We developed in vivo contrast-enhanced MRI and an image processing pipeline to image and assess the therapeutic effect of cervical vagus nerve stimulation (VNS) on gastric emptying and motility in rat. We found that: (1) VNS significantly promoted the rate of gastric emptying. (2) VNS significantly increased the degree to which the pyloric ring opened, and this outcome was correlated to the rate of gastric emptying. (3) The VNS parameters used in this study did not alter antral motility significantly. The proposed method allows non-invasive and repeated preclinical imaging of gastric physiology and diseases given electroceutical treatments.