed functional x-ray imaging technique that detects pulmonary ventilation impairment as a decrease in changes in lung density during respiration. However, the diagnostic performance of DCR is ... 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

A systematic assessment and optimization of photon-counting CT for lung density quantifications.

Journal article Med Phys · April 2024 BACKGROUND: Photon-counting computed tomography (PCCT) has recently emerged into clinical use; however, its optimum imaging protocols and added benefits remains unknown in terms of providing more accurate lung density quantification compared to energy-inte ... Full text Open Access Link to item Cite

Enhanced CT simulation using realistic vascular flow dynamics

Journal article Medical Imaging 2024 - Physics of Medical Imaging · April 1, 2024 Full text Open Access Link to item Cite

Development of physiologically-informed computational coronary artery plaques for use in virtual imaging trials.

Journal article Med Phys · March 2024 BACKGROUND: As a leading cause of death, worldwide, cardiovascular disease is of great clinical importance. Among cardiovascular diseases, coronary artery disease (CAD) is a key contributor, and it is the attributed cause of death for 10% of all deaths ann ... 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

Deep silicon photon-counting CT: A first simulation-based study for assessing perceptual benefits across diverse anatomies.

Journal article Eur J Radiol · February 2024 OBJECTIVES: To assess perceptual benefits provided by the improved spatial resolution and noise performance of deep silicon photon-counting CT (Si-PCCT) over conventional energy-integrating CT (ECT) using polychromatic images for various clinical tasks and ... Full text Link to item Cite

Development and Application of a Virtual Imaging Trial Framework for Longitudinal Quantification of Emphysema in CT.

Journal article Proc SPIE Int Soc Opt Eng · February 2024 Pulmonary emphysema is a progressive lung disease that requires accurate evaluation for optimal management. This task, possible using quantitative CT, is particularly challenging as scanner and patient attributes change over time, negatively impacting the ... 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

Modeling and identification of affective parameters on cadmium's durability and evaluating cadmium pollution indicators caused by using chemical fertilizers in long term.

Journal article Environ Geochem Health · December 2023 Soil contamination by anthropogenic heavy metals has become a global issue. This study aimed to investigate cadmium (Cd) concentration, mobility, and contamination indices of Cd in soils in the Hamadan province, west of Iran. To investigate the concentrati ... 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

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

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

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

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

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

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

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

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

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

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

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

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

Journal article J Med Imaging (Bellingham) · 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 methods ca ... Full text Open Access 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

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

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

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

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

Journal article AJR Am J Roentgenol · February 2021 Featured Publication 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

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

Journal article J Radiol Prot · November 11, 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 Link to item Cite

Virtual clinical trials in medical imaging: a review.

Journal article J Med Imaging (Bellingham) · July 2020 Featured Publication 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

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

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

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

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

Validation of algorithmic CT image quality metrics with preferences of radiologists

Journal article MEDICAL PHYSICS · November 1, 2019 Full text Open Access Link to item Cite

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

Journal article Biomed Phys Eng Express · August 2019 Featured Publication 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

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 Featured Publication 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

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

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

Journal article IEEE Trans Med Imaging · March 2018 Featured Publication 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

Effect of Iodine-based Contrast Material on Radiation Dose at CT.

Journal article Radiology · December 2017 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

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

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

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

Consequences of delayed diagnosis in treatment of retinoblastoma.

Journal article Iran J Pediatr · August 2014 OBJECTIVE: One of the primary factors in managing patients with retinoblastoma is early diagnosis. The main idea of this study was to recognize the consequences of delay in diagnosis on therapy of the disease. METHODS: A retrospective review of all childre ... Link to item Cite