CT scans may not reduce the negative appendectomy rate in children.

Background/purpose: Concern about an increased lifetime risk of cancer in children who have undergone a single computed tomography (CT) scan prompted us to review utilization of this diagnostic test in our appendicitis population.

Methods: From 1998 to 2001, the records of 720 children admitted to our hospital with a diagnosis of appendicitis were reviewed for adjunct diagnostic modalities, including ultrasonography (USG) and CT scanning. Negative appendectomy rates were determined by the final pathologic report. Statistical comparisons were made using the chi(2) test, and significance was assigned at P <.05.

Results: The use of ultrasound scan for diagnosing appendicitis decreased from 20.0% in 1998 to 7.0% in 2001 (P <.01). Conversely, the use of CT scans increased from 17.6% in 1998 to 51.3% in 2001 (P <.001). During this time period the difference in the negative appendectomy rate was not statistically significant (P < 0.20). Of the negative appendectomies, 11 of these patients had a USG interpreted as positive for appendicitis (22.0%), and 9 had a CT scan interpreted as positive (18.0%).

Conclusions: Liberal use of CT scans in diagnosing appendicitis in children has not resulted in a decreased negative appendectomy rate. Potentially harmful radiation exposure should prompt pediatric surgeons to reevaluate the role of CT scanning in the management of children with suspected appendicitis.