非对比剂增强磁共振血管成像评价门静脉血流动力学的可行性研究

目的探讨利用多反转空间标记脉冲非对比剂增强磁共振血管成像(non-contrast-enhanced magnetic resonance angiography using spatial labeling with multiple inversion pulses,SLEEK-MRA)评估门静脉血流动力学的可行性。材料与方法纳入25例门静脉高压患者先后行SLEEK-MRA和彩色多普勒超声(color doppler ultrasonograohy,CDUS)检查,SLEEK-MRA序列采用不同血流抑制反转时间(blood suppression inversion time,BSP TI):600、900、1200、1500 ms。对门静脉分支显示情况进行评级并与通过与CDUS血流速度测定结果进行相关性分析。依据CDUS所测流速将患者分组,并比较各组患者分支显示评级情况以及BSPTI参数应用情况。结果门静脉左、右支在全部BSPTI设定时SLEEK-MRA的分支显示评级均与CDUS所测得血流速度呈现出显著相关性。在门静脉流速明显减慢组患者,分支评级明显低于流速正常或轻度减慢组,应用BSP TI值明显高于流速正常或轻度减慢组。结论 SLEEK-MRA在提供高质量门静脉形态学成像同时,具有提示门静脉血流动力学变化的潜力,通过SLEEK-MRA获取血流动力学信息是可行的。

Feasibility of non-contrast-enhanced magnetic resonance angiography for evaluating portal venous hemodynamics

Objective:To investigate the feasibility of non-contrast-enhanced magnetic resonance angiography (NCE-MRA) using spatial labeling with multiple inversion pulses (SLEEK) in evaluating portal venous hemodynamics.Materials and Methods:Twenty-five patients with portal hypertension were examined with SLEEK-MRA and color Doppler ultrasonography (CDUS) respectively.SLEEK-MRA series were performed with different blood suppression inversion time (BSP TI) settings of 600 ms,900 ms,1200 ms and 1500 ms.Portal venous branching grade of SLEEK-MRA series were analyzed with CDUS-measured hemodynamics using Spearman rank correlation coefficient (rs).Patients were divided into 2 groups depending on portal venous velocity and portal venous branching grades as well as BSP TI settings of the 2 groups were compared.Results:At all BSP TI settings,branching grade scores of the left portal vein (LPV) and the right portal vein (RPV) were of statistically significant correlation with CDUS-measured flow velocity of LPV and RPV respectively.The correlation coefficient of LPV at each BSP TI settings (600,900,1200,1500 ms) were 0.534,0.408,0.563,0.621 respectively.The correlation coefficient of RPV at each BSP TI settings were 0.655,0.578,0.699,0.641 respectively.For patients of obviously decreased portal flow velocity,branching grade scores were significantly lower than patients of normal or slightly decreased portal flow velocity.To reach the same portal venous branching visualization,patients of obviously decreased portal flow velocity need to apply with higher BSP TI settings.While most of patients of normal or slightly decreased portal flow velocity applied 900 ms to reach grade 6,42.9％ of patients of obviously decreased portal flow velocity could not reach it even applied a BSP TI setting of 1500ms.Conclusions:SLEEK-MRA has the potential to suggest portal venous flow changes with high-quality morphological visualization of portal vein imaging simultaneously.It is feasible for SLEEK-MRA to provide hemodynamical information.