Computed tomography utilization in South Korean Emergency Medical Centers: national trends from 2014 to 2021

Background: The global use of computed tomography (CT) scans in emergency settings is rapidly increasing; however, nationwide data from South Korean Emergency Medical Centers (EMCs) remain limited. Methods: We conducted a retrospective cross-sectional analysis using nationwide data from the National Emergency Department Information System, which collects real-time emergency medical information from EMCs across South Korea. Approximately 11 million emergency department (ED) visits involving CT scans at EMCs between 2014 and 2021 were analyzed to evaluate annual trends in CT utilization, as well as trends by EMC level, age group, Korean Triage and Acuity Scale (KTAS), CT scan region, and scan type. Results: From 2014 to 2021, the total number of CT scans performed at EMCs increased by 96.97%. The proportion of ED visits involving CT scans (CT utilization proportion) increased from 10.23% in 2014 to 25.67% in 2021 (p < 0.001). Subgroups with high CT utilization included patients aged ≥80 years, Level I EMC patients, and KTAS Level I cases. The largest increases were observed in patients aged ≥80 years (160.34%), Level III EMCs (246.61%), and KTAS Level I cases (98.59%). Among patients aged ≤9 years, CT utilization increased by 133.42%. The most common CT scan types were non-contrast brain CT, contrast-enhanced abdominal CT, and non-contrast chest CT, with non-contrast chest CT increasing sharply after 2020. Discrepancies between scanned regions and presenting symptoms have also increased, particularly in chest and abdominal CT scans. Conclusions: CT utilization has substantially increased in South Korean EMCs, particularly among subgroups with high-utilization and those vulnerable to radiation exposure. Medical and ethical considerations regarding unnecessary radiation exposure and potential low-value diagnostic imaging (LVDI) should be carefully evaluated. We propose that continuous monitoring and systematic evaluation are essential to ensure appropriate imaging practices and minimize unnecessary radiation exposure.