T2WI Combined With EGE And LGE Of CMRI In Evaluation Of Myocarditis And Correlation Study With MPI And Left Ventricular Function

Objectives:To assess the value of T2WI,EGE and MPI of CMRI on edema,myocardial capillary leakage and microcirculation of patients with myocarditis.To investigate the relationship of left ventricular function and myocardial fibrosis by correlation study in left ventricular function parameters and LGE.Methods:The patients with myocarditis(Myocarditis Group)and the patients without heart disease(Control Group),from October 2014 to March 2017 in Department of Cardiology,the Second Affiliated Hospital of Kunming Medical University.The two Groups were examined by MPI parameters analysis(ratio of area under curve,the relative peak signal intensity,time to peak)and the left ventricular function parameters(LVEF,FS,LVEDD,LVEDV,LVESV,LVMM,LVSV,CO,CI).CMRI diagnosis of myocarditis based on the Lake Louise Standard.The study is divided into the following two parts:1.The Myocarditis Group A(the patients in Myocarditis Group,which the number of T2WI and EGE positive segments greater than or equal to 1)was divided into Group Aa(ratio of area under curve ? 30%)and Group Ab(ratio of area under curve<30%).Single factor analysis of variance and LSD-t test were used to compare the MPI parameters of Group Aa,Group Ab and Control Group.The ratio of area under curve in the Myocarditis Group A was correlated with the number of T2WI positive segments and the number of EGE positive segments by Spearman rank correlation analysis.2.Myocarditis Group was divided into Group BO(LGE negative)and Group B(LGE positive),the Group B was divided into Group Ba(LGE positive segments<3)and Group Bb(LGE positive segment?3).Using the single factor analysis of variance and LSD-t test to compare the left ventricular function parameters between the Group BO and the Group Ba,Group BO and Group Bb,Group Ba and Group Bb.Pearson linear correlation analysis was performed between LVEF and other left ventricular function parameters in Myocarditis Group B,and LVEF and LGE positive segments were analyzed by Spearman rank correlation.Results:1.The basic information:37 cases in Myocarditis Group,male to female ratio was 24:13,the average age(32.51±8.52)years;13 cases in Control Group,male to female ratio was 8:5,the average age(46.85±15.89)years;29 cases in Group A(18 cases in Group Aa,11 cases in Group Ab);23 cases in Group B(10 cases in Group Ba,13 cases in Group Bb);14 cases in Group B0.The total number of T2WI positive segments,the total number of EGE positive segments and the total number of LGE positive segments were 193,156,and 136 respectively.2.Single factor variance analysis of left ventricular MPI parameters among Control Group,Group Aa and Group Ab:ratio of area under curve(P<0.001),the relative peak signal intensity(P<0.001),peak time(P=0.014<0.05)and the difference was statistically significant.LSD-t test of Left ventricular MPI parameters in the three groups:ratio of area under curve(aP<0.001)and the relative peak signal intensity(bP<0.001,cdp=0.001<0.05)had significant difference among three groups.Peak time was statistically significant between Control Group and Group Aa(efp=0.011<0.05),as well as Control Group and Group Ab(egp=0.009<0.05).Peak time between Group Aa and Group Ab(fgP=0.680>0.05)showed no significant difference.Ratio of area under curve in Group A was negatively correlated with the number of T2WI positive segments(rs =-0.384,P=0.040<0.05).Ratio of area under curve in Group A was negatively correlated with the number of EGE positive segments(rs =-0.935,P<0.001).3.Single factor variance analysis of the left ventricular function parameters among Group B0,Group Ba and Group Bb:LVEF(P<0.001),LVEDV(P=0.001<0.05),LVESV(P=0.013<0.05),CI(P=0.020<0.05)showed statistically significant difference,and there was no statistically significant difference in FS(P=0.110>0.05),LVEDD(P=0.695>0.05),LVMM(P=0.297>0.05),SV(P=0.065>0.05)and CO(P=0.124>0.05).LSD-t test of LVEF,LVEDV,LVESV,CI in the three groups:LVEF(aP<0.001)showed statistically significant difference among three groups;LVEDV(bP<0.001),LVESV(dfp=0.003<0.05),CI(gip=0.005<0.05)had statistically significant difference in Group B0 and Group Bb;LVEDV(cp=0.069>0.05),LVESV(dep=0.214>0.05,efp=0.109>0.05)and CI(ghp=0.206>0.05,hip=0.155>0.05)showed no statistically significant difference between Group B0 and Group Ba,as well as Group Ba and Group Bb.The correlation coefficients between LVEF and FS?LVEDD?LVEDV?LVESV?LVMM?LVSV?CO?CI were respectively:r1?0.197(P=0.368>0.05),r2?-0.317(P=0.140>0.05),r3?-0.460(P=0.027<0.05),r4=-0.410(P=0.052>0.05),r5?-0.386(P=0.069>0.05),r6?0.203(P=0.353>0.05),r7=0.299(P=0.165>0.05)and r8?0.542(P=0.008<0.05),those suggesting that LVEF was negatively related to LVEDV,and positively correlated with CI.There was a negative correlation between LVEF and the number of LGE positive segments in Group B(rs =-0.777,P<0.001).Conclusions:1.Ratio of area under curve,the relative peak signal intensity and peak time of MPI showed that there were different degrees of microcirculatory disturbance in patients with myocarditis.Ratio of area under curve was negatively correlated with the number of T2WI positive segments and the number of EGE positive segments,suggesting that the disturbance of microcirculation may be related to myocardial edema.EGE is better than T2WI to reflect the microcirculation disturbance in patients with myocarditis.2.LVEF,LVEDV,LVESV and CI can reflect the myocardial interstitial fibrosis,and LVEF has correlativity with LVEDV and CI.The cardiac function of patients with myocarditis is decreased with the increase of myocardial fibrosis,and LGE is helpful to predict the occurrence of left ventricular dysfunction in patients with myocarditis.