Acute Appendicitis: Comparison of Low-Dose and Standard-Dose Unenhanced Multi–Detector Row CT

PURPOSE: To prospectively compare low- and standard-dose unenhanced multi–detector row computed tomography (CT) in patients suspected of having acute appendicitis. MATERIALS AND METHODS: Ninety-five consecutive patients underwent two unenhanced multi–detector row CT examinations with 4 × 2.5-mm collimation, 120 kVp, and 30 and 100 effective mAs. Two radiologists independently read the images obtained at each dose during two sessions. Readers recorded visualization of the appendix and presence of gas in its lumen, appendicolith, periappendiceal fat stranding, cecal wall thickening, and abscess or phlegmon to measure the diameter of the appendix and to propose diagnosis (appendicitis or alternative). Data were compared according to dose and reader, with definite diagnosis established on basis of surgical findings (n = 37) or clinical follow-up. χ2 tests and logistic regression were used. Measurement agreements were assessed with Cohen κ statistics. RESULTS: Twenty-nine patients had a definite diagnosis of a...