MR心肌应变力技术在肥厚型心肌病诊断及鉴别诊断中的应用研究

Application of MR myocardial strain technique in the diagnosis and differential diagnosis of hypertrophic cardiomyopathy

目的应用心脏磁共振组织追踪(cardiac magnetic resonance tissue tracking,CMR-TT)技术定量评价肥厚型心肌病(hypertrophic cardiomyopathy,HCM)患者与心肌淀粉样变性(cardiac amyloidosis,CA)所致左心室肥厚患者心肌功能,并分析其心肌应变改变的差异。材料与方法回顾性分析30例肥厚型心肌病患者(HCM组)、15例心肌淀粉样变性患者(CA组)和30名正常对照者(NC组)资料,应用CMR-TT技术及CVI42后处理软件测量心肌整体及节段(基底段、中间段、心尖段)的纵向应变(longitudinal strain,LS)、周向应变(circumferential strain,CS)、径向应变(radial strain,RS)等常规应变参数数值及相对心尖应变(relative apical sparing of strain,RAS),定量评估心肌整体及局部运动情况。结果NC组、HCM组、CA组间各应变参数数值依次递减,且三组间差异均有统计学意义(P<0.05);两两比较中除NC组与HCM组心尖段周向应变(apical circumferential strain,ACS)差异无统计学意义外,其余差异均存在统计学意义(P<0.05);相对心尖径向应变(RASRS)、相对心尖周向应变(RASCS)、相对心尖纵向应变(RASLS)组间差异均有统计学意义(P<0.05)。HCM组与NC组整体径向应变(global radial strain,GRS)、整体周向应变(global circumferential strain,GCS)、整体纵向应变(global longitudinal strain,GLS)、基底段径向应变(basal radial strain,BRS)、基底段周向应变(basal circumferential strain,BCS)、基底段纵向应变(basal longitudinal strain,BLS)的ROC曲线下面积分别为0.77、0.71、0.77、0.90、0.73、0.78(P均<0.05),BRS的曲线下面积显著高于其他参数。HCM组与CA组的RASRS、RASCS、RASLS的ROC曲线下面积分别为0.83、0.75、0.71(P均<0.05),对HCM与CA的鉴别诊断有一定价值。结论CMR-TT可以用来评价心脏整体及局部功能运动情况,HCM心肌应变均存在减低,HCM基底段应变下降明显并BRS存在较大的诊断价值;CA患者的心肌应变较HCM患者下降更为明显,相对心尖保留模式为两者的鉴别诊断提供一定的参考价值,相对心尖RS诊断效能最佳。

Objective:To apply cardiac magnetic resonance tissue tracking technology(CMR-TT)to quantitatively evaluate myocardial function in patients with hypertrophic cardiomyopathy(HCM)and myocardial function in patients with left ventricular hypertrophy caused by cardiac amyloidosis(CA),and to analyze the differences in myocardial strain changes.Materials and Methods:Select30 patients with hypertrophic cardiomyopathy(HCM group),15 patients with myocardial amyloidosis(CA group),and 30 normal people as normal controls(NC group),using CMR-TT technology and CVI42 post-processing software measure conventional strain parameters such as longitudinal strain(LS),circumferential strain(CS),radial strain(RS)of the whole myocardium and segments(basal,middle,apical)and relative apical sparing of strain(RAS),and quantitatively assess the overall and local movement of the myocardium.Results:The values of the strain parameters among the NC group,HCM group,and CA group decreased successively,and all three groups were statistically significant(P<0.05);in the pairwise comparison,apical circumferential strain(ACS)was not statistically significant except for the NC group and the HCM group,the rest were statistically significant(P<0.05);RASRS,RASCS,and RASLSwere all statistically significant(P<0.05).The area under the ROC curve of global radial strain(GRS),global circumferential strain(GCS),global longitudinal strain(GLS),basal radial strain(BRS),basal circumferential strain(BCS),basal longitudinal strain(BLS)in the HCM group and NC group were 0.77,0.71,0.77,0.90,0.73,0.78,respectively(P<0.05),and the area under the curve of BRS was significantly higher than other parameters.The area under the ROC curve of RASRS,RASCSand RASLSof HCM group and CA group were 0.83,0.75,0.71 respectively(P<0.05),which has certain value for the differential diagnosis of HCM and CA.Conclusions:CMR-TT can be used to evaluate the overall and local functional movement of the heart.HCM myocardial strain is reduced,HCM basal segment strain is significantly reduced,and BRS has greater diagnostic value;CA patients’myocardial strain decreases more than HCM patients for obvious reasons,the relative apical retention mode provides a certain reference value for the differential diagnosis of the two,and the relative apical RS has the best diagnostic efficiency.