FMRIB Centre, Department of Clinical Neurology, University of Oxford, John Radcliffe Hospital, Oxford, UK.
Magn Reson Med. 2010 Mar;63(3):641-7. doi: 10.1002/mrm.22256.
The purpose of this study was to establish a normal range for the arterial arrival time (AAT) in whole-brain pulsed arterial spin labeling (PASL) cerebral perfusion MRI. Healthy volunteers (N = 36, range: 20 to 35 years) provided informed consent to participate in this study. AAT was assessed in multiple brain regions, using three-dimensional gradient and spin echo (GRASE) pulsed arterial spin labeling at 3.0 T, and found to be 641 +/- 95, 804 +/- 91, 802 +/- 126, and 935 +/- 108 ms in the temporal, parietal, frontal, and occipital lobes, respectively. Mean gray matter AAT was found to be 694 +/- 89 ms for females (N = 15), which was significantly shorter than for men, 814 +/- 192 ms (N = 21; P < 0.0003), and significant after correcting for brain volume (P < 0.001). Significant AAT sex differences were also found using voxelwise permutation testing. An atlas of AAT values across the healthy brain is presented here and may be useful for future experiments that aim to quantify cerebral blood flow from ASL data, as well as for clinical comparisons where disease pathology may lead to altered AAT. Pulsed arterial spin labeling signals were simulated using an identical sampling scheme as the empiric study and revealed AAT can be estimated robustly when simulated arrival times are well beyond the normal range.
本研究旨在建立全脑脉冲动脉自旋标记（PASL）脑灌注 MRI 中动脉到达时间（AAT）的正常范围。健康志愿者（N=36，年龄范围：20 至 35 岁）同意参与本研究。使用三维梯度和自旋回波（GRASE）脉冲动脉自旋标记在 3.0T 下评估 AAT，并分别在颞叶、顶叶、额叶和枕叶中发现 AAT 为 641±95、804±91、802±126 和 935±108ms。女性（N=15）的平均灰质 AAT 为 694±89ms，显著短于男性 814±192ms（N=21；P<0.0003），且在校正脑体积后有显著差异（P<0.001）。使用体素置换检验也发现了 AAT 的显著性别差异。这里呈现了一个健康大脑 AAT 值的图谱，这可能对未来从 ASL 数据定量脑血流的实验以及可能导致 AAT 改变的临床比较有用。使用与经验研究相同的采样方案模拟了脉冲动脉自旋标记信号，结果表明当模拟到达时间远远超出正常范围时，可以可靠地估计 AAT。
