Placenta Accreta Spectrum Disorders: Update and Pictorial Review of the SAR-ESUR Joint Consensus Statement for MRI.

Placenta accreta spectrum (PAS) disorders are a major cause of maternal morbidity and mortality and are increasing in incidence owing to a rising rate of cesarean delivery. US is the primary imaging tool for evaluation of PAS disorders, which are most often diagnosed during routine early second-trimester US to assess fetal anatomy. MRI serves as a complementary modality, providing value when the diagnosis is equivocal at US and evaluating the extent and topography of myoinvasion for surgical planning in severe cases. While the definitive diagnosis is established by a combined clinical and histopathologic classification at delivery, accurate antenatal diagnosis and multidisciplinary management are critical to guide treatment and ensure optimal outcomes for these patients. Many MRI features of PAS disorders have been described in the literature. To standardize assessment at MRI, the Society of Abdominal Radiology (SAR) and European Society of Urogenital Radiology (ESUR) released a joint consensus statement to provide guidance for image acquisition, image interpretation, and reporting of PAS disorders. The authors review the role of imaging in diagnosis of PAS disorders, describe the SAR-ESUR consensus statement with a pictorial review of the seven major MRI features recommended for use in diagnosis of PAS disorders, and discuss management of these patients. Familiarity with the spectrum of MRI findings of PAS disorders will provide the radiologist with the tools needed to more accurately diagnose this disease and make a greater impact on the care of these patients. RSNA, 2023 Quiz questions for this article are available through the Online Learning Center. See the invited commentary by Jha and Lyell in this issue.