The Role of Positron Emission Tomography in Bariatric Surgery Research: a Review

Abstract

Bariatric surgery, initially understood as restricting or bypassing the amount of food that reaches the stomach to reduce food intake and/or increase malabsorption of food to promote weight loss, is now recognized to also affect incretin signaling in the gut and promote improvements in system-wide metabolism. Positron emission tomography (PET) is an imaging technique whereby patients are injected with picomolar concentrations of radioactive molecules, below the threshold of having physiological effects, to measure spatial distributions of blood flow, metabolism, receptor, and enzyme pharmacology. Recent advances in both wholebody PET imaging and radioligand development will allow for novel research that may help clarify the roles of peripheral and central receptor/enzyme systems in treating obesity with bariatric surgery.

Molecular Imaging of Central Dopamine in Obesity: A Qualitative Review across Substrates and Radiotracers

“…An answer is not possible based on the cross-sectional nature of the studies reviewed here. Only a few dopamine PET or SPECT studies assessed the effects of weight loss, mostly following bariatric surgery (reviewed in [24]). Longitudinal and intervention studies are required to understand and disentangle the causal effects of changes in adiposity, diet, physical (in)activity, and other relevant factors.…”

“…Existing molecular imaging findings have been discussed in a number of excellent reviews that focus on different subsets of the four available dopamine domains [15,16], [23][24][25][26][27]. The aim of the current review is to give a comprehensive overview of molecular neuroimaging studies that investigated the relation between BMI (on a continuum) or obesity (as a weight status) and any dopamine target in the striatal and midbrain regions of the human brain.…”