Radiological Physics and Technology最新文献_第6页

An image-based metal artifact reduction technique utilizing forward projection in computed tomography. 在计算机断层扫描中利用正投影技术减少基于图像的金属伪影。

IF 1.6

Radiological Physics and Technology Pub Date : 2024-06-01 Epub Date: 2024-03-28 DOI: 10.1007/s12194-024-00790-1

Katsuhiro Ichikawa, Hiroki Kawashima, Tadanori Takata

{"title":"An image-based metal artifact reduction technique utilizing forward projection in computed tomography.","authors":"Katsuhiro Ichikawa, Hiroki Kawashima, Tadanori Takata","doi":"10.1007/s12194-024-00790-1","DOIUrl":"10.1007/s12194-024-00790-1","url":null,"abstract":"The projection data generated via the forward projection of a computed tomography (CT) image (FP-data) have useful potentials in cases where only image data are available. However, there is a question of whether the FP-data generated from an image severely corrupted by metal artifacts can be used for the metal artifact reduction (MAR). The aim of this study was to investigate the feasibility of a MAR technique using FP-data by comparing its performance with that of a conventional robust MAR using projection data normalization (NMARconv). The NMARconv was modified to make use of FP-data (FPNMAR). A graphics processing unit was used to reduce the time required to generate FP-data and subsequent processes. The performances of FPNMAR and NMARconv were quantitatively compared using a normalized artifact index (AIn) for two cases each of hip prosthesis and dental fillings. Several clinical CT images with metal artifacts were processed by FPNMAR. The AIn values of FPNMAR and NMARconv were not significantly different from each other, showing almost the same performance between these two techniques. For all the clinical cases tested, FPNMAR significantly reduced the metal artifacts; thereby, the images of the soft tissues and bones obscured by the artifacts were notably recovered. The computation time per image was ~ 56 ms. FPNMAR, which can be applied to CT images without accessing the projection data, exhibited almost the same performance as that of NMARconv, while consuming significantly shorter processing time. This capability testifies the potential of FPNMAR for wider use in clinical settings.","PeriodicalId":46252,"journal":{"name":"Radiological Physics and Technology","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11128408/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140319507","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

Feasibility study of radioactivity estimation of ^99mTc and ¹²³I-labeled radiopharmaceuticals using shielded syringes. 使用屏蔽注射器估算 99mTc 和 123I 标记放射性药物放射性的可行性研究。

IF 1.6

Radiological Physics and Technology Pub Date : 2024-06-01 Epub Date: 2024-03-22 DOI: 10.1007/s12194-024-00789-8

Yuto Nakamura, Narumi Yasuno

{"title":"Feasibility study of radioactivity estimation of 99mTc and 123I-labeled radiopharmaceuticals using shielded syringes.","authors":"Yuto Nakamura, Narumi Yasuno","doi":"10.1007/s12194-024-00789-8","DOIUrl":"10.1007/s12194-024-00789-8","url":null,"abstract":"This study investigates the feasibility of estimating the radioactivity of radiopharmaceuticals using shielded syringes. The radioactivities of 99mTc-MDP, 99mTc-HMDP, 99mTc-ECD, 99mTc-MAG3, and 123I-IMP were measured using a dose calibrator. Correlation coefficients and regression equations were obtained from the radioactivity in the shielded and unshielded syringes. 99mTc-MDP was also measured for residual radioactivity after the administration. The correlation coefficients of 99mTc-MDP, 99mTc-HMDP, 99mTc-ECD, 99mTc-MAG3, and 123I-IMP were rs = 0.9998, rs = 0.9997, rs = 0.9999, rs = 0.9998, and rs = 0.9888, respectively. The regression equations were y = 0.0364x + 0.0913, y = 0.0349x + 0.0273, y = 0.0343x - 0.0018, y = 0.0522x + 0.1215, and y = 0.0383x + 0.0058, respectively. The correlation coefficient for the residual radioactivity of 99mTc-MDP was rs = 0.9887 and the regression equation was y = 0.1505x + 0.0853. The radioactivity of 99mTc- and 123I-labeled radiopharmaceuticals in shielded syringes was accurately measured. It was suggested that the measuring shielded syringes could provide an estimate of the actual radioactivity.","PeriodicalId":46252,"journal":{"name":"Radiological Physics and Technology","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140190250","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

Setup time analysis for stereotactic body radiotherapy in O-ring linear accelerator without rotational correction. 无旋转校正的 O 型环直线加速器立体定向体放射治疗的设置时间分析。

IF 1.6

Radiological Physics and Technology Pub Date : 2024-06-01 Epub Date: 2024-03-25 DOI: 10.1007/s12194-024-00791-0

Biplab Sarkar, Anirudh Pradhan

引用次数: 0

Long-term geometric quality assurance of radiation focal point and cone-beam computed tomography for Gamma Knife radiosurgery system. 伽玛刀放射外科系统辐射焦点和锥形束计算机断层扫描的长期几何质量保证。

IF 1.6

Radiological Physics and Technology Pub Date : 2024-06-01 Epub Date: 2024-03-11 DOI: 10.1007/s12194-024-00788-9

Shingo Ohira, Toshikazu Imae, Masanari Minamitani, Atsuto Katano, Atsushi Aoki, Takeshi Ohta, Motoyuki Umekawa, Yuki Shinya, Hirotaka Hasegawa, Teiji Nishio, Masahiko Koizumi, Hideomi Yamashita, Nobuhito Saito, Keiichi Nakagawa

{"title":"Long-term geometric quality assurance of radiation focal point and cone-beam computed tomography for Gamma Knife radiosurgery system.","authors":"Shingo Ohira, Toshikazu Imae, Masanari Minamitani, Atsuto Katano, Atsushi Aoki, Takeshi Ohta, Motoyuki Umekawa, Yuki Shinya, Hirotaka Hasegawa, Teiji Nishio, Masahiko Koizumi, Hideomi Yamashita, Nobuhito Saito, Keiichi Nakagawa","doi":"10.1007/s12194-024-00788-9","DOIUrl":"10.1007/s12194-024-00788-9","url":null,"abstract":"To investigate the geometric accuracy of the radiation focal point (RFP) and cone-beam computed tomography (CBCT) over long-term periods for the ICON Leksell Gamma Knife radiosurgery system. This phantom study utilized the ICON quality assurance tool plus, and the phantom was manually set on the patient position system before the implementation of treatment for patients. The deviation of the RFP position from the unit center point (UCP) and the positions of the four ball bearings (BBs) in the CBCT from the reference position were automatically analyzed. During 544 days, a total of 269 analyses were performed on different days. The mean ± standard deviation (SD) of the deviation between measured RFP and UCP was 0.01 ± 0.03, 0.01 ± 0.03, and -0.01 ± 0.01 mm in the X, Y, and Z directions, respectively. The deviations with offset values after the cobalt-60 source replacement (0.00 ± 0.03, -0.01 ± 0.01, and -0.01 ± 0.01 mm in the X, Y, and Z directions, respectively) were significantly (p = 0.001) smaller than those before the replacement (0.02 ± 0.03, 0.02 ± 0.01, and -0.02 ± 0.01 mm in the X, Y, and Z directions, respectively). The overall mean ± SD of four BBs was -0.03 ± 0.03, -0.01 ± 0.05, and 0.01 ± 0.03 mm in the X, Y, and Z directions, respectively. Geometric positional accuracy was ensured to be within 0.1 mm on most days over a long-term period of more than 500 days.","PeriodicalId":46252,"journal":{"name":"Radiological Physics and Technology","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11128398/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140102611","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

Variation in Hounsfield unit calculated using dual-energy computed tomography: comparison of dual-layer, dual-source, and fast kilovoltage switching technique. 使用双能量计算机断层扫描计算的 Hounsfield 单位变化：双层、双源和快速千伏开关技术的比较。

IF 1.6

Radiological Physics and Technology Pub Date : 2024-06-01 Epub Date: 2024-05-03 DOI: 10.1007/s12194-024-00802-0

Shingo Ohira, Junji Mochizuki, Tatsunori Niwa, Kazuyuki Endo, Masanari Minamitani, Hideomi Yamashita, Atsuto Katano, Toshikazu Imae, Teiji Nishio, Masahiko Koizumi, Keiichi Nakagawa

{"title":"Variation in Hounsfield unit calculated using dual-energy computed tomography: comparison of dual-layer, dual-source, and fast kilovoltage switching technique.","authors":"Shingo Ohira, Junji Mochizuki, Tatsunori Niwa, Kazuyuki Endo, Masanari Minamitani, Hideomi Yamashita, Atsuto Katano, Toshikazu Imae, Teiji Nishio, Masahiko Koizumi, Keiichi Nakagawa","doi":"10.1007/s12194-024-00802-0","DOIUrl":"10.1007/s12194-024-00802-0","url":null,"abstract":"The purpose of the study is to investigate the variation in Hounsfield unit (HU) values calculated using dual-energy computed tomography (DECT) scanners. A tissue characterization phantom inserting 16 reference materials were scanned three times using DECT scanners [dual-layer CT (DLCT), dual-source CT (DSCT), and fast kilovoltage switching CT (FKSCT)] changing scanning conditions. The single-energy CT images (120 or 140 kVp), and virtual monochromatic images at 70 keV (VMI70) and 140 keV (VMI140) were reconstructed, and the HU values of each reference material were measured. The difference in HU values was larger when the phantom was scanned using the half dose with wrapping with rubber (strong beam-hardening effect) compared with the full dose without the rubber (reference condition), and the difference was larger as the electron density increased. For SECT, the difference in HU values against the reference condition measured by the DSCT (3.2 ± 5.0 HU) was significantly smaller (p < 0.05) than that using DLCT with 120 kVp (22.4 ± 23.8 HU), DLCT with 140 kVp (11.4 ± 12.8 HU), and FKSCT (13.4 ± 14.3 HU). The respective difference in HU values in the VMI70 and VMI140 measured using the DSCT (10.8 ± 17.1 and 3.5 ± 4.1 HU) and FKSCT (11.5 ± 21.8 and 5.5 ± 10.4 HU) were significantly smaller than those measured using the DLCT120 (23.1 ± 27.5 and 12.4 ± 9.4 HU) and DLCT140 (22.3 ± 28.6 and 13.1 ± 11.4 HU). The HU values and the susceptibility to beam-hardening effects varied widely depending on the DECT scanners.","PeriodicalId":46252,"journal":{"name":"Radiological Physics and Technology","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11128400/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140859080","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

Native myocardial T₁ mapping using inversion recovery T₁-weighted turbo field echo sequence. 使用反转恢复 T1 加权涡轮场回波序列绘制原生心肌 T1 图。

IF 1.6

Radiological Physics and Technology Pub Date : 2024-06-01 Epub Date: 2024-03-26 DOI: 10.1007/s12194-024-00795-w

Katsuhiro Kida, Takamasa Kurosaki, Ryohei Fukui, Ryutaro Matsuura, Sachiko Goto

{"title":"Native myocardial T1 mapping using inversion recovery T1-weighted turbo field echo sequence.","authors":"Katsuhiro Kida, Takamasa Kurosaki, Ryohei Fukui, Ryutaro Matsuura, Sachiko Goto","doi":"10.1007/s12194-024-00795-w","DOIUrl":"10.1007/s12194-024-00795-w","url":null,"abstract":"This study proposes the use of the inversion recovery T1-weighted turbo field echo (IR-T1TFE) sequence for myocardial T1 mapping and compares the results obtained with those of the modified Look-Locker inversion recovery (MOLLI) method for accuracy, precision, and reproducibility. A phantom containing seven vials with different T1 values was imaged, thereby comparing the T1 measurements between the inversion recovery spin-echo (IR-SE) technique, MOLLI, and the IR-T1TFE. The accuracy, precision, and reproducibility of the T1-mapping sequences were analyzed in a phantom study. Fifteen healthy subjects were recruited for the in vivo comparison of native myocardial T1 mapping using MOLLI and IR-T1TFE sequences. After myocardium segmentation, the T1 value of the entire myocardium was calculated. In the phantom study, excellent accuracy was achieved using IR-T1TFE for all T1 ranges. MOLLI displayed lower accuracy than IR-T1TFE (p =0.016), substantially underestimating T1 at large T1 values (> 1000 ms). In the in vivo study, the first mean myocardial T1 values ± SD using MOLLI and IR-T1TFE were 1306 ± 70 ms and 1484 ± 28 ms, respectively, and the second were 1297 ± 68 ms and 1474 ± 43 ms, respectively. The native myocardial T1 obtained with MOLLI was lower than that of IR-T1TFE (p < 0.001). The reproducibility of native myocardial T1 mapping within the same sequence was not statistically significant (p = 0.11). This study demonstrates the utility and validity of myocardial T1 mapping using IR-T1TFE, which is a common sequence. This method was found to have high accuracy and reproducibility.","PeriodicalId":46252,"journal":{"name":"Radiological Physics and Technology","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140294940","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

Commissioning and dosimetric verification of volumetric modulated arc therapy for multiple modalities using electronic portal imaging device-based 3D dosimetry system: a novel approach. 使用基于电子门成像设备的三维剂量测定系统对多种模式的容积调制弧治疗进行调试和剂量测定验证：一种新方法。

IF 1.6

Radiological Physics and Technology Pub Date : 2024-06-01 Epub Date: 2024-03-16 DOI: 10.1007/s12194-024-00792-z

Raghavendra Hajare, Sreelakshmi K K, Anil Kumar, Rituraj Kalita, Shanmukhappa Kaginelli, Umesh Mahantshetty

{"title":"Commissioning and dosimetric verification of volumetric modulated arc therapy for multiple modalities using electronic portal imaging device-based 3D dosimetry system: a novel approach.","authors":"Raghavendra Hajare, Sreelakshmi K K, Anil Kumar, Rituraj Kalita, Shanmukhappa Kaginelli, Umesh Mahantshetty","doi":"10.1007/s12194-024-00792-z","DOIUrl":"10.1007/s12194-024-00792-z","url":null,"abstract":"The purpose of this study was to validate an electronic portal imaging device (EPID) based 3-dimensional (3D) dosimetry system for the commissioning of volumetric modulated arc therapy (VMAT) delivery for flattening filter (FF) and flattening filter free (FFF) modalities based on test suites developed according to American Association of Physicists in Medicine Task Group 119 (AAPM TG 119) and pre-treatment patient specific quality assurance (PSQA).With ionisation chamber, multiple-point measurement in various planes becomes extremely difficult and time-consuming, necessitating repeated exposure of the plan. The average agreement between measured and planned doses for TG plans is recommended to be within 3%, and both the ionisation chamber and PerFRACTION™ measurement were well within this prescribed limit. Both point dose differences with the planned dose and gamma passing rates are comparable with TG reported multi-institution results. From our study, we found that no significant differences were found between FF and FFF beams for measurements using PerFRACTION™ and ion chamber. Overall, PerFRACTION™ produces acceptable results to be used for commissioning and validating VMAT and for performing PSQA. The findings support the feasibility of integrating PerFRACTION™ into routine quality assurance procedures for VMAT delivery. Further multi-institutional studies are recommended to establish global baseline values and enhance the understanding of PerFRACTION™'s capabilities in diverse clinical settings.","PeriodicalId":46252,"journal":{"name":"Radiological Physics and Technology","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140140914","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

Assessment of the deep learning-based gamma passing rate prediction system for 1.5 T magnetic resonance-guided linear accelerator. 评估基于深度学习的 1.5 T 磁共振引导直线加速器伽马通过率预测系统。

IF 1.6

Radiological Physics and Technology Pub Date : 2024-06-01 Epub Date: 2024-04-30 DOI: 10.1007/s12194-024-00800-2

Ryota Tozuka, Noriyuki Kadoya, Kazuhiro Arai, Kiyokazu Sato, Keiichi Jingu

{"title":"Assessment of the deep learning-based gamma passing rate prediction system for 1.5 T magnetic resonance-guided linear accelerator.","authors":"Ryota Tozuka, Noriyuki Kadoya, Kazuhiro Arai, Kiyokazu Sato, Keiichi Jingu","doi":"10.1007/s12194-024-00800-2","DOIUrl":"10.1007/s12194-024-00800-2","url":null,"abstract":"Measurement-based verification is impossible for the patient-specific quality assurance (QA) of online adaptive magnetic resonance imaging-guided radiotherapy (oMRgRT) because the patient remains on the couch throughout the session. We assessed a deep learning (DL) system for oMRgRT to predict the gamma passing rate (GPR). This study collected 125 verification plans [reference plan (RP), 100; adapted plan (AP), 25] from patients with prostate cancer treated using Elekta Unity. Based on our previous study, we employed a convolutional neural network that predicted the GPRs of nine pairs of gamma criteria from 1%/1 mm to 3%/3 mm. First, we trained and tested the DL model using RPs (n = 75 and n = 25 for training and testing, respectively) for its optimization. Second, we tested the GPR prediction accuracy using APs to determine whether the DL model could be applied to APs. The mean absolute error (MAE) and correlation coefficient (r) of the RPs were 1.22 ± 0.27% and 0.29 ± 0.10 in 3%/2 mm, 1.35 ± 0.16% and 0.37 ± 0.15 in 2%/2 mm, and 3.62 ± 0.55% and 0.32 ± 0.14 in 1%/1 mm, respectively. The MAE and r of the APs were 1.13 ± 0.33% and 0.35 ± 0.22 in 3%/2 mm, 1.68 ± 0.47% and 0.30 ± 0.11 in 2%/2 mm, and 5.08 ± 0.29% and 0.15 ± 0.10 in 1%/1 mm, respectively. The time cost was within 3 s for the prediction. The results suggest the DL-based model has the potential for rapid GPR prediction in Elekta Unity.","PeriodicalId":46252,"journal":{"name":"Radiological Physics and Technology","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140868486","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

Adjustment of scan delay for bolus tracking with cardiothoracic ratio of CT scout image for hepatic artery phase of hepatic dynamic CT. 在肝脏动态 CT 的肝动脉阶段，利用 CT 扫描图像的心胸比率调整栓子追踪的扫描延迟。

IF 1.6

Radiological Physics and Technology Pub Date : 2024-05-17 DOI: 10.1007/s12194-024-00814-w

Koji Muroga, Kanta Kitahara

引用次数: 0

Predicting oxygen needs in COVID-19 patients using chest radiography multi-region radiomics. 利用胸片多区域放射组学预测 COVID-19 患者的氧气需求。

IF 1.6

Radiological Physics and Technology Pub Date : 2024-04-26 DOI: 10.1007/s12194-024-00803-z

Sa-Angtip Netprasert, Sararas Khongwirotphan, Roongprai Seangsawang, Supanuch Patipipittana, W. Jantarabenjakul, T. Puthanakit, Wariya Chintanapakdee, S. Sriswasdi, Y. Rakvongthai

引用次数: 0