Radiologists' confidence in interpretation of sonography and CT in suspected pediatric appendicitis

OBJECTIVE. We sought to determine radiologists' confidence in interpretatio n of sonography and CT performed using rectal contrast material for diagnos ing pediatric appendicitis. SUBJECTS AND METHODS. We prospectively examined 139 children and young adul ts with equivocal clinical findings for appendicitis who were seen in the e mergency department of an urban pediatric teaching hospital between July an d December, 1998, Patients were initially examined with pelvic sonography. If the sonographic results were equivocal or if the appendix was not visual ized, CT was performed. Radiologists recorded their level of confidence in interpretation of the sonograms and CT examinations. RESULTS. Sonography was interpreted with very low, low, or medium confidenc e in 59 (42.4%) of 139 patients and width high or very high confidence in 8 0 (57.6%) of 139, CT was interpreted with very low, low, or medium confiden ce in nine (8.3%) of 108 and with high or very high confidence in 99 (91.7% ) of 108 children. Radiologists were more confident in their interpretation of CT than sonography (p < 0.001), If the sonography was a true-positive e xamination, radiologists were more confident in its interpretation than if it was a false-positive study (P = 0,003). Radiologists were more confident in sonographic interpretation of a true-negative examination than of a fal se-negative study (p = 0,03). Patient age and sex and the radiologists' lev el of experience did not make a significant difference in the confidence of interpretation of sonography or CT. CONCLUSION.. In the evaluation of childhood appendicitis, radiologists' con fidence in interpretation is influenced by the choice of imaging technique as well as by the results of the study.