T2CSF Pitfalls using Water as Internal Reference for Metabolite Quantification

Markus Sack¹, Gabriele Ende¹, Wolgang Weber-Fahr¹

The internal water signal is often used as an internal reference for metabolite quantification. We conducted two T₂ measurements for an anterior cingulate single voxel MRS location to determine the T₂ times for BM and CSF. Spectra and T2maps were obtained from 23 subjects and fitted by a bi-exponential and a mono-exponential function, respectively. Both obtained datasets showed a strong dependency of the evaluated T₂^CSF values on the CSF content calculated by SegSpec. A computational model could mimic this dependency by overestimating the CSF content. Nevertheless, further investigations are necessary to discover the underlying mechanism or unknown additional compartment(s).