Ischemic bowel

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[edit] Discussion

  • Bowel ischemia or infarction is a common disorder with various primary causes and clinical presentations and high mortality.
  • It is caused by insufficient blood flow to the intestine from various causes including:
    • Thromboembolism
    • Nonocclusive causes
    • Bowel obstruction
    • Neoplasms
    • Vasculitis
    • Trauma
    • Drugs (chemotherapy)
    • Radiation

[edit] Imaging Findings

[edit] Plain film and fluoroscopic studies

[edit] CT and MRI

  • The CT and MR imaging findings represent a combination of those seen at plain radiography, barium studies, and angiography (vascular occlusion).
  • CT and/or MR imaging may be helpful in determining the primary cause of bowel ischemia as well as allowing direct evaluation of the bowel wall, adjacent mesentery, and vascular structures.
  • The most common CT finding in bowel ischemia is bowel wall thickening (nonspecific finding). The thickened bowel wall is sometimes associated with the target sign, alternating layers of high and low attenuation within the thickened bowel wall, which results from submucosal edema or hemorrhage.
  • Absent or poor enhancement of the bowel wall is the most specific finding for bowel ischemia.
  • Other CT findings of bowel ischemia reported in the literature include arterial occlusion, mesenteric or portal vein thrombosis, bowel dilatation, engorgement of mesenteric veins and mesenteric edema, intramural gas (intestinal pneumatosis), mesenteric or portal venous gas, lack of bowel wall enhancement, and infarction of other abdominal organs (eg, liver, spleen, or kidneys).
    • Bowel dilatation reflects the interruption of peristaltic activity in ischemic segments. It is a common but nonspecific finding in bowel ischemia.
    • Engorgement of mesenteric veins reflects venous congestion secondary to stasis.
    • Owing to the edema that accompanies bowel ischemia, the mesenteric fat may be abnormally increased in attenuation.
    • Intramural gas is a less common but more specific CT sign of ischemic bowel disease. The intramural gas is caused by dissection of luminal gas into the bowel wall across the compromised mucosa.
    • Mesenteric or portal venous gas is an even less common CT manifestation of ischemic bowel disease and represents the propagation of intramural gas into the mesenteric venous system. Free intraperitoneal gas is an ominous CT sign in ischemic bowel disease because it indicates perforation of an infarcted bowel segment.

[edit] Images

Patient #1: CT images of patient with ischemic bowel demonstrates pneumatosis and portal venous gas

Patient #2: CT images demonstrate mesenteric ischemia with marked atherosclerosis of arteries

[edit] See Also

[edit] External Links

[edit] References