Abstract: Objective To study the optimization of scan time for resting-state functional magnetic resonance imaging (fMRI) in clinical application. Methods Fractional amplitude of low-frequency fluctuation (fALFF) was performed to analyse the resting-state fMRI data of 6 and 12 min scan time, respectively. The resting-state fMRI data of 16 subacute pontine infarction patients and 16 normal controls were analysed. The activations of default mode network (DMN) were compared between the resting-state fMRI data of 6 and 12 min scan time. Results The activations of DMN were both found in patient and normal groups. There was no significant difference between the resting-state fMRI data of 6 and 12 min scan time (P > 0.05). Conclusion The optimization of scan time for resting-state fMRI was 6 min and it is very important for clinical application.

Key words: Magnetic resonance imaging, Brain infarction

摘要： 目的 探讨静息态fMRI 临床应用的最优化扫描时间。方法 采用分数低频振荡振幅（fALFF）值观察16 例亚急性期脑桥单发梗死患者（脑梗死组）静息态fMRI扫描6 和12 min 时各脑区默认网络，并与年龄、性别相匹配的正常对照者（对照组）脑默认网络激活范围和强度进行比较。结果 静息态fMRI扫描6和12 min 时，两组受试者各脑区默认网络均被激活，其中对照组两次扫描的脑区包括扣带回前后部、前楔叶、双侧角回和顶下小叶、前额叶，与以往对照者的脑默认网络研究结果相似；4 个经典脑区的默认网络在不同测量时间点（6 和12 min）的激活程度，差异无统计学意义（均P > 0.05）。脑梗死组患者两个测量时间点均获得与对照组相同的默认网络经典脑区，且两个测量时间点的激活程度差异亦无统计学意义（均P > 0.05），但12 min 时扫描的头动参数略大于6 min 时。结论 脑梗死组患者静息态fMRI以扫描6 min为更优化时间，对临床疾病的研究具有重要参考价值。

关键词: 磁共振成像, 脑梗死