Retrospective review of traumatic brain injury: is skull X-ray still clinically relevant?

Head computed tomography (CT) is the gold standard imaging modality for the evaluation of head injury. Skull radiography is no longer recommended in current guidelines due to its limited diagnostic value. Despite this, skull X-ray continues to be used in clinical practice. This study aimed to evaluate the diagnostic performance of skull X-ray and its association with intracranial injury.

We conducted a retrospective study of 12,392 patient encounters with head injury at a single centre between 2018 and 2023. We analysed imaging utilization and findings. Diagnostic performance of skull X-ray was assessed in 759 cases where both X-ray and CT were performed. CT served as the reference standard. Sensitivity, specificity, predictive values, and associations with intracranial haemorrhage were calculated.

Most X-rays were without a fracture (97.0 %). Skull X-ray demonstrated low sensitivity (43.6 %) and high specificity (91.4 %) for detecting skull fractures. Intracranial haemorrhage was present in 13.3 % of cases and occurred in 11.2 % of patients without a fracture on X-ray. Notably, 14.2 % of all CT scans (441 of 3,103) showed haemorrhage without fracture. Fracture on X-ray was associated with increased risk of intracranial haemorrhage (Odds Ratio [OR] 2.85, 95 % Confidence Interval [CI] 1.74-4.68). Clinically significant traumatic brain injury (csTBI) occurred in 17 of 759 encounters (2.2 %), with 12 admissions to intensive care unit, 10 neurosurgical interventions and 8 deaths after head injury. However, the association was not statistically significant (OR 2.64, 95 % CI 0.91-7.67, p = 0.075).

Skull radiography has limited diagnostic value, fails to detect intracranial injury and may provide false reassurance in a clinical setting. CT remains the preferred imaging modality, and routine use of skull X-ray should be reconsidered.