Assessment of inter- and intraobserver agreement between intravascular US and aortic angiography of thoracic aortic injury

PURPOSE: To compare inter- and intraobserver agreement at thoracic aortic angiography with that at intravascular ultrasonography (US) in the work-up of patients suspected of having thoracic aortic injury. MATERIALS AND METHODS: Three blinded readers performed a retrospective review of 95 thoracic aortic angiograms and 23 intravascular US images obtained in patients suspected of having traumatic aortic injury. Inter- and intraobserver agreement in the interpretation of the thoracic aortic angiograms and intravascular US images were determined by using Cohen kappa statistics. In addition, differences among demographic groups were evaluated by using bivariate analysis. RESULTS: Interobserver agreement was lowest in the interpretation of indeterminate angiograms (kappa = 0.55) and highest in the interpretation of determinate angiograms (kappa = 0.71). In contrast, interobserver agreement in the interpretation of intravascular US images was excellent. For all groups, intraobserver agreement in the interpretation of aortic angiograms was substantial and overall agreement was good (kappa = 0.88). Intraobserver agreement in the interpretation of intravascular US images was excellent (kappa = 1.00). Differences among demographic groups were not found to be significant. CONCLUSION: Intravascular US is an adjunct to aortic angiography and yields excellent overall inter- and intraobserver agreement. Subgroups of patients who are suspected of having aortic injury and have indeterminate angiograms may benefit from undergoing intravascular US.