A study of preoperative diagnosis using abdominal computed tomography in acute appendicitis

To evaluate the usefulness of computed tomography (CT) in differential diagnosis and decisions for operative indications in patients with acute appendicitis, CT was done in 45 patients diagnosed with acute appendicitis. CT was retrospectively analyzed for the following findings: enlarged appendix, hazy periappendiceal density, increased enhancement of the appendiceal wall, deficiency of the appendiceal wall, appendiceal stones, abscess, and ascites. Surgery was conducted 28 patients, of whom 25 were pathologically diagnosed with gangrenous or phlegmonous appendicitis. Seventeen improved without surgery, i.e., 9 with acute appendicitis, 7 with diverticulitis of the colon, and 1 with pelvic peritonitis. Except for 3 with severe abscess, enlarged appendix, hazy periappendiceal density, and increased enhancement of the appendiceal wall were observed in 22 with phlegmonous or gangrenous appendicitis. In 25 with phlegmonous or gangrenous appendicitis, appendiceal stones were observed in 32% and abscess or ascites in 60%. Sensitivity, specificity, and accuracy in CT diagnosis images were 100%, 80%, and 96%. CT findings thus provide useful information in differential diagnosis and decisions on operative indication in patients with acute appendicitis. (author)