Color Doppler US in the evaluation of uterine vascular abnormalities.

Uterine vascular lesions are rare but potentially life-threatening lesions that should be suspected in women of reproductive age with unexplained vaginal bleeding and in postmenopausal women in whom anechoic structures are detected at ultrasonography (US). This is especially true in patients with a history of infection, curettage, therapeutic abortion, pelvic surgery, endometrial carcinoma, or gestational trophoblastic disease. Color Doppler US is valuable in the detection and characterization of many uterine vascular lesions, including arteriovenous malformations (AVMs) (especially arteriovenous fistulas), true aneurysms, pseudoaneurysms, and chorioangioma of the placenta. Arteriovenous fistulas demonstrate a mosaic pattern representing turbulent flow. Spectral analysis of intralesional arterial flow demonstrates high-velocity flow with a low resistive index, and spectral analysis of intralesional venous flow shows high peak systolic velocities consistent with an arterial flow pattern. Spectral analysis of a true aneurysm demonstrates arterial signals, whereas a to-and-fro or swirling pattern of flow is seen at the neck of a pseudoaneurysm. Chorioangioma is a benign hypervascular lesion with arterial and venous flow that, like AVMs, contains numerous cystic spaces that produce color signals. Color Doppler US is useful in the early diagnosis and treatment of these potentially clinically significant disorders of the uterus and placenta. Response to treatment can also be assessed with this technique.