心脏磁共振和超声诊断肥厚性心肌病的价值

Value of cardiac magnetic resonance imaging and echocardiography in the diagnosis of hypertrophic cardiomyopathy

目的分析心脏磁共振(CMR)成像技术和超声心动图对肥厚性心肌病(HCM)的诊断,探讨两种方法诊断HCM的价值。方法53例HCM患者均进行3.0 T CMR和超声心动图检查。CMR检查包括常规成像、灌注及延迟强化,测量心肌厚度,评价心肌延迟强化特点。超声心动图测量左室壁各节段心肌厚度,评价左室流出道梗阻程度。比较CMR和超声心动图评价心肌厚度及纤维化能力的差异。结果肥厚性心肌病CMR和超声心动图测量心肌各节段厚度除侧壁外,两种方法测量其余室壁心肌厚度值的差异无统计学意义。CMR表现为延迟强化39例,7例局限性强化,5例弥漫性强化,2例透壁性强化,异常强化灶分布在游离壁和室间隔交界区、室间隔。超声心动图显示44例患者有左室流出道梗阻。结论心脏超声在测量心脏除侧壁外其余节段厚度时不劣于CMR,而测量侧壁时存在一定误差,易高估侧壁厚度。CMR可用于心肌纤维化的定量检测。超声心动图可以实时显示二尖瓣收缩期前向运动,评价左室流出道梗阻程度优于CMR。

Objective To assess the value of echocardiography(US)and 3T cardiac magnetic resonance imaging(CMR)in the diagnosis of hypertrophic cardiomyopathy(HCM).Methods 53 patients with HCM underwent both US and CMR.The myocardial thickness of each segment of the left ventricular(LV)wall and the severity of obstruction of the left ventricular outflow tract(LVOT)were evaluated on US.The wall thickness and delayed enhancement characteristics of each LV segment were determined on CMR including conventional imaging sequences,perfusion,and delayed enhancement.Each segment of LV thickness derived from US was compared with that from CMR.Results There was no significant difference between US and CMR in the wall thickness measurement of each LV segment in HCM excluding the lateral wall.LVOT obstruction with systolic anterior motion sign was found in 44 patients on US.CMR showed delayed(39),localized(7),diffuse(5),or transmural myocardial enhancement(2)in the interventricular septum as well as junction of interventricular septum and free wall.Conclusion US is comparable to CMR in measuring the LV wall thickness except for the lateral wall,which can be overestimated on US.CMR is useful for quantitative detection of myocardial fibrosis whereas US can demonstrate the abnormal forward movement of mitral valve in real time and evaluate the severity of LVOT obstruction in HCM.