Hit or miss: Use of CT or US for pediatric appendicitis varies by hospital type

Children who present to community hospitals with suspected appendicitis are much more likely than those who present to children’s hospitals to undergo preoperative CT imaging, according to a study published in this month's issue Pediatrics. Researchers called for strategies to streamline pediatric appendicitis evaluation and minimize radiation exposure.

Pediatric appendicitis, which accounts for 84,000 hospitalizations annually in the U.S., remains diagnostically challenging. CT has been employed as a sensitive and widely available imaging modality among children with acute abdominal pain. However, radiation exposure remains a concern, which has led to the use of abdominal ultrasound among this patient group. The disadvantages of ultrasound include variable sensitivity and less consistent availability.

Jacqueline M. Saito, MD, from the division of pediatric surgery at Washington University in St. Louis, and colleagues designed a retrospective study to analyze imaging utilization and accuracy among pediatric patients who underwent an operation for appendicitis between Jan. 1, 2009, and Dec. 31, 2010.

The study was comprised of 423 patients. A total of 93.4 percent of patients underwent preoperative imaging, and 15.1 percent of patients underwent both CT and ultrasound imaging. The negative appendectomy rate was 7.3 percent.

“Compared with no preoperative imaging, ultrasound alone was less likely, and CT scan alone was more likely with initial evaluation at a community hospital in comparison with the children’s hospital,” wrote Saito et al.

CT sensitivity for appendicitis was high overall but trended lower at community hospitals. The diminished accuracy may be related to several factors, according to the researchers. Multidetector CT may be less available at community hospitals. Lack of contrast, suboptimal contrast or patient movement may be more likely at community hospitals. Interpretation by general radiologists rather than pediatric imagers also may account for lower sensitivity.

Ultrasound sensitivity for appendicitis was moderate overall and was significantly lower in studies performed at community hospitals and on girls, according to Saito and colleagues.

The researchers suggested variations in diagnostic imaging might result from multiple factors, including imaging availability and the perceived need for diagnostic confirmation. Appendicitis is a leading diagnosis associated with malpractice claims, noted Saito and colleagues. In addition, diagnostic confidence may be higher for CT than for ultrasound.

Diagnostic algorithms and clinical scoring systems to reduce reliance on CT imaging have been developed; however, most were validated at children’s hospitals.

“To address CT use within community hospitals, clinical decision tools are needed that are applicable to practitioners with varying levels of pediatric or surgical expertise at all points of evaluation,” wrote Saito et al.

For more about the pediatric appendicitis dilemma, read “Pediatric CT: Growing Pains,” in Health Imaging magazine.