Moonen C T, Barrios F A, Zigun J R, Gillen J, Liu G, Sobering G, Sexton R, Woo J, Frank J, Weinberger D R
In Vivo NMR Research Center, National Institutes of Health, Bethesda, MD 20892.
Magn Reson Imaging. 1994;12(3):379-85. doi: 10.1016/0730-725x(94)92530-5.
Dynamic physiological scanning, based on temporary changes in local field homogeneity during the passage of a contrast agent bolus, has been performed hitherto with echo-planar imaging (EPI) or conventional gradient-recalled techniques (FLASH). Here, it is shown that the T2* sensitivity of conventional FLASH techniques can be improved drastically on a conventional whole body instrument by delaying the gradient-echo until the subsequent TR-period without increasing total imaging time. Examples are given for a full k-space matrix (128 x 256) obtained within 2 s with a TE of 25 ms, resulting in images free of artifacts. The method is applied to bolus tracking through the brain of healthy volunteers during visual stimulation and in the dark. An average increase of regional cerebral blood volume (rCBV) in the visual cortex of 10.9% (n = 9, p = .001) was found.
基于对比剂团注通过期间局部场均匀性的临时变化进行的动态生理扫描，迄今为止一直使用回波平面成像（EPI）或传统的梯度回波技术（FLASH）来进行。在此表明，在不增加总成像时间的情况下，通过将梯度回波延迟到随后的重复时间（TR）周期，可以在传统的全身仪器上大幅提高传统FLASH技术的T2*灵敏度。给出了在2秒内获得完整k空间矩阵（128×256）且回波时间（TE）为25毫秒的示例，所得到的图像无伪影。该方法应用于在视觉刺激期间和黑暗环境中对健康志愿者大脑进行团注追踪。结果发现，视觉皮层的局部脑血容量（rCBV）平均增加了10.9%（n = 9，p = .001）。
