4.0 T water proton T₁ relaxation times in normal human brain and during acute ethanol intoxication

Background: It has been reported that acute ethanol intoxication decreases the brain water proton magnetic resonance T₁ values, an effect that has been interpreted to indicate brain dehydration during this condition. Because water macromolecular interactions largely determine tissue water T₁, another possible explanation for reduced brain water proton T₁ values is that the interaction between water and brain macromolecules is altered by ethanol. Methods: A 4.0 T magnetic resonance imaging (MRI) instrument was used to measure brain water proton T₁ relaxation times before, during, and after ethanol intoxication (dose, 0.75 mg/kg) in healthy controls. Results: The T₁ relaxation times as assessed with MRI were highly reproducible. The mean, paired ethanol-induced differences in T₁ were -0.004 ± 0.007 sec (mean ± standard deviation) for white matter and 0.010 ± 0.015 sec for internal gray matter structures, neither of which was significant. Conclusions: This reasonably sensitive measurement does not support the view that tissue water content or water macromolecule interactions are significantly altered in the brain during acute alcohol intoxication in otherwise healthy subjects.