Evaluation Of Myocardial Fibrosis In Dilated Cardiomyopathy With MRI

Background and PurposeDilated cardiomyopathy (DCM) is a common myocardial disease with the main performans of ventricular enlargement and systolic dysfunction. The main clinical manifestations in DCM patients shows progressive heart failure, arrhythmia, sudden death, and most patients have a poor long-term prognosis and life. Myocardial fibrosis is an important characteristic in DCM, and it is considered as an independent risk factor in major adverse clinical events. Currently, MRI delayed gadolinium-enhanced (LGE) technology can be used to reflect the occurrence of cardiac focal myocardial fibrosis, however, there is deficiency in the evaluation of LGE for diffuse interstitial fibrosis. T1 mapping technique is a noninvasive, quantitative method to evaluate the characteristic of the organization. By measuring myocardial tissue T1 values of myocardial tissue to reflect myocardial fibrosis, T1 mapping technique can provide important values for clinical diagnosis and treatment.By using CMR traditional cine technology,this research evaluated left ventricular systolic function in dilated cardiomyopathy patients, then, LGE and T1 mapping technique were applied to evaluate the focal myocardial fibrosis and diffuse fibrosis, respectively. In order to discuss:1.The ability of T1 mapping technique noninvasively to detecti diffuse myocardial fibrosis in DCM patients.2. The relationships between focal myocardial fibrosis and diffuse myocardial fibrosis with left ventricular function in DCM patients.Materials and Methods1.44 DCM patients (DCM group) and 23 healthy volunteers (Control group) were prospectively enrolled.2. Frist, Everyone was scaned Short axis cine of left ventricular by using Siemens Skyra 3.0 T MRI; Then,before and after injection of gadolinium,Tl mapping and LGE images were scanned 1, respectively. Left ventricular function parameters can be obtained from the left ventricular short axis cines, including left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), left ventricular stroke volume (LVSV), left ventricular cardiacoutput (LVCO) and left ventricular myocardial mass (LVMM). Except LVEF, the rest of the other parameters were processed by body surface area and obtained the corresponding index:LVEDVI, LVESVI, LVSVI, LVCI and LVMMI. The average T1 value of the left ventricle were obtained form T1 mapping images. Depending on whether the presence of LGE, the DCM group were further divided into LGE (+) and LGE (-)subgroups.3. Firstly, the incidence of DCM patients with focal and diffuse myocardial fibrosis were analyzed; Then, the relationships myocardial fibrosis between and left ventricle systolic function were explord.4. All data were analysed by SPSS21.0 package in statistics, and the measurement data was expressed by x±s. We used the chi square test to compare the control group and the DCM group, the subgroup of genders. Moreover, We used t-test to Compare the measurement datas between control group and DCM group. ANOVA methods was used to analyse Control group and LGE (+) subgroup, LGE (-) subgroup in measurement datas. Pearson correlation test was used to analysis the variables correlation. A P value<0.05 was considered statistically significant.Results1. After scaning of the delayed enhanced, LGE (+) subgroup had 30 patients, LGE (-) subgroup had 14 patients in DCM group. No LGE was present in the control group.2. The values of LVEF, LVEDVI, LVESVI, LVSVI and LVMMI were all significant statistical significance between the DCM group and control group (respectively, P<0.001);3. The values of LVEF, LVEDVI, LVESVI, LVSVI and LVMMI were all significant statistical significance between the DCM LGE (+) subgroup, LGE (-) subgroup and control group (respectively, P< 0.001). Moreover,The values of LV-EDVI in LGE(+) subgroup (214.63±66.62 ml/m2) and LGE (-) subgroup (178.61±44.68 ml/m2) were statistically significant differences(P< 0.05). The values of LVEF, LVSVI, LVCI and LVMMI were no significant differences between the LGE (+) subgroup and LGE (-) subgroup(respectively, P> 0.05).4. The T1 value of DCM group (1326.90±59.75 ms) was larger than that in control group (1238.68±51.90 ms) (P< 0.001).5. The values of T1 between LGE (+) subgroup (1335.23±60.91 ms), LGE(-) subgroup(1309.05±55.02 ms) and the control group were statistically significant differences (P< 0.001). However, the values of T1 in LGE (+) and LGE (-) subgroup was no significant differences(P=0.1595).1、There was negative correlation between the T1 value and LVEF in DCM group(r=-0.324, P=0.037), and there were positive correlation between the T1 value and LVEDVI, LVESVI (respectively, r= 0.385 and 0.384, P=0.012).Conclusions1、T1 mapping technique can detect diffuse myocardial fibrosis in the patients with DCM, even the occurrence of early myocardial fibrosis..2、The focal and diffuse Myocardial fibrosis can affect the occurrence of left ventricular remodeling in DCM patients, moreover, the extent of myocardial diffuse interstitial fibrosis can affect the left ventricular systolic function.