The effect of paramagnetic manganese cations on 1H MR spectroscopy of the brain
Holm D, Vejby Sgaard L, Christoffersen G, Rowland I, Madsen K
Copenhagen University Hospital, Technical University of Denmark
The influence of paramagnetic manganese (Mn) cations on proton brain spectra was investigated in vivo and in phantom studies. Using a Mn-enhanced neural tracing model, spectra acquired from the two adjacent regions of the superior colliculi show minimal effects from the manganese within the spectroscopic voxel. The large relaxivity measured for NAA suggests that if the metabolite and paramagnetic Mn2+ cations are within the same cellular compartment, significant relaxation effects could influence the apparent 1H MRS metabolic profile obtained from brain tissue. This effect should be taken into account when performing spectroscopic investigations on brain regions with increased Mn concentrations.