Learning Radiology xray montage

Appendicolith with Appendicitis

General considerations

  • Also known as a fecolith, fecalith, coprolith
  • Calcified deposit within the appendix
  • Present in approximately 30% of children with acute appendicitis
  • May be an incidental finding on an abdominal radiograph done for other purposes
  • But, when associated with abdominal pain, there is a 90% probability of acute appendicitis
    • Also 50% higher risk of appendiceal perforation
  • Of some controversy, the finding of an appendicolith may be sufficient evidence to perform a prophylactic appendectomy in asymptomatic patients given the higher rate of perforation at the time of acute appendicitis
  • One of several causes of obstruction of the appendiceal lumen leading to acute appendicitis which also include
    • Lymphoid hyperplasia
    • Foreign bodies
    • Stricture
    • Tumor
    • Crohn’s disease
  • For more on clinical and imaging findings of acute appendicitis, click here
Imaging Findings
  • The role of imaging is to confirm clinically suspected appendicitis, rule out another diagnosis or a complication of the disease
  • Conventional radiography (abnormalities seen in <50%)
    • Plain-film findings become more distinctive after perforation, while clinical findings subside
    • Calcified, frequently laminated, appendicolith in RLQ (in 7-15%)
      • It may lie higher in a retrocecal appendix
    • Appendicolith in acute appendicitis means a high probability for perforation (50%), especially in children
    • Appendicolith is usually 1 cm in size of larger
      • Frequently laminated
    • Other signs
    • Localized dilatation of cecum from focal paralysis (cecal ileus)
    • Small bowel obstruction pattern
    • Soft-tissue mass and paucity or absence of intestinal gas in RLQ (more often with perforation and abscess)
    • Extraluminal gas bubbles (usually only with perforation and abscess)
    • Large pneumoperitoneum is rare because etiology of appendicitis involves obstruction of a very small lumen containing little air
    • Focal increase in thickness of lateral abdominal wall
    • Loss of properitoneal fat line on right side
  • CT
    • The imaging study of choice  (>95% accurate) is CT, or US
    • Signs of acute appendicitis include
      • Distended lumen
      • Circumferentially thickened and enhancing wall
      • Appendicolith – homogeneous or laminated calcification in up to 25% of cases
      • Peri-appendicular inflammation-linear streaky densities in peri-appendicular fat
      • Peri-cecal soft-tissue mass
      • Abscess
        • Poorly encapsulated
        • Single or multiple fluid collection(s) with air
      • Extraluminal contrast material
      • Focal cecal wall thickening
      • "Arrowhead" sign = funnel of contrast medium in cecum centering about occluded orifice of appendix
    • Perforation (13-30%)
    • Appendectomy



Appendicolith with Appendicitis. Upper: Frontal close-up of right lower quadrant show a laminated stone in the region of the appendix consistent with a calcification that has formed in a viscous (white arrow). Lower: Coronal reconstruction with close-up of right lower quadrant shows a dilated appendix
with a thickened wall and surrounding infiltration of the fate (yellow arrow) containing an appendicolith (red arrow).

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