Crelier G R, Hoge R D, Munger P, Pike G B
McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Quebec, Canada.
Magn Reson Med. 1999 Jan;41(1):132-6. doi: 10.1002/(sici)1522-2594(199901)41:1<132::aid-mrm18>3.0.co;2-5.
For perfusion-based functional magnetic resonance imaging, the previously introduced flow-sensitive alternating inversion recovery (FAIR) technique is combined with single-shot RARE (rapid acquisition with relaxation enhancement) and GRASE (gradient and spin echo) imaging sequences. The advantages of these sequences compared to commonly used echo-planar imaging (EPI) are an increased signal-to-noise ratio and the absence of distortions and artifacts due to magnetic field inhomogeneities. RARE- and GRASE-FAIR are applied to functional brain mapping studies in humans during visual stimulation. Results demonstrate that the presented techniques allow for perfusion maps with higher spatial resolution compared to EPI-FAIR. Relative regional cerebral blood flow change in the occipital cortex during visual stimulation was measured to be 41+/-4% (n = 5). The comparison of FAIR data obtained with RARE and GRASE techniques shows that RARE yields images with the higher signal-to-noise ratio. However, the GRASE technique features a shorter acquisition time and less RF power deposition and is thus better suited for multi-slice acquisitions.
对于基于灌注的功能磁共振成像，先前引入的血流敏感交替反转恢复（FAIR）技术与单次激发RARE（快速采集弛豫增强）和GRASE（梯度和自旋回波）成像序列相结合。与常用的回波平面成像（EPI）相比，这些序列的优点是信噪比增加，并且不存在由于磁场不均匀性导致的失真和伪影。RARE-FAIR和GRASE-FAIR应用于人类视觉刺激期间的功能性脑图谱研究。结果表明，与EPI-FAIR相比，所提出的技术能够生成具有更高空间分辨率的灌注图。在视觉刺激期间，枕叶皮质的相对局部脑血流变化测量为41±4%（n = 5）。用RARE和GRASE技术获得的FAIR数据比较表明，RARE产生的图像具有更高的信噪比。然而，GRASE技术具有更短的采集时间和更少的射频功率沉积，因此更适合多层采集。
