Fetal Echoplanar Imaging: Promises and Challenges.
Fetal Echoplanar Imaging: Promises and Challenges.
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DOI：
10.1097/rmr.0000000000000219
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发表时间：
2019-10-01
期刊：
影响因子：
--
通讯作者：
Gholipour, Ali
中科院分区：
文献类型：
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作者：
Afacan, Onur;Estroff, Judy A;Gholipour, Ali
胎儿磁共振成像(MRI)在临床放射学和研究中受到越来越多的关注。回声平面成像(EPI)提供了一种独特的潜力，因为它可以用来非常快速地获取图像。它可以用来冻结运动，或获得具有各种对比度机制的多幅图像，从而可以研究胎儿大脑和身体器官的微观结构和功能。本文就胎儿EPI的临床和研究应用现状作一综述。这包括T2*加权成像以更好地识别血液产品和血管，使用扩散加权磁共振成像来研究发育中大脑的连接，以及使用功能磁共振成像(FMRI)来识别发育中大脑的功能网络。当带状伪影或驻波伪影对常规用于结构胎儿MRI的主流序列产生不利影响时，EPI也可用作替代结构序列。我们还讨论了收购EPI面临的挑战，以及潜在的解决方案。由于EPI采集对易感性伪影具有固有的敏感性，几何失真限制了高分辨率EPI采集的使用。此外，层间运动以及发射和接收场的不均匀可能会在胎儿EPI中产生显著的伪影。最后，我们讨论了有前景的研究方向，以克服这些挑战，提高EPI在临床和研究应用中的使用。
Fetal magnetic resonance imaging (MRI) has been gaining increasing interest in both clinical radiology and research. Echoplanar imaging (EPI) offers a unique potential, as it can be used to acquire images very fast. It can be used to freeze motion, or to get multiple images with various contrast mechanisms that allow studying the microstructure and function of the fetal brain and body organs. In this article, we discuss the current clinical and research applications of fetal EPI. This includes T2*-weighted imaging to better identify blood products and vessels, using diffusion-weighted MRI to investigate connections of the developing brain and using functional MRI (fMRI) to identify the functional networks of the developing brain. EPI can also be used as an alternative structural sequence when banding or standing wave artifacts adversely affect the mainstream sequences used routinely in structural fetal MRI. We also discuss the challenges with EPI acquisitions, and potential solutions. As EPI acquisitions are inherently sensitive to susceptibility artifacts, geometric distortions limit the use of high-resolution EPI acquisitions. Also, interslice motion and transmit and receive field inhomogeneities may create significant artifacts in fetal EPI. We conclude by discussing promising research directions to overcome these challenges to improve the use of EPI in clinical and research applications.