Ultrasonography and limited computed tomography in the diagnosis and management of appendicitis in children

Context Limited computed tomography with rectal contrast (CTRC) has been sh own to be 98% accurate in the diagnosis of appendicitis in the adult popula tion, but data are lacking regarding the accuracy and effectiveness of this technique in diagnosing pediatric appendicitis. Objective To determine the diagnostic value of a protocol involving ultraso nography and CTRC in the diagnosis and management of appendicitis in childr en and adolescents, Design, Setting, and Participants Prospective cohort study of 139 children and adolescents aged 3 to 21 years (2 patients were older than 18 years) wh o had equivocal clinical findings for acute appendicitis and who presented to the emergency department of a large, urban, pediatric teaching hospital between July and December 1998. Interventions Children were first evaluated with pelvic ultrasonography. If the result was definitive for appendicitis, laparotomy was performed; if u ltrasonography was negative or inconclusive, CTRC was obtained. Patients wh o did not undergo laparotomy had telephone follow-up at 2 weeks and medical records of all patients were reviewed 4 to 6 months after study completion . Main Outcome Measures Specificity, sensitivity, positive predictive value, negative predictive value, and accuracy of tests based on final diagnoses; surgeons' estimated likelihood of appendicitis on a scale of 1 to 10 for ea ch case and their case management plans before imaging, after ultrasonograp hy, and after CTRC. Results A total of 108 patients underwent both ultrasonography and CTRC exa minations. The protocol had a sensitivity of 94%, specificity of 94%, posit ive predictive value of 90%, negative predictive Value of 97%, and accuracy of 94%. A normal appendix was identified by ultrasonography in 2 (2.4%) of 83 patients without appendicitis and by CTRC in 62 (84%) of 74 patients. A negative ultrasonography result did not change the surgeons' clinical conf idence level in excluding appendicitis (P =.06), while a negative CTRC resu lt did have a significant effect (P<.001). Positive results obtained for ei ther ultrasonography or CTRC significantly affected surgeons' estimated lik elihood of appendicitis (P=.001 and P<.001, respectively). Ultrasonography resulted in a beneficial change in patient management in 26 (18.7%) of 139 children while CTRC correctly changed management in 79 (73.1%) of 108. Conclusions These data show that CTRC following a negative or indeterminate ultrasonography result is highly accurate in the diagnosis of appendicitis in children.