4D-Flow MRI在肥厚型心肌病左室流出道血流评估中的价值探索

Value of 4D-Flow MRI in evaluating left ventricular outflow tract peak velocity in hypertrophic cardiomyopathy:A proof-of-concept study

目的 探索四维血流(four-dimensional flow,4D-Flow)磁共振成像(magnetic resonance imaging,MRI)技术在左心室腔内应用的可行性。材料与方法 本研究为前瞻性、横断面研究,纳入2022年8月至2023年1月于我院接受心脏MRI检查的21例肥厚型心肌病患者,采用3.0 T MRI扫描仪进行二维血流(tow-dimensional flow,2D-Flow)及4D-Flow成像,收集患者一周内进行的超声心动图检查结果。采用组内相关系数(inter-class correlation coefficient,ICC)、变异系数(coefficients of variation,COV)及Bland-Altman分析比较2D-Flow、4D-Flow评估左室流出道峰值流速的可重复性及一致性,并通过Pearson相关性分析探究二者与超声心动图测量结果的关系。结果 2D-Flow和4D-Flow观察者内/观察者间的ICC分别为0.999/0.999和0.995/0.992,COV分别为0.5%/0.5%和2.4%/2.6%。4D-Flow与超声心动图的测量结果呈中度相关,相关系数r值为0.574(P=0.006),但一致性较差,ICC为0.375(P=0.013)。2D-Flow与4D-Flow和超声心动图间无显著的一致性及相关性。结论 4D-Flow技术能够可视化心腔内血流模式,对左室流出道峰值流速的测量具有高度可重复性,且与超声心动图的测量结果具有显著的一致性。

Objective:To explore the feasibility of using four-dimensional flow(4D-Flow)magnetic resonance imaging(MRI)in left ventricle,and to evaluate the reproducibility and consistency of quantification of left ventricular outflow tract(LVOT)peak velocity by comparing with two-dimensional flow(2D-Flow)MRI and echocardiography.Materials and Methods:This research was a prospective and cross-sectional study.Twenty-one patients with hypertrophic cardiomyopathy(HCM)underwent cardiac MRI 2D-Flow and 4D-Flow data acquisition on a 3.0 T MRI scanner August 2022 to January 2023.Echocardiography within one weeks before or after MRI examination were collected.The inter-class correlation coefficient(ICC),coefficient of variation(COV)and Bland-Altman analysis were used to evaluate the reproducibility and consistency of LVOT peak velocity derived from 2D-Flow and 4D-Flow,and the relationship between 2D/4D-Flow and echocardiography was analyzed by Pearson correlation analysis.Results:The ICC of 2D-Flow and 4D-Flow were 0.999/0.999 and 0.995/0.992,respectively,and the COV of 2D-Flow and 4D-Flow were 0.5%/0.5%and 2.4%/2.6%,respectively.4D-Flow was moderately correlated with echocardiography(r=0.574,P=0.006),but the consistency between the two was poor(ICC=0.375,P=0.013).Besides,there were no significant consistency and correlation between 2D-Flow and 4D-Flow/echocardiography.Conclusions:4D-Flow cardiac MRI can visualize the flow patterns within the heart.The peak velocity of LVOT derived from 4D-Flow is highly reproducible and is significantly correlated with echocardiography.