Gray-Scale, Colour Doppler Ultrasound and Magnetic Resonance Imaging for Diagnosis of Placenta Accreta

Objective: To evaluate the precision of magnetic resonance imaging (MRI) in comparison to gray-scale (GS) and color Doppler ultrasonography (US) for the prenatal identification of placenta accreta. Patients and Methods: This prospective cohort study was carried out in the ultrasound unit of the Obstetrics and Gynecology Department at Ain Shams University Maternity Hospital from July 2018 to November 2019. 100 pregnant women with placenta previa and high risk for morbid placental adherence were enrolled for ultrasound and MRI examination. The gold standard for the diagnosis of placenta accreta was the operative findings at the time of surgery and or histopathological results following hysterectomy. Results: Women with morbidly adherent placenta previa were statistically significantly older than those with non-morbid placental adherence. No statistically significant differences were found between both groups regarding gestational ages at diagnosis or delivery and number of antepartum bleeding episodes. Estimated intra-operative blood loss, number of PRBCs (packed red blood cells) units transfused and need for cesarean hysterectomy were statistically significantly higher in the morbidly adherent placenta group, however, mean hemoglobin drop following delivery was not statistically significantly different between both groups. Magnetic resonance imaging showed an overall higher diagnostic validity for morbidly adherent placenta compared to ultrasonography. Conclusion: The combination of MRI and ultrasound is essential for the precise identification of placenta previa and the potentially severe condition of placenta accreta. Although using both modalities may yield more diagnostic information, magnetic resonance imaging outperformed ultrasonography in terms of overall diagnostic validity for placentas that are morbidly adherent.