小儿高原性心脏病的病理生理改变及磁共振表现

The pathophysiology changes and MR imaging features of high altitude heart disease in children

目的认识小儿高原性心脏病（high altitude heart disease,HAHD）的MRI表现特征,为临床提供更准确的诊断。材料与方法应用GE Vectr 0.5 T超导型磁共振扫描仪,对8例来自海拔3500~4500 m、年龄在8个月~2岁之间、临床已确诊的HAHD患儿行心脏MR扫描,采用0.5 T MRI设备自旋回波心电门控技术,以横轴、长轴和短轴为基本层面进行扫描,分别测量患者收缩期右室前壁（right ventricular anterior wall in the systolic,RVAWs）、舒张期右室前壁（right ventricular anterior wall in the diastolic,RVAWd）,收缩期左室后壁（left ventricular posterior wall in the systolic,LVPWs）、舒张期左室后壁（left ventricular posterior wall in the diastolic,LVPWd）、收缩期室间隔（interventricular septum systolic,IVSs）和舒张期室间隔（interventricular septum diastolic,IVSd）的厚度,以及肺动脉干内径（pulmonary artery diameter,PAD）。同时对6例与患病组相同年龄,生长在相同海平面下的正常小儿行MRI相同技术扫描观察、测量。结果MRI显示：（1）8例患儿均示右室壁增厚,其厚度大于或等于左室壁厚度,右室腔及右房腔扩大。RVAWs为（7.35±0.84）mm,RVAWd为（5.31±1.05）mm。正常组小儿的RVAWs为（3.58±0.02）mm,RVAWd为（1.98±0.12）mm。（2）8例患儿的LVPWs为（6.18±0.69）mm,LVPWd为（4.08±0.83）mm,其中1例患儿同时伴左室壁和室间隔增厚,LVAWd为6 mm。正常组小儿的LVAWd为（3.68±0.30）mm。（3）8例患儿室间隔平直或向左心室侧突出,IVSs为（4.74±1.29）mm,IVSd为（3.45±0.89）mm。室间隔增厚患儿的IVSd为5.6 mm。正常组小儿的IVSd为（3.17±0.46）mm。（4）8例患儿肺动脉干均扩张,PAD为（17.0±1.3）mm,而左右肺动脉增粗或正常表现。正常组小儿的PAD为（12.15±0.51）mm。结论右心室肥大和肺动脉扩张是小儿高原性心脏病的主要MRI表现,少数患者可出现左室肥厚和室间隔增厚。

Objective：To study the MRI characteristics of high altitude heart disease（HAHD） in children. Materials and Methods： Eight patients with clinically diagnosed with HAHD who lived at an elevation between 3500-4500 m, aged 8-24 months were scanned by using 0.5 T MRI equipment with ECG-gated spin-echo technique, the horizontal axis, major and minor axes were scanned as the basic levels to measure the right ventricular＇s anterior wall and left ventricular＇s post wall in systolic and diastolic（RVAWs and RVAWd, LVPWs and LVPWd）, interventricular septum in systolic and diastolic（IVSs and IVSd） in thickness, and the diameter of pulmonary artery diameter（PAD）. The six normal children who live the same sea level were measured by the same technique. Results： MRI show：（1） Eight patients were shown right ventricular wall thickening which was greater than or equal to left ventricular wall, right ventricular cavity and right atrial cavity was expanding. RVAWswas（7.35±0.84） mm, RVAWd（5.31±1.05） mm. The control of RVAWs was（3.58±0.02） mm, RVAWd was（1.98±0.12） mm.（2） Eight patients＇ LVPWs was（6.18 ±0.69） mm, LVPWd（4.08±0.83） mm, one case of children increased to left ventricular wall and interventricular septum thick thickening, LVAPWd 6 mm. The control of LVPWd was（3.68± 0.30） mm.（3） The ventricular septal straight or protrude, IVSs（4.74±1.29） mm, IVSd（3.45±0.89） mm. Septal thickening The IVSd is 5.6 mm. The control IVSd was（3.17±0.46） mm.（4） Eight patients＇ pulmonary artery dilation（PAD） was（17.0±1.3） mm, which is expanded compared with control subjects. The control subjects PAD is（12.15±0.51） mm. Conclusion： Right ventricular hypertrophy and pulmonary expansion was the main plateau of high altitude heart disease, with minority was left ventricular hypertrophy and ventricular septal thickening.