Physica Medica-European Journal of Medical Physics最新文献

{"title":"Analysis of CT Hounsfield units for fetal imaging: Basic data for creating dosimetry phantoms of pregnant women","authors":"Yuta Matsunaga ,&nbsp;Masanao Kobayashi ,&nbsp;Shoichi Suzuki ,&nbsp;Yasuki Asada ,&nbsp;Koichi Chida","doi":"10.1016/j.ejmp.2025.105021","DOIUrl":"10.1016/j.ejmp.2025.105021","url":null,"abstract":"<div><h3>Purpose</h3><div>The computed tomography (CT) numbers of key organs and biological structures are important for phantom production. This study aimed to provide basic data on the CT numbers of actual organs, including the placenta, amniotic fluid, fetal bones, and fetal organs. Additionally, the abdominal circumference of pregnant women and skin surface-to-fetus distance were measured.</div></div><div><h3>Methods</h3><div>Maternal and fetal anatomical data were obtained from the imaging data of 14 pregnant patients who had previously undergone abdominal and pelvic CT examinations. All anatomical measurements were performed on a workstation using the CT images of each patient. The imaging data of the 14 pregnant patients did not include repeated data from the same individuals.</div></div><div><h3>Results</h3><div>For each organ, the average CT numbers did not significantly differ across tube voltage or gestational age groups. The average CT numbers of the fetal brain, lungs, liver, and caput femoris were 22.2, 28.9, 55.3, and 504.9 HU, respectively. The average values for the fetal depth and maternal abdominal circumference were 28.0 and 861.5 mm, respectively.</div></div><div><h3>Conclusions</h3><div>The CT numbers of the placenta, amniotic fluid, and fetal organs are similar to those of adult soft tissues and should be represented by equivalent materials. However, the fetal lung phantom should not be made of the same material used for adult lung phantoms; instead, it should consist of materials simulating soft tissue. Because the position of the fetus varies among individuals, determining the measurement point inside the phantom requires a customizable design, particularly for pregnant women with minimal subcutaneous fat.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"135 ","pages":"Article 105021"},"PeriodicalIF":3.3,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144168157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improved patient-specific quality assurance for VMAT on film measurement with 2.5D gamma analysis","authors":"Hideharu Miura ,&nbsp;Masanori Miyazawa ,&nbsp;Shuichi Ozawa ,&nbsp;Koichi Shida ,&nbsp;Masahiro Hayata ,&nbsp;Masayuki Kagemoto","doi":"10.1016/j.ejmp.2025.105019","DOIUrl":"10.1016/j.ejmp.2025.105019","url":null,"abstract":"<div><h3>Purpose</h3><div>This study proposed a “2.5D gamma analysis” method for patient-specific quality assurance (PSQA) in volumetric modulated arc therapy (VMAT) using film measurements.</div></div><div><h3>Methods</h3><div>A custom-designed water phantom was used, consisting of a main body and an insert box, each with a wall thickness of 10 mm, and filled with water. The insert box contained a film holder designed to accommodate several radiochromic films. The holder consisted of four separate 2 mm-thick plates and a cover, allowing the positioning of one to five films. For consistency, three films were used per case, positioned at 0 and ± 2 mm. Quasi-volumetric data were generated from the measured Gafchromic film data at various positions using B-spline interpolation, producing additional data points at 0.5 mm intervals. Five spine SBRT cases were analyzed by comparing 2.5D and 2D gamma analyses using different criteria and dose thresholds.</div></div><div><h3>Results</h3><div>The 2.5D gamma analysis showed higher gamma pass rates compared to the 2D analysis, with an average gamma pass rate of 98.6 % for the 2.5D analysis and 87.4 % for the 2D analysis, using 3 %/1 mm gamma criteria with a 5 % dose threshold. This represented an 11.2 % point increase in the gamma pass rate.</div></div><div><h3>Conclusions</h3><div>The 2.5D gamma analysis provided higher gamma pass rates than the 2D analysis for film measurements, providing increased confidence in the accuracy of the spine VMAT treatment plan.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"135 ","pages":"Article 105019"},"PeriodicalIF":3.3,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144168154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Proof of concept of near real-time intra-fractional 3D monitoring of prostate position using a scheme based on the skeletonization of implanted marker images and recursive least squares approximation motion tracking","authors":"Hsiang-Chi Kuo,&nbsp;Cesar Della Biancia,&nbsp;Antonio L. Damato,&nbsp;Laura Happersett,&nbsp;Seng Boh Lim,&nbsp;Laura I. Cerviño,&nbsp;Sean L. Berry","doi":"10.1016/j.ejmp.2025.105009","DOIUrl":"10.1016/j.ejmp.2025.105009","url":null,"abstract":"<div><h3>Background</h3><div>The on-board imaging system using monoscopic X-ray technology struggles to detect motion along the beam direction. This study presents a method that combines skeletonization for marker recognition with a Recursive Least Squares Approximation (RLSA) algorithm to convert 2D motion data into a 3D representation.</div></div><div><h3>Methods</h3><div>Fiducial markers were represented as 2D lines through masking and skeletonization of paired-planar images, allowing for the construction of a 3D motion model. An iterative closest point (ICP) algorithm determined the 6D transformation from online to planning images. The accuracy of 3D motion estimation was evaluated across various angular separations (10°–170°) for both large (10 mm, 3°) and small (3 mm) marker offsets. The RLSA algorithm was validated against different motion drift patterns.</div></div><div><h3>Results</h3><div>The marker recognition process was robust against varying contrast noise ratios. Mean errors of various angle separation tests in the X and Y directions were within 0.3 mm for large offsets and 0.2 mm for small offsets across all angular separations. With The RLSA applied at 10-° intervals during a 360-° gantry rotation, mean errors in the beam direction for continuous drift and low, intermediate, and high-frequency excursions were (0.2 ± 0.3) mm, (0.2 ± 0.3) mm, (0.4 ± 0.5) mm, and (0.4 ± 0.5) mm, respectively, with a maximum error of 1.3 mm across all excursion conditions.</div></div><div><h3>Conclusion</h3><div>The proposed method demonstrates significant potential in effectively converting 2D motion into 3D and enabling real-time 3D motion tracking during intrafraction radiation therapy.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"135 ","pages":"Article 105009"},"PeriodicalIF":3.3,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144168155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Motion-resolved parametric imaging derived from short dynamic [18F]FDG PET/CT scans","authors":"Alessia Artesani ,&nbsp;Joyce van Sluis ,&nbsp;Laura Providência ,&nbsp;Johannes H. van Snick ,&nbsp;Riemer H.J.A. Slart ,&nbsp;Walter Noordzij ,&nbsp;Charalampos Tsoumpas","doi":"10.1016/j.ejmp.2025.105010","DOIUrl":"10.1016/j.ejmp.2025.105010","url":null,"abstract":"<div><h3>Purpose</h3><div>This study aims to assess the added value of utilizing short-dynamic whole-body PET/CT scans and implementing motion correction before quantifying metabolic rate, offering more insights into physiological processes. While this approach may not be commonly adopted, addressing motion effects is crucial due to their demonstrated potential to cause significant errors in parametric imaging.</div></div><div><h3>Methods</h3><div>A 15-minute dynamic FDG PET acquisition protocol was utilized for four lymphoma patients undergoing therapy evaluation. Parametric imaging was obtained using a population-based input function (PBIF) derived from twelve patients with full 65-minute dynamic FDG PET acquisition. AI-based registration methods were employed to correct misalignments between both PET and ACCT and PET-to-PET. Tumour characteristics were assessed using both parametric images and standardized uptake values (SUV).</div></div><div><h3>Results</h3><div>The motion correction process significantly reduced mismatches between images without significantly altering voxel intensity values, except for SUV_max. Following the alignment of the attenuation correction map with the PET frame, an increase in SUV_max in FDG-avid lymph nodes was observed, indicating its susceptibility to spatial misalignments. In contrast, Patlak <em>K_i</em> parameter was highly sensitive to misalignment across PET frames, that notably altered the Patlak slope. Upon completion of the motion correction process, the parametric representation revealed heterogeneous behaviour among lymph nodes compared to SUV images. Notably, reduced volume of elevated metabolic rate was determined in the mediastinal lymph nodes in contrast with an SUV of 5 g/ml, indicating potential perfusion or inflammation.</div></div><div><h3>Conclusions</h3><div>Motion resolved short-dynamic PET can enhance the utility and reliability of parametric imaging, an aspect often overlooked in commercial software.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"135 ","pages":"Article 105010"},"PeriodicalIF":3.3,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144168156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aims & Scope & Editorial Board","authors":"","doi":"10.1016/j.ejmp.2025.105008","DOIUrl":"10.1016/j.ejmp.2025.105008","url":null,"abstract":"","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"134 ","pages":"Article 105008"},"PeriodicalIF":3.3,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144134669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ActiveNaf: A novel NeRF-based approach for low-dose CT image reconstruction through active learning","authors":"Ahmad Zidane,&nbsp;Ilan Shimshoni","doi":"10.1016/j.ejmp.2025.104997","DOIUrl":"10.1016/j.ejmp.2025.104997","url":null,"abstract":"<div><h3>Background:</h3><div>CT imaging provides essential information about internal anatomy; however, conventional CT imaging delivers radiation doses that can become problematic for patients requiring repeated imaging, highlighting the need for dose-reduction techniques. This study aims to reduce radiation doses without compromising image quality. We propose an approach that combines Neural Attenuation Fields (NAF) with an active learning strategy to better optimize CT reconstructions given a limited number of X-ray projections.</div></div><div><h3>Method:</h3><div>Our method uses a secondary neural network to predict the Peak Signal-to-Noise Ratio (PSNR) of 2D projections generated by NAF from a range of angles in the operational range of the CT scanner. This prediction serves as a guide for the active learning process in choosing the most informative projections. In contrast to conventional techniques that acquire all X-ray projections in a single session, our technique iteratively acquires projections. The iterative process improves reconstruction quality, reduces the number of required projections, and decreases patient radiation exposure.</div></div><div><h3>Results:</h3><div>We tested our methodology on spinal imaging using a limited subset of the VerSe 2020 dataset. We compare image quality metrics (PSNR3D, SSIM3D, and PSNR2D) to the baseline method and find significant improvements. Our method achieves the same quality with 36 projections as the baseline method achieves with 60.</div></div><div><h3>Conclusions:</h3><div>Our findings demonstrate that our approach achieves high-quality 3D CT reconstructions from sparse data, producing clearer and more detailed images of anatomical structures. This work lays the groundwork for advanced imaging techniques, paving the way for safer and more efficient medical imaging procedures.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"135 ","pages":"Article 104997"},"PeriodicalIF":3.3,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144107234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Medical physicists at the forefront of multidisciplinary AI integration in healthcare","authors":"M.K. Badawy ,&nbsp;D. Carrion ,&nbsp;M. Mahesh","doi":"10.1016/j.ejmp.2025.105007","DOIUrl":"10.1016/j.ejmp.2025.105007","url":null,"abstract":"","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"135 ","pages":"Article 105007"},"PeriodicalIF":3.3,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144116970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimating the number of ≥100 mSv patients from CT, fluoroscopic guided interventions, and PET exams in 27 OECD countries","authors":"Andrew E. Ferretti,&nbsp;Nathaniel D. Mercaldo,&nbsp;Madan M. Rehani","doi":"10.1016/j.ejmp.2025.105006","DOIUrl":"10.1016/j.ejmp.2025.105006","url":null,"abstract":"<div><h3>Purpose</h3><div>To estimate the number of patients in 27 OECD (Organization for Economic Co-operation and Development) countries receiving a cumulative effective dose (CED) ≥100 mSv from recurrent imaging in computed tomography (CT), fluoroscopic guided intervention (FGI), and positron emission tomography (PET) examinations.</div></div><div><h3>Methods</h3><div>CT and PET utilization and population data for 27 OECD countries were retrieved from a publicly available OECD 2022 report, and FGI utilization data from the European Commission 2015 Report. Data on the number of exams per patient of each modality and the prevalences of ≥100 mSv patients were extracted via a literature review and used to estimate the total number of imaging patients and ≥100 mSv patients in each country.</div></div><div><h3>Results</h3><div>An estimated 1.36 million patients (0.27 %) received a dose ≥100 mSv among the 513 million residents of the 27 countries. One-third of the countries have more than 3 patients/1,000 population with ≥100 mSv dose in a 5-year period ranging from 1.09 (Finland) to 4.52 (Belgium). A linear trend between the number of ≥100 mSv patients and the total number of CTs in a country was observed, and this can be used for extrapolation at the regional or global level.</div></div><div><h3>Conclusion</h3><div>This is the first study estimating the number of patients who may have received CED ≥100 mSv through recurrent multimodality (CT, FGI, and PET) exams. With the number of such patients being large, a call for attention is needed from relevant national and international organizations.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"134 ","pages":"Article 105006"},"PeriodicalIF":3.3,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144106590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A systematic review of the dosimetric consequences of the interplay effect","authors":"Asmaa M. Ali ,&nbsp;Jason B. Greenwood ,&nbsp;Alan Hounsell ,&nbsp;Conor McGarry","doi":"10.1016/j.ejmp.2025.105004","DOIUrl":"10.1016/j.ejmp.2025.105004","url":null,"abstract":"<div><h3>Purpose</h3><div>The presence of intrafraction motion introduces challenges to thoracic irradiation. The objective of this review is to evaluate the impact of intra-fraction motion on target dose in lung cancer (interplay effect).</div></div><div><h3>Method</h3><div>A comprehensive search was conducted in 2024 across three databases using predefined keywords related to the interplay effect in conjunction with lung cancer. Inclusion criteria encompassed studies involving all external beam radiotherapy modalities, conducted from 2013 onwards. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed.</div></div><div><h3>Results</h3><div>Forty-three journal articles were identified meeting the criteria for inclusion in this analysis. The impact of the interplay effect was found to cause discrepancies in the delivered dose distribution to the target structure and organs at risk. The interplay dose discrepancies were quantified using simulation-based and measurement-based approaches in phantoms and retrospectively in patients. Further analysis revealed associations between interplay dose deviation and various breathing features, and beam delivery features. These findings underscore the multifactorial nature of interplay dose deviation, highlighting the need for comprehensive evaluation and consideration of various patient-specific and treatment-related factors in treatment planning and delivery.</div></div><div><h3>Discussion</h3><div>This systematic review emphasises the significance of personalised assessment and treatment optimisation strategies. Acquiring parameters during clinical trials for secondary analysis can allow technical features to be correlated with patient outcomes, enhancing our understanding of interplay dose error. Developing sophisticated simulation-based tools that incorporate all patient and machine-related factors will ensure dosimetric accuracy and improve patient outcomes.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"134 ","pages":"Article 105004"},"PeriodicalIF":3.3,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144098781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative analysis of deep learning methods for breast ultrasound lesion detection and classification","authors":"Noelia Vallez ,&nbsp;Israel Mateos-Aparicio-Ruiz ,&nbsp;Miguel Angel Rienda ,&nbsp;Oscar Deniz ,&nbsp;Gloria Bueno","doi":"10.1016/j.ejmp.2025.104993","DOIUrl":"10.1016/j.ejmp.2025.104993","url":null,"abstract":"<div><h3>Purpose</h3><div>Breast ultrasound (BUS) computer-aided diagnosis (CAD) systems aims to perform two major steps: detecting lesions and classifying them as benign or malignant. However, the impact of combining both steps has not been previously addressed. Moreover, the specific method employed can influence the final outcome of the system.</div></div><div><h3>Materials and methods</h3><div>In this work, a comparison of the effects of using object detection, semantic segmentation and instance segmentation to detect lesions in BUS images was conducted. To this end, four approaches were examined: a) multi-class object detection, b) one-class object detection followed by localized region classification, c) multi-class segmentation, and d) one-class segmentation followed by segmented region classification. Additionally, a novel dataset for BUS segmentation, called BUS-UCLM, has been gathered, annotated and shared publicly. The evaluation of the methods proposed was carried out with this new dataset and four publicly available datasets: BUSI, OASBUD, RODTOOK and UDIAT.</div></div><div><h3>Results</h3><div>Among the four approaches compared, multi-class detection and multi-class segmentation achieved the best results when instance segmentation CNNs are used. The best results in detection were obtained with a multi-class Mask R-CNN with a COCO AP50 metric of 72.9%. In the multi-class segmentation scenario, Poolformer achieved the best results with a Dice score of 77.7%.</div></div><div><h3>Conclusions</h3><div>The analysis of detection and segmentation models in BUS highlights several key challenges, emphasizing the complexity of accurately identifying and segmenting lesions. Among the methods evaluated, instance segmentation has proven to be the most effective for BUS images, offering superior performance in delineating individual lesions.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"134 ","pages":"Article 104993"},"PeriodicalIF":3.3,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144068496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}