Diagnostic value of ultrasonography and magnetic resonance imaging in pregnant women at risk for placenta accreta.

OBJECTIVE

The purpose of this study was to evaluate whether ultrasonography and magnetic resonance imaging can detect placenta accreta reliably in at-risk patients.

PATIENTS AND METHODS

Thirty-nine gravid women with abnormal placentation and previous uterine surgery were collected after meeting the inclusion criteria depending on gray scale sonographic findings which suggested placenta accreta. Ultrasonography (US) and resonance imaging (MRI) findings were classified as positive and negative according to presence or absence of imaging criteria of placenta accreta.

RESULTS

The surgical findings of our patients confirmed placenta accreta in 8/39 (20.5%) patients. According to gray scale and color Doppler US 11/39 (28.2%) patients were positive and 28/39 (71.8%) were negative for placenta accreta. According to MRI findings, 12/39 (30.7%) patients were positive for placenta accreta and 27/39 (69.3%) were negative. Sensitivity, specificity, positive predictive value, negative predictive value of US and MRI were 82.0%, 89.6%, 72.7%, 92.8% and 88.8%, 86.8%, 66.6%, 96.2%, respectively.

CONCLUSION

US and MRI were useful in the diagnosis of placenta accreta with lacunae and an abnormal color Doppler imaging pattern are the most helpful findings. MRI is most clearly indicated when US findings are ambiguous or there is a posterior placenta.