Figure 19a. Retained products of conception in a postpartum woman with vaginal bleeding who was referred for evaluation of a possible uterine arteriovenous malformation. (a) Coronal gadolinium-enhanced T1-weighted image obtained at another institution shows enhancing tissue within the endometrial cavity (arrow). (b) Coronal arterial phase gadolinium-enhanced MR angiogram from the same study shows increased vascularity of the uterus (arrow). This finding was thought to represent a uterine arteriovenous malformation. Subsequent dilation and curettage revealed retained products of conception, and MR imaging was repeated after 6 weeks. (c) Repeat coronal gadolinium-enhanced MR angiogram shows normal pelvic vascularity. (d) Repeat sagittal T2-weighted image shows a normal endometrium (arrow).