Comparison of Computer Tomography and Sonography in Patients Suspected of Having Appendicitis

ABSTRACT

BACKGROUND: This study was conducted to compare the accuracy of computered tomography(CT) and sonography(US) in diagnosing acute appendicitis and to analyze the radiologic factors which influence the result. METHODS: We retrospectively studied the cases of 53 patients who were suspected of having appendicitis and who were examined by CT and US covered a three-year period. The final diagnosis was determined from the surgico-pathologic diagnosis and clinical follow-up for two months, as well as from the discharge diagnosis. RESULTS: Thirty-eight(38) patients had acute appendicitis; 15 patients did not. In the analysis, CT and US, respectively, revealed sensitivities of 89.5% and 73.7%, specificities of 93.3% and 60.0%, positive predictive values of 97.1% and 82.4%, negative predictive values of 77.8% and 47.4%. Among patients diagnosed with acute appendicitis, 10 patients were discordant in the US and the CT examinations; CT findings were correct in 8 and US findings in 2. Among non-appendicitis patients, 5 patients were discordant in the US and the CT examinations; CT was correct in 5 and US in 0. Nighteen(19) patients had complications such as an abscess or a perforation. Among these patients, the degree and the extent of the complication were accurately evaluated by CT in 15 patients and by US in 5 patients. CONCLUSION: CT is more accurate than US in diagnosing and excluding acute appendicitis. The use of CT will substantially decrease unnecessary laparotomies and post-operation complications.