Importance of the new radiographic sign of fecal loading in the cecum in the presence of acute appendicitis in comparison with other inflammatory diseases of the right abdomen

BACKGROUND: The value of plain abdominal radiography in acute appendicitis has not been completely studied. Therefore, the purpose of this investigation was to verify a new radiographic sign: the presence of fecal loading in the cecum for the diagnosis of acute appendicitis in comparison with other diseases of the right abdomen. METHODS: A total of 470 consecutive patients of both sexes admitted to the hospital due to acute abdominal pain were prospectively studied. Group 1 (n=170), the acute appendicitis group, included patients subjected to an abdominal radiographic study a few hours before surgical treatment; group 2 (n=100) had right nephrolithiasis; group 3 (n=100) had right acute inflammatory pelvic disease; and group 4 (n=100) had acute cholecystitis. RESULTS: The sign of fecal loading in the cecum was present in 165 patients in group 1, in 19% of those in group 2, in 12% of those in group 3, and in 13% in group 4. The sensitivity of the radiographic sign for acute appendicitis was 97.05% and its specificity was 85.33%. The positive predictive value of this sign for acute appendicitis was 78.94% and its negative predictive value was 98.08%. This sign disappeared in 66 (94.28%) of the 70 patients who had plain abdominal radiographs on the first postoperative day. CONCLUSIONS: The radiographic image of fecal loading in the cecum is associated with acute appendicitis and disappears after appendectomy. This sign is uncommon in other acute inflammatory diseases of the right side of the abdomen.