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