Measurement of brain glucose metabolism in obesity and diabetes.

The brain consumes a large amount of glucose to fuel its high metabolic demands. Understanding brain glucose metabolism is critical for understanding the brain's normal physiology and the pathological states of diabetes and obesity. However, accurately measuring brain glucose metabolism in humans presents significant challenges. Most studies depend on non-invasive neuroimaging techniques, such as positron emission tomography and magnetic resonance spectroscopy, which each have distinct advantages and limitations. This review outlines the primary neuroimaging modalities used to assess brain glucose metabolism, focusing on modalities and studies that have paired brain imaging with controlled physiological manipulations of circulating glucose and insulin levels, to examine how metabolic diseases influence brain glucose metabolism.