• Findings: The appendix is fluid filled and thick with hyperenhancing walls, periappendiceal stranding, appendicolith

  • Objectives:

    • To review the anatomy of the appendix and how to identify it on CT

    • To review the CT signs of uncomplicated appendicitis

    • To review the complications of appendicitis and their imaging appearance

  • Protocolling:

    • Contrast vs non-contrast CT – discuss oral and IV contrast use

  • Key Points:

    • Identifying the appendix on CT:

      • Follow the colon from the rectum to the cecum

      • Identify the ileo-cecal valve (sail sign, fat density)

      • Appendix should arise from the cecum DISTAL (not necessarily inferior) to the IC valve, AND from the same side of the cecum as the IC valve

    • CT signs of uncomplicated appendicitis

      • Dilated appendix (>7mm)

      • Hyper-enhancing, thick appendix wall

      • Focal cecal thickening (cecal bar sign, arrow sign)

      • Periappendiceal stranding

      • Appendicolith

    • Complications to look for:

      • Perforation - extraluminal gas, discontinuous wall, fluid collection

      • Abscess (in the setting of perforation)

      • Thrombosis of portal venous system (SMV, portal vein)

      • Hepatic abscess

      • Fistula

  • Differential diagnosis:

    • Tumors of the appendix

    • Chronic appendicitis, as in Crohn appendicitis