心脏MR初始T1值及组织追踪技术在心肌淀粉样变和肥厚型心肌病的初步应用价值

目的:探讨磁共振初始T1值及组织追踪技术(CMR-TT)在鉴别心肌淀粉样变(CA)和肥厚型心肌病(HCM)中的价值。方法:对14名CA患者、16名HCM患者及16名健康受试者行3.0T心脏磁共振检查,测量基底部、乳头肌部及心尖部心肌初始T1值,采用CMR-TT技术测量左心室三维(3D)整体纵向应变(GLS)、周向应变(GCS)及径向应变(GRS),描绘左心室心肌应变曲线。采用受试者操作特征曲线(ROC)评估初始T1值及各应变指标对CA和HCM的鉴别诊断价值。结果:CA组总体、基底部、乳头肌部、心尖部心肌初始T1值分别为(1455.68±153.23)ms、(1446.97±170.53)ms、(1442.31±151.92)ms、(1468.31±141.83)ms]高于HCM组分别为(1329.14±40.19)ms、(1329.45±46.14)ms、(1330.04±41.49)ms、(1327.41±46.55)ms],差异有统计学意义(P均<0.001)。CMR-TT应变分析结果示,CA组3D GRS(14.08±4.22)、3D GCS(-13.69±2.50)均低于HCM组(3D GRS、3D GCS分别为26.87±13.45,-17.23±4.76,P均<0.05)。ROC曲线显示心肌初始T1值(整体、基底部、乳头肌部、心尖部AUC分别为0.866、0.821、0.839、0.866,P均<0.001)鉴别诊断效能优于各应变参数3D GLS(AUC=0.661,P=0.12)、3D GCS(AUC=0.786,P=0.003)、3D GRS(AUC=0.786,P=0.003)]。三组受试者左心室应变曲线下降的趋势不同:CA组呈“缓升-缓降-速降”表现,HCM组呈“缓升—速降”表现,而健康对照组则呈“速升—速降”表现。结论:初始T1值及3D GRS、3D GCS对于CA和HCM有较高的鉴别诊断价值。

Preliminary application value of native T1 value of cardiac MRI and tissue tracking technique in the differential diagnosis of cardiac amyloidosis and hypertrophic cardiomyopathy

Objective:The purpose of this study was to explore the value of MRI native T1 value and tissue tracking technique(CMR-TT)in the differential diagnosis of myocardial amyloidosis(CA)from hypertrophic cardiomyopathy(HCM).Methods:A total of 14 patients with CA,16 patients with HCM and 16 healthy subjects underwent cardiac magnetic resonance(CMR)scan at a 3.0T machine.Basal,mid-cavity,apical myocardium native T1 value were measured.CMR-TT technique was used to measure 3-dimensional(3D)global longitudinal strain(GLS),global circumferential strain(GCS)and global radial strain(GRS)of left ventricle.The myocardial strain curve of the left ventricle was drawn.The native T1 value and strain indexes in the differential diagnosis of CA and HCM was evaluated by curve of receiver operating characteristic(ROC).Results:The native T1 value of global,basal,papillary muscle and apical myocardium in CA group(1455.68±153.23)ms,(1446.97±170.53)ms,(1442.31±151.92)ms,(1468.31±141.83)ms respectively]were higher than those in HCM group(1329.14±40.19)ms,(1329.45±46.14)ms,(1330.04±41.49)ms,(1327.41±46.55)ms respectively](P<0.001).The results of CMR-TT strain analysis showed that 3D GRS(14.08±4.22 vs.26.87±13.45)and 3D GCS(-13.69±2.50 vs.-17.23±4.76)in CA group were lower than those in HCM group(P<0.05).ROC curve showed that the differential diagnosis efficiency of native T1 value in each part and global(the AUC of global,basal,papillary and apical myocardium are 0.866,0.821,0.839,0.866,respectively,P<0.001)was higher than that of each strain index3D GLS(AUC=0.661,P=0.12),3D GCS(AUC=0.786,P=0.003),3D GRS(AUC=0.786,P=0.003)].The left ventricular myocardial mechanics strain curve of the CA,HCM and healthy control were different.The CA patients presented as"slowly up-slowly down-rapidly down"pattern,the HCM presented as"slowly up-rapidly down"pattern,and healthy control presented as"rapidly up-rapidly down"pattern.Conclusion:Nnative T1 value,3D GRS and 3D GCS are valuable in the differential diagnosis of CA and HCM.