Background: Evidence-based guidelines (NICE NG232) are designed to safely identify ED trauma patients who truly need CT head scans. Practitioners may understandably request scans in the absence of these criteria defensively, yet this can expose patients to unnecessary radiation and costs.  The authors aimed to assess how often CT head requests adhere to these guidelines and to evaluate the necessity of scans performed when criteria are not met.

Methods: The authors undertook a two-cycle audit of adult trauma CT head scans at a West Midlands DGH in 2025. Each request was assessed against NICE criteria, and it was recorded whether any intracranial pathology was identified or management was affected. In cycle 1, a poster (“No Reds? No CT Heads”) was introduced, visually demonstrating all criteria in one cartoon mnemonic. In cycle 2, the poster was further amended to incorporate local audit data, emphasising that none of the previous inappropriate scans had been positive, and including information on radiation dose (2mSv/scan) and cost (£120/scan).

Results: Across three two-week periods, 148 scans were reviewed. At baseline, 78.8% (41/52) met criteria. This increased to 81.6% (40/49) after cycle 1 (not significant) and 89.4% (42/47) after cycle 2, a statistically significant improvement over baseline (p=0.042). Yield for acute injury increased from 11.5% to 17.0%. No inappropriate scan identified an acute injury in either cycle.

Conclusions: Defensive ordering is prevalent. Non-specific interventions alone had little effect. When combined with targeted local feedback, cost, and radiation data, inappropriate scanning halved without loss of sensitivity.