Intraplacental T2-hypointense bands may help predict placental invasion depth and postpartum hemorrhage in placenta accrete spectrum disorders in high-risk gravid patients

Abstract

Introduction: Accurate noninvasive prenatal diagnosis of placenta accreta spectrum (PAS) disorder is critical for delivery management.

Purpose: To evaluate the diagnostic ability of MRI features in predicting the PAS, invasive depth and postpartum hemorrhage (PPH) in high-risk gravid patients.

Materials and methods: Between February 2019 and November 2020, women with ultrasound (US)-suspected PAS were enrolled. With the exclusion criteria, 80 women were included in the study. Two experienced genitourinary radiologists reviewed and recorded the MRI features. The chi square test was used to compare the effectiveness of MRI features. Relative risk ratios were computed to test the association of intraplacental T2-hypointense bands with poor outcomes of cesarean section. Receiver operating characteristic (ROC) analyses based on the number and area of intraplacental T2-hypointense bands were used to predict PAS, invasion depth, and PPH.

Results: PAS was diagnosed in 56 of 80 women (70%). At delivery, 24 of 80 women (30%) experienced PPH (≥1000 mL). Intraplacental T2-hypointense bands were detected at MRI in 28 of 56 women with PAS (50%). The relative risk ratio of intraplacental T2-hypointense bands was 1.51 for PAS, 3.17 for depth of PAS invasiveness and 4.74 for PPH. The largest areas of intraplacental T2-hypointense bands for predicting PAS, invasion depth and PPH were 0.66 cm², 1.68 cm² and 1.99 cm², respectively.

Discussion: The appearance of intraplacental T2-hypointense bands has important diagnostic value for PAS, its invasion depth and PPH. The area of the largest T2-hypointense band in the placenta can predict poor outcomes of cesarean section.

Keywords: Intraplacental T2-hypointense band; Magnetic resonance imaging; Placenta accreta spectrum.