Magnetic Resonance Imaging Guided Neuromodulation of Gastric Physiology
thesisposted on 25.06.2020, 17:39 by Kun-Han LuKun-Han Lu
The stomach is a digestive organ in the gastrointestinal tract that regulates food intake and paces digestion of nutrients and fluids. The emptying and motility patterns of the stomach are crucial rate-determining processes in maintaining energy homeostasis in the body. Dysregulation of gastric functions often leads to distressing conditions such as gastroesophageal reflux diseases, functional dyspepsia, gastroparesis and obesity. Gastric disorders affect more than 60 million people in the US, producing significant medical and economic burden. These diseases are often chronic and greatly compromise quality of life. As the causes of these diseases remain largely unknown, effects of current pharmacological, dietary, or surgical treatments are often dismal. In this regard, neuromodulation of peripheral nerves emerges as a promising electroceutical therapy for remedying gastric disorders. However, therapeutic effects were shown to be modest, largely due to the inability to validate or calibrate the efficacy and stability of neuromodulation methods with appropriate physiological readouts. To address these problems, here I developed a non-invasive, repeatable online high-resolution magnetic resonance imaging protocol, empowered with advanced image processing algorithms, to track gastric emptying, antral motility, pyloric motility, intestinal filling and absorption in a rat model. The protocol can be used to guide tuning and optimization of stimulation parameters of neuromodulation without perturbing ongoing and spontaneous physiology. The proposed technology and findings are expected to pave the way for the use of gastric MRI to evaluate the efficacy of therapeutics in treating gastric disorders under both preclinical and clinical settings.