Workload and diagnostic yield of acute neuroradiology scans during on-call hours: past 15-year trends at a European tertiary care center

OBJECTIVES: To determine past 15-year trends in workload, negative findings, and incidental findings in acute neuroradiology during on-call hours at a European tertiary care center. MATERIALS AND METHODS: This study analyzed a sample of 2494 CT and 264 MRI scans of the head and/or neck performed during on-call hours at a tertiary care center on random dates between 2009 and 2023. RESULTS: The workload significantly increased by 130% between 2009 and 2023 (Kendall tau of 0.76, p < 0.001), both due to an increased number and complexity of CT scans (80% and 50% increase, respectively). The workload for MRI remained stable (Kendall tau of 0.03, p = 0.869). The proportion of negative CT scans showed temporal stability (Kendall tau of 0.25, p = 0.139), at an average of 65%. The proportion of negative MRI scans showed an irregular but significant upward pattern over time, ending at 74% in 2023 (Kendall tau 0.42, p = 0.003). The percentage of CT scans with incidental findings exhibited a fluctuating yet significant upward trend over time, ending at 4% in 2023 (Kendall tau 0.62, p < 0.001), and was associated with increasing age (p = 0.010) and the use of a larger scan coverage (p < 0.001). No incidental findings were reported for MRI. CONCLUSION: The acute neuroradiology workload during on-call hours has considerably grown in the past 15 years, both due to a rise in the number and complexity of CT scans. Overuse of CT did not appear to increase, but MRI may be increasingly overutilized. The frequency of incidental findings on CT was non-negligible and increased. KEY POINTS: Question Both an increase in the number and complexity of CT scans has led to a 130% rise in acute neuroradiology workload during on-call hours over the past 15 years. Findings There are indications that MRI overuse may be increasing (but not CT), while the frequency of incidental findings on CT is also on the rise. Clinical relevance Policymakers should address the rising acute neuroradiology workload driven by CT and the potential overuse of MRI in this setting. Further investigation is needed into the consequences of the increase in incidental findings on CT.