CT enteroclysis

Computed tomographic (CT) enteroclysis refers to a hybrid technique that combines the methods of fluoroscopic intubation-infusion small bowel examinations with that of abdominal CT.

Indications

CT enteroclysis is complementary to capsule endoscopy in the elective investigation of small-bowel disease, with a specific role in the investigation of Crohn disease, small-bowel obstruction , and unexplained gastrointestinal bleeding.

CT enteroclysis is considered significantly superior to conventional enteroclysis in depicting Crohn disease-associated intra- and extra-mural abnormalities .

Technique

CT enteroclysis utilizes mainly two types of contrast:

  • neutral contrast media
    • these have attenuation similar to that of water, e.g. water, methylcellulose
    • intravenous contrast is used with neutral agents
    • these agents allow better assessment of mucosal enhancement, mural thickness as well as mesenteric vasculature
    • better used in unexplained subacute gastrointestinal bleeding due to vascular malformation and assessment of inflammatory activity and complications of small bowel Crohn disease
  • ​positive enteral contrast material
    • e.g. 4 to 15% water-soluble (sodium diatrizoate) solution or a dilute (1%) barium solution
    • no intravenous contrast is used with these agents
    • mainly used to detect lower grades of small bowel obstruction and internal fistula
Procedure

The technique of CT enteroclysis can be summarized and simplified as follows :

  • bowel preparation: low-residue diet, ample amount of fluids, laxative on the day prior to the examination, and nil by mouth on the day of the examination
  • conscious sedation (optional, according to patient's preference)
  • introduction of the 12 to 14-F enteroclysis tube (under fluoroscopy or through duodenoscope), the tube tip is usually placed distal to the ligament of Treitz
  • contrast is administered either on the fluoroscopy table or after transferring the patient to the CT unit for commencement of the CT scan (usually 1.5-2 L of oral contrast)
  • in the CT unit, the position of the enteroclysis tube is checked in the topogram
  • in case negative oral contrast is to be used, intravenous contrast injection will be given (approximately 100-150 mL)
  • after completing the scan, the tube is withdrawn gradually to the stomach and any extra contrast volume is suctioned
  • See also

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