- 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
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
- 伊藤 大輔 永坂 竜男 梁川 功 吉田 さやか 高瀬 圭
- 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.64, no.12, pp.1562-1567, 2008-12-20 (Released:2009-01-17)
- 参考文献数
- 5
- 被引用文献数
- 4 3
We studied the feasibility of high spatial and temporally resolved imaging by a combination of keyhole imaging, which is a fast imaging method, and a 3.0T MRI system which inherently has a high signal-to-noise ratio (SNR). In keyhole imaging, full k-space reference data are collected, followed by repeated dynamic acquisition of the central low-frequency data alone, and this makes dynamic acquisition faster. The purpose of our article is to describe the effects of the reference data on the reconstructed dynamic images with the assumption of vessel visualization. For efficient use of keyhole imaging, it is important to optimize the keyhole percentage and timing of reference data acquisition for the object of interest.