心脏磁共振评价扩张型心肌病患者心肌纤维化和左心室功能

目的 采用MRI技术评价扩张型心肌病(DCM)患者心肌纤维化,并分析其与左心室功能的关系。方法 连续收集44例DCM患者(DCM组)和23名健康志愿者(对照组);根据DCM患者心肌是否存在LGE,将DCM组再分为LGE(+)亚组和LGE(-)亚组。所有被检者首先行左心室短轴电影扫描;并于注射对比剂前、后分别行改良的look-locker反转恢复和相位敏感反转恢复序列扫描,以取得短轴位T1 mapping和延迟增强图像。通过短轴电影序列获得左心室心功能参数,包括左心室射血分数(LVEF)、左心室舒张末期容积(LVEDV)、左心室收缩末期容积(LVESV)、左心室每搏量(LVSV)、左心室心排出量(LVCO)、左心室心肌质量(LVMM),并获得除LVEF外其余参数的标准化指数;获得左心室短轴平均T1值。对以上参数进行统计学分析。结果 DCM组LVEF和LVEDV指数、LVESV指数、LVSV指数及LVMM指数值与对照组比较差异均有统计学意义(P均<0.01);LGE(+)亚组LVEDV指数 明显大于LGE(-)亚组;DCM组心肌T1值 显示明显大于对照组;DCM组心肌T1值与LVEF呈负相关(r=-0.324,P<0.05),与LVEDV指数、LVESV指数呈正相关(r=0.385、0.384,P均<0.05)。结论 T1 mapping技术和LGE均可检测DCM心肌纤维化,且弥漫性心肌纤维化的程度与左心功能存在一定关系。

Cardiovascular MR evaluation of myocardial fibrosis and left ventricular function in dilated cardiomyopathy patients

Objective To investigate the value of MRI in evaluateing myocardial fibrosis of patients with dilated cardiomyopathy (DCM), and analyze the correlation between myocardial fibrosis with left ventricular (LV) function. Methods Totally 44 DCM patients (DCM group) and 23 healthy volunteers (control group) were prospectively enrolled. All the subjects underwent short axis cine of left ventricular; before injection of contrast agent, T1 mapping images were scanned by using modified look-locker inversion recovery sequence; after injection of contrast agent, delayed enhancement images were scanned by phase-sensitive inversion recovery sequence. By using short axis film sequences to obtain LV function parameters, including left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), left ventricular stroke volume (LVSVI), left ventricular cardiac output (LVCO) and left ventricular myocardial mass (LVMM). Except LVEF, other left ventricular parameters were turned into standard indexes. The average T1 values of the left ventricular short axis were obtained. Depending on whether the presence of LGE, the DCM group were further divided into LGE (+) and LGE (-) subgroup. The statistical analysis was performed. Results Left ventricular function parameters of LVEF, LVEDV index, LVESV index, LVSV index and LVMM index were all statistical significance between the DCM and control group (all P<0.01). The value of LVEDV index in the LGE (+) subgroup (ml/m²) was larger than that in LGE (-) subgroup (ml/m², P<0.05). The T1 value of DCM group (ms) was larger than that in control group (ms, P<0.001). There was negative correlation between the T1 value and LVEF in DCM group (r=-0.324, P<0.05), and there were positive correlation between the T1 value and LVEDV index, LV-ESV index (r=0.385, 0.384, P<0.05). Conclusion Both of T1 mapping and LGE can detect myocardial fibrosis in DCM; myocardial diffuse fibrosis is correlated with left ventricular function.