Radiological Physics and Technology最新文献_第8页

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

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":" ","pages":"458-466"},"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":" ","pages":"425-432"},"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

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":" ","pages":"451-457"},"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

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":" ","pages":"412-424"},"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

Deep learning-based PET image denoising and reconstruction: a review. 基于深度学习的 PET 图像去噪与重建：综述。

IF 1.7

Radiological Physics and Technology Pub Date : 2024-03-01 Epub Date: 2024-02-06 DOI: 10.1007/s12194-024-00780-3

Fumio Hashimoto, Yuya Onishi, Kibo Ote, Hideaki Tashima, Andrew J Reader, Taiga Yamaya

引用次数: 0

The effects of mega-voltage CT scan parameters on offline adaptive radiation therapy. 巨电压 CT 扫描参数对离线自适应放射治疗的影响。

IF 1.6

Radiological Physics and Technology Pub Date : 2024-03-01 Epub Date: 2024-02-09 DOI: 10.1007/s12194-023-00773-8

Kento Hoshida, Ayumu Ohishi, Asumi Mizoguchi, Sunao Ohkura, Hidemichi Kawata

{"title":"The effects of mega-voltage CT scan parameters on offline adaptive radiation therapy.","authors":"Kento Hoshida, Ayumu Ohishi, Asumi Mizoguchi, Sunao Ohkura, Hidemichi Kawata","doi":"10.1007/s12194-023-00773-8","DOIUrl":"10.1007/s12194-023-00773-8","url":null,"abstract":"TomoTherapy involves image-guided radiation therapy (IGRT) using Mega-voltage CT (MVCT) for each treatment session. The acquired MVCT images can be utilized for the retrospective assessment of dose distribution. The TomoTherapy provides 18 distinct imaging conditions that can be selected based on a combination of algorithms, acquisition pitch, and slice interval. We investigated the accuracy of dose calculation and deformable image registration (DIR) depending on MVCT scan parameters and their effects on adaptive radiation therapy (ART). We acquired image values for density calibration tables (IVDTs) under 18 different MVCT conditions and compared them. The planning CT (pCT) was performed using a thoracic phantom, and an esophageal intensity-modulated radiation therapy (IMRT) plan was created. MVCT images of the thoracic phantom were acquired under each of the 18 conditions, and dose recalculation was performed. DIR was performed on the MVCT images acquired under each condition. The accuracy of DIR, depending on the MVCT scan parameters, was compared using the mean distance to agreement (MDA) and Dice similarity coefficient (DSC). The dose distribution calculated on the MVCT images was deformed using deformed vector fields (DVF). No significant differences were observed in the results of the 18 IVDTs. The esophageal IMRT plan also showed a small dose difference. Regarding verifying the DIR accuracy, the MDA increased, and the DSC decreased as the acquisition pitch and slice interval increased. The difference between the dose distributions after dose mapping was comparable to that before DIR. The MVCT scan parameters had little effect on ART.","PeriodicalId":46252,"journal":{"name":"Radiological Physics and Technology","volume":" ","pages":"248-257"},"PeriodicalIF":1.6,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139708189","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

Simplified assessment for chemical exchanged saturation transfer (CEST) imaging: local offset frequency and CEST effect. 化学交换饱和转移（CEST）成像的简化评估：局部偏移频率和CEST效应。

IF 1.6

Radiological Physics and Technology Pub Date : 2024-03-01 Epub Date: 2023-10-28 DOI: 10.1007/s12194-023-00752-z

Daiki Chiba, Yuki Kanazawa, Tosiaki Miyati, Masafumi Harada, Mitsuharu Miyoshi, Hiroaki Hayashi, Akihiro Haga

{"title":"Simplified assessment for chemical exchanged saturation transfer (CEST) imaging: local offset frequency and CEST effect.","authors":"Daiki Chiba, Yuki Kanazawa, Tosiaki Miyati, Masafumi Harada, Mitsuharu Miyoshi, Hiroaki Hayashi, Akihiro Haga","doi":"10.1007/s12194-023-00752-z","DOIUrl":"10.1007/s12194-023-00752-z","url":null,"abstract":"The aim of this study is to develop a novel phantom for the evaluation of clinical CEST imaging settings, e.g., B0 and B1 field inhomogeneities, CEST contrast, and post-processing. We made a phantom composed of two slice sections: a grid section for local offset frequency evaluation and a sample section for CEST effect evaluation using different concentrations of an egg white albumin solution. On a 3 Tesla MR scanner, a phantom study was performed using CEST imaging; the mean B1 amplitudes were set at 1.2 and 1.9 µT, and CEST images with and without B0 corrections were acquired. Next, region of interest (ROI) analysis was performed for each slice. Then, CEST images with and without B0 corrections were compared at each B1 amplitude. The B0 corrected Z-spectrums at each local region in the grid section showed a shifting of the curve bottom to 0 ppm. Z-spectrum at B1 = 1.9 µT showed a broader curve shape than that at 1.2 µT. Moreover, MTRasym values at 3.5 ppm for each albumin sample at B1 = 1.9 µT were about two times higher than those at 1.2 µT. Our phantom enabled us to evaluate and optimize B0 inhomogeneity and the CEST effect at the B1 amplitude.","PeriodicalId":46252,"journal":{"name":"Radiological Physics and Technology","volume":" ","pages":"93-102"},"PeriodicalIF":1.6,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66784465","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 montage method improves the classification of suspected acute ischemic stroke using the convolution neural network and brain MRI. 蒙太奇方法利用卷积神经网络和脑MRI改进了疑似急性缺血性中风的分类。

IF 1.6

Radiological Physics and Technology Pub Date : 2024-03-01 Epub Date: 2023-11-07 DOI: 10.1007/s12194-023-00754-x

Daisuke Oura, Masayuki Gekka, Hiroyuki Sugimori

引用次数: 0

Development and evaluation of an integrated liver nodule diagnostic method by combining the liver segment division and lesion localization/classification models for enhanced focal liver lesion detection. 通过结合肝段划分和病变定位/分类模型，开发和评估用于增强局灶性肝病变检测的综合性肝结节诊断方法。

IF 1.6

Radiological Physics and Technology Pub Date : 2024-03-01 Epub Date: 2023-11-02 DOI: 10.1007/s12194-023-00753-y

Tomomi Takenaga, Shouhei Hanaoka, Yukihiro Nomura, Takahiro Nakao, Hisaichi Shibata, Soichiro Miki, Takeharu Yoshikawa, Naoto Hayashi, Osamu Abe

{"title":"Development and evaluation of an integrated liver nodule diagnostic method by combining the liver segment division and lesion localization/classification models for enhanced focal liver lesion detection.","authors":"Tomomi Takenaga, Shouhei Hanaoka, Yukihiro Nomura, Takahiro Nakao, Hisaichi Shibata, Soichiro Miki, Takeharu Yoshikawa, Naoto Hayashi, Osamu Abe","doi":"10.1007/s12194-023-00753-y","DOIUrl":"10.1007/s12194-023-00753-y","url":null,"abstract":"The purpose of the study was to develop a liver nodule diagnostic method that accurately localizes and classifies focal liver lesions and identifies the specific liver segments in which they reside by integrating a liver segment division algorithm using a four-dimensional (4D) fully convolutional residual network (FC-ResNet) with a localization and classification model. We retrospectively collected data and divided 106 gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance examinations into Case-sets 1, 2, and 3. A liver segment division algorithm was developed using a 4D FC-ResNet and trained with semi-automatically created silver-standard annotations; performance was evaluated using manually created gold-standard annotations by calculating the Dice scores for each liver segment. The performance of the liver nodule diagnostic method was assessed by comparing the results with those of the original radiology reports. The mean Dice score between the output of the liver segment division model and the gold standard was 0.643 for Case-set 2 (normal liver contours) and 0.534 for Case-set 1 (deformed liver contours). Among the 64 lesions in Case-set 3, the diagnostic method localized 37 lesions, classified 33 lesions, and identified the liver segments for 30 lesions. A total of 28 lesions were true positives, matching the original radiology reports. The liver nodule diagnostic method, which integrates a liver segment division algorithm with a lesion localization and classification model, exhibits great potential for localizing and classifying focal liver lesions and identifying the liver segments in which they reside. Further improvements and validation using larger sample sizes will enhance its performance and clinical applicability.","PeriodicalId":46252,"journal":{"name":"Radiological Physics and Technology","volume":" ","pages":"103-111"},"PeriodicalIF":1.6,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71427787","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