Abaci Turk Esra, Stout Jeffrey N, Ha Christopher, Luo Jie, Gagoski Borjan, Yetisir Filiz, Golland Polina, Wald Lawrence L, Adalsteinsson Elfar, Robinson Julian N, Roberts Drucilla J, Barth William H, Grant P Ellen
Fetal-Neonatal Neuroimaging and Developmental Science Center, Boston Children's Hospital, Boston, MA.
School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.
Top Magn Reson Imaging. 2019 Oct;28(5):285-297. doi: 10.1097/RMR.0000000000000221.
The Human Placenta Project has focused attention on the need for noninvasive magnetic resonance imaging (MRI)-based techniques to diagnose and monitor placental function throughout pregnancy. The hope is that the management of placenta-related pathologies would be improved if physicians had more direct, real-time measures of placental health to guide clinical decision making. As oxygen alters signal intensity on MRI and oxygen transport is a key function of the placenta, many of the MRI methods under development are focused on quantifying oxygen transport or oxygen content of the placenta. For example, measurements from blood oxygen level-dependent imaging of the placenta during maternal hyperoxia correspond to outcomes in twin pregnancies, suggesting that some aspects of placental oxygen transport can be monitored by MRI. Additional methods are being developed to accurately quantify baseline placental oxygenation by MRI relaxometry. However, direct validation of placental MRI methods is challenging and therefore animal studies and ex vivo studies of human placentas are needed. Here we provide an overview of the current state of the art of oxygen transport and quantification with MRI. We suggest that as these techniques are being developed, increased focus be placed on ensuring they are robust and reliable across individuals and standardized to enable predictive diagnostic models to be generated from the data. The field is still several years away from establishing the clinical benefit of monitoring placental function in real time with MRI, but the promise of individual personalized diagnosis and monitoring of placental disease in real time continues to motivate this effort.
人类胎盘项目已将关注点聚焦于，需要基于非侵入性磁共振成像（MRI）的技术来在整个孕期诊断和监测胎盘功能。人们希望，如果医生能有更直接、实时的胎盘健康指标来指导临床决策，那么与胎盘相关病症的管理将会得到改善。由于氧气会改变MRI上的信号强度，且氧气运输是胎盘的一项关键功能，因此许多正在研发的MRI方法都聚焦于量化胎盘的氧气运输或氧气含量。例如，在母体高氧状态下对胎盘进行血氧水平依赖性功能磁共振成像测量，其结果与双胎妊娠的结局相关，这表明胎盘氧气运输的某些方面可以通过MRI进行监测。正在研发其他方法，通过MRI弛豫测量法来准确量化胎盘的基线氧合情况。然而，对胎盘MRI方法进行直接验证具有挑战性，因此需要开展动物研究以及对人类胎盘进行离体研究。在此，我们概述了利用MRI进行氧气运输及量化的当前技术水平。我们建议，在研发这些技术时，应更加注重确保它们在个体间的稳健性和可靠性，并实现标准化，以便能够根据数据生成预测性诊断模型。距离通过MRI实时监测胎盘功能所带来的临床益处得到确立，该领域仍有几年的路要走，但实时进行个体个性化诊断和监测胎盘疾病的前景，仍在持续推动这项工作。
