磁共振相位编码速度标识技术在儿童二尖瓣反流定量分析中应用

目的利用磁共振相位编码速度标识技术对儿童二尖瓣反流作定量分析。方法本组二尖瓣反流组共19例,男11例,女8例。正常对照组10例,男5例,女5例。19例二尖瓣反流病人先行心脏超声检查,利用半定量方法,诊断19例二尖瓣反流,轻度反流5例,中度反流10例,重度反流4例。利用磁共振的相位编码速度标识技术分别对正常对照组、二尖瓣轻、中、重度反流的病例进行左心室流入量和主动脉流量测定,随后对所测的结果进行统计学分析。结果在正常对照组中,左心室流入量与主动脉流量之间的相关性良好。正常组与轻度二尖瓣反流反流量与反流指数无显著性差异,正常组分别与中度、重度二尖瓣反流组反流量与反流指数有显著性差异,轻、中、重度二尖瓣反流组间有显著性差异,二尖瓣反流指数与超声的二尖瓣反流程度的估计相关性良好。结论磁共振相位编码速度标识技术为非创伤检查中对儿童二尖瓣反流定量分析的较好方法,并为以后的外科手术以及术后随访提供更为精确的信息。

Quantification of mitral regurgitation in children by velocity-encoded cine MR imaging

Objective To evaluate the feasibility of velocity-encoded cine MR imaging by measuring mitral regurgitation in children. Methods Ninteen children (11 boys, 8 girls) were diagnosed as mitral regurgitation. Ten normal children (5 boys, 5 girls) were as control group. All patients were examined by echocardiography, severity of mitral regurgitation was estimated by echocardiography using semi-quantification methods. Mild mitral regurgitation 5 cases, moderate mitral regurgitation 10, severe mitral regurgitation 4. All cases were performed velocity-encoded cine MR imaging. The left ventricular inflow volume and aortic flow volume were measured. Results In normal subjects, there was good concordance between left ventricular inflow and aortic flow volume. These values were not significantly different for patients with mild mitral regurgitation compared with control groups. The regurgitant volume and regurgitant fraction were significantly greater in moderate and severe regurgitation. The regurgitant fraction correlated well with the echocardiographic severity of mitral regurgitation. Conclusion Velocity-encoded cine MR imaging is the better noninvasive modality to evaluate regurgitant volume and regurgitant fraction of mitral regurgitation. It can provide accurate information for the operator and monitor the effect of therapy.