Department of Epileptology, University of Bonn Medical Center, Bonn, Germany.
German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.
Sci Rep. 2020 Oct 27;10(1):18299. doi: 10.1038/s41598-020-74680-y.
Arterial spin labeling (ASL) is increasingly applied for cerebral blood flow mapping, but [Formula: see text] relaxation of the ASL signal magnetization is often ignored, although it may be clinically relevant. To investigate the extent, to which quantitative [Formula: see text] values in gray matter (GM) obtained by pseudocontinuous ASL (pCASL) perfusion MRI can be reproduced, are reliable and a potential neuroscientific biomarker, a prospective study was performed with ten healthy volunteers (5F,28 ± 3y) at a 3 T scanner. A [Formula: see text]-prepared pCASL sequence enabled the measurement of quantitative [Formula: see text] and perfusion maps. [Formula: see text] times were modeled per voxel and analyzed within four GM-regions-of-interest (ROI). The intraclass correlation coefficients (ICCs) of the quantified ASL-[Formula: see text] varied across brain regions. When averaged across subjects and postlabeling delays (PLDs), the ICCs ranged from reasonable values in parietal regions (ICC = 0.56) to smaller values in frontal regions (ICC = 0.36). Corresponding subject-averaged within-subject coefficients of variation (WSCVs) showed good test-retest measurement precision ([Formula: see text] for all PLDs), but more pronounced inter-subject variance. Reliability and precision of quantified ASL-[Formula: see text] were region-, PLD- and subject-specific, showing fair to robust results in occipital, parietal and temporal ROIs. The results give rise to consider the method for future cerebral studies, where variable perfusion or altered [Formula: see text] times are suspected.
动脉自旋标记 (ASL) 越来越多地应用于脑血流mapping，但 ASL 信号磁化率的[Formula: see text]弛豫通常被忽略，尽管它可能具有临床相关性。为了研究通过伪连续 ASL (pCASL) 灌注 MRI 获得的灰质 (GM) 中的定量[Formula: see text]值在多大程度上可以重现、可靠且是潜在的神经科学生物标志物，我们在 3T 扫描仪上对 10 名健康志愿者（5 名女性，28±3 岁）进行了前瞻性研究。[Formula: see text] 准备的 pCASL 序列可用于测量定量[Formula: see text]和灌注图。对每个体素进行[Formula: see text]时间建模，并在四个 GM 感兴趣区 (ROI) 内进行分析。定量 ASL-[Formula: see text]的组内相关系数 (ICC) 在脑区之间有所不同。当平均跨受试者和标记后延迟 (PLD) 时，ICC 范围从顶叶区域的合理值（ICC=0.56）到额叶区域的较小值（ICC=0.36）。相应的受试者平均个体内变异系数 (WSCV) 显示出良好的测试-重测测量精度 ([Formula: see text]对于所有 PLD)，但个体间变异性更大。定量 ASL-[Formula: see text]的可靠性和精度具有区域、PLD 和受试者特异性，在枕叶、顶叶和颞叶 ROI 中表现出良好到稳健的结果。这些结果表明，在怀疑存在可变灌注或改变的[Formula: see text]时间的情况下，该方法可用于未来的大脑研究。
