Rad

CT Angiography in Gastrointestinal Bleeding

search

CT Angiography in Gastrointestinal Bleeding, CTA Abdomen for Lower GI Bleed

  • Indications
  1. Brisk Gastrointestinal Bleeding obscures source on Colonoscopy
  2. Gastrointestinal Bleeding with a patient too unstable for endoscopy
  3. Acute, high risk Lower Gastrointestinal Bleeding while awaiting preparation for endoscopy
  • Imaging
  1. CT Angiography WITHOUT Oral Contrast (preferred)
  2. Do not use high density oral or rectal contrast
    1. Oral Contrast obscures bleeding
    2. Oral Contrast not needed for other causes (e.g. Diverticulitis, Ischemic Bowel)
  • Evaluation
  1. CTA may be test of choice in heavy Lower GI Bleeding in which endoscopy cannot be performed
  2. CTA may direct exploratory laparotomy (identifying source)
  3. PACS imaging density >90 Hounsfield Units (HU) is consistent with blood on CTA
  • Efficacy
  1. Test Sensitivity for Gastrointestinal Bleeding: 38% (similar to RBC Scan)
  2. CTA localizes the bleeding source in 53% (contrast with 30% for RBC Scan)
  3. CTA without bleeding predicts lower recurrent bleeding rate