连续三维时飞法磁共振血管成像对脑动脉的显示能力评价

目的评价连续3D-TOF和高速度编码的三维相位对比法(Venc3D-PC)MRA对脑动脉的显示能力。方法前瞻性选取脑MRI表现正常且连续3D-TOF及高Venc3D-PC磁共振脑动脉成像表现正常者15例,用以评价2种MRA技术显示脑动脉的差异。回顾性选取进行脑动脉MRA及DSA2种检查者43例,以DSA为标准,取其中38侧表现正常者用以评价MRA显示脑动脉的能力。结果3D-TOF与高Venc3D-PC技术显示ACA、MCA或PCA的最大级数均无显著统计学差异,但前者的图像质量优于后者。MRA显示ACA、MCA和PCA的分支级数与DSA均有显著差异性。MRA对ACA和MCA的显示能力均较DSA减少1个级别,对PCA的显示能力差别不大。结论连续3D-TOFMRA对脑动脉的显示能力小于DSA,但已能满足大多数脑血管疾病的临床应用。

Consecutive Three-dimensional Time-of-Flight MRA:Its Capacity in Determining Cerebral Arteries

Objective To evaluate the capacity of consecutive three-dimensional time of flight(3D-TOF)MRA and velocity-encoding(Venc)three-dimensional phase-contrast MRA(3D-PC MRA)in determining cerebral arteries.Methods 15 persons being normal on MR images,consecutive 3D-TOF and 3D-PC MR angiograms were selected prospectively to evaluate the difference between two MRA techniques in determining cerebral arteries.The 38 normal sides of 43 cerebral arteriographic cases undergone MRA and DSA were selected retrospectively to evaluate the capacity of MRA technique in determining cerebral arteries with DSA criterion.Results The branch grades of ACA,MCA or PCA demonstrated by 3D-TOF technique were not respectively different from that by 3D-PC.But the former imaging quality was much better than that of the later.The branch grades of ACA,MCA or PCA shown by MRA were respectively different from those by DSA.These grades of ACA,MCA shown by MRA were one less than those by DSA,and that of PCA shown by MRA was a few different from that by DSA.Conclusion The capacity of consecutive 3D-TOF MRA in demonstrating cerebral arteries is less than that of DSA,but it is enough to most cerebral vascular diseases.