96 Role of Ultrasound Scan in the Diagnosis of Acute Appendicitis in Children: A 5 year Single Center Experience

Abstract Introduction In children ultrasound scans are preferred as a diagnostic tool for appendicitis over CT scans due to the risk of radiation. We aim to evaluate the efficacy of ultrasound scan in diagnosing appendicitis. Methods Retrospective analysis of five year data from a single center in southeast of England. Children under the age of 16 were included. Data was collected using hospital information management systems. Analyzed using Excel Spreadsheet 16.88. Results 204 children underwent Appendicectomy from 2017 to 2022. 119 patients did not have any imaging. 75 had ultrasound, 4 had CT scans while 3 had both. Out of 75 patients who had ultrasound scans, 54 suggested appendicitis, 18 could not find any abnormality while 3 were indeterminate. Nine out of 54 patients who had an ultrasound suggestive of appendicitis did not have appendicitis on histology. 15 out of these 18(83.3%) patients with normal ultrasound had appendicitis on their histology. In this subset the mean WCC for the group with appendicitis was 15.1 and 15.8 for the group without appendicitis, this difference was not statistically significant. Similarly, no significant difference was found in CRP. The overall sensitivity of an ultrasound was found to be 76% while the specificity was 25%. The positive predictive value was 83%, while the negative predictive value was 17%. Conclusion While ultrasound scans are a useful adjunct to clinical assessment for the diagnosis of appendicitis, it has a low specificity and negative predictive value which means it is not a good tool to rule out appendicitis.