Jun Zhang MD, Presenter: Nothing to Disclose

To compare magnetic resonance imaging (MRI) and ultrasonography (US) for diagnosing placenta abnormality antenatally.

71 patients with low-lying anterior placenta diagnosed at US underwent MR imaging. MR imaging were performed with a Philips 1.5T superconductive system. Images were interpreted propectively for signs of placenta abnormality. The sonographic and MRI diagnoses were compared with the final pathological or operative findings or with both.

42 patients had true pathologic confirmation of accreta, increta, percreta, placental abruption, gestational trophoblastic tumor or placental hemangioma. In 29 diagnostic cases, US and MR imaging findings were in complete agreement with pathologic diagnosis. MR imaging correctly provided additional information to the US-determined diagnosis in another 8. MR imaging correctly changed the US diagnosis in 10. The MR imaging-determined diagnosis was incorrect and the US diagnosis was correct in three cases. In twelve cases, the diagnoses at US were incorrect when correlated with the pathologic diagnosis. Five women who had no MRI signs of placenta abnormality had accreta confirmed by pathology.

MRI had predictive value in the diagnosis of placenta abnormality. When placenta abnormality is detected or suspected at US, MR imaging may demonstrate additional findings that can alert diagnosis, sometimes MR imaging may change the diagnosis of US in complicated pregnancies. Further refinement in the techniques of both MRI and US is needed for these tests to be used to reliably diagnose these pathologic conditions.

antenatal diagnosis with MRI

Zhang, J, Antenatal Diagnosis of Placenta Abnormality: Comparison of Magnetic Resonance Imaging and Ultrasonography.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8015953.html