Effect of cellulose concentration on the efficacy of a cellulose-based oral contrast agent for gastrointestinal ultrasonography.

We investigated the value of an ingested gastrointestinal ultrasonographic transmission (GUT) agent in improving the visualization of visceral and retroperitoneal anatomy during the standard abdominal sonographic examination. In particular, we examined the effect of varying the cellulose dispersion concentration on the ability of this agent to facilitate visualization of bowel mucosa and adjacent organs and compared degassed cellulose dispersions to degassed water in the same subjects. Fasting abdominal ultrasonography was performed on 24 healthy human volunteers before and after ingestion of a degassed cellulose-based liquid transmission agent. Each agent was assessed using 22 microns fiber length cellulose dispersions at 1, 2 and 3% wt/vol. Ingestion of all concentrations of the gastrointestinal sonographic transmission agent resulted in clear differentiation of the bowel from adjacent structures. Statistically significant improvement in visualization of the pancreas, retroperitoneal vessels, left kidney, and spleen was noted at 20 minutes postingestion. No statistically significant difference was identified between the three cellulose concentrations. No toxicity or limiting side effects were encountered. Such agents may obviate additional imaging in patients who previously would have had a suboptimal ultrasonographic examination.