Gastrointestinal MRI with Conscious Rats

Anesthesia has been required for preclinical gastrointestinal MRI but may confound gastric physiology. This study demonstrates, for the first time, the feasibility of gastrointestinal MRI with awake rats, and reports the effects of anesthesia on gastric motor function. Results suggest that awake rats show greater rates of gastric emptying and intestinal filling, and stronger gastric and intestinal motility relative to those anesthetized. Anesthesia with 2.5% isoflurane can entirely stop muscle contraction. The methods and findings reported herein lay the foundation for using awake GI-MRI in preclinical studies of gastrointestinal function or dysfunction.