Case report. Antenatal diagnosis of chorioangioma of the placenta: MR features.

We report a case of chorioangioma of the placenta, in which MR findings were useful in establishing the antenatal diagnosis. Polyhydramnios and a placental tumor that was 5 cm in size were visualized. The tumor had relatively high signal intensities on proton density imaging and T2-weighted imaging and showed partially high intensity signal rims on T1-weighted imaging, especially when using a breath-holding technique. Magnetic resonance imaging has an important role in detection and diagnosis of these lesions, particularly the larger tumors, so that appropriate steps can be taken to deal with the complications that may accompany this tumor.