中文摘要：

目的 研究不同MR扫描仪之间正常成人后循环脑区三维动脉自旋标记灌注成像（3DASL）技术的可重复性.方法 12名健康成年人在2台同一机型的3.0TMR扫描仪上分别进行1次全脑3D ASL扫描,扫描间隔时间为10 ～15 d.3D ASL序列扫描的标记延迟时间（PLD）分别为1.5和2.5s.基于3D ASL序列获得脑血流量（CBF）图.使用统计参数图（SPM）软件提取后循环各个脑区的CBF值,即双侧小脑半球、中脑、脑桥、延髓、丘脑和枕叶.统计分析采用组内相关系数（ICC）及Bland-Altman法.结果 PLD为1.5s时,后循环脑区CBF平均值为36 ～47 ml·min^-1·100 g^-1；PLD为2.5s时,CBF平均值为36 ～46 ml·min^-1·100 g^-1.2次测量结果比较,PLD为1.5s时,ICC值为0.851 （P ＜0.05）；PLD为2.5s时,ICC值为0.914（P ＜0.05）.Bland-Altman图形分析证实后循环脑区对应的点绝大部分位于95％一致性界限内,PLD为2.5s数据的分布范围比PLD为1.5s小.结论 2台MR之间的3D ASL测量重复性好,该序列的测量数据可用于多中心研究,PLD较长时后循环脑区的CBF测量重复性更好.

英文摘要：

Objective To assess the inter-scanner reliability and reproducibility of 3D whole-brain pseudo-continuous arterial spin labeling （pCASL） of posterior circulation territory in healthy adults.Methods Twelve healthy subjects were scanned twice on two different 3.0 T MR scanners with 3D wholebrain pCASL technique.Intervals between tests were among 10-15 days.The ASL data with two post labeling delay time （PLD） of 1.5 and 2.5 seconds were acquired during every scanning.The cerebral blood flow （CBF） values of posterior circulation territory including cerebellum,midbrain,pons,medulla oblongata,thalamus and occipital lobe were extracted based on SPM technique for comparison.The interscanner reliability and reproducibility were evaluated with the intraclass correlation coefficient （ICC） and Bland-Altman plot.Results The CBF values of posterior circulation territory were 36-47 ml ·min^-1·100 g^-1 （PLD =1.5 s） and 36-46 ml ·min^-1· 100 g^-1 （PLD =2.5 s）.Comparing the data between the two tests,the ICC was 0.851 at PLD =1.5 s and 0.914 at PLD =2.5 s.The Bland-Altman showed the reproducibility at PLD =2.5 s was better than that at PLD =1.5 s.Conclusions The 3D whole-brain pCASL technique is available for measuring the CBF at posterior circulation territory with high reliability and reproducibility especially using longer PLD.It can be used for MR multicenter study on blood flow of posterior circulation territory.