肥厚型心肌病的MRI诊断

目的：探讨磁共振成像(MRl)对肥厚型心肌病(HCM)的诊断价值，并与超声心动图的结果相对比；同时通过磁共振电影观察心脏功能的改变及心室壁厚度于心动周期内的变化情况。材料和方法：15例肥厚型心肌病患者，MRI扫描时应用心电门控，分别进行自旋回波(SE)序列和梯度回波(GE)序列(电影)检查观察心室壁和心内血流动力学的改变；同时进行超声心动图检查。结果：于舒张末期在左心室中部水平(短轴位)分别测得心室前壁、侧壁、后壁和室间隔的室壁厚度，在心脏长轴位测得心尖部的室壁厚度，并与二维超声结果相比较，并根据心脏电影MRI计算出室间隔和心室侧壁的室壁增厚率。结论：(1)肥厚型心肌病以心室壁的异常肥厚为特点，MRI表现既有左室壁对称性普遍肥厚；亦有非对称性局部心肌肥厚的各类亚型。根据血流动力学的改变MRI可区分梗阻型和非梗阻型。(2)对于心室(前)侧壁、心尖部和室间隔局限性增厚的HCM，MRI能准确定位和分段，对室壁厚度的测量较二维超声心动图亦更准确。(3)电影MRI可反映心动周期内心腔内的血流动力学改变；同时更清楚地显示出心肌于舒张期和收缩期不同时相的动态变化情况。

MRI Diagnosis of Hypertrophic Cardiomyopathy

To evaluate MRI in the diagnosis of hypertrophic cardiomyopathy (HCM) an d observe the change of heart function and variety of ventricular thickness in c ardiac cycle by MRI cine.The results of MRI are compared with that of ultrasound cardiogram.Materials and Methods:Fifteen cases of HCM were performed MRI with E CG-gated and ultrasound cardiogram.Sequence of pulses include spin-echo(SE) an d gradient-echo(GE).The ventricular wall and endocardiac hemodynamics were obse rved by MRI and ultrasound cardiogram respectively.Results:The ventricular wall thickness in the end-diastolic phase was measured at anterior,lateral,posterior and interventricular septum along the short-axis and middle-level of the left ventricle and at apical of heart along the long-axis.Above results were compar ed with those of ultrasound cardiogram.The increase ratio of ventricular wall th ickness was calculated on the series of cine-MRI.Conclusion:(1)The characterist ic of HCM is abnormal of the ventricular wall thickness.The type of thickening a lmost manifests as symmetrical and wideapread.But other sub-types are showed as asymmetrical and local thickening.(2)In the part of (anterior) lateral,apical a nd septum MRI measure the thickness more accurately than ultrasound cardiogram.M RI also can accurately locate the focal lesions and segments.(3)Cine-MRI can re flexes variety of endocardiac hemodynamics in cardiac cycle,and furthermore it c an display the dynamic changes of myocardia in the different phases of cardiac c ycle.