二维相位对比磁共振血管成像测量脑血流量：颈动脉及其同侧分支血流量的验证

课题组前期研究证实，相位对比磁共振血管成像测量脑血流量的最佳速度编码为60～80cm/s。为验证二维相位对比磁共振血管成像测量脑血流量的准确性，实验以三维时间飞越法磁共振血管成像定位颈部血管感兴趣区，设定速度编码为80cm/s，对10名健康志愿者的20组颈总动脉、颈内动脉和颈外动脉的血流量测量结果显示，颈总动脉与其分支颈内动脉和颈外动脉血流量之和误差为（7.0±6.0）%，二者比较差异无显著性意义，且具有明显的相关性，同时颈总动脉血流量也与同侧颈内动脉血流量相关。造成误差的主要原因来自于颈外动脉及其分支。合理运用扫描参数及方案，二维相位对比磁共振血管成像可准确测量脑血流量。

Cerebral blood flow volume measurements of the carotid artery and ipsilateral branches using two-dimensional phase-contrast magnetic resonance angiography

The optimal velocity encoding of phase-contrast magnetic resonance angiography (PC MRA) in measuring cerebral blood flow volume (BFV) ranges from 60 to 80 cm/s. To verify the accuracy of two-dimensional (2D) PC MRA, the present study localized the region of interest at blood vessels of the neck using PC MRA based on three-dimensional time-of-flight sequences, and the velocity encoding was set to 80 cm/s. Results of the measurements showed that the error rate was 7.0 ± 6.0% in the estimation of BFV in the internal carotid artery, the external carotid artery and the ipsilateral common carotid artery. There was no significant difference, and a significant correlation in BFV between internal carotid artery + external carotid artery and ipsilateral common carotid artery. In addition, the BFV of the common carotid artery was correlated with that of the ipsilateral internal carotid artery. The main error was attributed to the external carotid artery and its branches. Therefore, after selecting the appropriate scanning parameters and protocols, 2D PC MRA is more accurate in the determination of BFV in the carotid arteries.