磁共振T1 mapping成像评价肥厚型和扩张型心肌病弥漫性心肌纤维化

目的 探讨磁共振纵向弛豫时间定量(T1 mapping)成像评价肥厚型心肌病(HCM)和扩张型心肌病(DCM)心肌纤维化的价值,及心肌纤维化与左心室射血分数的关系。方法 收集经临床诊断证实的30例HCM患者(HCM组)、27例DCM患者(DCM)和符合纳入标准的33例患者(对照组)。对所有受检者均行心脏电影成像、对比增强前、后T1 mapping成像、延迟对比增强(LGE)成像。测量不同受检者增强前、后左心室平均T1值及心功能参数并进行统计学分析,分析心肌平均T1值与心功能指标的相关性。结果 HCM组22例(22/30,73.33%)患者存在延迟强化,DCM组15例(15/27,55.56%)患者存在延迟强化,对照组无延迟强化。比增强前,HCM组(1294.79±85.22)ms]、DCM组(1312.88±59.57)ms]左心室心肌T1值均较对照组(1266.56±57.33)ms]显著增加(P均<0.05);对比增强后,HCM组(491.31±121.59)ms]、DCM组(466.77±126.34)ms]左心室心肌T1均值较对照组(534.09±92.73)]显著减低(P均<0.05)。HCM患者左心室心肌增强前T1值与左心室射血分数呈负相关(r=-0.58,P<0.05),增强后T1值与其呈正相关(r=0.59,P<0.05);DCM患者左心室心肌增强前T1值与左心室射血分数呈负相关(r=-0.55,P<0.05),增强后T1值与其呈正相关(r=0.51,P<0.05)。结论 HCM和DCM患者心肌纤维化与心功能相关;T1 mapping成像有助于评价HCM和DCM患者心肌纤维化。

MR T1 mapping imaging in assessment of diffuse myocardial fibrosis of hypertrophic and dilated cardiomyopathy

Objective To investigate the value of T1 mapping in detection of myocardial fibrosis in hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM), and the correlation between myocardial fibrosis and cardiac function. Methods Thirty cases of HCM (HCM group), 27 cases of DCM (DCM group) and 33 cases meeting the inclusion criteria (control group) were enrolled. All the subjects underwent cardiac cine MR, pre-contrast and post-contrast T1 mapping, late gadolinium enhancement (LGE) imaging. The pre- and post-contrast left ventricle T1 value and cardiac function were measured and compared statistically, and the correlation between myocardial T1 value and left ventricle ejection fraction (EF) was analyzed. Results In HCM group, 22 cases (22/30, 73.33%) had LGE; in DCM group, 15 cases (15/27, 55.56%) had LGE, and none of controls had LGE. Compared with control group, HCM and DCM group presented with higher pre-contrast T1 value (HCM group:1294.79±85.22] ms; DCM group: 1312.88±59.57]ms; control group: 1266.56±57.33]ms, both P<0.05) and lower post-contrast T1 value (HCM group: 491.31±121.59]ms; DCM group: 466.77±126.34]ms; control group: 534.09±92.73]ms, both P<0.05). There were negative correlation between T1 value in pre-contrast and left ventricle EF in HCM and DCM patients (r=-0.58, -0.55, P<0.05), but positive correlation between both parameters in HCM and DCM patients (r=0.59, 0.51, P<0.05). Conclusion Myocardial fibrosis is correlated with cardiac function in HCM and DCM patients. Left ventricle pre- and post-contrast T1 value are helpful for detection of myocardial fibrosis in HCM and DCM patients.