Placenta previa; MRI as an adjunct to ultrasound in assessment of suspected placental invasion

Evaluate adding MRI to ultrasound in imaging of placenta previa with suspected placenta accreta. evaluation of 23 pregnant females presenting with placenta previa was done. The age ranged from 20 to 39 years (mean = 30.9). All of the patients were subjected to ultrasonography (US) and magnetic resonance imaging (MRI) of the pelvis at gestational age of 25–37 weeks prior to elective delivery. 11 out of 23 patients were proved placenta accreta based on surgical and pathological reports. US suggested diagnosis of placenta previa/accreta in 8 patients and placenta previa without accreta in 15 cases. 7/8 was true positive (87.5%) & one was false positive (12.5%) with sensitivity 63.64%, accuracy 78.26%, and specificity 91.67%. MRI has suggested diagnosis of placenta previa/accreta in 8/23 & placenta previa with no accreta in 15/23 patients. MRI was found to give true positive results in 8/8 patients proved to be accreta. MRI gave true negative in 12 patients (80%) & false negative in 3 (20%) with sensitivity 72.73%, accuracy 86.96%, and specificity 100%. Combining MRI and ultra sound provide more diagnostic information and may reduce unnecessary interventions with favorable outcome.