Enteric MRI contrast agents: comparative study of five potential agents in humans

Area of Science:

• Medical Imaging
• Gastroenterology
• Biomedical Engineering

Background:

• Enteric contrast agents are crucial for visualizing the gastrointestinal tract during magnetic resonance imaging (MRI).
• Evaluating the efficacy and tolerability of different oral contrast agents is essential for optimizing diagnostic imaging.

Purpose of the Study:

• To compare the effectiveness of various oral agents, including 1 mM Geritol, 12% corn oil emulsion, Kaolin-pectin, barium sulfate, and effervescent granules, as enteric MRI contrast agents.
• To determine the optimal agent for small bowel and pancreas delineation using specific MRI pulse sequences.

Main Methods:

• Five healthy volunteers participated in the study.
• Each volunteer ingested 500 ml of liquid preparations or effervescent granules producing 400 ml of CO2.
• Abdominal MR images were acquired using a 1.5 T imager with SE and FISP pulse sequences.

Main Results:

• Corn oil emulsion was the best tolerated agent, with barium sulfate causing the most nausea.
• FISP 40/18/40 degrees pulse sequences allowed for 60%-80% small bowel delineation with oil emulsion, Kaolin-pectin, or barium sulfate.
• Corn oil emulsion demonstrated superior performance in delineating the small bowel and pancreas.

Conclusions:

• Corn oil emulsion is the most effective enteric MRI contrast agent identified in this study.
• The combination of corn oil emulsion and gradient echo pulse sequences provides excellent visualization of the small bowel and pancreas.
• Corn oil emulsion's high acceptability due to lack of side-effects and good taste makes it a preferred choice for enteric MRI.