Retrospective Comparison of Ultrasound and Magnetic Resonance Imaging as Diagnostic Tools in Pregnant Women with Abnormal Placentation

Abstract

Postpartum hemorrhage is the leading cause of maternal death worldwide, and Placenta Accreta (PA) is a major contributor. Although advancements in obstetric practices have led to a decline in maternal mortality, PA remains challenging to diagnose and manage. Current diagnostic tools include ultrasound (U/S) and Magnetic Resonance Imaging (MRI); however, the sensitivity and specificity of these techniques in diagnosing Placenta Accreta Spectrum (PAS) are widely debated. Objective: To compare the accuracy of U/S and MRI in the diagnosis of PAS. Methods: A retrospective analysis of pregnant women in their second and third trimesters suspected to have PAS was conducted. Women with both antenatal U/S and MRI who delivered in Dr. Soliman Fakeeh Hospital between 1st October 2014 and 2nd February 2019 were included. Results: Of the 46 women included in the study, MRI corrected the diagnosis of 13 patients (28%) and confirmed the U/S diagnosis of 19 patients (41%). However, MRI also resulted in an incorrect change in diagnosis of eight patients (17%), and an incorrect confirmation of U/S diagnosis of six patients (13%). Statistical analyses of both U/S and MRI in the diagnosis of PAS showed that U/S sensitivity and specificity were 40% and 75%, respectively, whereas MRI sensitivity and specificity were 86% and 58%, respectively. Conclusion: MRI was more sensitive than U/S in identifying placental invasion into the uterine wall. Therefore, we recommend MRI examination for all patients suspected to have PAS. Keywords: Abnormal placentation, magnetic resonance imaging (MRI), placenta accreta spectrum, ultrasound, prenatal diagnosis, surgical findings, histopathology.