7.0 T MRI对小血管病患者豆纹动脉血流动力学特征的研究

Hemodynamic characteristics of lenticulostriate artery in patients with cerebral small vessel disease:a 7.0 T MRI study

目的探讨采用7.0 T二维(2D)相位对比法MRI(PC-MRI)研究伴深部近期皮层下小梗死灶(RSSI)的脑小血管病(CSVD)患者豆纹动脉(LSA)血流动力学特征的价值。方法前瞻性收集2021年7月至2022年6月在首都医科大学附属北京天坛医院诊断为CSVD伴深部RSSI的患者16例以及年龄、性别匹配的健康志愿者18名(HC组)。所有受试者均接受7.0 T 2D PC-MRI,扫描层面位于基底节层面,并应用自主研发的血流分析处理软件Flow analyze V1.0进行LSA血流动力学分析,计算双侧LSA的最大速度(Vmax)、平均速度(Vavg)、搏动指数(PI)和阻力指数(RI)。将CSVD患者有RSSI的一侧定义为CSVD症状侧组,无RSSI灶的一侧定义为CSVD非症状侧组。采用方差分析或Mann-WhitneyU检验比较3组间血流动力学参数的差异。结果CSVD症状侧组、非症状侧组和HC组间的Vmax、Vavg、PI差异均有统计学意义(F=5.22,P=0.006;F=3.47,P=0.033;F=4.37,P=0.014),其中CSVD组症状侧组Vmax、Vavg较HC组明显减低(P=0.004、0.017),PI较HC组明显增高(P=0.007)。CSVD非症状侧组Vmax较HC组减低、PI较HC组增加(P=0.026、0.039)。结论应用7.0 T 2D PC-MRI显示CSVD伴RSSI患者LSA表现为血流速度下降、PI升高的血流动力学特征。CSVD伴RSSI病变可能具备相应的血流动力学机制。

Objective To investigate the hemodynamic characteristics of the lenticulostriate artery(LSA)in cerebral small vessel disease(CSVD)patients with recent small subcortical infarcts(RSSI)using 7.0 T two-dimensional phase-contrast MRI(2D PC-MRI).Methods A total of 16 CSVD patients with deep RSSI and 18 age-and sex-matched healthy controls(HC group)meeting the inclusion criteria were prospectively recruited from July 2021 to June 2022 at Beijing Tiantan Hospital,Capital Medical University.All participants underwent 7.0 T 2D PC-MRI with imaging plane localized at the level of the basal ganglia.A self-developed software(Flow analyze V1.0)was used to analyze the hemodynamic status of bilateral LSAs.The hemodynamic parameters including the maximum velocity(Vmax),average velocity(Vavg),pulsatility index(PI),and resistance index(RI)of LSAs were calculated and recorded.As for the CSVD cases,the symptomatic side was defined as the ipsilateral side to the RSSI(CSVD symptomatic-side group),and the contralateral side was defined as the asymptomatic side(CSVD asymptomatic-side group).ANOVA or Mann-Whitney U test was used to compare hemodynamic parameters among the three groups.Results Significant differences in Vmax,Vavg and PI were observed among the CSVD symptomatic-side group,CSVD asymptomatic-side group,and HC group(F=5.22,P=0.006;F=3.47,P=0.033;F=4.37,P=0.014).Specifically,CSVD symptomatic-side group showed significantly reduced Vmax(P=0.004)and Vavg(P=0.017),and increased PI(P=0.007)compared to the HC group.The CSVD asymptomatic-side group showed decreased Vmax(P=0.026)and increased PI(P=0.039)compared to the HC group.Conclusions Hemodynamic assessment based on 7.0 T 2D PC-MRI reveal that CSVD patients with RSSI decrease blood flow velocity and increase arterial PI of LSAs.These findings suggest potential corresponding hemodynamic mechanisms associated with CSVD with RSSI lesions.