Figure 5a. Endometrioma in a 39-year-old woman with infertility and pelvic pain. (a) Transverse transvaginal US image demonstrates the typical appearance of an endometrioma: a unilocular cyst (C) with low-level echoes, which in this case obscures the right ovary. UT = uterus. (b) Axial T1-weighted MR image of the pelvis shows a high-signal-intensity right adnexal mass (C), a finding that is consistent with an endometrioma. Note also the large simple cyst arising from the left ovary (*).