MRI of pregnancy-related issues: abnormal placentation

In this article, we review the clinical significance of abnormal placentation and the role of MRI in diagnosis and management of this potentially morbid condition. We present our clinical perspective on diagnosing this challenging problem with MRI and review the imaging findings that can lead to a correct diagnosis. As abnormal placentation becomes more prevalent, in large part due to the markedly rising rates of cesarean delivery, there is a need for accurate antenatal diagnosis of this condition to prevent maternal morbidity and mortality. Maternal and fetal outcomes can be optimized through multidisciplinary planning to achieve accurate diagnosis and anticipation of the extent of abnormal placentation in the antenatal period. Imaging findings of abnormal placentation have been described for both ultrasound and MRI, although limitations exist for each technique. Although ultrasound remains the primary screening modality for the detection of abnormal placentation, MRI is a complementary technique that should be considered when ultrasound is inconclusive or incomplete. Familiarity with MRI techniques to assess the placenta, MRI appearance of normal placenta, and imaging findings that suggest abnormal placentation can help radiologists contribute to a successful maternal outcome.