Reliability of Magnetic Resonance Imaging in diagnosis and assessment the depth of invasion of placental accreta in high risk gravid women.

OBJECTIVES: To evaluate sensitivity, specificity and accuracy of Magnetic Resonance Imaging (MRI) in diagnosis and assessment the depth of invasion of placenta accreta (PA) in high risk gravid women.

MATERIALS & METHODS: The study included 58 pregnant women with multiple risk factors for PA. Placental mapping by ultrasound was followed by MRI when the patients were diagnosed or suspicious by ultrasound to have PA. Focal myometrial interruption, dark intra-placental band, heterogeneous placenta, focal uterine bulge and invasion to the surrounding organs were used as a sign of diagnosis of PA. The results of the MRI were compared with intraoperative findings and/or histopathological diagnosis.

RESULTS: Placenta Previa was detected at MRI in 58 cases and PA in 49 cases. The sensitivity, specificity and accuracy of MRI in the diagnosis of PA were (100%, 75%, and 94.8% respectively) and (100%, 42.8%, and 79.3% respectively) in assessing the depth of invasion. Invasion to the surrounding organs sign was the most reliable sign in diagnosis of placenta percreta.

CONCLUSION: MRI is a reliable method in the diagnosis of PAbut less reliable in assessing the depth of invasion of placenta accreta and increta making the task of differentiating between them difficult. Placenta percreta diagnosed accurately by invasion to the surrounding organs.