Recognition of the Ovaries and Ovarian Origin of Pelvic Masses with CT

Knowledge of the morphologic features and ligamentous attachments of the ovaries, the relationship of the ovary to the ureter, and the course of the ovarian vein and artery is necessary for confident recognition of the ovaries and differentiation between ovarian and nonovarian masses with computed tomography (CT). The suspensory ligament attaches the ovary to the pelvic sidewall and transmits the ovarian vein and artery. This ligament may be seen at CT as a linear or fan-shaped soft-tissue band leading to the ovary. The utero-ovarian ligament is occasionally visualized with CT as a soft-tissue band between the uterus and ovary. The ovaries are usually located anterior or anteromedial to the pelvic ureters, whereas iliac lymph nodes are lateral or posterolateral to the ureters. Therefore, an ovarian mass displaces the ureter posteriorly or posterolaterally, whereas a large lymph node mass displaces the ureter medially or anteromedially. An ovarian mass may be draped by ovarian parenchyma, thus revealing the origin of the mass. Tracking the ovarian vein from near the level of the renal vessels caudally to the pelvis leads to the suspensory ligament region and is often helpful in identifying the ovary and differentiating ovarian and nonovarian masses. © RSNA, 2004