Radiological Physics and Technology最新文献

{"title":"Enhancing patient positioning precision: a comparative analysis of surface-guided radiation therapy systems.","authors":"Takeshi Ohno, Akihiko Kamiguchi, Miki Honda, Yoshinobu Shimohigashi, Akiko Kuraoka, Masahiko Toyota, Yoshifumi Oku, Yushi Niiyama, Tomomi Umeda, Shunichi Osako","doi":"10.1007/s12194-025-00937-8","DOIUrl":"https://doi.org/10.1007/s12194-025-00937-8","url":null,"abstract":"<p><p>This study evaluated the positioning precision of various surface-guided radiation therapy (SGRT) systems to enhance patient setup accuracy in radiotherapy. A female torso phantom (Electronics Research & Development Corporation) was employed to assess and compare the accuracy of four SGRT devices: AlignRT (Vision RT, United Kingdom), Catalyst (C-rad AB, Sweden), VOXELAN (Electronics Research&Development Corporation, Okayama, Japan) and ExacTrac Dynamic (Brainlab, Germany). The external body contour was used as a reference surface image. For positioning precision measurement, the treatment couch was moved in predetermined directions, distances, and angles and the amount of movement evaluated by the SGRT system was compared to the known amount. The results demonstrated that while all SGRT systems-maintained positioning errors within nominal precision thresholds (1 mm for translational movements and 1° for rotational movements), significant inter-device variability was observed. AlignRT and ExacTrac Dynamic exhibited superior accuracy across all movement categories. In contrast, Catalyst demonstrated a higher fraction of positioning errors (16.0%) in the abdominal region, primarily due to lower camera resolution and the use of a deformable registration algorithm. VOXELAN displayed increased errors in the anterior-posterior direction, likely due to interpolation-based surface estimation. These findings highlight the need for standardized evaluation protocols to ensure fair comparisons and improve clinical adoption of SGRT systems.</p>","PeriodicalId":46252,"journal":{"name":"Radiological Physics and Technology","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144668658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of a retrieval-augmented generation system using a Japanese Institutional Nuclear Medicine Manual and large language model-automated scoring.","authors":"Yusuke Fukui, Yuhei Kawata, Kazumasa Kobashi, Yukihiro Nagatani, Harumi Iguchi","doi":"10.1007/s12194-025-00941-y","DOIUrl":"https://doi.org/10.1007/s12194-025-00941-y","url":null,"abstract":"<p><p>Recent advances in large language models (LLMs) enable domain-specific question answering using external knowledge. However, addressing information that is not included in training data remains a challenge, particularly in nuclear medicine, where examination protocols are frequently updated and vary across institutions. In this study, we developed a retrieval-augmented generation (RAG) system using 40 internal manuals from a single Japanese hospital, each corresponding to a different examination in nuclear medicine. These institution-specific documents were segmented and indexed using a hybrid retrieval strategy combining dense vector search (text-embedding-3-small) and sparse keyword search (BM25). GPT-3.5 and GPT-4o were used with the OpenAI application programming interface (API) for response generation. The quality of the generated answers was assessed using a four-point Likert scale by three certified radiological technologists, of which one held an additional certification in nuclear medicine and another held an additional certification in medical physics. Automated evaluation was conducted using RAGAS metrics, including factual correctness and context recall. The GPT-4o model combined with hybrid retrieval achieved the highest performance, as per expert evaluations. Although traditional string-based metrics such as ROUGE and the Levenshtein distance poorly align with human ratings, RAGAS provided consistent rankings across system configurations, despite showing only a modest correlation with manual scores. These findings demonstrate that integrating examination-specific institutional manuals into RAG frameworks can effectively support domain-specific question answering in nuclear medicine. Moreover, LLM-based evaluation methods such as RAGAS may serve as practical tools to complement expert reviews in developing healthcare-oriented artificial intelligence systems.</p>","PeriodicalId":46252,"journal":{"name":"Radiological Physics and Technology","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144668659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterizing and minimizing uncertainties in diagnostic X-ray beam calibrations using a Monte Carlo-based model and experimental validation.","authors":"Abdelouahab Abarane, Mustapha Bougteb, Taibi Zidouz, Abdellatif Talbi, Abderrahim Allach, Mounir Mkimel, Mohamed Zaryah, Mohammed Reda Mesradi, Anas Ardouz, Redouane El Baydaoui","doi":"10.1007/s12194-025-00943-w","DOIUrl":"https://doi.org/10.1007/s12194-025-00943-w","url":null,"abstract":"<p><p>This study aims to develop a flexible Geant4 application capable of modeling all IEC 61267 defined radiation qualities for the HOPEWELL Designs 225 kV X-ray generator, while systematically analyze the impact of various environmental and systematic factors. Using Geant4, we replicated the experimental setup of the LEGEX laboratory and simulated all IEC 61267 radiation qualities by adjusting relevant beam parameters. The model was validated by comparing simulated HVLs and spectra, measured with a CdTe X-123 spectrometer against experimental data, SRS78 software results, and IEC reference values. The simulation demonstrated strong agreement with experimental measurements and published data, confirming the validity of our Geant4 application. We derived the function that characterizes the behavior of Kinetic Energy Released per unit Mass (KERMA) in response to variations in each influencing factor. Geometrical misalignment is the primary contributor to deviations, followed by aluminum purity and diaphragm movement, while environmental factors induced minor fluctuations. Additionally, we quantified backscattered radiation and applied corrective measures to eliminate its impact on measurements. The developed Geant4 application provides a reliable tool for simulating IEC 61267 radiation qualities and optimizing dosimetric accuracy. Our framework offers a cost-effective alternative to replicate different scenarios multiple times to identify and minimizes uncertainties.</p>","PeriodicalId":46252,"journal":{"name":"Radiological Physics and Technology","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144668657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Linear energy transfer correction using Al₂O₃:Cr thermoluminescent and radiophotoluminescence glass dosimeters for therapeutic proton dosimetry.","authors":"Weishan Chang, Hina Suzuki, Kenji Hotta, Puspen Chakraborty, Yusuke Koba, Nozomi Ohba, Kiyomitsu Shinsho","doi":"10.1007/s12194-025-00942-x","DOIUrl":"https://doi.org/10.1007/s12194-025-00942-x","url":null,"abstract":"<p><p>Solid-state luminescence dosimeters face challenge in achieving accurate dosimetry in proton therapy owing to the linear energy transfer (LET)-dependent response. In this study, we proposed a two-dosimeter-based methodology to improve the accuracy of proton dosimetry by correcting the LET-dependent response of a radiophotoluminescence glass dosimeter (RPLD) and an Al₂O₃:Cr-based ceramic-type thermoluminescence dosimeter (TLD) for postal dosimetry. The LET dependent response for the RPLD and Al₂O₃:Cr TLD was investigated using an unmodulated 235 MeV proton beam delivered by a passive scattering system. Both dosimeters were individually calibrated in terms of the absorbed dose to water using a 6 MV X-ray beam. The luminescence efficiency ratio between the RPLD and Al₂O₃:Cr TLD ( <math><msub><mi>η</mi> <mrow> <msub><mrow><mtext>RPLD</mtext> <mo>,</mo> <mspace></mspace> <mtext>Al</mtext></mrow> <mn>2</mn></msub> <msub><mtext>O</mtext> <mn>3</mn></msub> <mo>:</mo> <mtext>Cr</mtext></mrow> </msub> </math> ) was used as an index to determine the LET dependence correction factor for the RPLD and Al₂O₃:Cr TLD ( <math><msubsup><mi>k</mi> <mrow><mtext>LET</mtext></mrow> <mtext>RPLD</mtext></msubsup> </math> and <math><msubsup><mi>k</mi> <mrow><mtext>LET</mtext></mrow> <mrow><msub><mtext>Al</mtext> <mn>2</mn></msub> <msub><mtext>O</mtext> <mn>3</mn></msub> <mo>:</mo> <mtext>Cr</mtext></mrow> </msubsup> </math> ). Modulated proton beams with different spread-out Bragg peak (SOBP) widths were used to evaluate the feasibility of the proposed two-dosimeter methodology. <math><msub><mi>η</mi> <mrow> <msub><mrow><mtext>RPLD</mtext> <mo>,</mo> <mspace></mspace> <mtext>Al</mtext></mrow> <mn>2</mn></msub> <msub><mtext>O</mtext> <mn>3</mn></msub> <mo>:</mo> <mtext>Cr</mtext></mrow> </msub> </math> decreased with increasing LET. <math><msubsup><mi>k</mi> <mrow><mtext>LET</mtext></mrow> <mtext>RPLD</mtext></msubsup> </math> and <math><msubsup><mi>k</mi> <mrow><mtext>LET</mtext></mrow> <mrow><msub><mtext>Al</mtext> <mn>2</mn></msub> <msub><mtext>O</mtext> <mn>3</mn></msub> <mo>:</mo> <mtext>Cr</mtext></mrow> </msubsup> </math> were fitted using exponential curves. Proton dosimetry based on the proposed methodology underestimated the absorbed dose to water by an averages of 1.88% and 3.21% for RPLD and Al₂O₃:Cr TLD, respectively. This demonstrated the feasibility of the proposed methodology. Although the method shows promise for LET correction, the uncertainties in the LET-dependent correction factors, namely 2.39% for the RPLD and 5.84% for the Al₂O₃:Cr TLD, indicate the need for further refinement.</p>","PeriodicalId":46252,"journal":{"name":"Radiological Physics and Technology","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144668660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating the efficacy of biological versus physical cost functions with constrained mode for inverse plan optimization of head and neck cancer.","authors":"Mukesh N Meshram, Laishram Amarjit Singh, Umesh A Palikundwar","doi":"10.1007/s12194-025-00939-6","DOIUrl":"https://doi.org/10.1007/s12194-025-00939-6","url":null,"abstract":"<p><p>This study aims to compare and evaluate the potential benefits of using single DV-based, multiple DV-based physical cost function, and biological-based cost functions for organs at risk (OARs) sparing in IMRT as well as VMAT plans of head and neck cancer. Forty head and neck cancer patients treated with inverse plan optimization techniques were retrospectively enrolled for this study. Three different treatment plans were optimized by single DV-based, multiple DV-based physical cost functions, and biological-based cost functions on MONACO 6.1® TPS. All three optimized plans were normalized to deliver the same prescribed target dose. All 120 optimized plans were analyzed using dose evaluation parameters. For IMRT plans, the biological cost functions (BCF) were superior to both DV-based optimizations when it came to the mean dose of parallel organs. For VMAT plans, multiple DV-based physical cost function optimization resulted in a lower mean dose of parallel organs when compared with other two optimization. The biological cost function significantly reduced the mean dose of parallel organs, for which multiple DV-based cost functions were not used. In both IMRT and VMAT plans, the DV-based physical cost function significantly reduced the maximum dose of serial organs, with the exception of the mandible. Biological-based optimization made it more likely that the parallel OARs would be spared in IMRT plans, while multiple DV-based optimization made it more likely that the parallel OARs would be spared in VMAT plans. Both DV-based optimization in IMRT and VMAT plans effectively spared the maximum dose of the serial organ.</p>","PeriodicalId":46252,"journal":{"name":"Radiological Physics and Technology","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144627321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dosimetric comparison in various stereotactic radiosurgery modalities for trigeminal neuralgia treatment.","authors":"Mageshraja Kannan, Sathiyan Saminathan, C Prasobh, Aditya Gupta, Karuppusamy Arumugam, Nithin Bhaskar, Varatharaj Chandraraj, B Shwetha, K M Ganesh","doi":"10.1007/s12194-025-00935-w","DOIUrl":"https://doi.org/10.1007/s12194-025-00935-w","url":null,"abstract":"<p><p>Trigeminal neuralgia (TN) is characterized by severe facial pain and is treated with medications, surgery, percutaneous procedures, and stereotactic radiosurgery (SRS). The Gamma Knife (GK) has historically been the gold standard for SRS in TN, with alternatives such as the CyberKnife (CK) and standard linear accelerator (LA) having recently emerged. This study compared GK, CK, and LA treatments for TN via dosimetric analysis. Twenty patients (10 right- and 10 left-sided) with TN were planned in the three modalities. Dosimetric parameters, including D_Max, D_Min, D_Mean, D_98%, D_90%, D_50%, D_30%, and V_4Gy, were evaluated. The statistical significance was assessed using paired t tests. The CK and LA plans achieved a 60 Gy target coverage comparable to the GK plan. The GK plan exhibited superior brain stem sparing and lower V_4Gy compared with CK (p = 0.0013) and LA (p = 0.0001). Significant differences in D_Min, D_98%, D_90%, D_50%, and D_30% were observed between GK and CK (p < 0.05) and GK and LA (p < 0.05), but not for the CK-LA comparisons. The brain stem dose parameters (D_0.03 cc, D_1%, and D_2%) were significantly lower in the GK plan (p < 0.05). The GK exhibited better normal tissue sparing and brain stem dose distribution than CK and LA, attributable partly to its higher beam count. CK and LA require more intricate planning times. Despite the established efficacy of GK, CK and LA offer viable alternatives, underscoring the need for further research on the clinical outcomes of TN treatment in the respective modalities.</p>","PeriodicalId":46252,"journal":{"name":"Radiological Physics and Technology","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144627320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection and dual-label classification of tooth number and condition in dental panoramic radiographs including deciduous teeth.","authors":"Koki Sakai, Chisako Muramatsu, Yuta Seino, Ryo Takahashi, Tatsuro Hayashi, Wataru Nishiyama, Xiangrong Zhou, Takeshi Hara, Akitoshi Katsumata, Hiroshi Fujita","doi":"10.1007/s12194-025-00936-9","DOIUrl":"https://doi.org/10.1007/s12194-025-00936-9","url":null,"abstract":"<p><strong>Objectives: </strong>The purpose of this study is to automatically extract the information necessary for chart recording from panoramic radiographs, to reduce the workload for dentists.</p><p><strong>Study design: </strong>Using 1,085 dental panoramic radiographs (994 of permanent dentition and 91 of mixed dentition) taken at 10 facilities, we conducted tooth detection, numbering, and condition classification. Tooth condition was defined into five classes: natural, partial restoration, prosthetic crown, implant, and pontic. First, the YOLOv7 model was used to simultaneously detect 10 classes of deciduous teeth, 16 classes of permanent teeth, and four classes of tooth condition (excluding natural). We applied rule-based post-processing to the detected objects. Precision, Recall, and F1-score were used to evaluate our method, with an IoU (Intersection over Union) threshold set at 0.5.</p><p><strong>Results: </strong>We achieved Precision, Recall, and F1-score of 98.51%, 98.38%, and 98.45%, respectively, in tooth numbering. In tooth condition classification, the average F1-score across the 5 classes was 95.47%.</p><p><strong>Conclusions: </strong>Our method, which detects and classifies the tooth numbers of permanent and deciduous teeth and their tooth condition simultaneously, is expected to contribute to reducing the workload of dentists and improving accuracy.</p>","PeriodicalId":46252,"journal":{"name":"Radiological Physics and Technology","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144592622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Issues in radiation dose measurement using electronic personal dosimeters during disaster relief activities.","authors":"Akira Suzuki, Yoshiaki Hirofuji, Noriaki Miyaji, Ayaka Oikawa, Kentarou Funashima, Isami Takahashi","doi":"10.1007/s12194-025-00934-x","DOIUrl":"https://doi.org/10.1007/s12194-025-00934-x","url":null,"abstract":"<p><strong>Purpose: </strong>In this study, we measured the radiation exposure of the medical relief team of the Japanese Red Cross Society (JRCS) members during the Noto Peninsula earthquake using electronic personal dosimeters (EPDs) and investigated the frequency of electromagnetic interference (EMI) events that caused abnormally high dose readings.</p><p><strong>Methods: </strong>Six JRCS medical relief team members (two physicians, three nurses, and one logistics officer) involved in the Noto Peninsula earthquake disaster relief activities were provided with EPDs to measure their radiation exposure during the activity period. A background radiation dosimeter was also installed on-site to record ambient radiation levels.</p><p><strong>Results: </strong>Over 2.5 days of disaster relief activities, the background radiation dose was 3.0 ± 3.0 μSv. However, the highest recorded dose among the team members was 2075.0 ± 207.5 μSv for a nurse, while the average dose for the other members was 40.0 ± 39.5 μSv. A significant radiation dose was observed despite no radioactive material dispersion.</p><p><strong>Conclusions: </strong>Among the four individuals who exhibited abnormally high dose readings, three were operating digital devices at the time of measurement, suggesting a strong likelihood that electromagnetic interference was the cause. The effective management of radiation doses using EPDs during nuclear disasters requires the implementation of countermeasures against EMI from digital devices.</p>","PeriodicalId":46252,"journal":{"name":"Radiological Physics and Technology","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144592623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Content-based X-ray image retrieval using fusion of local neighboring patterns and deep features for lung disease detection.","authors":"Ankur Prakash, Vibhav Prakash Singh","doi":"10.1007/s12194-025-00932-z","DOIUrl":"https://doi.org/10.1007/s12194-025-00932-z","url":null,"abstract":"<p><p>This paper introduces a Content-Based Medical Image Retrieval (CBMIR) system for detecting and retrieving lung disease cases to assist doctors and radiologists in clinical decision-making. The system combines texture-based features using Local Binary Patterns (LBP) with deep learning-based features extracted from pretrained CNN models, including VGG-16, DenseNet121, and InceptionV3. The objective is to identify the optimal fusion of texture and deep features to enhance the image retrieval performance. Various similarity measures, including Euclidean, Manhattan, and cosine similarities, were evaluated, with Cosine Similarity demonstrating the best performance, achieving an average precision of 65.5%. For COVID-19 cases, VGG-16 achieved a precision of 52.5%, while LBP performed best for the normal class with 85% precision. The fusion of LBP, VGG-16, and DenseNet121 excelled in pneumonia cases, with a precision of 93.5%. Overall, VGG-16 delivered the highest average precision of 74.0% across all classes, followed by LBP at 72.0%. The fusion of texture (LBP) and deep features from all CNN models achieved 86% accuracy for the retrieval of the top 10 images, supporting healthcare professionals in making more informed clinical decisions.</p>","PeriodicalId":46252,"journal":{"name":"Radiological Physics and Technology","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144561530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A simplified method for generating maximum slope maps in ultrafast dynamic contrast-enhanced breast magnetic resonance imaging.","authors":"Ayumu Funaki, Masaki Ohkubo, Kazunori Ohashi, Toshiro Shukuya, Yuka Yashima, Kazunori Kubota","doi":"10.1007/s12194-025-00931-0","DOIUrl":"https://doi.org/10.1007/s12194-025-00931-0","url":null,"abstract":"<p><p>Clinical measurement of the maximum slope (MS) using ultrafast dynamic contrast-enhanced (UF-DCE) breast magnetic resonance imaging (MRI) is typically performed by placing a region of interest (ROI) in the most enhanced area within a lesion. However, previous studies have not clarified whether visually identified enhanced areas consistently exhibit the highest MS values. These ROI-based MS measurements require MS maps to ensure appropriate ROI placement. However, generating MS maps requires specialized software capable of pixel-by-pixel MS calculations, which are available only at a few facilities. Therefore, this study proposed a simplified method for generating MS maps. This method involves subtracting consecutive UF-DCE images, applying temporal maximum intensity projection, normalizing the resulting image by dividing it by the pre-contrast image signal intensity, and converting it to a slope by dividing it by the temporal resolution. The MS maps generated using the proposed method were compared with those obtained using a robust pixel-by-pixel curve-fitting method, in addition to the final-phase UF-DCE images. In all cases with breast lesions (n = 13), the signal intensity distributions on the proposed MS maps closely resembled those on the curve-fitting maps, with a significantly higher similarity than those on the final-phase UF-DCE images (p < 0.001). The derived mean absolute error of MS values after regression-based modification was 0.78 ± 0.72 (%/s). The proposed method improves the reliability of ROI placement in conventional ROI-based MS measurements and supports the direct quantification of MS values from map pixel data.</p>","PeriodicalId":46252,"journal":{"name":"Radiological Physics and Technology","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144545373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}