Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, Tübingen, Germany.
Magn Reson Med. 2010 Oct;64(4):1109-13. doi: 10.1002/mrm.22476.
Quantification of perfusion in white matter is still difficult due to its low level, causing an often insufficiently low signal-to-noise ratio, and its long and inhomogeneous transit delays. Here, a technique is presented that accurately measures white matter perfusion by combining a spectroscopic single-voxel localization technique (point-resolved spectroscopy) with a pulsed arterial spin labeling encoding scheme (flow-sensitive alternating inversion recovery) to specifically address the properties of white matter. The transit delay was measured by shifting the position of a slice-selective saturation pulse between inversion and acquisition. Perfusion measurements resulted in values of 15.6 ± 3.2 mL/100 g/min in the left and 15.2 ± 4.8 mL/100 g/min in the right hemispheric white matter and 83.2 ± 15.2 mL/100 g/min in cortical gray matter. Taking dispersion of the transit times into account does not cause a significant change in the measured values.
由于水平低、信噪比往往不够低，以及传输延迟时间长且不均匀，因此对脑白质的灌注进行定量分析仍然较为困难。这里提出了一种技术，通过将单体素定位光谱技术（点分辨光谱）与脉冲动脉自旋标记编码方案（流动敏感交替反转恢复）相结合，来精确测量脑白质的灌注，专门针对脑白质的特性进行了优化。通过在反转和采集之间移动片选饱和脉冲的位置来测量传输延迟。在左半球和右半球的脑白质中，灌注测量值分别为 15.6 ± 3.2 mL/100 g/min 和 15.2 ± 4.8 mL/100 g/min，而在皮质灰质中则为 83.2 ± 15.2 mL/100 g/min。考虑到传输时间的分散性，测量值不会发生显著变化。
