USE OF COMPUTED-TOMOGRAPHY SCANNING BEFORE AND AFTER SITING IN AN EMERGENCY DEPARTMENT

Rationale and Objectives. Before a computed tomography (CT) scanner wa s installed ill the emergency department, this hospital had no dedicat ed CT scanner for patients in the emergency department, and transporti ng these patients to the CT scanners in the radiology department took approximately 8-10 min each way. We sought to determine whether the pr esence of a CT scanner within the emergency department would lead to a n increase in the number of emergent cranial CT examinations and a dec rease in the diagnostic yield of these examinations. Methods. More tha n 8,000 records of cranial CT examinations were reviewed for the 12 mo nths before and the 12 months after the installation of the CT scanner in the emergency department. A positive case was defined as one that showed acute abnormality such as ischemia, hemorrhage, edema, or mass effect. Results. Our results show a 30.1% increase in the number of CT scans of the head ordered by physicians in the emergency department a fter the installation of a CT scanner (p < .0001). This is compared wi th the background 1.8% increase in the total number of emergency depar tment visits. However, in both periods, 12% of the total number of hea d scans done were positive. Conclusion. The convenience of having a CT scanner in the emergency department leads to greater use of CT examin ations. However, the increase in the number of emergent CT studies is justified because the number of positive CT examinations increases pro portionately.