Figure 6a. Retained placenta in a 37-year-old woman. (a) Sagittal T2-weighted image shows an enlarged uterus with a high-signal-intensity subendometrial layer. A protruding lesion with high signal intensity (arrow) is seen in the uterine cavity, which is filled with low-signal-intensity blood (arrowheads). (b) Sagittal contrast-enhanced T1-weighted image shows marked enhancement of the protruding lesion (arrow), which indicates a retained placenta. The nonenhancing area in the lesion corresponds to a clot. Arrowheads = blood in the uterine cavity. Dilation and curettage performed after MR imaging demonstrated the presence of retained placenta.