DIAGNOSTIC ACCURACY OF ULTRASOUND (USG) AND MAGNETIC RESONANCE IMAGING (MRI) IN PRENATAL DIAGNOSIS OF PLACENTA ACCRETA TAKING OPERATIVE FINDINGS AS GOLD STANDARD

Background: Placenta Accreta (PA) is the extension of chorionic villi into myometrium due to abnormality in decidua basalis which may lead to massive peripartum haemmorhage, hence putting the life of patient at risk. Therefore, antenatal diagnosis of PA is essential for which ultrasonography (USG) and magnetic resonance imaging (MRI) play a pivotal role. However, USG is an easily accessible and low cost imaging modality as compared to MRI and that is why it is more widely used for screening purposes.  Objective: To determine diagnostic accuracy of USG and MRI in prenatal diagnosis of placenta accreta taking operative findings as gold standard as limited local research has been done on this. Methods: A prospective study was conducted in radiology department of Khyber Teaching Hospital, Peshawar from June, 2014 to June, 2016.  Twenty five antenatal patients who were at high clinical risk of placenta accreta were identified and undergone USG and MRI for confirmation of diagnosis. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated both for USG and MRI. Results: Twenty five patients at risk of placenta accreta underwent both USG and MRI. Seven cases were diagnosed with placenta accreta per operatively (gold standard). The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of the USG were 85.7%, 83.3%, 66.7%, 93.8% and 84% respectively. While the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of the MRI were 71.4%, 72.2%, 50%, 86.7% and 72% respectively. Conclusion: The study concluded that diagnostic accuracy of USG is higher than MRI for the antenatal diagnosis of placenta accreta. Key words: Magnetic Resonance Imaging; Placenta Accreta; Prenatal Diagnosis; Ultrasonography.