著者

根本 整 永坂 竜男 大田 英揮 山下 裕市 二科 孝志 町田 好男

出版者

公益社団法人 日本放射線技術学会

雑誌

日本放射線技術学会雑誌 (ISSN:03694305)

巻号頁・発行日

vol.74, no.7, pp.675-684, 2018 (Released:2018-07-20)

参考文献数

21

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With shortening of the gantry of magnetic resonance imaging (MRI) systems, large field-of-view (FOV) imaging has become difficult because static magnetic field nonuniformity and gradient magnetic field nonlinearity exacerbate geometric distortion of MR images. However, results of earlier studies have demonstrated that view angle tilting (VAT) can reduce severe image distortion attributable to local susceptibility effects of metals. Although VAT is usually applied to local magnetic field nonuniformity, in principle VAT is expected to correct distortion also for peripheral images in large-FOV MRI. Results from this phantom experiment using VAT with large-FOV verified the effectiveness of distortion correction. The experiment using VAT showed reduction of maximum distortion from 23.6 to −1.9 mm. Furthermore, results of a volunteer study confirmed the distortion correction capability of VAT: it reduced distortion and improved visibility of the anatomical structure. In conclusion, experimentally obtained results underscore VAT effectiveness for improving distortion in large-FOV MRI.

著者

大田 英揮

出版者

医用画像情報学会

雑誌

医用画像情報学会雑誌 (ISSN:09101543)

巻号頁・発行日

vol.30, no.1, pp.12-17, 2013 (Released:2013-03-26)

参考文献数

14

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The number of CT examinations has increased over the last decade using multidetector CT. With the development of technology, multidetector CT, enabling scan faster and wider, can be used as a one-stop-shop procedure in many clinical settings. Routine CT scan protocols are necessary to meet the growing clinical demands. However, we often encounter situations where routine protocols are not enough to assess a patient's condition and specify the diagnosis. Tips for CT image acquisition that can help diagnosis and treatment are discussed through case presentations.