Recent innovations in placental MRI: Integrating visualization and functional imaging.

The placenta is a highly specialized organ that regulates oxygen, nutrient, and waste exchange between the maternal and fetal circulations and is essential for normal fetal development and pregnancy outcome. Placental dysfunction underlies many obstetric complications, including fetal growth restriction, pre-eclampsia, congenital heart disease, and stillbirth, yet in vivo assessment of placental structure and function remains limited in routine clinical care. Magnetic resonance imaging (MRI) has emerged as a powerful, noninvasive modality for placental evaluation, offering whole-organ coverage, superior soft-tissue contrast, and the ability to interrogate placental morphology, microstructure, perfusion, and oxygenation across gestation. This review summarizes recent advances in structural, microstructural, and functional placental MRI, with emphasis on quantitative and multimodal approaches. Emerging integrated and multicontrast frameworks that capture placental spatiotemporal heterogeneity and disentangle maternal, fetal, and tissue compartments are highlighted. Finally, we address key technical challenges, including physiological confounders. Continued methodological advancement and large longitudinal studies are essential to translate placental MRI into clinically robust measures of placental health.