"We reviewed 633 CT studies done over a six month period in the emergency room at our facility," says Susanna Lee, MD, an author of the study.
The patient's records and the request for the CT scan by the referring physician were reviewed to determine if there was a suspected diagnosis indicated before the CT examination. Two-thirds of the referring physicians had a suspected diagnosis before the CT examination; 50-60% of the time the CT scan confirmed the suspected diagnosis, says Dr. Lee. "This yield is just about right. If the yield was higher, it would have indicated that a lot of CT examinations were being done even though the referring physician already had enough information to make a correct diagnosis. If the yield was much lower, it would have indicated that CT examinations were being ordered that weren't providing information needed by the referring physician," says Dr. Lee.
One-third of the time, there wasn't a pre-scan suspected diagnosis, says Dr. Lee. CT scans were positive in 40% of these cases. One-quarter of the time CT scans indicated a diagnosis that was not even considered (based on the patient's symptoms) before the CT scan, adds Dr. Lee.
Abdominal CT is being used more often to diagnose appendicitis, renal colic, diverticulitis, and other diseases. "Our study shows it is being utilized more because it is doing what it is supposed to be doing," says Dr. Lee.
The study will be presented on May 6 during the American Roentgen Ray Society Annual Meeting in San Diego.