Incidence, outcome, and risk factors of contrast media extravasation injury during contrast-enhanced computed tomography scans: an observational cohort study

Contrast media (CM) is widely used in contrast-enhanced computed tomography (CECT) to enhance the visualization of abnormal structures. CM extravasation, a recognized complication, may cause mild swelling or severe injuries (e.g., ulceration, necrosis). Current research on severe extravasation is limited to case reports or lacks large-cohort analyses of risk factors. This study aimed to explore risk factors, validate incidence and outcomes, and compare patient/technique/CM-related factors between mild and severe CM extravasation injuries using large-scale clinical data to aid early recognition and prevention. This is a retrospective cohort study. A total of 586,812 CM injections were performed during CECT scans at a single institution between November 2012 and December 2023. Among these, 709 cases (334 males, 375 females; age: 62.9±15.2 years) with CM extravasation injuries were included. Extravasation injuries were classified by severity. The frequency and clinical outcomes of different severities of injuries were investigated. Risk factors of serious injuries were evaluated using logistic regression with generalized estimating equation analyses. CM extravasation occurred in 0.12% (709/586,812) of cases. Of the 709 extravasation injuries, 672 (94.8%) were mild, 32 (4.5%) were moderate, and 5 (0.7%) were severe. Only 5 patients received consultations from dermatologists or burn specialists, and none required surgery. Multivariate analysis underscored the presence of diabetes mellitus [DM, odds ratio (OR) =8.04; P<0.01], injections in the dorsum of the hand (OR =4.86; P<0.01), without saline test (OR =2.58; P=0.02), and large-volume extravasation (OR =5.49; P<0.01) as potential risk factors of moderate or severe CM extravasation injury. Most CM extravasation injuries are mild and without serious consequences. Multiple modifiable risk factors for serious CM extravasation injury have been identified that could mitigate the severity of the injury.