Initial Study Of Cardiovascular Magnetic Resonance T1 Mapping And Myocardial Deformation Analysis Based On Deformable Registration Algorithm In Hypertrophic Cardiomyopathy

Objective: The aim of this study was to investigate the application value of the cardiac magnetic resonance T1 mapping and myocardial strain analysis based on deformable registration algorithm(DRA)in the quantitative diagnosis of myocardial fibrosis and myocardial deformation in patients with hypertrophic cardiomyopathy.Method: 35 patients with hypertrophic cardiomyopathy and 40 healthy volunteers diagnosed in our hospital from January 2020 to January 2022 were collected as subjects.Cardiac magnetic resonance examination was performed in all cases,and the scanning sequence included routine anatomical scan sequence,film sequence,native T1 mapping sequence,and delayed enhancement sequence scanning was added in the HCM group.The native T1 mapping images was imported into Medis Suite software for processing to obtain native T1 values of left ventricular.We imported the short axis,two-,three-and four-chamber film sequences into Trufi Strain 2.1 software to obtain the global circumferential strain(GCS),radial(GRS)and longitudinal strain(GLS)of the left ventricle.According to the left ventricular myocardial delayed reinforcement mode,the HCM group was divided into enhanced group and non-enhanced group.According to the end-diastolic wall thickness(EDTH),they were divided into three groups: 15mm≤EDTH<20mm(A),20mm≤EDTH(B)and apical hypertrophy group 13mm≤EDTH<18mm(C).The differences of native T1 values and myocardial strain indexes were compared among HCM patients,healthy volunteers and subgroups.Result:(1)Statistical results of CMR T1 mapping technology among hypertrophic cardiomyopathy patients,healthy volunteers and subgroups: The native T1 values of the left ventricular in the HCM group was significantly higher than that in the control group [(1323.15±48.95)ms vs(1228.76±36.84)ms,P<0.001].The native T1 values had significant differences among the enhanced group,the non-enhanced group and control group[T1:(1343.25±43.31)ms,(1284.65±34.54)ms,(1228.76±36.84)ms.Pairwise,P values were all <0.001].The native T1 values had no differences between the group of A,B and C.(2)Statistical results of myocardial deformation analysis among hypertrophic cardiomyopathy patients,healthy volunteers and subgroups: The GRS and GLS in HCM group were significantly lower than those in the control group(P<0.05)[GRS:(13.50±3.00)% vs(34.22±6.50)%;GLS:(-12.91±5.03)% vs(-15.82±1.71)%].The GLS and GRS in the enhanced group were lower than those in the control group and the difference was statistically significant(P<0.05)[GRS:(13.41±3.51)%vs(34.22±6.50)%;GLS:(-12.54±5.22)%vs(-15.82±1.71)%].The myocardial strain had no differences between the group of A,B and C.(3)ROC curve analysisThe diagnostic efficacy of left ventricular GRS(AUC=0.992,P<0.001)in hypertrophic cardiomyopathy was better than other strain parameters [GLS(AUC=0.693,P=0.002);GCS(AUC=0.462,P=0.588)]and native T1 values(AUC=0.944,P<0.001).The sensitivity and specificity of left ventricular GRS in the diagnosis of hypertrophic cardiomyopathy were 97.1% and 97.5%.The native T1 values(AUC=0.862,P<0.001)showed high efficacy in the diagnosis of enhanced subgroup,and the sensitivity and specificity were 65.2% and 100%.Conclusion: Native myocardial T1 values,GRS and GLS can be used to identify and quantitatively evaluate myocardial fibrosis in hypertrophic cardiomyopathy and analyze myocardial strain in multiple dimensions.GRS has the highest diagnostic efficacy.The native T1 values had the highest diagnostic efficacy among enhanced subgroups.Cardiac magnetic resonance T1 mapping technique and myocardial deformation analysis combined with multiparameter quantitative evaluation of hypertrophic cardiomyopathy provided effective diagnostic evidence for clinical treatment and prognosis.