Enterography

Enterography refers to imaging of the small intestine. It may be performed with simple x-ray (often called just enterography), CT enterography, or MR enterography.

Indications

It may be used to evaluate for:

• Ileus
• Gastrointestinal perforation
• Inflammation of the small bowel (in Crohn disease)
• Intussiception/invagination of bowel in children
  • Most commonly due to Meckel diverticulum, polyp, or tumour
• Intestinal ischaemia
• Necrotising enterocolitis
• Duodenal atresia

Patient preparation

Ahead of the examination, the patient should fast for 6 hours, to reduce the activity and movement of the small intestine. A moderate laxative like lactulose can be used.

Procedure

During the procedure, Buscopan® (butylscopolamine, an anticholinergic) or glucagon may be administered to slow intestinal motility, reducing motion artifacts.

Interpretation

With simple x-ray enterography, not much information is gathered and so it is rarely used. It may be able to visualise ileus, in which case the diameter of the small bowel is > 3 cm, or perforation, in which case there is air in the abdomen. CT and MR give much more information and are more frequently used.

Presence of air in the bowel wall is called pneumatosis intestinalis and is seen in intestinal ischaemia or necrotising enterocolitis.

The presence of the "double bubble sign" on enterography is typical for duodenal atresia.

Enteroclysis

Enteroclysis refers to usage of fluoroscopy and oral contrast to visualise the movement of foodstuff through the small bowel. The oral contrast used is barium, given together with methylcellulose. Methylcellulose is not a contrast agent itself, but it increases the volume of the contrast material. Methylcellulose has low x-ray absorbance (it’s radiolucent). Barium and methylcellulose are administered by nasoduodenal tube.