基于磁共振定性定量精确扫描技术的胎儿先心病诊断研究

Echocardiography has been the primary imaging method for prenataldiagnosis of fetal congenital heart diseases. But, the other adjunct method is very necessary. Magnetic resonance imaging (MRI) is used with increasing frequency as a complementary imaging modality to ultrasound (US) in prenatal diagnosis of fetal anomalies. But fetal cardiovascular magnetic resonance (CMR) has just been developed. The study intends to usethe new technologies of fetal CMR to thequalitative and quantitative evaluation of fetal CDH and cardiac function assessment. The new technology of fetal heart CMR will be studied by the control study of fetal sheep CMR and cardiac anatomy, e.g., high spatial resolution (steady-state free precession sequence with negative intervals), no gating real-time sequence, functionala ssessment (phase contrast CMR sequence with metric optimized gating) and artifact reduction (radial sampling). The qualitative and quantitative evaluation of fetal sheep cardiovascular structure and quantitative assessment of cardiac function will be studied. We will find the new technology of fetal CMR clearly showing cardiovascular structure, the method of assessment of cardiac function, the method of qualitative and quantitative evaluation of fetal cardiovascular structure, the accuracy of quantitative indicators. Further, the diagnostic criteria and accuracy, the methods of quantitative evaluation and quantitative indicators of fetal CDH, the feasibility and scientific value of quantification of cardiac function of fetal CMR new technology will be studied by controlled clinical fetal CMR with CDH and these fetal follow-up results. It will provide scientific methods and quantitative indicators, which qualitatively and quantitatively evaluate fetal CHD and these fetal cardiac functions.

超声心动图是胎儿先天性心脏病（CHD）的首选影像方法，但另一种方法的补充是必要的。磁共振成像（MRI）对超声已经起到了补充作用，但胎儿心血管磁共振（CMR）刚刚起步。本项目拟采用CMR新技术进行胎儿CDH定性定量评价及心功能评估研究，通过胎羊心脏CMR和心脏解剖对照研究空间分辨率高（负间隔稳态自由进动序列）、实时无门控序列、功能评估（采用量化优化门控（MOG）的相位对比CMR序列）及伪影消除（径向采集）的胎心CMR新技术，研究胎心结构定性定量评价和心功能评估方法，得出能清晰显示胎心结构和功能评估的CMR新技术、定性定量评价心血管结构方法和量化指标的准确性；进而通过临床CDH人胎心脏CMR及随访结果对照探索，得出CMR新技术定性诊断胎儿CHD的诊断规范及准确性、定量评价胎儿CDH的方法和量化指标、量化心功能的可行性和科学价值，为胎儿CHD的产前定性定量评价及心功能评估提供科学方法和量化指标。

超声心动图是胎儿先天性心脏病（CHD）的首选影像方法，但超声有其局限性，但另一种方法的补充是必要的。磁共振成像（MRI）在胎儿畸形诊断中对超声已经起到了补充作用，但胎儿心血管磁共振（CMR）刚刚起步。本项目采用CMR新技术进行胎儿先天性心脏病定性定量评价及血流量评估研究，顺利如期完成了动物实验，并超额完成了临床研究部分，完成胎羊动物实验15例、胎儿先天性心脏病332例。我们通过胎羊心脏CMR和心脏解剖对照研究空间分辨率高（负间隔稳态自由进动序列）、功能评估（采用量化优化门控（MOG）的相位对比CMR序列）及伪影消除（径向采集）的胎心CMR新技术，我们发现径向采集扫描方式可以效抑制胎儿心脏MRI检查中的条带状伪影，提供具有良好的空间分辨率图像。负间隔扫描是个重要扫描技术。得出了胎心心脏MRI评价心血管结构的五个标准切面，尤其是主动脉弓层面和四腔心层面最为重要。. 通过332例临床先天性心脏病胎儿心脏CMR及随访结果对照探索，得出了切实可行的胎儿先天性心脏病的节段定性分析方法, 胎儿心脏MRI联合产前超声心动图将胎儿先天性心脏病中的产前诊断准确率提高至79%。产前心脏MRI在胎儿主动脉异常、体静脉异常、结节硬化方面具有较高的诊断价值，并能够行胎儿心轴及主动脉弓直径测量，研究结果得出胎儿正常心轴为34.5～56.8◦，法洛氏四联症是最常见的心轴小于35◦的先天性心脏病，主动脉弓直径随孕周增大而线性增加。所有研究结果的得出了CMR新技术定性诊断胎儿CHD的诊断规范及准确性、定量评价胎儿CHD的方法和量化指标，为胎儿CHD的产前定性定量评价及心功能评估提供了科学方法和量化指标。