Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.
Center for Biomedical Imaging (CIBM), Lausanne, Switzerland.
Sci Rep. 2017 Nov 14;7(1):15540. doi: 10.1038/s41598-017-15701-1.
Fast magnetic resonance imaging (MRI) led to the emergence of 'cine MRI' techniques, which enable the visualization of the beating heart and the assessment of cardiac morphology and dynamics. However, established cine MRI methods are not suitable for fetal heart imaging in utero, where anatomical structures are considerably smaller and recording an electrocardiogram signal for synchronizing MRI data acquisition is difficult. Here we present a framework to overcome these challenges. We use methods for image acquisition and reconstruction that robustly produce images with sufficient spatial and temporal resolution to detect the heart contractions of the fetus, enabling a retrospective gating of the images and thus the generation of images of the beating heart. To underline the potential of our approach, we acquired in utero images in six pregnant patients and compared these with their echocardiograms. We found good agreement in terms of diameter and area measurements, and low inter- and intra- observer variability. These results establish MRI as a reliable modality for fetal cardiac imaging, with a substantial potential for prenatal evaluation of congenital heart defects.
快速磁共振成像（MRI）催生了“电影磁共振成像”技术，该技术可用于观察心跳并评估心脏形态和动态。然而，成熟的电影磁共振成像方法并不适用于子宫内胎儿心脏成像，因为子宫内胎儿的解剖结构要小得多，并且记录心电图信号以同步磁共振数据采集较为困难。在这里，我们提出了一种克服这些挑战的框架。我们使用图像采集和重建方法，这些方法可以稳健地生成具有足够空间和时间分辨率的图像，以检测胎儿的心脏收缩，从而可以对图像进行回顾性门控，从而生成心跳图像。为了强调我们方法的潜力，我们在六名孕妇中采集了子宫内图像，并将这些图像与他们的超声心动图进行了比较。我们发现，在直径和面积测量方面有很好的一致性，并且观察者之间和观察者内部的变异性较低。这些结果确立了 MRI 作为一种可靠的胎儿心脏成像方式，具有对先天性心脏缺陷进行产前评估的巨大潜力。
