3DASL脑灌注成像:不同标记后延迟时间对血流测量的影响

3D arterial spin-labeling MR:effect of post-labeling delay on cerebral blood flow measurement

目的：探讨3D-ASL MRI中不同标记后延迟时间对脑血流量测量值的影响。方法：选取43例健康成人志愿者（男21例,女22例;年龄25~60岁,平均41岁）,采用不同标记后延迟时间（1025ms,1525ms,2025ms）行3D-ASL检查,测量6个部位的血流量（CBF）,包括小脑皮层、丘脑核团、枕叶、颞叶、顶叶和额叶皮层。三组（不同标记后延迟时间）间各脑区CBF值的比较采用方差分析,并进行两两比较分析。结果：方差分析结果显示三组间双侧小脑半球和左侧顶叶CBF值的差异有统计学意义（右小脑半球,F值6.629,P值0.011;左小脑半球,F值6.986,P值0.007;左顶叶,F值5.143,P值0.020）。进一步两两比较结果显示,双侧小脑半球、右枕叶和左顶叶的CBF值在1025ms组与1525ms、1025ms组与2025ms组间差异有统计学意义（P〈0.05）,在1525ms组与2025ms组间差异无统计学意义比较（P〉0.05）。结论：3D-ASL MRI中不同标记后延迟时间对脑血流量的测量有一定影响。

Objective：To investigate whether the post-labeling delay （PLD） has influence on regional cerebral blood [low in 3D-ASL MR]. Methods：Forty-three healthy adults （21 men and 22 women;age range was 25-60 years with means of 41 yrs） were included in this prospective study. All subjects underwent head MRI using 3D-ASL sequence for three times with different PLD （1025,1525 and 2025ms）, cerebral blood flow （CBF） of bilateral symmetric parts in thalamus nuclei and cerebellar, frontal, temporal, parietal and occipital cortex was measured, CBF values among three groups with different PLDs were compared using ANOVA method and further pair-wise comparison was made. Results： There was statistical signifi- cance in the CBF values of bilateral cerebellar and left parietal cortex among the three groups （F= 6. 629, P--0. 011 for right cerehellar ;F= 6. 986, P = 0. 007 for left cerebellar ; F = 5. 143, P = 0. 020 for left parietal cortex）. Further pair-wise comparison results showed that the differences of CBFs between 1025ms-PLD group and 1525ms-PLD group, between 1025ms-PLD group and 2025ms-PLD group were statistically significant, the difference between 1525ms-PLD group and 2025ms-PLD group was not statistically significant. Conclusion：Different post-labeling delays in 3D-ASL MRI have impacts on CBF values of certain brain areas.