PC-MR大脑中动脉血流测量的临床研究

Measurement of Middle Cerebral Artery Blood Flow by PC-MR

目的：使用GE 1.5T磁共振相位对比法（PC-MR）序列测量大脑中动脉（MCA）血流,探讨不同编码速率（Venc）对MCA血流信号的影响及其与性别、年龄和血压的关系。方法：对85例健康受检者（男46名,女39名,年龄20-75岁,平均（47.2±10.8）岁）分别按性别、年龄、收缩压及舒张压分组。每例预置Venc：55cm/s、65cm/s、75cm/s、85cm/s、95cm/s,对左侧MCA进行5次扫描。在工作站上测得不同Venc相对应的左侧MCA的信号强度,并进行统计学分析。结果：不同预置Venc左侧MCA信号强度差别有统计学意义（F=11.654,P=0.000）,Venc85cm/s时信号最强。Venc预置85cm/s时,左侧MCA信号强度在不同性别（t=-1.254,P=0.187）、年龄组（F=2.156,P=0.157）及不同收缩压组（F=1.125,P=0.368）之间差别无统计学意义;在不同舒张压组间差别有统计学意义（F=3.658,P=0.045）,舒张压〉80mm Hg时,左侧MCA信号随强度减低。结论：MCA PC-MR测量的最佳Venc为85cm/s。MCA血流信号与性别、年龄和收缩压无关;与舒张压有关,信号强度随着舒张压升高而减低。

Purpose： To explore the effect of Venc of GE 1.5T MR cine phase contrast（PC-MR） technique on the blood flow measurements in the middle cerebral artery（MCA）, and to assess the relationship between blood flow and sex, age and blood pressure. Methods Eighty-five healthy volunteers（46 males and 39 females; age ranged 20-75 years; mean age 47.2±10.8 year） were selected in the study. The volunteers were divided into different groups by sex, age, systolic blood pressure and diastolic blood pressure, respectively. For every volunteer, the left MCA was scanned for 5 times repeatedly, with the Venc of 55, 65, 75, 85 and 95cm/s respectively. The signal intensity of the left MCA with different Venc was measured on the workstation, and statistical analysis was carried out. Results： The differences of signal intensity of the left MCA with different Venc were shown with statistical significance（F = 11.654, P = 0.000）. When Venc was set at 85cm/s, the signal intensity was the strongest. The left MCA signal intensity was independent of sex（t =-1.254, P=0.187）, age group（F = 2.156, P = 0.157）, and systolic blood pressure group（F = 1.125,P = 0.368）, when Venc was set at 85cm/s. There were significant differences（F = 3.658, P = 0.045） among diastolic blood pressure group, and when diastolic blood pressure was higher than 80 mm Hg, the left MCA signal intensity was reduced significantly. Conclusion： The best Venc for PC-MR MCA measurement was 85cm/s. MCA blood flow signal intensity was independent of sex, age and systolic blood pressure, but the MCA blood flow signal intensity was decreased with the increase of diastolic blood pressure.