巻号一覧
28 巻 (2011)
- 4 号 p. 87-
- 3 号 p. 57-
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28 巻, 4 号
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特別講演資料
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—中枢神経領域と腫瘍を中心に—原田 雅史2011 年 28 巻 4 号 p. 87-91
発行日: 2011年
公開日: 2011/12/23
ジャーナル フリーI introduced various kinds of functional imaging using a high magnetic field MR clinical instrument. Diffusion-weighted imaging and MR angiography are very useful for the diagnosis of transient ischemic attack(TIA), and MRI is an indispensable method to decide a therapeutic way for TIA. Furthermore, MRI and MRS spectroscopy can detect neuronal networks and neurotransmitters non-invasively, which are very useful to evaluate cerebral function and pathology of psychiatry diseases. In addition, angiogenesis and perfusion changes on tumors can be estimated using dynamic contrast methods by administration of Gd-DTPA. This information may be used to evaluate the molecular background and therapeutic perspective. MRI has been used for clinical diagnosis by visual estimation of morpholigical changes so far, but according to the increase of magnetic field and mechanical quality, it is now re-evaluated as an important modality to evaluate biological function quantitatively.抄録全体を表示PDF形式でダウンロード (2715K)
論文
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高長 雅子, 林 則夫, 宮地 利明, 川島 博子, 濱口 隆史, 大野 直樹, 飯田 泰治, 松井 修2011 年 28 巻 4 号 p. 92-96
発行日: 2011年
公開日: 2011/12/23
ジャーナル フリーTo compare qualitative and quantitative measures of the contrast-enhanced dual-echo Dixon technique with the commonly used standard three-dimensional(3D)gradient echo(GRE)using spectrally selective fat suppression technique in breast MRI. Dixon and standard fat suppression techniques were compared with phantom and clinical images. A total of 16 women, who underwent the breast MRI, were recruited to our study. For quantitative assessment, we calculated the coefficient of variance(CV)of fat region and contrast between fat region, normal tissue, and lesion on MR images acquired using Dixon technique and spectrally selective fat suppression technique. The CV of Dixon image was significantly higher than that of 3D-GRE images.(P < 0.05). Contrast between fat region and normal tissue and between fat region and lesion for Dixon images were also higher than were 3D-GRE images(P < 0.001). Dixon technique showed greater degree of fat suppression and image uniformity. Dixon technique was superior to the spectrally selective fat suppression technique in breast MRI.抄録全体を表示PDF形式でダウンロード (975K) -
Tatsuhiko MATSUSHITA, Tosiaki MIYATI, Naoki OHNO, Tetsuo OGINO, Tomoyu ...2011 年 28 巻 4 号 p. 97-101
発行日: 2011年
公開日: 2011/12/23
ジャーナル フリーWe evaluated the R2* (iron content)and fat-fraction of liver tissue simultaneously using the modulus and real multiple gradient-echo(MRM-GRE)sequence at low-field MRI. Using a 0.4-Tesla open MRI, modulus images of 4 gradient-echoes(typically 8.9, 17.8, 26.7, and 35.6ms)were obtained by MRM-GRE. The real part of the first echo image was also reconstructed to differentiate below and above the 50percent fat-fraction. R2* and the fat-fraction were obtained from the parameters of a theoretically fitted formula for each echo signal. R2* and fat-fraction were measured with MRM-GRE from phantom data, liver of healthy volunteers(n=12)and from patients with fatty liver(n=3). The phantom MRI-derived fat-fraction was in good agreement with the actual value, with R2* showing a strongly positive correlation to actual iron content. MRI-derived fat-fraction in fatty liver was higher than that in the volunteer. However, no significant difference in R2* was found between fatty liver and volunteers. These results show that MRM-GRE enables a method to differentiate causes of signal reduction whether due to an increasing R2* or increasing fat-fraction. MRM-GRE enables a simple and accurate assessment of fat and iron content at low-fields.抄録全体を表示PDF形式でダウンロード (615K)
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