上矢状窦生理流动模式的相位对比磁共振研究

Phase-contrast MRI study of the physiological flow pattern in superior sagittal sinus

目的:利用相位对比磁共振成像(PC-MRI)观察上矢状窦(SSS)不同解剖段的生理流动模式及血流动力学的差异。方法:选取19例健康志愿者,采用MRV定位,对SSS的前、中及后段分别行PC-MRI扫描,在工作站采用Q-Flow软件包进行后处理,获得各段的时相-流速曲线,测量和记录各解剖段的平均流量(MF)、平均流速(MV)、血管面积、收缩期最高流速(PSV)和舒张期最低流速(PDV)及其对应的时相点(TH),计算峰值时相差率(R_(△TH))及峰值流速差(△V)。结果:前、中及后段SSS在心动周期内呈单向、低幅、振荡式流动,时相-流速曲线平滑,呈"缓降-缓升-缓降"型,三段间R_(△TH)及△V的差异无统计学意义(H时相差率=3.70,P=0.16;F_(△V)=0.43,P=0.65)。前、中及后段SSS的血管面积及MF依次递增,各段间的差异均有统计学意义(H_(血管面积)=35.18,H_(MF)=41.98;P<0.01);三段间MV的差异有统计学意义(H=15.14,P<0.01),其中前段与中段MV的差异无统计学意义(P>0.05),而后段的MV显著高于前段和中段(P<0.01)。结论:前、中及后段上矢状窦的生理流动模式相似,PC-MRI能直观、准确地评估上矢状窦的流动模式。

Objective:To explore the differences of physiological flow modes and hemodynamics in different anatomical segments of superior sagittal sinus(SSS)using phase-contrast magnetic resonance imaging(PC-MRI).Methods:Nineteen healthy volunteers were selected and PC-MRI scanning was performed at the anterior,middle and posterior segments of SSS by MRV localization.Then all images were post-processed on Q-Flow workstation,phase-flow velocity curve was obtained and analyzed.The peak diastolic velocity(PDV),peak systolic velocity(PSV)and their corresponding time phases were recorded.Then difference ratio of the time phases(R△TH)and difference value(△V)between the PDV and PSV were calculated.Mean velocity(MV),mean flux(MF)and vascular area were recorded.Results:The flow modes in different anatomical segments of SSS appeared as one-way with low amplitude.The type of time-flow velocity curve was smooth and appeared as"slow descen-ding-slow rising-slow descending".The difference of R△TH and△V among the three groups were not statistically significant(HR△TH=3.70,P=0.16;F△V=0.43,P=0.65).The vascular area and MF in anterior,middle and posterior segments of SSS increased in turn and the difference among the three segments were statistically significant(H vascular area=35.18,H MF=41.98;both P<0.01).The difference in MV among the three groups was statistically significant(H=15.14,P<0.01),the difference in MV between anterior segment and middle segment had no statistical significance(P>0.05),but the MV of posterior segment was obviously higher than that of the anterior and middle segment with statistical difference(P<0.01).Conclusion:The physiological flow modes of the anterior,middle and posterior segments of SSS are similar.PC-MRI can show the flow modes of SSS visually and accurately.