A prospective cohort study: can advanced ultrasonography replace magnetic resonance imaging in the diagnosis of placental adhesion disorders?

To define and compare the diagnostic accuracy of ultrasonography (USG) and magnetic resonance imaging (MRI) for the placental adhesive disorder (PAD).A prospective study was conducted between January 2019 and February 2020 in a tertiary referral university hospital. A total of 115 placenta previa cases were included in the study during the third trimester of gestation. USG examination was performed, and the placenta was scanned in a systematic manner using gray-scale ultrasound, color Doppler flow mapping, and 3-D imaging for each participant. Thereafter, all participants underwent an MRI examination. USG and MRI findings were compared with histopathological findings.Loss of the retroplacental sonolucent zone (71% [95% CI 47-88]) and an irregular retroplacental sonolucent zone (71% [95% CI 47-88]) were the most sensitive USG parameters. For MRI, the uterine bulging parameter was the most sensitive (60% [95% CI 36-80]) and specific (91% [95% CI 83-96]) findings, and it had the highest accuracy rate (85% [95% CI 77-91]). Overall, the USG sensitivity, specificity, and accuracy rates were 77% (95% CI 54-92), 87% (95% CI 79-93), and 85% (95% CI 77-91), respectively. The MRI sensitivity, specificity, and accuracy rates for all participants were 81% (95% CI 59-94), 85% (95% CI 76-92), and 84% (95% CI 76-90), respectively.In the diagnosis of PAD, the specificity and accuracy of USG are higher than that of MRI, whereas the sensitivity of MRI is better than that of USG.