著者

本郷 隆治 小倉 明夫 井上 博志 林 浩二 石黒 秋弘

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.57, no.5, pp.573-580, 2001-05-20 (Released:2017-06-30)

参考文献数

8

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In recent years, as gradient magnetic resonance imaging (MRI)systems have become larger and faster, the influence of low-frequency alternating magnetic fields on the human body during rapid scanning have become significant in terms of patient health. It has become more important to monitor time-variant magnetic fields (dB/dt). From this point of view, we measured the maximum dB/dt for clinical scanning using a self-made search coil and storage oscilloscope that conformed to international standard IEC 60601-2-33(1995). The results were almost the same as the calculated values. In this brief report, we introduce to clinical operators the method of measuring maximum dB/dt.

著者

山崎 勝 東田 満治 井上 博志 林 浩二 小倉 明夫 大竹野 浩史 本郷 隆治

出版者

公益社団法人日本放射線技術学会

雑誌

日本放射線技術學會雜誌 (ISSN:03694305)

巻号頁・発行日

vol.53, no.1, 1997-01-20

被引用文献数

3

著者

小倉 明夫 前田 富美恵 宮井 明 本郷 隆治

出版者

公益社団法人日本放射線技術学会

雑誌

日本放射線技術學會雜誌 (ISSN:03694305)

巻号頁・発行日

vol.60, no.11, pp.1543-1549, 2004-11-20

被引用文献数

14

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The contrast-to-noise ratio (CNR.) is often used to evaluate magnetic resonance images, because it has two components, contrast and SNR, and indicates the detectability of clinical lesions. Two methods (using a phantom and using clinical images) are employed to measure CNR. In addition, there are some methods of measurement that use clinical images. In this report, the accuracy of measurement and correlation for signal detectability were evaluated in four methods of measuring CNR using clinical images. The results indicated that the inter-tissue method using an air signal provided good accuracy and was consistent with signal detectability using observer performance. In addition, a small region of interest (ROI) was better suited as the target for CNR measurement using clinical images.