University of Michigan
Department of Pediatrics
Evidence-Based Pediatrics Web Site

Question

• In girls, ages 12-18, with a clinical exam performed by pediatric surgeons consistent with appendicitis, does an abdominal U/S and abdominal and pelvic CT improve sensitivity and specificity and effect a change in therapy?

Clinical Bottom Lines

1. Conclusive diagnosis of appendicitis in children may require a complete H&P, Abdominal U/S and Abdominal CT.
2. Continued observation of a radiologically benign acute abdomen may be appropriate.
3. Greatest radiological sensitivity comes with U/S & CT.  Greatest specificity comes with U/S alone.
4. On average, the addition of a CT exam does NOT affect a surgeon's decision regarding disposition.

Summary of Key Evidence

1. When considering CT independent of exam, in girls older than 10 years, CT imaging was not significantly more accurate in predicting appendicitis than examination alone (93.9% vs. 87.5%; P = 0.46).  Helical CT had a higher sensitivity (95% vs. 78%, p = 0.009), accuracy (94% vs. 89%, p = 0.05), but the same specificity (93%).
2. When considering U/S alone vs. U/S & CT, U/S alone has a sensitivity of 86% and specificity of 94%.  U/S & CT has a sensitivity of 99% and specificity of 89%.  U/S alone:  +LR = 17.2, (-)LR = 0.15; U/S & CT:  + LR = 9.0, (-)LR = 0.01.
3. The area under the curve for U/S alone = 0.972, U/S and CT = 0.980.

Additional Comments

• Sound outcomes-based methods though poor analysis regarding key evidence
• Questionable applicability given different patient population and local practices.

Citation

1. Kaiser S, Jorulf H, Soderman E, Frenckner B. Impact of radiologic imaging on the surgical decision-making process in suspected appendicitis in children. Academic Radiology. 2004;11:971-9.
2. Kaiser S, Jorulf H, Frenckner B.  Suspected appendicitis in children: US and CT--a prospective randomized study. Radiology. 2002;223:633-8.
3. Stephen AE, Segev DL, Ryan DP, Mullins ME, Kim SH, Schnitzer JJ, Doody DP. The diagnosis of acute appendicitis in a pediatric population: to CT or not to CT. Journal of Pediatric Surgery. 2003;38:367-71.
4. Sivit CJ, Applegate KE, Stallion A, et al. Imaging evaluation of suspected appendicitis in a pediatric population: effectiveness of sonography versus CT. AJR. American Journal of Roentgenology. 2000;175:977-80.

CAT Author: Adam C. Kean, MD, MPH

CAT Appraisers: Kerry Mychaliska, MD

Date appraised: March 5, 2008