Improvement of performance for flexible film dosimeter by incorporating additive agents
Phys Med Biol. 2024 Apr 2. doi: 10.1088/1361-6560/ad39c1. Online ahead of print.ABSTRACTOBJECTIVE: To evaluate the reduction in energy dependence and aging effect of the lithium salt of pentacosa-10,-12-diynoic acid (LiPCDA) films with additives including aluminum oxide (Al2O3), propyl gallate (PG), and disodium ethylenediaminetetracetate (EDTA).APPROACH: LiPCDA films exhibited energy dependence on kilovoltage (kV) and megavoltage (MV) photon energies and experienced deterioration over time. Evaluations were conducted with added Al₂O₃ and antioxidants to mitigate these issues, and films were produced with and without A...
Source: Physics in Medicine and Biology - April 2, 2024 Category: Physics Authors: Jin Dong Cho Seongmoon Jung Jung-In Kim Chang Heon Choi Source Type: research
Markerless liver online adaptive stereotactic radiotherapy: feasibility analysis
Phys Med Biol. 2024 Apr 2. doi: 10.1088/1361-6560/ad39a1. Online ahead of print.ABSTRACTObjective 
Radio-opaque markers are recommended for image-guided radiotherapy in liver stereotactic ablative radiotherapy (SABR), but their implantation is invasive. We evaluate in this in-silico study the feasibility of cone-beam computed tomography-guided stereotactic online-adaptive radiotherapy (CBCT-STAR) to propagate the target volumes without implanting radio-opaque markers and assess its consequence on the margin that should be used in that context. 
Approach 
An emulator of a CBCT-STAR-dedicated treatmen...
Source: Physics in Medicine and Biology - April 2, 2024 Category: Physics Authors: Julien Pierrard St éphanie Deheneffe David Dechambre Edmond Sterpin Xavier Geets Genevi ève Van Ooteghem Source Type: research
The impact of motion on onboard MRI-guided pencil beam scanned proton therapy treatments
Phys Med Biol. 2024 Mar 27. doi: 10.1088/1361-6560/ad3885. Online ahead of print.ABSTRACTOnline magnetic resonance imaging (MRI) guidance could be especially beneficial for pencil beam scanned (PBS) proton therapy of tumours affected by respiratory motion. For the first time to our knowledge, we investigate the dosimetric impact of respiratory motion on MRI-guided proton therapy compared to the scenario without magnetic field.

Approach. A previously developed analytical proton dose calculation algorithm accounting for perpendicular magnetic fields was extended to enable 4D dose calculations. For two geomet...
Source: Physics in Medicine and Biology - March 27, 2024 Category: Physics Authors: Alisha Duetschler Sairos Safai Damien Charles Weber Antony John Lomax Ye Zhang Source Type: research
Glioma segmentation based on dense contrastive learning and multimodal features recalibration
Phys Med Biol. 2024 Mar 27. doi: 10.1088/1361-6560/ad387f. Online ahead of print.ABSTRACTAccurate segmentation of different regions of gliomas from multimodal magnetic resonance (MR) images is crucial for glioma grading and precise diagnosis, but many existing segmentation methods are difficult to effectively utilize multimodal MR image information to recognize accurately the lesion regions with small size, low contrast and irregular shape. To address this issue, this work proposes a novel 3D glioma segmentation model DCL-MANet. DCL-MANet has an architecture of multiple encoders and one single decoder. Each encoder is used...
Source: Physics in Medicine and Biology - March 27, 2024 Category: Physics Authors: Xubin Hu Lihui Wang Li Wang Qijian Chen Licheng Zheng YueMin Zhu Source Type: research
CT respiratory motion synthesis using joint supervised and adversarial learning
This study presents a deep image synthesis method that addresses the limitations of conventional 4DCT by generating pseudo-respiratory CT phases from static images. Although further studies are needed to assess the dosimetric impact of the proposed method, this approach has the potential to reduce radiation exposure in radiotherapy treatment planning while maintaining accurate motion representation. Our training and testing code can be found at https://github.com/cyiheng/Dynagan.PMID:38537289 | DOI:10.1088/1361-6560/ad388a (Source: Physics in Medicine and Biology)
Source: Physics in Medicine and Biology - March 27, 2024 Category: Physics Authors: Yi-Heng Cao Vincent Bourbonne Fran çois Lucia Ulrike Schick Julien Bert Vincent Jaouen Dimitris Visvikis Source Type: research
New semi-analytical method for fast transcranial ultrasonic field simulation
Phys Med Biol. 2024 Mar 27. doi: 10.1088/1361-6560/ad3882. Online ahead of print.ABSTRACTTo optimize and ensure the safety of ultrasound brain therapy, personalized transcranial ultrasound simulations are very useful. They allow to predict the pressure field, depending on the patient skull and probe position. Most transcranial ultrasound simulations are based on numerical methods which have a long computation time and a high memory usage. The goal of this study is to develop a new semi-analytical field computation method that combines realism and computation speed.

Instead of the classic ray tracing, the u...
Source: Physics in Medicine and Biology - March 27, 2024 Category: Physics Authors: C élestine Angla Hamza Chouh Paul Mondou Gwenael Toullelan K évyn Perlin Vincent Brulon Emmanuel De Schlichting Jean-Luc Gennisson Benoit Larrat Sylvain Chatillon Source Type: research
Advancing medical imaging with language models: featuring a spotlight on ChatGPT
Phys Med Biol. 2024 Mar 27. doi: 10.1088/1361-6560/ad387d. Online ahead of print.ABSTRACTThis review paper aims to serve as a comprehensive guide and instructional resource for researchers seeking to effectively implement language models in medical imaging research. First, we presented the fundamental principles and evolution of language models, dedicating particular attention to large language models. We then reviewed the current literature on how language models are being used to improve medical imaging, emphasizing a range of applications such as image captioning, report generation, report classification, findings extra...
Source: Physics in Medicine and Biology - March 27, 2024 Category: Physics Authors: Mingzhe Hu Joshua Yuan Qian Shaoyan Pan Yuheng Li Richard L J Qiu Xiaofeng Yang Source Type: research
Generative adversarial network-based synthesis of contrast-enhanced MR images from precontrast images for predicting histological characteristics in breast cancer
This study aimed to investigate the feasibility of generating contrast-enhanced MR images from precontrast images and to evaluate the potential use of synthetic images in diagnosing breast cancer.APPROACH: This retrospective study included 322 women with invasive breast cancer who underwent preoperative DCE-MRI. A generative adversarial network (GAN)-based postcontrast image synthesis (GANPIS) model with perceptual loss was proposed to generate contrast-enhanced MR images from precontrast images. The quality of the synthesized images was evaluated using the peak signal-to-noise ratio (PSNR) and structural similarity (SSIM)...
Source: Physics in Medicine and Biology - March 27, 2024 Category: Physics Authors: Ming Fan Xuan Cao Fuqing L ü Sangma Xie Zhou Yu Yuanlin Chen Zhong L ü Lihua Li Source Type: research
Automation to facilitate optimisation of breast radiotherapy treatments using EPID-based in-vivo dosimetry
Phys Med Biol. 2024 Mar 27. doi: 10.1088/1361-6560/ad387e. Online ahead of print.ABSTRACT
To use automation to facilitate the monitoring of each treatment fraction using an EPID based in-vivo dosimetry (IVD) system, allowing optimisation of breast radiotherapy delivery for individual patients and cohorts.

Approach:
A suite of in-house software was developed to reduce the number of manual interactions with the commercial IVD system, Dosimetry Check. An EPID specific pixel sensitivity map facilitated use of the EPID panel away from the central axis. Point dose difference and the change in sta...
Source: Physics in Medicine and Biology - March 27, 2024 Category: Physics Authors: Joshua Kirby Katherine Chester Source Type: research
Combining quantitative and qualitative analysis for scoring pleural line in lung ultrasound
Phys Med Biol. 2024 Mar 27. doi: 10.1088/1361-6560/ad3888. Online ahead of print.ABSTRACTOBJECTIVE: Accurate assessment of pleural line is crucial for the application of lung ultrasound (LUS) in monitoring lung diseases, thereby aim of this study is to develop a quantitative and qualitative analysis method for pleural line.APPROACH: The novel cascaded deep learning models based on convolution and multilayer perceptron was proposed to locate and segment the pleural line in LUS images, whose results were applied for quantitative analysis of textural and morphological features, respectively. By using gray-level co-occurrence ...
Source: Physics in Medicine and Biology - March 27, 2024 Category: Physics Authors: Wenyu Xing Chao He Yebo Ma Yiman Liu Zhibin Zhu Qingli Li Wenfang Li Jiangang Chen De-An Ta Source Type: research
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Phys Med Biol. 2024 Mar 27. doi: 10.1088/1361-6560/ad3887. Online ahead of print.ABSTRACTThe in vivo evolution of radiotherapy necessitates innovative platforms for preclinical investigation, bridging the gap between bench research and clinical applications. Understanding the nuances of radiation response, specifically tailored to proton and photon therapies, is critical for optimizing treatment outcomes. Within this context, preclinical in vivo experimental setups incorporating image guidance for both photon and proton therapies are pivotal, enabling the translation of findings from small animal models to clinical setting...
Source: Physics in Medicine and Biology - March 27, 2024 Category: Physics Authors: Moritz Schneider Joshua Dietrich Schilz Michael Sch ürer Sebastian Gantz Anne Dreyer Gert Rothe Falk Tillner Elisabeth Bodenstein Felix Horst Elke Beyreuther Source Type: research
A cardiac MRI motion artifact reduction method based on edge enhancement network
Phys Med Biol. 2024 Mar 27. doi: 10.1088/1361-6560/ad3884. Online ahead of print.ABSTRACTCardiac magnetic resonance imaging (MRI) usually requires a long acquisition time. The movement of the patients during MRI acquisition will produce image artifacts. Previous studies have shown that clear MR image texture edges are of great significance for pathological diagnosis. In this paper, a motion artifact reduction method for cardiac MRI based on edge enhancement network is proposed. Firstly, the four-plane normal vector adaptive fractional differential mask is applied to extract the edge features of blurred images. The four-pla...
Source: Physics in Medicine and Biology - March 27, 2024 Category: Physics Authors: Nanhe Jiang YuCun Zhang Qun Li Xianbin Fu Dongqing Fang Source Type: research
Implementation of a new EGSnrc particle source class for computed tomography: validation and uncertainty quantification
Phys Med Biol. 2024 Mar 27. doi: 10.1088/1361-6560/ad3886. Online ahead of print.ABSTRACTPersonalized dose monitoring and risk management are of increasing significance with the growing number of computer tomography (CT) examinations. These require high-quality Monte Carlo (MC) simulations that are of the utmost importance for the new developments in personalized CT dosimetry. 
This work aims to extend the MC framework EGSnrc source code with a new particle source. This, in turn, allows CT-scanner-specific dose and image calculations for any CT scanner. The novel method can be used with all modern EGSnrc user codes...
Source: Physics in Medicine and Biology - March 27, 2024 Category: Physics Authors: Marie-Luise Kuhlmann Stefan Pojtinger Source Type: research
Three-row MRI receive array with remote circuitry to preserve radiation transparency
Phys Med Biol. 2024 Mar 27. doi: 10.1088/1361-6560/ad388c. Online ahead of print.ABSTRACTObjectiveUp to this point, 1.5T linac-compatible coil array layouts have been restricted to one or two rows of coils because of the desire to place radiation-opaque circuitry adjacent to the coils and outside the radiolucent window through which the linac beam travels. Such layouts can limit parallel imaging performance. The purpose of this work was to design and build a three-row array in which remotely located circuits permitted a central row of coils while preserving the radiolucent window.
ApproachThe remote circuits consis...
Source: Physics in Medicine and Biology - March 27, 2024 Category: Physics Authors: Karthik Lakshmanan Bili Wang Jerzy Walczyk Christopher M Collins Ryan Brown Source Type: research
A photon source model for alpha-emitter radionuclides
Phys Med Biol. 2024 Mar 27. doi: 10.1088/1361-6560/ad3881. Online ahead of print.ABSTRACTA Monte Carlo virtual source model that generates photons emitted in the complex decay chain process of alpha-emitter radionuclides is proposed, typically for use during simulation of SPECT image acquisition. 
Given an alpha-emitter radionuclide, the model extracts from Geant4 databases the photon emission lines from all decaying daughters for both isometric transition and atomic relaxation processes. According to a given time range, abundances and activities in the decay chain are considered thanks to the Bateman equations, ta...
Source: Physics in Medicine and Biology - March 27, 2024 Category: Physics Authors: David Sarrut Ane Etxebeste Jean Michel L étang Source Type: research
