Polyethylene glycol solution as an oral contrast agent for small bowel MRI

Purpose: The purpose of the study was to evaluate an oral iso-osmotic polyethylene glycol (PEG) solution as an oral contrast agent for MR imaging of the small bowel.

Methods and materials: 19 patients with inflammatory bowel disease (m/f 1:2.8, mean age 43) underwent abdominal MRI examination after drinking 0.6–1.5 liters (mean: 1.1 liters) of PEG solution in a period of 30–60 minutes (mean: 40min). The examinations were performed on a 1T scanner. Coronal and axial T1-weighted gradient-echo and T2-weighted single-shot fast spin-echo sequences were used after the administration of i.v. smooth muscle relaxant. I.v. contrast material was used in all cases for contrast enhancement of the bowel wall.

Results: Oral administration of PEG solution was well tolerated in all subjects. In 12/19 patients the distention of jejunum and ileum was good or optimal. In 4/19 patients bowel distention was unsatisfactory caused by insufficient oral intake of PEG solution (less than 1 liter). In the remaining 3/19 patients the contrast media distended the ascending colon too because of a drinking period longer than 45 minutes resulting in a distention of small bowel to a lesser degree.

Conclusion: Polyethylene glycol solution the properties of water as it relates to signal intensity, with the added advantage of nonabsorbability, thus providing good distention of all the small bowel loops from the jejunum to the terminal ileum if at least 1 liter of solution is administered in less than 40 minutes.