Diagnostic Imaging: Plain Films: Accuracy

Plain radiographs of the abdomen are normal in 20 - 50 % of cases (14). However in infants with appendicitis, over 80% will have abnormalities on abdominal radiographs suspicious of this disease(1). The results of plain radiography can almost never exclude appendicitis (15). Generally, plain radiographic findings are non-specific. Abnormalities do not occur with adequate frequency to justify the routine use of this examination (16).

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Diagnostic Imaging: Plain Films: Findings in Appendicitis

Abnormal findings on plain radiographs include:

• indistinctness of the right psoas muscle margin, scoliosis with splinting of the spine to the right side , and focal obliteration of the properitoneal fat line (these findings are the result of inflammation of the retroperitoneal/properitoneal fat),
• soft tissue mass effect in the right lower quadrant (due to the presence of a periappendiceal inflammation or abscess),
• colon cut-off sign (resulting from transverse colonic ileus and proximal colonic spasm),
• localized or generalized small bowel dilatation with multiple air-fluid levels (due to ileus or small bowel obstruction related to a periappendiceal abscess).

• A calcified appendicolith is seen in 10-50% of all cases of appendicitis (15,17). Appendicoliths are often laminated and may be multiple. In a symptomatic child, the radiographic identification of a calcified appendicolith has a high correlation with the diagnosis of acute appendicitis.
• A right pleural effusion, peritoneal fluid, and a small pneumoperitoneum may be identified in neonates.
• Free air in the peritoneal cavity rarely accompanies ruptured appendix without abscess formation (1).

Review Plain Film and Barium Enema Findings in Appendicitis case presentations

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Proceed to Barium Enema