Determining the organ of origin of large pelvic masses in females using multidetector CT angiography and three-dimensional volume rendering CT angiography.

Objective: To study the value of tumour feeding arteries and the ovarian vein in determining the organ of origin of large pelvic tumours in females using multidetector CT.

Methods: One hundred and thirty patients with 131 pathologically proven tumours (>6.5 cm) were retrospectively reviewed. Conventional CT images and CT angiography were evaluated, with focus on assessing the value of tumour feeding arteries and the ovarian vein in differentiating ovarian from non-ovarian tumours.

Results: For 97 ovarian tumours, the feeding arteries included the ovarian artery (n = 51) and the ovarian branch of uterine artery (n = 64). For 34 non-ovarian tumours, the feeding arteries included the ovarian artery (n = 2), the uterine artery (n = 21), the mesenteric artery (n = 5), and the internal iliac artery (n = 1). The ovarian vein was identified in 86 ovarian tumours and 12 non-ovarian tumours. When the feeding arteries and the ovarian vein were combined to confirm ovarian origin, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 97.8 %, 84.2 %, 93.8 %, 94.1 %, and 93.9 %, respectively. The accuracy was significantly higher than that of independently using the ovarian vein or the ovarian feeding arteries.

Conclusion: Combined application of tumour feeding arteries and the ovarian vein is valuable to differentiate large ovarian from non-ovarian tumours.

Key Points: • CT is a valuable modality for diagnosing pelvic tumours. • Determining the organ of origin is difficult for large pelvic tumours. • Contrast-enhanced CT and CT angiography are helpful in depicting abdominopelvic vessels. • Tracking tumour-associated vessels can help differentiate large ovarian from non-ovarian tumours.