Figure 1. Positron emission tomography brain images of an alcoholic subject showing increases in brain metabolism between 10 and 30 days after cessation of alcohol consumption. (Source: Volkow et al. 1994)


Figure 2. Positron emission tomography images of cross-sections through the heart of a normal subject (top) and of a patient with presumed alcohol-indused heart muscle disease (i.e., cardiomyopathy) (bottom) using a radiolabeled fatty acid, palmitate. The yellow and red colors in the normal subject represents the heart's metabolism of radiolabeled palmitate. In contrast, the myocardium (i.e., heart muscle) of the patient with alcohol-induced cardiomyopathy is enlarged and does not process palmitate normally, suggesting defective metabolism. (The bright signals to the left of the hearts in the rightmost images represent the top of the liver.)

gabaFigure 3. Some effects of alcohol may be related to interactions with the chemical messenger gamma-aminobutyric acid (GABA) in the brain. Results of single-photon emission tomography suggest differences in GABA function between (A) a 26-year-old alcoholic mand and (B) a 26- year-old nonalcoholic man. These images were obtained using a radioactive tracer that binds to brain proteins involved in GABA function. Image sourtesy of Anissa Abi-Dargham.











positron_topFigure 4. Positron tomography, the most powerful of current imaging tools, uses radioactive tracers to study brain energy metabolism and blood flow. Image courtesy of daniel Hommer.