A5084741856- Advanced X-ray and CT Imaging
- Radiation Dose and Imaging
- Medical Imaging Techniques and Applications
- Radiomics and Machine Learning in Medical Imaging
- Digital Radiography and Breast Imaging
- Radiology practices and education
- Advanced Radiotherapy Techniques
- Antenna Design and Optimization
- Antenna Design and Analysis
- Advanced MRI Techniques and Applications
- Biomedical and Engineering Education
- Functional Brain Connectivity Studies
- Radiopharmaceutical Chemistry and Applications
- Atomic and Subatomic Physics Research
- Neural dynamics and brain function
- Advances in Oncology and Radiotherapy
- Cardiac Imaging and Diagnostics
- Competency Development and Evaluation
- Glycosylation and Glycoproteins Research
- Innovation and Knowledge Management
- Structural Analysis and Optimization
- Endoplasmic Reticulum Stress and Disease
- Research Data Management Practices
- Neural Networks and Reservoir Computing
- Crystallography and Radiation Phenomena
Stanford University
2023-2024
Neurosciences Institute
2023-2024
Duke University Health System
2015-2023
Duke University
2007-2021
Duke Medical Center
2006-2018
Duke University Hospital
2012-2018
Advanced Imaging Research (United States)
2013-2017
The University of Texas MD Anderson Cancer Center
2015
Institute of Electrical and Electronics Engineers
2014
U.S. Air Force Institute of Technology
2012-2013
Purpose: For nonlinear iterative image reconstructions (IR), the computed tomography (CT) noise and resolution properties can depend on specific imaging conditions, such as lesion contrast level. Therefore, it is imperative to develop a reliable method measure under clinically relevant conditions. This study aimed robust methodology three-dimensional CT conditions provide guidelines achieve desirable levels of accuracy precision. Methods: The was developed based previously reported quality...
The purpose of this work was to assess the inherent image quality characteristics a new multidetector computed tomography system in terms noise, resolution, and detectability index as function acquisition reconstruction for range clinically relevant settings.A multisized phantom (37, 30, 23, 18.5, 12 cm physical diameter) imaged on SOMATOM Force scanner (Siemens Medical Solutions) under variable dose, kVp, tube current modulation settings. Images were reconstructed with filtered back...
To investigate whether dual-energy multi-detector row computed tomography (CT) with virtual monochromatic imaging can overcome renal cyst pseudoenhancement in a phantom experiment and clinical study.This retrospective single-center HIPAA-compliant study was approved by the institutional review board, waiver of informed consent. Four compartments inserted into torso phantoms were filled saline to simulate unenhanced state iodinated solutions three levels parenchyma enhancement (140, 180, 240...
Purpose: This work involved the development of a phantom‐based method to quantify performance tube current modulation and iterative reconstruction in modern computed tomography (CT) systems. The quantification included resolution, HU accuracy, noise, noise texture accounting for impact contrast, prescribed dose, algorithm, body size. Methods: A 42‐cm‐long, 22.5‐kg polyethylene phantom was designed model four sizes. Each size represented by uniform section, measurement noise‐power spectrum...
To determine the variance in virtual monochromatic computed tomography (CT) numbers from same lesion, comparing two clinically available dual-energy multidetector CT hardware implementations (single-source projection-based and dual-source image-based), a phantom-based simulated abdominal environment.This study was exempt institutional review board oversight. Polyethylene terephthalate spheres (15 18 mm) with iodine-to-saline dilutions (0.8 1.2 mg of iodine per millilliter) were serially...
The purpose of this article is to investigate the effect body size on selection optimal monochromatic energy level for maximizing conspicuity hypervascular liver tumors during late hepatic arterial phase using dual-energy MDCT.An anthropomorphic phantom in three sizes and iodine-containing inserts simulating low- high-contrast lesions was imaged with dual- single-energy MDCT at various levels (80, 100, 120, 140 kVp). Dual-energy also performed 48 patients 114 tumors; virtual images were...
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 explicitly include noise CT examinations simultaneously target both and quality through corresponding values. MATERIALS AND METHODS. study consisted 2851 adult performed with scanners from two manufacturers clinical protocols: abdominopelvic IV contrast administration chest without administration....
人工智能（Artificial Intelligence, AI）与教育测量的结合促进了测评方法的转变，通过机器学习和自然语言处理，实现了自动评分、快速内容分析和个性化反馈。这些发展为学生的表现提供了宝贵的见解，同时也提升了整体测评体验。然而，AI在教育领域的应用也引发了有关效度、信度、透明性、公平性和公正性的重大伦理问题。算法偏差和AI决策过程不透明等问题有可能加剧不平等，影响测评结果。为此，包括教育工作者、政策制定者和测试机构在内的各利益相关方制定了指导方针，以确保AI在教育领域中的应用符合伦理规范。美国国家教育测量委员会测量与教育中的人工智能特别兴趣小组（AI in Measurement and Education, AIME）致力于制定该领域的伦理规范并推动研究的进一步发展。在本文中，不同背景的AIME成员共同探讨了AI工具在教育测量中的伦理影响，分析了自动化偏差和环境影响等重大挑战，并提出了确保AI在教育领域负责任且高效应用的解决方案。
Retrograde vesicular transport from the Golgi to ER requires Dsl1 tethering complex, which consists of three subunits Dsl1, Dsl3, and Tip20. It forms a stable complex with SNAREs Ufe1, Use1, Sec20 mediate fusion COPI vesicles endoplasmic reticulum. Here, we analyze molecular interactions between five (Ufe1, Sec20, Sec22, Ykt6) in vitro vivo. Of two R-SNAREs, Sec22 is preferred over Ykt6 Dsl-SNARE complex. The NSF homolog Sec18 can displace but not suggesting regulatory function for Ykt6. In...
<div class="section abstract"><div class="htmlview paragraph">In spite of growing popularity scale resolved transient simulations, like the Detached Eddy Simulation (DES), among mainstream automotive OEMs for aerodynamic optimization production vehicles, Reynolds Averaged Navier-Stokes (RANS) simulations is still most widely used Computational Fluid Dynamics (CFD) approach in motorsports. This partially due to usage-limitations imposed by sanctioning bodies like, FIA and NASCAR,...
To determine whether virtual monochromatic imaging from a dual-energy acquisition can improve patient-to-patient uniformity of aortic enhancement during multi-detector row computed tomographic (CT) angiography.This retrospective single-center HIPAA-compliant study was approved by the institutional review board, with waiver informed consent. A proprietary tapered hollow phantom that contained bone-mimicking insert and tube mimicked aorta used. The filled different iodine dilutions to mimic...
Phantoms are useful tools in diagnostic CT, but practical limitations reduce phantoms to being only a limited patient surrogate. Furthermore, phantom with single cross sectional area cannot be used evaluate scanner performance modern CT scanners that use dose reduction techniques such as automated tube current modulation (ATCM) and iterative reconstruction (IR) algorithms adapt x-ray flux size, radiation dose, achieve uniform image noise. A new multisized (Mercury Phantom, MP) has been...
The integration of artificial intelligence (AI) in educational measurement has revolutionized assessment methods, enabling automated scoring, rapid content analysis, and personalized feedback through machine learning natural language processing. These advancements provide timely, consistent valuable insights into student performance, thereby enhancing the experience. However, deployment AI education also raises significant ethical concerns regarding validity, reliability, transparency,...
Attenuation artifacts in PET are seen when attenuation correction (AC) is not performed and AC but based on an incorrect map. generally more profound than the straightforward differences photon through surrounding tissue from one source location to another. Effects such as apparent radioactivity gas pockets body or concave contours of surface, distortions, a pronounced contour all addition expected nonuniformities due depth body. We have investigated effects time-of-flight (TOF)...
Patient-Informed Organ Dose Estimation in Clinical CT: Implementation and Effective Assessment 1048 PatientsWanyi Fu, MS1,2,3, Francesco Ria, PhD3,4, William Paul Segars, PhD1,3,5,6, Kingshuk Roy Choudhury, PhD3, Joshua M. Wilson, PhD4,5, Anuj J. Kapadia, PhD1,3,5,7 Ehsan Samei, PhD1,2,3,4,5,6,7Audio Available | Share
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 performance and should ideally be characterized in the context real cases. objective study was characterize with a new metric that includes radiation dose across clinical population. Materials methods included 1526 examinations performed by three scanners (one GE Healthcare Discovery CT750HD, one Lightspeed VCT, Siemens...
Purpose The purpose of this study was to simulate and validate organ doses from different computed tomography (CT) localizer radiograph geometries using Monte Carlo methods for a population patients. Methods A method developed estimate CT radiographs PENELOPE. validated by comparing dosimetry estimates with measurements an anthropomorphic phantom imbedded thermoluminescent dosimeters (TLDs) scanned on commercial system (Siemens SOMATOM Flash). simulation platform then applied conduct 57...
PET image quality measurements of lesion detectability frequently use a small, radioactive sphere in larger phantom. The typical analysis small single background has several shortcomings as measure for and quantitation: the measurement low statistical power; region interest (ROI) is susceptible to large pixel-to-pixel fluctuations; only point axial transaxial field view analyzed; noise regions away from signal may bias user-placed ROIs can cause inconsistent measurements. For more robust...
The purpose of this study was to conduct longitudinal analyses radiation dose data from adult patients undergoing clinically indicated, repeat identical thoracoabdominal CT examinations.Radiation were electronically collected 2851 subjects 12,635 scans (mean number per patient, 4.8; range, 2-33) in one health system. Included protocols chest-abdomen-pelvis with contrast administration (n = 4621 studies 1064 patients), abdomen-pelvis 876 261 renal stone 1053 380 and chest 6085 1146 patients)...
Abstract A 2D-line-scan MRI sequence has been reported to directly measure neural responses stimuli (the “DIANA response”). Attempts replicate the DIANA response have failed, even with higher field strength and more repetitions. Part of this discrepancy is likely due a limited understanding how physiological noise manifests in acquisition sequences. Specifically, it unclear what consequences are breaking assumption that imaging substrate remains constant between each line acquisition. To...
Purpose The purpose of this study was to determine whether a proposed suite objective image quality metrics for digital chest radiographs is useful monitoring in clinical setting unique from the one where were developed. Methods Seventeen gridless AP GE Optima portable radiography (DR) unit (“sub‐standard” images; Group 2) and 17 PA (“standard‐of‐care” 1) 15 (non‐routine) (images with gross technical error; 3) Discovery DR chosen analysis. 2 images acquired lower kVp (100 vs 125) shorter...