Meckel Diverticulum



Meckel Diverticulum


Michael P. Federle, MD, FACR





Key Facts


Terminology



  • Ileal outpouching due to persistence of omphalomesenteric or vitelline duct



    • 50% contain ectopic gastric mucosa (90% present with GI bleeding in children)


Imaging



  • Rule of 2s



    • Seen in ˜ 2% of population


    • Located within 2 feet of ileocecal valve


    • Length of 2 inches (on average)


    • Symptomatic usually before age 2


    • 2 main complications in adults: Diverticulitis (20%) and intestinal obstruction (40%)


  • CT: Meckel diverticulitis



    • Blind-ending pouch containing fluid, air, or particulate matter


    • Inflamed: Mural thickening of diverticulum and adjacent SB


    • Shows mural enhancement on CECT


    • Mesenteric fat infiltration and fluid ± gas ± nodes


    • ± partial or complete small bowel obstruction


    • ± intussusception


Top Differential Diagnoses



  • Appendicitis


  • Crohn disease


  • Mesenteric adenitis and enteritis


  • Cecal diverticulitis


Clinical Issues



  • Children: Present with GI bleeding before age 2


  • Adults: Present with diverticulitis or obstruction






(Left) Graphic shows a blind-ended outpouching image from the antimesenteric border of the distal ileum, typical of a Meckel diverticulum. (Right) Axial CECT shows enteroliths image within a blind-ended sac in the right lower quadrant that proved to be a Meckel diverticulum at surgery.






(Left) Axial CECT in a 27-year-old man with RLQ pain shows calcified enteroliths image lying within a blind-ending sac in the RLQ. (Right) Surgery confirmed a Meckel diverticulum with mild chronic inflammation of the wall and multiple calcified enteroliths (shown here) within it.



TERMINOLOGY


Abbreviations



  • Meckel diverticulum (MD)


Definitions



  • Ileal outpouching due to persistence of omphalomesenteric or vitelline duct


IMAGING


General Features



  • Best diagnostic clue



    • Blind-ended sac or outpouching on antimesenteric border of distal ileum


  • Size



    • 4-10 cm in length


  • Morphology



    • Tubular outpouching of ileum


  • Other general features



    • Most common congenital anomaly of GI tract


    • True diverticulum (contains all layers of bowel wall)


    • Arises from antimesenteric border of distal ileum


    • Formed by incomplete obliteration of ileal end of vitelline duct


    • Usually located within 50-60 cm of ileocecal valve


    • 50% contain ectopic gastric mucosa



      • ± pancreatic, duodenal, and colonic mucosa


    • 90% of cases with bleeding contain gastric mucosa


    • Fibrous band (obliterated part of vitelline duct may connect apex of diverticulum to umbilicus)


    • Rule of 2s



      • Seen in ˜ 2% of population


      • Located within 2 feet of ileocecal valve


      • Length of 2 inches (on average)


      • Symptomatic usually before age 2


      • 2 main complications in adults: Diverticulitis (20%) and intestinal obstruction (40%)


Radiographic Findings

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Jun 13, 2016 | Posted by in GASTROINTESTINAL IMAGING | Comments Off on Meckel Diverticulum

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