Evaluation of the fetal abdomen by magnetic resonance imaging. Part 1: malformations of the abdominal cavity

Abstract Although ultrasound continues to be the mainstay modality for the evaluation of fetal disorders, fetal magnetic resonance imaging (MRI) has often been used as a valuable adjunct in recent years. The exponential growth of the use of fetal MRI has been facilitated by technological advancements such as ultrafast T2-weighted sequences and diffusion-weighted imaging. Fetal MRI can achieve results that are comparable to or better than those of ultrasound, particularly in cases of maternal obesity, severe oligohydramnios, or abnormal fetal position. Because of its superior soft tissue contrast, wide field of view, and multiplanar imaging, fetal MRI is able to evaluate the large fetal organs, such as the lungs, liver, bowel, and kidneys. In addition, fetal MRI allows large or complex malformations to be examined, facilitating the understanding of the malformation within the context of the body as a whole. Initial fetal MRI studies were focused on the central nervous system. With advances in software and hardware, fetal MRI gained importance in the evaluation of the fetal abdomen. The purpose of this article is to review the recent literature and developments in MRI evaluation of the fetal abdomen, with an emphasis on imaging aspects, protocols, and common clinical indications.

摘要 尽管超声仍是胎儿疾病评估的主流影像学检查手段，近年来胎儿磁共振成像（MRI）已成为极具价值的辅助检查方式。超快T2加权序列、弥散加权成像等技术进步，推动了胎儿MRI应用的指数级增长。胎儿MRI的检查效果可媲美甚至优于超声，尤其适用于孕妇肥胖、重度羊水过少或胎儿体位异常的场景。由于其优异的软组织对比度、宽广的视野以及多平面成像能力，胎儿MRI可对胎儿肺脏、肝脏、肠道、肾脏等大型脏器进行评估。此外，胎儿MRI可检出大型或复杂畸形，有助于从全身整体层面理解畸形的发生与表现。早期胎儿MRI研究主要聚焦于中枢神经系统，随着软硬件技术的迭代升级，胎儿MRI在胎儿腹部评估中的应用价值日益凸显。本文旨在综述胎儿腹部MRI评估的近期文献与技术进展，重点涵盖影像学要点、检查方案以及常见临床适应证。