Trends in Head CT Use in US Emergency Department Patients

Despite the widespread perception among neurologists that head CTs are routinely ordered in emergency departments, a nationwide analysis of 15 years of data reveals that only 6% to 10% of ED visits actually result in a head CT—though that number nearly doubled from 7.8 million in 2007 to 16 million in 2022. The study, led by Elaine Dilla of Yale University, highlights stark disparities: Black patients, those in rural areas, and Medicaid recipients were significantly less likely to receive head CTs, while patients aged 65 and older saw a steady increase in scans despite no change in clinical indications. The rise is attributed not to evolving diagnostic criteria, but to an aging population with more comorbidities and heightened risk tolerance—especially among anticoagulated patients. The data also lacks granularity on repeat scans, diagnostic yield, or individual patient trajectories, limiting insights into overuse and equity. The authors call for AI-powered clinical decision tools to address gaps in risk assessment, particularly for older adults who fall outside current decision rules. This episode underscores a critical tension: the growing use of imaging in vulnerable populations, driven more by demographic shifts than clinical change, demands better data and smarter tools to ensure equitable, evidence-based care. The findings challenge the assumption that imaging use is uniform or driven by clear medical necessity.