The Role of Non-Contrast Cone Beam CT in Identifying Incomplete Treatment during Uterine Artery Embolization

Purpose: To describe the utility of post-procedure noncontrast cone-beam computed tomography (CT) in identifying cases of incomplete treatment and the need to search for additional vascular supply during uterine artery embolization (UAE). Materials and Methods: From June 2013 to June 2018, 427 patients (age, 45 ± 5 years) underwent 430 consecutive UAEs with post-embolization noncontrast cone-beam CT. If noncontrast cone-beam CT showed an area of the uterus lacking contrast retention, aortography was performed to search for collateral supply. Procedures were characterized as suspected complete bilateral UAEs or suspected incomplete UAEs, such as in cases of a unilateral uterine artery or diminutive uterine arteries. Rates of inadequate contrast retention on noncontrast cone-beam CT and discovered collateral artery supply were calculated. In 10 consecutive cases in which both noncontrast cone-beam CT and aortography were performed, dose-area product radiation exposure from noncontrast cone-beam CT and aortography was compared using a 2-sided paired-sample t-test. Results: Of the 411 suspected complete bilateral UAEs, noncontrast cone-beam CT showed an area of the uterus lacking contrast retention in 38 (9.2%) cases. Of the 19 suspected incomplete UAEs, noncontrast cone-beam CT demonstrated incomplete treatment in 6 (31.6%) patients. Aortography was performed in 40 of the 44 cases of incomplete treatment on noncontrast cone-beam CT, and collateral supply was found in 28 (70.0%) cases. In 22 of these cases (5.2% of the 427 patients studied), noncontrast cone-beam CT led to the discovery of significant collateral supply requiring further embolization. Dose-area product radiation exposure from noncontrast cone-beam CT was less than from aortography (P =.007). Conclusions: Post-UAE noncontrast cone-beam CT can be used to select a subset of patients with a higher likelihood of collateral supply who may benefit from post-embolization aortography.