MR Spectroscopy Detection of Lactate and Lipid Signals in the Brains of Healthy Elderly People

Abstract: Magnetic resonance spectroscopy was used on a clinical 1.5 T MRI system to assess the presence of brain lactate and lipid signals, frequently associated with the presence of pathology, in healthy persons of 60–90 years old (n=540). Lactate and lipid signals were observed in, respectively, 25% and 6% of women and 18% and 2% of men. Upon adjustment for age, and for MRI detected cerebral atrophy and white matter lesions, the sex differences in lactate and lipid remained the same (P=0.05 and P=0.03, respectively). Brain lactate and lipid signals appear to be intrinsic to aging. However, the presence of these metabolites in very focal areas only rather than in any distributed fashion within the brain (the latter generally the case with cerebral atrophy and white matter lesions), strongly suggests the existence of asymptomatic focal pathology not showing on MR. In the very near future, we will perform similar studies at 3T and expect that improved metabolite signal-to-noise ratios will help to pinpoint the detected lactate and lipid signals to specific abnormalities.