Neuroinflammation is a pathomechanism implicated in several neruological, neurodegenerative and psychiatric disorders and is expressed in activation of microglia, the resident brain macrophages. Currently the only neuroimaging method for detecting microglial activation is PET with translocator protein (TSPO) ligands. A well-known model of experimentally inducing systemic inflammation is the administration of lipopolysaccharides (LPS). Here we report a significant increase in the apparent diffusion coefficient of the glial metabolite choline (tCho) in the human thalamus, following injection of LPS. This finding suggests that the ADC(tCho) is a putative marker for glial activation and may be useful in measuring neuroinflammation in disease.