Department of Radiology, Seoul National University Hospital, Seoul 110-744, Korea.
Korean J Radiol. 2010 Jan-Feb;11(1):19-24. doi: 10.3348/kjr.2010.11.1.19. Epub 2009 Dec 28.
The aim of this study was to evaluate the differences in normal brain MRI findings between under 3.0 Tesla (T) and 1.5T MRI conditions with the use of the fluid attenuated inversion recovery (FLAIR) sequences.
Eleven normal adults underwent imaging with the use of the FLAIR sequences on both 1.5T and 3.0T scanners. Two neuroradiologists compared the signal intensity (SI) of the centrum semiovale (CS), pulvinar thalami (PT) and normal iron deposit structures (IDSs) on the 3.0T and 1.5T FLAIR images, and they evaluated three MRI findings qualitatively: high SI of CS; low SI of PT; low SI of IDS. We also evaluated signal-to-noise ratios (SNRs) for the CS, PT, red nucleus and cerebellar dentate nucleus on the FLAIR images.
Based on qualitative analyses, the 3.0T FLAIR images showed all three MRI findings for all cases. Low SI for the PT in seven cases (64%), high SI of the CS in one case (9%) and low SI of the cerebellar dentate nucleus in one case (9%) were visualized only on 3.0T FLAIR images. The mean SNRs of the PT, red nucleus and dentate nucleus in patients where 3.0T FLAIR imaging was performed were significantly lower as compared with the SNRs on 1.5T FLAIR images. The SNR of the CS was not significantly different between under the two magnetic field strengths (p > 0.05).
We have demonstrated that normal, high and low SIs of the CS, PT and IDS on 3.0T FLAIR images were depicted more frequently and more prominently as compared with those on 1.5T FLAIR images in normal adult brains.
本研究旨在评估使用液体衰减反转恢复(FLAIR)序列时,3.0T 与 1.5T MRI 条件下正常脑 MRI 表现的差异。
11 名正常成年人分别在 1.5T 和 3.0T 扫描仪上进行 FLAIR 序列成像。两位神经放射科医生比较了 3.0T 和 1.5T FLAIR 图像上半卵圆中心(CS)、丘脑髓质(PT)和正常铁沉积结构(IDS)的信号强度(SI),并对三种 MRI 表现进行了定性评估:CS 高 SI;PT 低 SI;IDS 低 SI。我们还评估了 FLAIR 图像上 CS、PT、红核和小脑齿状核的信噪比(SNR)。
基于定性分析,3.0T FLAIR 图像在所有病例中均显示出所有三种 MRI 表现。7 例(64%)出现 PT 低 SI,1 例(9%)出现 CS 高 SI,1 例(9%)出现小脑齿状核低 SI,仅在 3.0T FLAIR 图像上可见。进行 3.0T FLAIR 成像的患者的 PT、红核和齿状核的平均 SNR 明显低于 1.5T FLAIR 图像的 SNR。CS 的 SNR 在两种磁场强度下无显著差异(p>0.05)。
我们已经证明,在正常成年人的大脑中,与 1.5T FLAIR 图像相比,3.0T FLAIR 图像更频繁、更明显地显示出 CS、PT 和 IDS 的正常、高和低 SI。