Rajesh Krishnamoorthi MD, Presenter: Nothing to Disclose

Naresh Ramarajan, Abstract Co-Author: Nothing to Disclose

Ewen Wang, Abstract Co-Author: Nothing to Disclose

Pejman Ghanouni MD, PhD, Abstract Co-Author: Nothing to Disclose

Shlomit Goldberg-Stein MD, Abstract Co-Author: Nothing to Disclose

Richard A. Barth MD, Abstract Co-Author: Nothing to Disclose

Beverley Newman MD, Abstract Co-Author: Nothing to Disclose

Erika Rubesova MD, Abstract Co-Author: Nothing to Disclose

Claudia Mueller, Abstract Co-Author: Nothing to Disclose

00030490-DMT et al, Abstract Co-Author: Nothing to Disclose

CT scanning for pediatric appendicitis is a common diagnostic test performed in the United States. However, increased radiation exposure in children may contribute to future risk of carcinogenesis. Ultrasound (US) is a radiation-free alternative but the accuracy of US alone does not approach the sensitivity of CT. This study evaluates a staged US and CT imaging protocol for appendicitis that aims to preserve diagnostic accuracy while minimizing unnecessary radiation exposure in children.

This is a retrospective study of all imaging studies for suspected appendicitis in children who presented to a suburban pediatric ED between 2003 and 2008. A staged protocol utilizing ultrasound first for suspected appendicitis and following with a CT when US findings were equivocal was established in 2003 by pediatric radiology, pediatric surgery and emergency medicine at our facility. US was defined as diagnostic when either a normal or abnormal appendix was identified or an alternate diagnosis was confirmed. US was equivocal when the appendix was not identified and an alternate diagnosis was not rendered. Outcomes for operative and non-operative management were collected from pathology reports and discharge diagnoses. Sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), negative appendectomy rate (NAR), missed appendicitis rate (MAR), and the number of CT scans saved by the staged protocol were analyzed.

A total of 1345 children received imaging for suspected appendicitis during the study period. The compliance with the staged US & CT protocol was 48% (646). The prevalence of appendicitis in the compliant group was 35.1 %. The sensitivity, specificity, NPV and PPV of the combined protocol was 98.7%, 91.8%, 99.2% and 86.9% respectively. The NAR was 7.9% (n=19) and MAR was 0.17% (n=1). 52.2 % (337) of CT scans were saved in compliant group. US and CT confirmed alternate diagnosis in 64 patients (US 22/CT 42).

Staged US followed by CT protocol results in high diagnostic accuracy, significantly reduces the number of CT scans, and represents a significant step towards the ALARA (As Low As Reasonably Achievable) goal.

Clinicians evaluating a child with suspected appendicitis should consider a staged US and CT protocol in order to reduce radiation exposure in children.

Krishnamoorthi, R, Ramarajan, N, Wang, E, Ghanouni, P, Goldberg-Stein, S, Barth, R, Newman, B, Rubesova, E, Mueller, C, et al, 0, Effectiveness of a Staged US and CT Protocol for the Diagnosis of Pediatric Appendicitis: Reducing Radiation Exposure in the Age of ALARA.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8013398.html