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Results for "field strengths": 14 found

A Perturbative Approach to Determine the Charge Collection Efficiency in High Dose-per-Pulse Beams

Authors: Julien Bancheri, Jan P. Seuntjens

Affiliation: Medical Biophysics, University of Toronto, Princess Margaret Cancer Centre & University of Toronto

Abstract Preview: Purpose: To obtain an analytical expression for the charge collection efficiency of parallel-plate ionization chambers in high dose-per-pulse (DPP) beams that takes into account the square pulse time ...

AI-Based Registration-Free 3T T2-Weighted MRI Synthesis Using Truefisp MRI Acquired on a 0.35T MR-Linac System

Authors: Hilary P Bagshaw, Mark K Buyyounouski, Cynthia Fu-Yu Chuang, Yu Gao, Dimitre Hristov, Lianli Liu, Lawrie Skinner, Lei Xing

Affiliation: Department of Radiation Oncology, Department of Radiation Oncology, Stanford University

Abstract Preview: Purpose:
MR-guided radiation therapy has introduced a significant leap in cancer treatment by allowing adaptive treatment. The low-field MR-guided system predominantly uses the TrueFISP sequence, w...

Absolute Measurement of HDR Ir-192 Air-Kerma Strength Using an Exradin A3 Known-Volume Ionization Chamber

Authors: Larry A. DeWerd, Sean Jollota, Karen Rex Pius Vincent

Affiliation: Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin - Madison

Abstract Preview: Purpose: Absolute measurements, often used to establish primary standards, offer lower measurement uncertainty. For 192Ir high-dose-rate (HDR) brachytherapy, the interim primary standard for air-kerma...

An Assessment of the Potential Impact of the Elekta Unity’s 1.5T Magnetic Field upon the Performance of a Conventional Linac Installed in an Adjacent Vault: A Case Study

Authors: Matthew Stephen Andriotty, Taoran Cui, Josh Kilian-Meneghin, Ke Nie, Xiao Wang, Zhenyu Xiong, Ning J. Yue, Yin Zhang

Affiliation: Rutgers Cancer Institute of New Jersey, RWJBarnabas Health

Abstract Preview: Purpose: To investigate the potential impact of the Elekta Unity’s 1.5T magnetic field upon the performance of a conventional linac installed in an adjacent vault.
Methods: The linac vaults for thi...

BEST IN PHYSICS IMAGING: Volumetric Sampling Properties of Longitudinal Multiple X-Ray-Source Array Computed Tomography (MXA-CT)

Authors: Craig K Abbey, John M. Boone, Richard E. Colbeth, Andrew M. Hernandez, Vance Robinson, Paul Schwoebel, Jeffrey H. Siewerdsen, Alejandro Sisniega, Wojciech B. Zbijewski, Huanyi Zhou

Affiliation: UC Santa Barbara, University of California, UT MD Anderson Cancer Center, Johns Hopkins University, University of New Mexico Albuquerque, UC Davis Health, Varex Imaging Corporation

Abstract Preview: Purpose: A new CT configuration utilizing a multiple X-ray-source array (MXA) is under development to mitigate cone-beam (CB) artifacts in single-rotation wide coverage imaging. We investigate the sam...

BEST IN PHYSICS MULTI-DISCIPLINARY: Quantitative MRI Oximetry: Combining EPR and OE-MRI for Volumetric Mapping of Hypoxia in Tumors

Authors: Victor B. Kassey, Maciej M. Kmiec, Periannan Kuppusamy, Sergey V. Petryakov, Conner Ubert

Affiliation: Dartmouth College

Abstract Preview: Purpose: Tumor hypoxia—a state of reduced oxygen supply—is well known to affect treatment response, particularly in radiotherapy and chemotherapy. Oxygen-enhanced magnetic resonance imaging (OE-MRI) u...

Comparison of Cine Cardiac Magnetic Resonance (CMR) Imaging Performance: 0.6 T Versus 1.5 T, Is 0.6 T Fit for Purpose?

Authors: Jacinta E. Browne, Tzu Cheng Chao, Ajit Deveraj, Ece Ercan, Tim Leiner, Alessio Perazzolo, Michal Povazan, Jouke Smink, Camilla Vita, Spencer Waddle, Dinghui Wang

Affiliation: Università Cattolica del Sacro Cuore, Philips Healthcare, Mayo Clinic

Abstract Preview: Purpose:
In recent years, mid-field MRI has shown promise to meet the technical demands of cardiac imaging1. Mid-field strengths offer advantages to CMR due to shorter T1-relaxation times, lower sp...

Dosimetric Changes of Magnetic Control System to Improve Anatomy in Abdominal SBRT

Authors: Justus Adamson, Wesley Andrew Cunningham, Chang-Sei Kim, Yeongoh Ko, Anna E. Rodrigues

Affiliation: Duke University, Chonnam National University, Duke University Medical Center

Abstract Preview: Purpose: Radiation induced toxicities in bowel remains a challenge for SBRT. Due to sharp dose falloffs, small displacements of the bowel can lead to meaningful dose reduction. Remote magnetic navigat...

Generalizable 7T T1 Map Synthesis from 1.5T and 3T T1W MRI for High-Resolution MRI-Guided Radiation Therapy

Authors: Zachary Buchwald, Chih-Wei Chang, Zach Eidex, Hui Mao, Richard L.J. Qiu, Justin R. Roper, Mojtaba Safari, Hui-Kuo Shu, Xiaofeng Yang, David Yu

Affiliation: Emory University and Winship Cancer Institute, Emory University, Department of Radiation Oncology and Winship Cancer Institute, Emory University, Emory University School of Medicine

Abstract Preview: Purpose: MRI-guided radiation therapy (MRgRT) benefits significantly from enhanced soft-tissue contrast and spatial resolution, which aid in accurately delineating tumors and organs at risk. Although ...

Multidimensional Diffusion MRI Based Microstructural Heterogeneity Model on a 5T MR System

Authors: Jiayi Chen, Shaolei Li, Fuhua Yan, Yingli Yang, Jie Zhang

Affiliation: Department of Radiology, Ruijin Hospital, Institute for Medical Imaging Technology, Ruijin Hospital, Department of Radiology, Ruijin Hospital Shanghai Jiaotong University School of Medicine, Shanghai United imaging Healthcare Advanced Technology Research Institute, Department of Radiation Oncology, Ruijin Hospital

Abstract Preview: Purpose: The aim of this exploratory study is to investigate the feasibility of establishing a model to explore tissue component heterogeneity using multidimensional diffusion magnetic resonance imagi...

Novel Design for a Mechanically Tunable Ceramic Volume Resonator for 9.4T Pre-Clinical MRI

Authors: Victor B. Kassey, Maciej M. Kmiec, Periannan Kuppusamy, Ryan C. O'Connell, Sergey V. Petryakov, Conner Ubert

Affiliation: Dartmouth College

Abstract Preview: Purpose: High-resolution magnetic field uniformity is essential for quantitative and pre-clinical MRI research. Imaging uniformity is affected by the B0 field, which can be corrected using manual or a...

Optimization of Impulsed Acquisition Protocols on 1.5T MRI Using Simulation-Based Bayesian Experimental Design for Cell Size Imaging

Authors: Yan Dai, Jie Deng, Xun Jia, Wen Li, Junzhong Xu

Affiliation: Johns Hopkins University, Medical Artificial Intelligence and Automation (MAIA) Lab & Department of Radiation Oncology, UT Southwestern Medical Center, Department of Radiology, Vanderbilt University Medical Center, Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Medical Artificial Intelligence and Automation (MAIA) Laboratory, Department of Radiation Oncology, UT Southwestern Medical Center

Abstract Preview: Purpose: Cell size is a vital parameter in evaluating the tumor microenvironment, including cell apoptosis and radiotherapy(RT)-induced immune cell infiltration. The IMPULSED(Imaging Microstructural P...

Radial Waveguide Structures for Enhanced Power Transmission Efficiency in Dielectric Wall Accelerators

Authors: Julien Bancheri, Chau Giang Bui, David G Cooke, Christopher M Lund, Morgan J Maher, Jan P. Seuntjens, Jason Z Yuan

Affiliation: Princess Margaret Cancer Centre & University of Toronto, Medical Biophysics, University of Toronto, University of Toronto, Medical Physics Unit, McGill University, Department of Physics, McGill University

Abstract Preview: Purpose: The dielectric wall accelerator (DWA) offers a low-cost solution for proton therapy, using non-resonant waveguides to accelerate particles. Radial waveguides (RWGs), consisting of a dielectri...

Simultaneous Motion Estimation and Image Reconstruction with Spatiotemporal Implicit Neural Representation Initial (STINR-SMEIR) for Gas Bubble Motion Artifact Reduction in on-Board CBCT Imaging

Authors: Hua-Chieh Shao, Shanshan Tang, Jing Wang, Kai Wang, You Zhang

Affiliation: Department of Radiation Oncology, UT Southwestern Medical Center, Medical Artificial Intelligence and Automation (MAIA) Lab, Department of Radiation Oncology, UT Southwestern Medical Center, Medical Artificial Intelligence and Automation (MAIA) Laboratory, Department of Radiation Oncology, UT Southwestern Medical Center, Department of Radiation Oncology, University of Maryland Medical Center

Abstract Preview: Purpose: Artifacts caused by gas bubble movement in the gastrointestinal tract can severely degrade the image quality of on-board abdominal cone-beam computed tomography (CBCT), impacting its utility ...