Comparison of MRI findings for predicting massive hemorrhage during cesarean section in patients with placental malposition: partial placental volume of lower uterine segment is an accurate and objective indicator

To comprehensively compare the diagnostic ability and inter-reader agreement of magnetic resonance imaging (MRI) findings for predicting massive hemorrhage after cesarean section in patients with placental malposition, aiming to identify the most reliable and objective indicators. Totally, 148 consecutive patients with placental malposition underwent MRI and cesarean section at our hospital between January 2014 and July 2021. The patients were divided into massive and non-massive hemorrhage groups. MRI findings of placenta accreta, placental position, and placental volume were evaluated by two radiologists, and inter-reader agreement was calculated. Diagnostic ability for predicting massive hemorrhage was evaluated using receiver operating characteristic analysis. Intraplacental T2 dark bands (100% vs. 58.2%, p = 0.001), placental bulge (50% vs. 3.7%, p