Extrafetal findings at fetal MR: evaluation of the normal placenta and correlation with ultrasound.

Despite the increasing use of magnetic resonance (MR) for fetal imaging, few studies have addressed the MR appearance of the normal placenta. The goal of this paper is to describe the MR features and thickness of the normal placenta during the second and early third trimester of gestation, based on a retrospective study comparing MR with the reference standard of obstetric imaging, ultrasound.