Diagnostic yield and distribution of initial head CT findings in adult trauma patients: a retrospective cross-sectional study from a level I trauma center

Head trauma is a common presentation to the emergency department, and non-contrast head computed tomography (CT) is the choice modality for evaluating suspected traumatic brain injury (TBI). This study evaluated the diagnostic yield and distribution of initial CT findings and factors independently associated with CT-positive examinations in adult head trauma patients. We conducted a retrospective cross-sectional study of adults with head trauma who underwent initial non-contrast head CT at a Level I trauma center in Shiraz, Iran, from March to September 2024. Patients with non-diagnostic imaging, contrast-enhanced CT, prior head trauma or cranial surgery, intracranial neoplasm, or other prespecified criteria were excluded. CT examinations were initially interpreted by a senior radiology resident and a board-certified radiologist, with adjudication by a senior attending radiologist when interpretations differed. Patients were classified as CT-positive if at least one acute traumatic intracranial or skull abnormality was identified. Group comparisons used chi-square or Fisher’s exact tests and independent-samples t-tests or Mann–Whitney U tests, as appropriate. Multivariable logistic regression identified factors independently associated with CT-positive status. Among 1,808 eligible patients, 164 (9.1%) were CT-positive, and 1,644 (90.9%) were CT-negative. CT-positive patients were younger than CT-negative patients (mean (SD) age, 37.8 (17.1) vs. 58.9 (17.2) years; P < 0.001) and had lower mean (SD) Glasgow Coma Scale scores (8.8 (2.4) vs. 13.1 (1.3); P < 0.001). Sex and injury mechanism also differed between groups ( P = 0.001 and P = 0.011, respectively). Cerebral contusion (62.2%), epidural hematoma (37.2%), and linear skull fracture (29.9%) were the most frequent findings. Multivariable analysis demonstrated that older age (aOR, 0.93; 95% CI, 0.91–0.95) and higher Glasgow Coma Scale score (aOR, 0.33; 95% CI, 0.28–0.39) were independently associated with lower odds of CT-positive findings (both P < 0.001), whereas neither sex nor injury mechanism showed an independent association with CT-positive status. Acute traumatic findings were identified in a relatively low proportion of adults undergoing initial head CT after trauma. Younger age and lower GCS score were independently associated with CT-positive findings. These findings characterize the imaging profile of a high-volume trauma population and support further investigation of risk stratification and CT utilization. Not applicable.