CT utilization and radiation risk in the elderly: let us not downplay frequent imaging

Abstract

Objectives: To evaluate trends in CT utilization and recurrent exam frequency among elderly patients and assess implications for radiation risk.

Methods: We retrospectively analysed CT exams performed at a quaternary-care academic hospital from 2014 to 2024. Patients were stratified into decade-based age groups, with the elderly defined as ≥60 years. Annual CT volume share and per-patient exam frequencies were computed, with emphasis on high-frequency use (≥2, ≥3, ≥5, and ≥10 exams/year). Temporal trends were assessed using centred log-ratio transformation and linear regression analysis.

Results: The proportion of CTs performed in patients aged 60-90 years rose from 50.4% in 2014 to 58.3% in 2024 (+7.9%). Elderly patients undergoing ≥2 exams/year increased from 25.6% to 26.6% (+1.0%), while for non-elderly patients it decreased from 17.4% to 12.7% (-4.8%). Similar trends were observed for those undergoing ≥10 exams/year. Elderly patients represent the largest group receiving recurrent CTs. The proportion of CTs in elderly is expected to rise to nearly 66% in 2035, a projected 7.2% increase from 58.3% in 2024.

Conclusions: CT imaging is becoming increasingly concentrated in elderly populations, reflecting both demographic and clinical drivers. While the radiation risk per individual exam remains small, cumulative exposure and the growing demand for imaging in older adults highlight the need for balanced strategies that ensure clinical benefit while maintaining optimized, justified radiation use.

Advances in knowledge: CT utilization among elderly patients is projected to reach two-thirds of all CTs by 2035, underscoring that radiation safety considerations for the elderly should not be neglected.

Keywords: CT in geriatric patients; CT utilization in the elderly; multiple imaging in the elderly; recurrent imaging in the elderly.