Nihon Hoshasen Gijutsu Gakkai zasshi最新文献_第4页

[Simulation Image Generation Used to Produce Contrast-detail Diagram in X-ray CT]. [用于制作 X 射线 CT 对比细节图的模拟图像生成]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-1443

Kenichi Sakai, Masaki Ohkubo, Akihiro Narita, Naoya Takahashi, Yoshiyuki Noto

{"title":"[Simulation Image Generation Used to Produce Contrast-detail Diagram in X-ray CT].","authors":"Kenichi Sakai, Masaki Ohkubo, Akihiro Narita, Naoya Takahashi, Yoshiyuki Noto","doi":"10.6009/jjrt.25-1443","DOIUrl":"10.6009/jjrt.25-1443","url":null,"abstract":"Purpose: To propose a method for generating simulated images that are used to produce a contrast detail (C-D) diagram in X-ray computed tomography (CT).Methods: We numerically generated object functions assuming ideal spheres of 7 diameters and 9 contrasts between sphere density and background density. Sphere images were calculated from the object functions by the simulation technique of image blurring based on the 3-dimensional spatial resolution measured in the CT system. The calculated sphere images were added in images of the uniform water-equivalent section of a phantom acquired at different tube currents. Obtained images were arranged according to the sphere diameter and contrast and were applied to produce the C-D diagram. For each tube current, the C-D diagram was created by a board-certified diagnostic radiologist.Results: The calculated sphere images showed good agreements with actually acquired sphere images of the phantom. Standard deviations (SDs) in subtraction images of them were equivalent to the SD in the background region of the actual image, suggesting the accuracy of the calculated sphere images. The obtained C-D diagram showed that smaller spheres and spheres with lower contrast tended to be detected as the tube current increased.Conclusion: The proposed method was suggested to be feasible for producing the C-D diagram for CT.","PeriodicalId":74309,"journal":{"name":"Nihon Hoshasen Gijutsu Gakkai zasshi","volume":"81 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143797361","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

[Global Business Solution Using WTO/TBT Agreement]. [使用WTO/TBT协议的全球商业解决方案]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-0203

Yuji Yanagida

引用次数: 0

[Radioproteomics for Discriminating the Activity and Inactivity of Immune Checkpoint Molecules in Breast Cancer]. 放射蛋白质组学用于鉴别乳腺癌免疫检查点分子的活性和不活性。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-0301

Fuyu Harada

引用次数: 0

[Introduction]. (介绍)。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-0403

Kenta Miwa

引用次数: 0

[Application of the IR Method Using a Normal Database Created by FBP Method with No Correction in ^99mTc Myocardial Perfusion SPECT]. [无校正FBP法建立正常数据库的IR方法在99mTc心肌灌注SPECT中的应用]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-1524

Keiko Segawa, Takayuki Shibutani, Yusuke Yamaguchi, Hajime Ichikawa, Takahiro Konishi, Hiroto Yoneyama, Kenichi Nakajima

{"title":"[Application of the IR Method Using a Normal Database Created by FBP Method with No Correction in 99mTc Myocardial Perfusion SPECT].","authors":"Keiko Segawa, Takayuki Shibutani, Yusuke Yamaguchi, Hajime Ichikawa, Takahiro Konishi, Hiroto Yoneyama, Kenichi Nakajima","doi":"10.6009/jjrt.25-1524","DOIUrl":"10.6009/jjrt.25-1524","url":null,"abstract":"Purpose: Japanese normal databases (NDB) for quantitative evaluation of 99mTc myocardial perfusion SPECT have traditionally been created by the filtered back projection (FBP) method but are also applied to the iterative reconstruction (IR) method in some institutions. Although creating the NDB specifically for the IR method is desirable, it has not been done partly due to the ethical aspects of creating an institution-specific database. This study investigated the impact of using NDBs created by the FBP method on quantitative evaluations performed with the IR method.Methods: We analyzed single-photon emission computed tomography (SPECT) images from patients undergoing myocardial perfusion study in two hospitals with three SPECT vendors. Images were processed with and without various corrections, and a polar map was created by QPS software using a 17-segment model to obtain %uptake and scores. The effects of the reconstruction and correction methods were evaluated to determine the difference in the number of local segmental analyses by coronary artery territories.Results: In most segments, quantitative values showed no significant difference across device types, with or without corrections. However, both choices of the SPECT device and correction methods influenced the scores in specific coronary artery regions. Application of attenuation correction resulted in lower defect scores in the right coronary artery region.Conclusion: Applying FBP-derived NDB to the IR method generally yielded a consistent patient diagnosis in terms of defect score analysis. However, since the quantitative evaluation was partly affected by various correction methods and devices, recognizing these characteristics is crucial for enhancing diagnostic accuracy.","PeriodicalId":74309,"journal":{"name":"Nihon Hoshasen Gijutsu Gakkai zasshi","volume":"81 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143495051","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 Exposure Dose Reduction Effect for Cone-beam Computed Tomography with Bismuth Sheet in Image-guided Radiation Therapy of Prostate Cancer]. [图像引导前列腺癌放射治疗中锥形束ct加铋片照射剂量降低效果评价]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-1531

Tatsuya Yoshida, Koji Sasaki, Tomoki Hayakawa, Toshiyuki Kawadai, Takako Shibasaki, Yoshiyuki Kawasaki

{"title":"[Evaluation of Exposure Dose Reduction Effect for Cone-beam Computed Tomography with Bismuth Sheet in Image-guided Radiation Therapy of Prostate Cancer].","authors":"Tatsuya Yoshida, Koji Sasaki, Tomoki Hayakawa, Toshiyuki Kawadai, Takako Shibasaki, Yoshiyuki Kawasaki","doi":"10.6009/jjrt.25-1531","DOIUrl":"10.6009/jjrt.25-1531","url":null,"abstract":"Purpose: Image-guided radiation therapy using cone-beam computed tomography (CBCT) for prostate cancer is problematic due to the increasing exposure dose at each treatment session. This study aimed to evaluate the effect of exposure dose reduction using bismuth sheets for pelvic CBCT.Methods: Using a radiophotoluminescence dosimeter (GD-352M) and CBCT imaging conditions with three X-ray tube rotation angles (292°-88°, 92°-248°, and 92°-88°), absorbed doses were measured in the rectum, anterior and posterior bladder walls, right and left pelvic subcutaneous at 5 cm superior the prostate center of the pelvic phantom and in a testis. Next, the same measurements were performed when these measurement points were covered with a bismuth sheet.Results: The absorbed doses at 92°-248° with the bismuth sheets were reduced by 31.3% from 16.3±0.2 mGy to 11.2±0.2 mGy for the rectum and by 57.1% from 45.0±2.7 mGy to 19.3±1.0 mGy for the testis, which were the lowest among the imaging conditions. Although the anterior and posterior bladder walls were the highest dose at 48.7±11.5 and 20.2±0.4 mGy, the high reduction rates of 42.0% and 36.9%, respectively.Conclusion: From the viewpoint of the exposure risk to the bladder, rectum, and testis, using bismuth sheets and the X-ray tube rotation angle of 92°-248° effectively reduced the exposure dose.","PeriodicalId":74309,"journal":{"name":"Nihon Hoshasen Gijutsu Gakkai zasshi","volume":"81 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143538192","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

[Image Quality Assessment of Non-contrast Brain Computed Tomography Using High-pitch Double Spiral Scan: A Basic Evaluation Using Phantom]. [使用高音高双螺旋扫描的非对比脑计算机断层成像质量评估：基于Phantom的基本评估]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-1499

Yuichiro Sato, Tomomi Ohmura, Shun Muramatsu, Yuki Shinohara, Fumiaki Sasaki, Kazunori Matsumoto, Kouya Nakaizumi, Mamoru Kato

{"title":"[Image Quality Assessment of Non-contrast Brain Computed Tomography Using High-pitch Double Spiral Scan: A Basic Evaluation Using Phantom].","authors":"Yuichiro Sato, Tomomi Ohmura, Shun Muramatsu, Yuki Shinohara, Fumiaki Sasaki, Kazunori Matsumoto, Kouya Nakaizumi, Mamoru Kato","doi":"10.6009/jjrt.25-1499","DOIUrl":"https://doi.org/10.6009/jjrt.25-1499","url":null,"abstract":"Purpose: Motion artifacts likely occur in patients with acute intracerebral hemorrhage (ICH). This study aimed to validate the image quality characteristics of non-contrast brain computed tomography (CT) with high-speed imaging technology, named Flash spiral (FS) (Siemens Healthineers, Erlangen, Germany). We verified the differences in CT values using a phantom that simulated hematoma.Methods: A dual-source CT scanner (SOMATOM Drive; Siemens Healthineers) was used to obtain reference and FS images of a Catphan700 phantom (The Phantom Laboratory, Greenwich, NY, USA). The CT values were measured in the hematoma-simulated acrylic module and urethane within the phantom. The noise power spectrum (NPS), task transfer function (TTF), and system performance function (SPF) between reference and FS images were obtained to compare image quality in each scan.Results: Compared with the phantom's reference and FS images, no significant differences were observed in the CT values between the samples simulating hematoma and their surrounding areas. The NPS showed lower values in the FS images than the reference images at spatial frequencies above approximately 0.4 cycles/mm, while the peak frequencies were nearly equivalent. The 10% TTF values were almost the same between both images. The SPF values were also equivalent between the two images at spatial frequencies above approximately 0.5 cycles/mm.Conclusion: In the phantom experiment, the 10% TTF values of the FS images were comparable to those of the reference images, indicating similar resolution in the high spatial frequency domain. FS is expected to expand the applicability for detecting cerebral hemorrhage in patients with significant body movement, where detection is challenging under standard conditions.","PeriodicalId":74309,"journal":{"name":"Nihon Hoshasen Gijutsu Gakkai zasshi","volume":"81 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144082625","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

[Development and Accuracy Evaluation of the Beam Width Using a Tungsten Ring in a Wide-beam CT System]. [宽波束CT系统中钨环波束宽度的研制与精度评价]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-1488

Takuma Hayashi, Atsushi Fukuda, Nao Ichikawa, Kosuke Matsubara

{"title":"[Development and Accuracy Evaluation of the Beam Width Using a Tungsten Ring in a Wide-beam CT System].","authors":"Takuma Hayashi, Atsushi Fukuda, Nao Ichikawa, Kosuke Matsubara","doi":"10.6009/jjrt.25-1488","DOIUrl":"https://doi.org/10.6009/jjrt.25-1488","url":null,"abstract":"Purpose: This study aims to devise and identify the errors of the beam width measurements in a wide beam CT system using three tungsten rings (TR) in comparison with a flat-panel detector (FPD), and develop a new method to correct the errors.Methods: A pencil-type ionization chamber was placed at the isocenter. The Kerma-length product ( KLP) was measured at 80 and 120 kV, 400 mA, and a rotation time of 0.5s with nominal beam widths ranging from 20 to 160 mm in 20 mm increments. Subsequently, each TR was attached to the chamber to measure the KLPmask at the isocenter, and the beam width was calculated as KLP×ring length/( KLP-KLPmask). To compare the measurement accuracy, the beam widths were measured using the FPD with a double-exposure technique. The X-ray exposures were performed at 80 kV, rotation time of 0.5 s, and 10 and 20 mA were used for the measurements. Finally, the heel effect correction, replacing the KLP at the anode side, was also compared.Results: The measured beam widths using 5-, 10-, and 15-mm TRs at 80/120 kV, and the FPD were 182.5 /182.1, 167.5/165.7, 168.2/163.0, and 172.9 mm in the nominal beam width of 160 mm, respectively. The heel effect correction with 10- and 15-mm TRs at 80 kV improved the measurement accuracy, and the corrected beam widths were 172.4 and 173.2 mm, respectively.Conclusion: In conclusion, 10- and 15-mm TRs in conjunction with the heel effect correction are appropriate for the beam width measurements in a wide beam CT system.","PeriodicalId":74309,"journal":{"name":"Nihon Hoshasen Gijutsu Gakkai zasshi","volume":"81 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144096080","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

[3. Radiation Biological Effects in Targeted Radionuclide Therapy]. (3。靶向放射性核素治疗中的放射生物学效应[j]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-0605

Tetsuya Sakashita

引用次数: 0

[8. The Tendency of Internal Exposure Dose for Residents in Fukushima Prefecture by the Fukushima Daiichi Nuclear Power Plant Accident]. (8。福岛第一核电站事故对福岛县居民内照射剂量的影响[j]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-0603

Takashi Ohba

引用次数: 0