Variability of radiological grading of blunt cerebrovascular injuries in trauma patients

CONTEXT: Blunt cerebrovascular injury (BCVI) occurs in 1%–2% of all blunt trauma patients. Computed tomographic angiography of the neck (CTAn) is commonly used for the diagnosis and grading of BCVIs. Grade of injury dictates treatment, and there remains a lack in understanding the inter-reader reliability of these interpretations. AIMS: The aim of this study is to determine the extent of variability in BCVIs among specialized neuroradiologist interpretation of CTAn. SETTINGS AND DESIGN: Retrospective review of trauma patients admitted to a level one trauma center with a BCVI from January 2012 to December 2017. Patients were randomly assigned for CTAn re-evaluation by two of three blinded, neuroradiologists. STATISTICAL ANALYSIS USED: The variability in BCVI grades was measured using the coefficient of unalikeability (u), and inter-reader reliability was calculated using weighted Cohen's kappa (k). RESULTS: Two hundred and twenty-eight BCVIs were analyzed with initial grades of 71 (31%) grade one, 74 (32%) grade two, 26 (11%) grade three, 57 (25%) grade four, and 0 grade five. Variability was present in 93 (41%) of all BCVIs. Grade one injuries had the lowest occurrence of total agreement (31%) followed by grade three (61%), grade two (63%), and grade four (92%). Total variability of grade interpretations (u = 100) occurred most frequently with grade three BCVIs (21%). Weighted Cohen's k calculations had a mean of 0.07, indicating poor reader agreement. CONCLUSIONS: This novel study demonstrated the BCVI variability of radiological grade interpretation occurs in more than a third of patients. The reliability of CTAn interpretation of BCVI grades is not uniform, potentially leading to undertreatment and overtreatment.