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Related papers: Photon Fluence and Dose Estimation in Computed Tom…

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Purpose: Multiple Coulomb scattering (MCS) poses a challenge in proton CT (pCT) image reconstruction. The assumption of straight paths is replaced with Bayesian models of the most likely path (MLP). Current MLP-based pCT reconstruction…

Medical Physics · Physics 2020-02-10 Mark Brooke , Scott Penfold

Purpose: To develop a Monte Carlo (MC) therapeutic dose calculation toolkit of a recently released ring gantry linac in Geant4 (Version 10.7) for secondary dose validation of radiotherapy plan. Methods: For the Halcyon (Varian Medical…

Medical Physics · Physics 2022-10-04 Ruirui Liu , Zhen Ji , Xiandong Zhao , Tianyu Zhao , Abhishek Sethi , Daren Sawkey , Bin Cai

The quasi-random discrete ordinates method (QRDOM) is here proposed for the approximation of transport problems. Its central idea is to explore a quasi Monte Carlo integration within the classical source iteration technique. It preserves…

Numerical Analysis · Mathematics 2023-07-19 Pedro H. A. Konzen , Leonardo F. Guidi , Thomas Richter

The non-equilibrium high-speed compressible flows present wealthy applications in engineering and science. With the deepening of Thermodynamic Non-Equilibrium (TNE), higher-order non-conserved kinetic moments of the distribution function…

Fluid Dynamics · Physics 2022-09-07 Dejia Zhang , Aiguo Xu , Yudong Zhang , Yanbiao Gan , Yingjun Li

In this paper we investigate, with a detailed Monte-Carlo simulation based on Geant4, the novel approach [Nucl. Instrum. Methods A588 (2008) 457] to 3D imaging with photon scattering. A monochromatic and well collimated gamma beam is used…

Medical Physics · Physics 2011-09-23 M. Lenti , M. Veltri

We report on using a laser Doppler processing of Fourier-domain optical coherence tomography (OCT) data for the assessment of pulsatile blood flow in the choriocapillaris. Signal fluctuations in B-scans recorded at 2 kHz were analyzed by…

Fast dose calculation is critical for online and real time adaptive therapy workflows. While modern physics-based dose algorithms must compromise accuracy to achieve low computation times, deep learning models can potentially perform dose…

Medical Physics · Physics 2023-07-19 Oscar Pastor-Serrano , Peng Dong , Charles Huang , Lei Xing , Zoltán Perkó

As part of a consortium between academic and industry, this PhD work investigates the interest and capabilities of organic photo-sensors (OPS) for the optical characterization of suspensions and two-phase flows. The principle of new optical…

Optics · Physics 2015-03-16 Matthias Sentis

Sub-nanometer and nanometer-sized tips provide high coherence electron sources. Conventionally, the effective source size is estimated from the extent of the experimental biprism interference pattern created on the detector by applying the…

Instrumentation and Detectors · Physics 2017-03-07 Tatiana Latychevskaia

Microbeam radiation therapy (MRT) utilizes coplanar synchrotron radiation beamlets and is a proposed treatment approach for several tumour diagnoses that currently have poor clinical treatment outcomes, such as gliosarcomas. Prescription…

A single photon source is a key enabling technology in device-independent quantum communication, quantum simulation for instance boson sampling, linear optics-based and measurement-based quantum computing. These applications involve many…

Inter-observer variation is a significant problem in clinical target volume(CTV) segmentation in postoperative settings, where there is no gross tumor present. In this scenario, the CTV is not an anatomically established structure, but one…

We have observed strong photoluminescence from a single CdSe quantum dot embedded in a ZnSe nanowire. Exciton, biexciton and charged exciton lines have been identified unambiguously using photon correlation spectroscopy. This technique has…

The linear Boltzmann model for proton beams is a six-dimensional partial differential equation (PDE). We propose a deterministic solver for the linear Boltzmann model based on scattering decomposition and depth-splitting methods. The main…

Numerical Analysis · Mathematics 2025-04-02 Xiaojiang Zhang , Xuemin Bai , Min Tang

This dissertation relates to the transition of the state of the art of swept source optical coherence tomography (SS-OCT) systems to a new realm in which the image acquisition speed is improved by an order of magnitude. With the aid of a…

Image and Video Processing · Electrical Eng. & Systems 2020-02-21 Amir Tofighi Zavareh

Monte Carlo (MC) simulations provide gold-standard accuracy for carbon ion therapy dose calculations but are computationally intensive. Analytical pencil beam algorithms offer speed but reduced accuracy in heterogeneous tissues. We…

Dose volume histograms are a useful tool in state-of-the-art radiotherapy planning, and it is essential to be aware of their limitations. Dose distributions computed by treatment planning systems are affected by several sources of…

Medical Physics · Physics 2007-06-13 Francisco Cutanda-Henriquez , Silvia Vargas-Castrillon

Multi-source static Computed Tomography (CT) systems have introduced novel opportunities for adaptive imaging techniques. This work presents an innovative method of fluence field modulation using spotlight collimators. These instruments…

Medical Physics · Physics 2025-02-24 Matthew Tivnan , Amar Gupta , Kai Yang , Dufan Wu , Rajiv Gupta

Noninvasive, non-contact and \textit{in vivo} monitoring of blood glucose is a long needed pathology tool for saving patients from recurring pain and hassle that can accompany conventional blood glucose testing methods. Optical coherence…

Biological Physics · Physics 2008-08-04 R Poddar , S R Sharma , P Sen , J T Andrews

The purpose of this work is to provide a fast and accurate scatter artifacts correction algorithm for cone beam CT (CBCT) imaging. The method starts with an estimation of coarse scatter profiles for a set of CBCT data in either image domain…

Medical Physics · Physics 2016-04-27 Wei Zhao , Don Vernekohl , Jun Zhu , Luyao Wang , Lei Xing
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