Appendicitis Diagnosis By CT

Diagram displaying appendicitis clinical course and complications.

Appendicitis is inflammation of the vermiform appendix caused by an obstruction attributable to infection, stricture, fecal mass, foreign body or tumor. Appendicitis can affect either gender at any age, but is most common in males ages 10 to 30. Appendicitis is the most common disease requiring surgery. If left untreated, appendicitis may progress to abscess, perforation,peritonitis, and death.

Appendicitis

Radiological features:

• Abdominal X-Ray: Look for a calcified appendicolith in the right lower quadrant (RLQ). Other indicators include free air; small bowel ileus; extra-luminal  gas; caecal wall thickening; loss of pelvis fat planes around the bladder suggests pelvic free fluid; loss of the properitoneal fat line; psoas line distortion and abrupt cut-off of the normal gaseous pattern at the hepatic flexure due to colonic spasm.



Large calcified appendicolith (arrowhead)

•  Ultrasonography: Suggestive features include an obstructing appendicolith – a blind ending non-peristaltic, non-compressible tubular structure and prominent vasculature within the meso-appendix; wall thickness should be 2mm in a normal appendix or 6mm in total diameter.

Inflammed appendix displaying thick wall

• CT: Sensitive and specific investigation. Not routine due to radiation dose. Luminal distension with a thickened enhancing wall (+/-) an appendicolith. Local inflammation shows as linear streaking in the adjacent fat. Abscesses may be present.



Inflammed appendix with multiple appendicoliths

• Contrast investigations: Occasionally picked up coincidently. Suggested by non-filling or localised mucosal oedema within the caecal pole.

Normal appendix; barium enema radiographic examination