Water-equivalent oral contrast agents in dual-modality PET/computed tomography scanning: does a little barium make the difference?

Objective: To retrospectively evaluate the performance of two water-equivalent oral contrast agents [locust bean gum (LBG)-mannitol and VoLumen] concerning their potential to distend the bowel while avoiding contrast-associated artifacts in PET/computed tomography.

Methods: PET/computed tomography examinations of 30 patients with two different oral contrast agents were reviewed. Bowel distension, intraluminal density, and potential contrast-associated artifacts were assessed for stomach, jejunum, and ileum. Statistical significance was tested by Student's t-test.

Results: Distension was slightly better in the stomach with VoLumen as compared with LBG-mannitol whereas LBG-mannitol was found to slightly better distend the small bowel. This difference proved to be statistically significant for the jejunum. A statistically significant difference was detected for intraluminal density with higher densities for VoLumen. This difference, however, did not result in a higher incidence of PET artifacts with VoLumen.

Conclusions: LBG-mannitol provides excellent bowel distension, thereby avoiding contrast-associated PET artifacts. If this solution is not available, VoLumen provides a satisfactory alternative for bowel distension without relevant PET artifacts.