Computed tomography use in a tertiary care university hospital

Improvements in computed tomography (CT) technology, with shorter scan times and better image quality, have contributed to an increase in the use of CT in the United States in recent years. This increased use has implications for health policy and radiation risk assessment. The purpose of this study was to evaluate trends in CT use.

The CT performance records at a university-based, tertiary care, level 1 trauma center hospital were evaluated from 1998 to 2005. The hospital's decision support infrastructure was used to track overall patient visits and stays. From these data sets, the age and sex dependency of CT use rates were evaluated for outpatients, inpatients, and emergency department (ED) patients.

Outpatient use rates averaged over the age groups of 21 to 30 years, 41 to 50 years, and 61 to 70 years were 20, 59, and 87 CT scans per 1,000 outpatient visits, respectively. Inpatient use rates for these same age groups were 88, 148, and 162 CT scans per 1,000 inpatient days, respectively. ED patient use rates for these same age groups were 705, 687, and 394 CT scans per 1,000 ED patient visits, respectively. Male patients outnumbered female patients for both ED and inpatient CT use from the early teens to the mid-40s age range.

The overall CT use increased 27% and 48% from 2000 to 2004 for outpatient and inpatient visits, respectively. CT use in the hospital's high-volume ED increased 131% from 2000 to 2004, which may be partly attributable to the installation of 2 CT scanners near the ED.