Figure R1-1 Typical case of RPOC after an incomplete first trimester pregnancy loss. A and B (gray-scale views) show the ill-defined margins of the endometrium at the fundus with irregular cystic spaces. The color Doppler in C shows that these spaces are blood vessels in this very vascular case of RPOC.

Figure R1-2 A to D, The uterine cavity contains an echogenic mass, filling the cavity (A) and extending to the edge of the endometrium, blurring the margins (B, calipers). C shows the abundant color flow at the site of the RPOC. D shows the 3-D appearance of the same case, demonstrating an asymmetric enlargement and deformity of the left fundus/cornu, representing the RPOC.

Figure R1-3 A to C, Sclerotic RPOC, 6 months after a term delivery (2-D, Doppler, and 3-D images). Note the complex-appearing vascular mass involving the endometrium. If this were seen in a postmenopausal patient with bleeding, the appearance would be consistent with endometrial cancer. The history of a symptomatic postpartum patient enabled the correct diagnosis of longstanding RPOC (sclerotic on pathologic examination).

Figure R1-4 Patient with an endometrial polyp. Note the similarity to the RPOCs. This patient had never been pregnant

Figure R1-5 Rare case of spontaneous AVM unrelated to pregnancy. The entire uterus is replaced by cystic areas on gray-scale imaging. Color flow Doppler shows abnormal vessels reaching to the serosa and involving much of the myometrium. The pattern and clinical history were very different in this nulliparous patient.