T1 mapping技术定量分析肥厚型心肌病纤维化

Quantitative analysis of fibrosis in hypertrophic cardiomyopathyby T1 mapping technique

目的利用T1 mapping技术定量分析肥厚型心肌病(hypertrophic cardiomyopathy,HCM)纤维化特征,并对HCM患者的基本资料做统计学分析。方法对28例HCM患者及正常组16例行T1 mapping序列、延迟强化(late gadoliniumenhancement,LGE)扫描及实验室检查,就病例组、正常组及病例组的肥厚区域、非肥厚区域心肌初始T1值做统计学分析,比较LGE阴性、LGE阳性及正常组心肌T1值及基本资料的差异。构建ROC曲线,计算T1值的诊断效能。结果HCM组左室心肌初始T1值大于正常组,病例组肥厚区域T1值大于非肥厚区域,差异有统计学意义(P<0.001),LGE阴性、LGE阳性组及正常组组间T1值差异有统计学意义(P<0.001),LGE阴性、LGE阳性组间的射血分数、NT⁃proBNP差异无统计学意义,但LGE阴性组标准四腔心层面心肌最大短径低于LGE阳性组,最大长径大于LGE阳性组,左室心肌初始T1值鉴别LGE阴性组与正常组的敏感度、准确率均在85%以上,鉴别LGE阳性组与正常组准确率为93.1%。结论T1 mapping技术能够定量心肌纤维化程度,T1值的大小与心肌的肥厚程度有关。

Objective To quantitatively analyze the fibrosis characteristics of hypertrophic cardiomyopathy(HCM)by T1 mapping technique,and analyze the basic data of HCM patients.Methods Twenty⁃eightcases with HCM patients and 16 cases(normal group)were examined with T1 mapping sequence,delayed enhanced scan and laboratory examination.The initial T1 values of hypertrophic and non⁃hypertrophic myocardium in case group,normal group and case group were statistically analyzed.According to delayed enhanced scan,patients were divided into negative group and positive group.The differences of myocardial T1 and basic data between LGE negative,LGE positive and normal groups were compared.The ROC curve was constructed to analyze the diagnostic value of T1 value in distinguishing LGE negative from normal group,LGE positive from normal group.Results The native T1 value in the HCM group were larger than those in the normal group.The initial T1 values of hypertrophic aera were larger than those in non⁃hypertrophic myocardium.The difference was statistically significant(P<0.001).There were significant differences among LGE negative,LGE positive and normal groups(P<0.001).There was no significant difference in ejection fraction and NT⁃proBNPamong the two groups,but the maximum short diameter of LGE negative group was lower than that of LGE positive group,and the maximum long diameter was opposite.The sensitivity and accuracy of T1 value in distinguishing LGE negative from normal group were more than 85%,respectively,and the accuracy were 93.1%between LGE positive and normal groups.Conclusion T1 mapping technique can quantify the degree of myocardial fibrosis.The value of T1 is related to the degree of myocardial hyper⁃trophy.