Accuracy of Gray‑scale and Three‑dimensional Power Doppler Ultrasound Parameters in the Diagnosis of Morbidly Adherent Placenta

Abstract

Background: Morbidly adherent placenta (MAP) is usually associated with excess blood loss, bladder injuries, and hysterectomies.
Aim: This study was designed to evaluate the accuracy of grayscale and three-dimensional (3D) power Doppler ultrasound parameters in the diagnosis of MAP. Subjects and Methods: Fifty pregnant women ≥28 weeks’ gestation with suspected MAP were included randomly in this prospective study. Two-dimensional (2D) transabdominal gray-scale ultrasound and 3D power Doppler scans were done for studied women to confirm placental location and findings suggestive of MAP. Intraoperative findings and histopathology results of removed uteri in the cases were managed by hysterectomies compared to preoperative sonographic findings using Student’s t-test and Mann–Whitney U-test for quantitative data, Chi-square test for qualitative data to detect the accuracy of 2D transabdominal gray-scale ultrasound and 3D power Doppler parameters in the diagnosis of MAP. Results: Best 2D gray scale ultrasound parameters for the detection of emergency hysterectomies in the studied cases were disruption of uterine serosa– bladder interface (81.8% sensitivity) and exophytic mass invading bladder (94.9% specificity, 66.7% positive predictive value (PPV), and 84.1% negative predictive value [NPV]). Best 3D power Doppler parameters for the detection of emergency hysterectomies in the studied cases were disruption of uterine serosa–bladder interface (90.9% sensitivity, 68.8% specificity, and 47% PPV) and crowded vessels over peripheral subplacental zone (93.2% NPV). Conclusion: 3D power Doppler is a useful complementary tool to 2D gray-scale ultrasound for antenatal diagnosis of MAP. Crowded vessels over peripheral sub-placental zone and disruption of uterine serosa–bladder interface were the best 3D power Doppler parameters for the detection of difficult placental separation, considerable intraoperative blood loss, and emergency hysterectomies in the studied cases.

KEY WORDS: Three‑dimensional power Doppler, gray-scale, morbidly adherent placenta