Browsing by Author "Samei, Ehsan"
Now showing items 1-20 of 37
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A comparison of COVID-19 and imaging radiation risk in clinical patient populations.
(J Radiol Prot, 2020-10-07)OBJECTIVE: 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 ... -
A database of 40 patient-based computational models for benchmarking organ dose estimates in CT.
(Medical physics, 2020-07-06)PURPOSE:Patient radiation burden in CT can best be characterized through risk estimates derived from organ doses. Organ doses can be estimated by Monte Carlo simulations of the CT procedures on computational phantoms assumed ... -
A mathematical framework to quantitatively balance clinical and radiation risk in Computed Tomography
(2021-12-01)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 ... -
A patient-informed approach to predict iodinated-contrast media enhancement in the liver
(European Journal of Radiology, 2022-10) -
Accuracy of Noise Magnitude Measurements from Patient CT Images
(https://aapm.onlinelibrary.wiley.com/doi/epdf/10.1002/mp.16525, 2023-07-23)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 ... -
Automated quality control in nuclear medicine using the structured noise index.
(Journal of applied clinical medical physics, 2020-04)<h4>Purpose</h4>Daily flood-field uniformity evaluation serves as the central element of nuclear medicine (NM) quality control (QC) programs. Uniformity images are traditionally analyzed using pixel value-based metrics, ... -
Classification of COVID-19 in chest radiographs: assessing the impact of imaging parameters using clinical and simulated images
(Medical Imaging 2021: Computer-Aided Diagnosis, 2021-02-15)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 ... -
Clinical Decision Making in CT: Risk Assessment Comparison Across 12 Risk Metrics in Patient Populations
(Journal of Medical Physics, 2020-06-30)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 ... -
Clinical Decision Making in CT: Risk Assessment Comparison Across 12 Risk Metrics in Patient Populations
(Journal of Medical Physics, 2020-06-30)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 ... -
Comparative Risk Assessment of Clinical and Radiation Risk across a Cohort of Patient and Individualized Risk Optimization
(https://aapm.onlinelibrary.wiley.com/doi/epdf/10.1002/mp.16525, 2023-07-23)Purpose Informed by a recent mathematical framework, we formulated an imaging strategy to balance interpretative performance-based clinical risk (i.e., false positive and false negative rates) and radiation risk ... -
Comparison of 12 surrogates to characterize CT radiation risk across a clinical population.
(European radiology, 2021-02-23)<h4>Objectives</h4>Quantifying radiation burden is essential for justification, optimization, and personalization of CT procedures and can be characterized by a variety of risk surrogates inducing different radiological ... -
Computed tomography dose index and dose length product for cone-beam CT: Monte Carlo simulations.
(Journal of applied clinical medical physics, 2011-01-19)Dosimetry in kilovoltage cone beam computed tomography (CBCT) is a challenge due to the limitation of physical measurements. To address this, we used a Monte Carlo (MC) method to estimate the CT dose index (CTDI) and the ... -
CT Radiomic Features of Superior Mesenteric Artery Involvement in Pancreatic Ductal Adenocarcinoma: A Pilot Study.
(Radiology, 2021-09-07)Background Current imaging methods for prediction of complete margin resection (R0) in patients with pancreatic ductal adenocarcinoma (PDAC) are not reliable. Purpose To investigate whether tumor-related and perivascular ... -
Deep learning classification of COVID-19 in chest radiographs: performance and influence of supplemental training
(Journal of Medical Imaging, 2021-12-01) -
Development and Testing of a Clinical Tool to Predict and Optimize Liver Contrast-Enhanced CT Imaging
(https://aapm.onlinelibrary.wiley.com/doi/epdf/10.1002/mp.16525, 2023-07-23)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 ... -
Dose coefficients for organ dosimetry in tomosynthesis imaging of adults and pediatrics across diverse protocols.
(Medical physics, 2022-06-11)<h4>Purpose</h4>The gold-standard method for estimation of patient-specific organ doses in digital tomosynthesis (DT) requires protocol-specific Monte Carlo (MC) simulations of radiation transport in anatomically accurate ... -
Estimation of in vivo noise in clinical CT images: comparison and validation of three different methods against ensemble noise gold-standard
(Proc. SPIE 11595, Medical Imaging 2021: Physics of Medical Imaging, 115952P, 2021-02-15)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 ... -
Expanding the Concept of Diagnostic Reference Levels to Noise and Dose Reference Levels in CT.
(AJR. American journal of roentgenology, 2019-06-10)OBJECTIVE. Diagnostic reference levels were developed as guidance for radiation dose in medical imaging and, by inference, diagnostic quality. The objective of this work was to expand the concept of diagnostic reference ... -
Image noise and dose performance across a clinical population: patient size adaptation as a metric of CT performance.
(Med Phys, 2017-02-24)PURPOSE: Modern CT systems adjust x-ray flux accommodating for patient size to achieve certain image noise values. The effectiveness of this adaptation is an important aspect of CT performance and should ideally be characterized ...
