Proton MR Spectroscopy (H-MRS)
H-MRS identifies biochemical changes in the brain such as the quantity of metabolic products of neural tissue including choline, creatine, N-acetylaspartate (NAA), mobile lipids and lactic acid. When demyelination is occurring, there is breakdown of cell membranes resulting in an increase in the level of choline. NAA is specific to neurons and thus, a reduction in NAA concentration indicates neuronal or axonal dysfunction. As such, the levels of choline and NAA can be measured to determine if there is demyelination activity and inflammation in the brain. Usually, the ratio of choline to NAA is used.