arXiv: Medical Physics
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Electrical impedance tomography (EIT) is a noninvasive imaging method whereby electrical measurements on the boundary of a conductive medium (the data) are taken according to a prescribed protocol set and inverted to map the internal conductivity (the model). This paper introduces a sensitivity analysis method and corresponding inversion and protocol optimization that generalizes the criteria for tomographic inversion to minimize the model-space dimensionality and maximize data importance. Sensi...
#1Xiaoqing Wang (GAU: University of Göttingen)H-Index: 10
Last. Martin UeckerH-Index: 26
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Purpose: To develop a free-breathing myocardial T1 mapping technique using free-running inversion-recovery (IR) radial fast low-angle shot (FLASH) and calibrationless motion-resolved model-based reconstruction. Methods: A free-running inversion-recovery radial FLASH sequence is used for data acquisition at 3T. To reduce the waiting time between inversions, an analytical formula is derived that takes the incomplete T1 recovery into account for an accurate T1 calculation. The respiratory motion si...
#1José Antonio Briz (CSIC: Spanish National Research Council)H-Index: 8
Last. Enrique NácherH-Index: 13
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Proton therapy is a cancer treatment technique currently in growth worldwide. It offers advantages with respect to conventional X-ray and \gammaray radiotherapy, in particular, a better control of the dose deposition allowing to reach a higher conformity in the treatments. Therefore, it causes less damage to the surrounding healthy tissue and less secondary effects. However, in order to take full advantage of its potential, improvements in treatment planning and dose verification are required...
PET is an established medical diagnostic imaging method. Continuous improvements are aimed at refining image reconstruction, reducing the amount of radioactive tracer and combining with targeted therapy. TOF-PET provides the localization of the tracer through improved time resolution, nuclear physics may contribute to this goal via selection of radioactive nuclei emitting additional \gammarays. This additional radiation, when properly detected, localizes the decay of the tracer at the line of...
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#1M. Ramish AshrafH-Index: 1
#2Mahbubur RahmanH-Index: 4
Last. Petr BruzaH-Index: 12
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Ultra-high dose rate electron sources require dose rate independent dosimeters and a calibrated dose control system for accurate delivery. In this study, we developed a single-pulse dose monitoring and a real-time dose-based control system for a converted clinical linear accelerator (LINAC). A point scintillator detector was coupled to a gated amplifier and a real-time controller for dose monitoring and feedback control loop. The controller was programmed to integrate dose and measure pulse widt...
#1Paul Kyu HanH-Index: 7
#2Thibault MarinH-Index: 7
Last. Chao Ma (Harvard University)H-Index: 28
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Purpose: To develop a cardiac T1 mapping method for free-breathing 3D T1 mapping of the whole heart at 3T with transmit B1 (B1+) correction Methods: A free-breathing, ECG-gated inversion recovery sequence with spoiled gradient-echo readout was developed and optimized for cardiac T1 mapping at 3T. High-frame rate dynamic images were reconstructed from sparse (k,t)-space data acquired along a stack-of-stars trajectory using a subspace-based method for accelerated imaging. Joint T1 and flip-angle (...
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#1Stephan RadonicH-Index: 1
#2Jürgen BessererH-Index: 17
Last. Valeria Meier (UZH: University of Zurich)H-Index: 8
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Purpose: In this modelling study we pursued two main goals. The first was to establish a new CTV-to-PTV expansion which considers the closest and most critical organ at risk (OAR). The second goal was to investigate the impact of the planning target volume (PTV) margin size on the tumor control probability (TCP) dependent on the geometrical setup uncertainties. The aim was to achieve a smaller margin expansion close to the OAR while allowing a moderately larger expansion in less critical areas f...
#2Leila IssaH-Index: 4
Last. Issam LakkisH-Index: 9
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Topological structure of bronchial trees affects transport of gases and aerosols in the respiratory system. We start by providing a quantitative assessment of the ability of the alternative tree representations to predict observable geometric and mechanistic characteristics, such as network resistance, dead space volume, and path length. Then we present a model of dynamic transport of oxygen and carbon dioxide along the airways, in the alveoli, across the alveolar membrane, and along the pulmona...
\textbf{Purpose:}To quantify the effectiveness of EPID-based cine transmission dosimetry to detect gross patient anatomic errors. \textbf{Method and Materials:}EPID image frames resulting from fluence transmitted through multiple patients anatomies are simulated for 100 msec delivery intervals for hypothetical 6 MV VMAT deliveries. Frames simulated through 10 head-and-neck CTs and 19 prostate CTs with and without 1-3 mm shift and 1-3 degree rotations were used to quantify expected in-toler...
#1Pawan Kumar PandeyH-Index: 2
#2Malay K. Das (IITK: Indian Institute of Technology Kanpur)H-Index: 14
In this work, we virtually study the intra-arterial targeted drug delivery. Specifically, this work models and quantifies the uncertainties associated with catheter steerability limitations. We classify catheter's limited steerability into two types, i.e., zero steerability, and wall pressing steerability. Further, we investigate the effects of steerability limitations on uncertainty of causing systemic toxicity levels, i.e., percentage of drug particles missing target. Proposed method quantifie...
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