Gholipour Ali, Estroff Judith A, Barnewolt Carol E, Robertson Richard L, Grant P Ellen, Gagoski Borjan, Warfield Simon K, Afacan Onur, Connolly Susan A, Neil Jeffrey J, Wolfberg Adam, Mulkern Robert V
Department of Radiology, Boston Children's Hospital, Boston, Massachusetts, USA.
Boston Maternal Fetal Medicine, Boston, Massachusetts, USA.
Concepts Magn Reson Part A Bridg Educ Res. 2014 Nov;43(6):237-266. doi: 10.1002/cmr.a.21321.
Fetal magnetic resonance imaging (MRI) examinations have become well-established procedures at many institutions and can serve as useful adjuncts to ultrasound (US) exams when diagnostic doubts remain after US. Due to fetal motion, however, fetal MRI exams are challenging and require the MR scanner to be used in a somewhat different mode than that employed for more routine clinical studies. Herein we review the techniques most commonly used, and those that are available, for fetal MRI with an emphasis on the physics of the techniques and how to deploy them to improve success rates for fetal MRI exams. By far the most common technique employed is single-shot T2-weighted imaging due to its excellent tissue contrast and relative immunity to fetal motion. Despite the significant challenges involved, however, many of the other techniques commonly employed in conventional neuro- and body MRI such as T1 and T2*-weighted imaging, diffusion and perfusion weighted imaging, as well as spectroscopic methods remain of interest for fetal MR applications. An effort to understand the strengths and limitations of these basic methods within the context of fetal MRI is made in order to optimize their use and facilitate implementation of technical improvements for the further development of fetal MR imaging, both in acquisition and post-processing strategies.
胎儿磁共振成像（MRI）检查在许多机构已成为成熟的程序，当超声（US）检查后仍存在诊断疑问时，可作为超声检查的有用辅助手段。然而，由于胎儿的活动，胎儿MRI检查具有挑战性，并且需要以与更常规临床研究不同的模式使用MR扫描仪。在此，我们回顾了胎儿MRI最常用的技术以及可用技术，重点是技术的物理原理以及如何运用这些技术提高胎儿MRI检查的成功率。到目前为止，由于其出色的组织对比度和对胎儿活动的相对不敏感性，最常用的技术是单次激发T2加权成像。然而，尽管存在重大挑战，但传统神经和体部MRI中常用的许多其他技术，如T1和T2*加权成像、扩散加权成像和灌注加权成像以及光谱方法，对胎儿MR应用仍然具有吸引力。为了优化这些基本方法在胎儿MRI中的使用，并促进在采集和后处理策略方面的技术改进，以推动胎儿MR成像的进一步发展，我们努力了解这些基本方法在胎儿MRI背景下的优势和局限性。
