Radiological Physics and Technology最新文献_第6页

Impact of a novel respiratory motion reduction block for myocardial perfusion SPECT image quality: a phantom study.

IF 1.7

Radiological Physics and Technology Pub Date : 2025-02-18 DOI: 10.1007/s12194-025-00887-1

Hajime Ichikawa, Toyohiro Kato, Takayuki Shibutani, Mitsuaki Terabe, Hideki Shimada

{"title":"Impact of a novel respiratory motion reduction block for myocardial perfusion SPECT image quality: a phantom study.","authors":"Hajime Ichikawa, Toyohiro Kato, Takayuki Shibutani, Mitsuaki Terabe, Hideki Shimada","doi":"10.1007/s12194-025-00887-1","DOIUrl":"https://doi.org/10.1007/s12194-025-00887-1","url":null,"abstract":"Patient motion, particularly due to respiration, often introduces image distortions that compromise diagnostic accuracy in myocardial perfusion single-photon emission computed tomography (SPECT). To address this issue, we developed a novel respiratory motion reduction block (RRB) designed to minimize the respiratory motion of the heart. This study aims to evaluate the impact of the cardiac-centered with RRB (CCRRB) orbit, achieved using the RRB, on myocardial perfusion SPECT image quality. SPECT acquisition of a cardiac phantom was performed at the circular, neighboring elliptical (NE), and CCRRB orbits. The CCRRB orbit was achieved with RRB placed in front of the phantom based on the NE orbit. Count profile curves of the lesion and uniform slice images were obtained from the circumferential profile. Lesion contrast, normal accumulation uniformity, and count distortion were calculated from the circumferential profiles. Full width at half maximum (FWHM) was measured in the lateral, anterior, septal, and inferior walls of the myocardium, and both the mean and standard deviation (SD) were calculated. The lesion contrast was the highest in the NE orbit, slightly lower in the CCRRB orbit, and remarkably lower in the circular orbit than in the NE orbit. The uniformity and count distortion were superior for the CCRRB orbits. The SD of FWHM was greater in the circular and NE orbits. The CCRRB orbit effectively improves uniformity in SPECT imaging, preserving lesion contrast and spatial resolution. The CCRRB orbit provides a practical, accessible approach for enhancing image quality in clinical settings.","PeriodicalId":46252,"journal":{"name":"Radiological Physics and Technology","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143450617","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}

引用次数: 0

Radiation dose at the eye lens of patients undergoing radiation therapy for head and neck cancer.

IF 1.7

Radiological Physics and Technology Pub Date : 2025-02-09 DOI: 10.1007/s12194-025-00886-2

Panatsada Awikunprasert, Jumneanphan Rueansri, Kittipong Suangamiam, Chaknarin Koedsawat, Surasak Tamon, Nattakarn Kittiva, Tanapol Dachviriyakij

{"title":"Radiation dose at the eye lens of patients undergoing radiation therapy for head and neck cancer.","authors":"Panatsada Awikunprasert, Jumneanphan Rueansri, Kittipong Suangamiam, Chaknarin Koedsawat, Surasak Tamon, Nattakarn Kittiva, Tanapol Dachviriyakij","doi":"10.1007/s12194-025-00886-2","DOIUrl":"https://doi.org/10.1007/s12194-025-00886-2","url":null,"abstract":"Linear accelerator irradiation, the most common treatment for head and neck cancer, requires accurate prediction of lens radiation doses to ensure patient safety. The eye lens, being highly radiosensitive and vulnerable to scattered radiation, is at increased risk of developing cataracts. This study compared radiation doses calculated by the treatment planning system (TPS) with those measured in vivo using optically stimulated luminescence (OSL) dosimeters placed on the eyes of 18 patients undergoing radiotherapy for various head and neck cancers. Bland-Altman analysis was used to assess the agreement between the two methods. The results showed that TPS-calculated doses were significantly higher than OSL-measured doses, with TPS values averaging twice as high. However, in three cases, the measured OSL doses exceeded the TPS predictions. The Bland-Altman plot revealed poor agreement between the two methods. The mean doses to the left and right eye lenses were 182 cGy and 170 cGy, respectively, with the highest recorded doses being 492 cGy for the left eye and 513 cGy for the right eye. Patients with nasopharyngeal cancer received the highest doses, and four patients had doses in the 3-5 Gy range, increasing their risk of cataracts. These findings emphasize the importance of validating TPS accuracy in clinical practice to ensure optimal patient care. Further research is necessary to explore the discrepancies between dose measurements and enhance TPS precision, improving clinical outcomes and patient safety in radiation therapy.","PeriodicalId":46252,"journal":{"name":"Radiological Physics and Technology","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143374629","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}

引用次数: 0

Selection of Radiological Physics and Technology Awards 2024.

IF 1.7

Radiological Physics and Technology Pub Date : 2025-02-06 DOI: 10.1007/s12194-025-00884-4

Nobuyuki Kanematsu, Katsuhiro Ichikawa, Noriyuki Kadoya, Tosiaki Miyati, Takeji Sakae, Junji Shiraishi, Yoshikazu Uchiyama, Yoichi Watanabe, Taiga Yamaya

引用次数: 0

Assessing knowledge about medical physics in language-generative AI with large language model: using the medical physicist exam. 利用大型语言模型评估语言生成人工智能中的医学物理知识：使用医学物理学家考试。

IF 1.7

Radiological Physics and Technology Pub Date : 2024-12-01 Epub Date: 2024-09-10 DOI: 10.1007/s12194-024-00838-2

Noriyuki Kadoya, Kazuhiro Arai, Shohei Tanaka, Yuto Kimura, Ryota Tozuka, Keisuke Yasui, Naoki Hayashi, Yoshiyuki Katsuta, Haruna Takahashi, Koki Inoue, Keiichi Jingu

{"title":"Assessing knowledge about medical physics in language-generative AI with large language model: using the medical physicist exam.","authors":"Noriyuki Kadoya, Kazuhiro Arai, Shohei Tanaka, Yuto Kimura, Ryota Tozuka, Keisuke Yasui, Naoki Hayashi, Yoshiyuki Katsuta, Haruna Takahashi, Koki Inoue, Keiichi Jingu","doi":"10.1007/s12194-024-00838-2","DOIUrl":"10.1007/s12194-024-00838-2","url":null,"abstract":"This study aimed to evaluate the performance for answering the Japanese medical physicist examination and providing the benchmark of knowledge about medical physics in language-generative AI with large language model. We used questions from Japan's 2018, 2019, 2020, 2021 and 2022 medical physicist board examinations, which covered various question types, including multiple-choice questions, and mainly focused on general medicine and medical physics. ChatGPT-3.5 and ChatGPT-4.0 (OpenAI) were used. We compared the AI-based answers with the correct ones. The average accuracy rates were 42.2 ± 2.5% (ChatGPT-3.5) and 72.7 ± 2.6% (ChatGPT-4), showing that ChatGPT-4 was more accurate than ChatGPT-3.5 [all categories (except for radiation-related laws and recommendations/medical ethics): p value < 0.05]. Even with the ChatGPT model with higher accuracy, the accuracy rates were less than 60% in two categories; radiation metrology (55.6%), and radiation-related laws and recommendations/medical ethics (40.0%). These data provide the benchmark for knowledge about medical physics in ChatGPT and can be utilized as basic data for the development of various medical physics tools using ChatGPT (e.g., radiation therapy support tools with Japanese input).","PeriodicalId":46252,"journal":{"name":"Radiological Physics and Technology","volume":" ","pages":"929-937"},"PeriodicalIF":1.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142298277","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}

引用次数: 0

Evaluation of calculation accuracy and computation time in a commercial treatment planning system for accelerator-based boron neutron capture therapy. 评估基于加速器的硼中子俘获疗法商业治疗计划系统的计算精度和计算时间。

IF 1.7

Radiological Physics and Technology Pub Date : 2024-12-01 Epub Date: 2024-08-14 DOI: 10.1007/s12194-024-00833-7

Akihiko Takeuchi, Katsumi Hirose, Ryohei Kato, Shinya Komori, Mariko Sato, Tomoaki Motoyanagi, Yuhei Yamazaki, Yuki Narita, Yoshihiro Takai, Takahiro Kato

{"title":"Evaluation of calculation accuracy and computation time in a commercial treatment planning system for accelerator-based boron neutron capture therapy.","authors":"Akihiko Takeuchi, Katsumi Hirose, Ryohei Kato, Shinya Komori, Mariko Sato, Tomoaki Motoyanagi, Yuhei Yamazaki, Yuki Narita, Yoshihiro Takai, Takahiro Kato","doi":"10.1007/s12194-024-00833-7","DOIUrl":"10.1007/s12194-024-00833-7","url":null,"abstract":"This study aims to evaluate the feasibility of using a commercially available boron neutron capture therapy (BNCT) dose calculation program (NeuCure® Dose Engine) in terms of calculation accuracy and computation time. Treatment planning was simulated under the following calculation parameters: 1.5-5.0 mm grid sizes and 1-10% statistical uncertainties. The calculated monitor units (MUs) and computation times were evaluated. The MUs calculated on grid sizes larger than 2 mm were overestimated by 2% compared with the result of 1.5 mm grid. We established the two-step method for the routine administration of BNCT: multiple calculations involved in beam optimization should be done at a 5 mm grid and a 10% statistical uncertainty (the shortest computation time: 10.3 ± 2.1 min) in the first-step, and final dose calculations should be performed at a 2 mm grid and a 10% statistical uncertainty (satisfied clinical accuracy: 6.9 ± 0.3 h) in the second-step.","PeriodicalId":46252,"journal":{"name":"Radiological Physics and Technology","volume":" ","pages":"907-917"},"PeriodicalIF":1.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141976920","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}

引用次数: 0

LIT-Unet: a lightweight and effective model for medical image segmentation. LIT-Unet：用于医学图像分割的轻量级有效模型。

IF 1.7

Radiological Physics and Technology Pub Date : 2024-12-01 Epub Date: 2024-09-20 DOI: 10.1007/s12194-024-00844-4

Ru Wang, Qiqi Kou, Lina Dou

{"title":"LIT-Unet: a lightweight and effective model for medical image segmentation.","authors":"Ru Wang, Qiqi Kou, Lina Dou","doi":"10.1007/s12194-024-00844-4","DOIUrl":"10.1007/s12194-024-00844-4","url":null,"abstract":"This study aimed to design a simple and efficient automatic segmentation model for medical images, so as to facilitate doctors to make more accurate diagnosis and treatment plan. A hybrid lightweight network LIT-Unet with symmetric encoder-decoder U-shaped architecture is proposed. Synapse multi-organ segmentation dataset and automated cardiac diagnosis challenge (ACDC) dataset were used to test the segmentation performance of the method. Two indexes, Dice similarity coefficient (DSC ↑) and 95% Hausdorff distance (HD95 ↓), were used to evaluate and compare the segmentation ability with the current advanced methods. Ablation experiments were conducted to demonstrate the lightweight nature and effectiveness of our model. For Synapse dataset, our model achieves a higher DSC score (80.40%), an improvement of 3.8% over the typical hybrid model (TransUnet). The 95 HD value is low at 20.67%. For ACDC dataset, LIT-Unet achieves the optimal average DSC (%) of 91.84 compared with other networks listed. Compared to patch expanding, the DSC of our model is intuitively improved by 1.62% with the help of deformable token merging (DTM). These results show that the proposed hierarchical LIT-Unet can achieve significant accuracy and is expected to provide a reliable basis for clinical diagnosis and treatment.","PeriodicalId":46252,"journal":{"name":"Radiological Physics and Technology","volume":" ","pages":"878-887"},"PeriodicalIF":1.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142298279","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}

引用次数: 0

The effect on gastrointestinal peristalsis for magnetic resonance cholangiopancreatography during breath-holding methods. 憋气法对磁共振胰胆管造影胃肠道蠕动的影响。

IF 1.7

Radiological Physics and Technology Pub Date : 2024-12-01 Epub Date: 2024-09-27 DOI: 10.1007/s12194-024-00846-2

Yuhei Otsuka, Tomoya Nakamura, Nao Kajihara, Takao Tashiro

{"title":"The effect on gastrointestinal peristalsis for magnetic resonance cholangiopancreatography during breath-holding methods.","authors":"Yuhei Otsuka, Tomoya Nakamura, Nao Kajihara, Takao Tashiro","doi":"10.1007/s12194-024-00846-2","DOIUrl":"10.1007/s12194-024-00846-2","url":null,"abstract":"The breath-hold (BH) 3D magnetic resonance cholangiopancreatography method has been reported to suppress \"respiratory artifacts\"; however, the influence of gastrointestinal peristalsis around the target organs has not been discussed. In contrast, the autonomic nervous system has been reported to affect gastrointestinal peristalsis and BH imaging has been reported to influence venous blood flow signal (BFS) through its involvement with the autonomic nervous system. We examined the impact of BH imaging on gastrointestinal peristalsis. Seven healthy volunteers participated. Three respiratory patterns-free breathing (FB), BH at maximum inspiration (Insp-BH), and BH at maximum expiration (Exp-BH)-were used. Gastrointestinal peristalsis was measured using cine MRI. Cine MRI data were analyzed using the normalized interframe difference method, focusing on the duodenum and gastric body. Hemodynamic changes resulting from BH methods were evaluated using 2D phase contrast, targeting the inferior vena cava (IVC). The BFS was examined for all phases of each respiratory pattern. Peristalsis variation in the duodenum showed no significant differences among FB, Exp-BH, and Insp-BH. In the gastric body, no significant differences were observed between FB and Exp-BH or between Exp-BH and Insp-BH. However, a significant difference emerged between FB and Insp-BH. Regarding BFS, in the IVC, significant differences were observed between Exp-BH and Insp-BH and between FB and Insp-BH (both, p < 0.01), with no significant difference between FB and Exp-BH. Insp-BH reduces venous blood flow and suppresses the influence of peristalsis variation.","PeriodicalId":46252,"journal":{"name":"Radiological Physics and Technology","volume":" ","pages":"888-895"},"PeriodicalIF":1.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142356119","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}

引用次数: 0

Effect of deep learning reconstruction on the assessment of pancreatic cystic lesions using computed tomography. 深度学习重建对使用计算机断层扫描评估胰腺囊性病变的影响。

IF 1.7

Radiological Physics and Technology Pub Date : 2024-12-01 Epub Date: 2024-08-15 DOI: 10.1007/s12194-024-00834-6

Jun Kanzawa, Koichiro Yasaka, Yuji Ohizumi, Yuichi Morita, Mariko Kurokawa, Osamu Abe

{"title":"Effect of deep learning reconstruction on the assessment of pancreatic cystic lesions using computed tomography.","authors":"Jun Kanzawa, Koichiro Yasaka, Yuji Ohizumi, Yuichi Morita, Mariko Kurokawa, Osamu Abe","doi":"10.1007/s12194-024-00834-6","DOIUrl":"10.1007/s12194-024-00834-6","url":null,"abstract":"This study aimed to compare the image quality and detection performance of pancreatic cystic lesions between computed tomography (CT) images reconstructed by deep learning reconstruction (DLR) and filtered back projection (FBP). This retrospective study included 54 patients (mean age: 67.7 ± 13.1) who underwent contrast-enhanced CT from May 2023 to August 2023. Among eligible patients, 30 and 24 were positive and negative for pancreatic cystic lesions, respectively. DLR and FBP were used to reconstruct portal venous phase images. Objective image quality analyses calculated quantitative image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) using regions of interest on the abdominal aorta, pancreatic lesion, and pancreatic parenchyma. Three blinded radiologists performed subjective image quality assessment and lesion detection tests. Lesion depiction, normal structure illustration, subjective image noise, and overall image quality were utilized as subjective image quality indicators. DLR significantly reduced quantitative image noise compared with FBP (p < 0.001). SNR and CNR were significantly improved in DLR compared with FBP (p < 0.001). Three radiologists rated significantly higher scores for DLR in all subjective image quality indicators (p ≤ 0.029). Performance of DLR and FBP were comparable in lesion detection, with no statistically significant differences in the area under the receiver operating characteristic curve, sensitivity, specificity and accuracy. DLR reduced image noise and improved image quality with a clearer depiction of pancreatic structures. These improvements may have a positive effect on evaluating pancreatic cystic lesions, which can contribute to appropriate management of these lesions.","PeriodicalId":46252,"journal":{"name":"Radiological Physics and Technology","volume":" ","pages":"827-833"},"PeriodicalIF":1.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11579065/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141989183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Estimation of the lateral variation of photon beam energy spectra using the percentage depth dose reconstruction method. 利用百分比深度剂量重建法估算光子束能量谱的横向变化。

IF 1.7

Radiological Physics and Technology Pub Date : 2024-12-01 Epub Date: 2024-09-06 DOI: 10.1007/s12194-024-00835-5

Puspen Chakraborty, Hidetoshi Saitoh, Yuta Miyake, Tenyoh Suzuki, Weishan Chang

{"title":"Estimation of the lateral variation of photon beam energy spectra using the percentage depth dose reconstruction method.","authors":"Puspen Chakraborty, Hidetoshi Saitoh, Yuta Miyake, Tenyoh Suzuki, Weishan Chang","doi":"10.1007/s12194-024-00835-5","DOIUrl":"10.1007/s12194-024-00835-5","url":null,"abstract":"In photon-collapsed cone convolution (pCCC) algorithm of the Monaco treatment planning system (TPS), the central-axis energy spectrum is assumed constant throughout the entire irradiation area. To consider lateral variations, an off-axis softening factor is applied to attenuation coefficients during the total energy released per unit mass calculation. We evaluated this method through comparison studies of percentage depth doses (PDDs) and off-axis ratios (OARs) calculated by Monaco and measured for a 6 MV photon beam at various off-axis angles and depths. Significant differences were observed, with relative differences exceeding ± 1%. Therefore, this method may not accurately represent lateral variations of energy spectra. We propose directly implementing energy spectra on both central-axis and off-axis to improve dose calculation accuracy for large field. To this end, we introduce reconstruction of PDDs from monoenergetic depth doses (MDDs) along off-axis angles, thereby estimating energy spectra as functions of radial distance. This method derives energy spectra quickly without significantly increasing the beam modeling time. MDDs were computed through Monte Carlo simulations (DOSRZnrc). The variances between reconstructed and measured PDDs were minimized using the generalized-reduced-gradient method to optimize energy spectra. Reconstructed PDDs along off-axis angles of 0°, 1.15°, 2.29°, 3.43°, 4.57°, 5.71°, 6.84°, 7.97°, 9.09°, 10.2° to estimate energy spectra at radial distances of 0-18 cm in 2 cm increments and OARs calculated using estimated energy spectra at 5, 10, and 20 cm depths, well agreed with measurement (relative differences within ± 0.5%). In conclusion, our proposed method accurately estimates lateral energy spectrum variation, thereby improving dose calculation accuracy of pCCC algorithm.","PeriodicalId":46252,"journal":{"name":"Radiological Physics and Technology","volume":" ","pages":"834-842"},"PeriodicalIF":1.7,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11579137/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142141310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optimum delineation of skin structure for dose calculation with the linear Boltzmann transport equation algorithm in radiotherapy treatment planning. 在放射治疗规划中使用线性玻尔兹曼传输方程算法计算剂量时的皮肤结构最佳划分。

IF 1.7

Radiological Physics and Technology Pub Date : 2024-12-01 Epub Date: 2024-09-09 DOI: 10.1007/s12194-024-00840-8

Keisuke Hamada, Toshioh Fujibuchi, Hiroyuki Arakawa

引用次数: 0