Measurement of Metabolite 1H Transverse Relaxation Times (T2) in the Human Visual Cortex Over an Extended Echo-Time Range During Visual Stimulation at 7T

Francesca Branzoli¹, Ece Ercan¹, Andrew Webb¹, Itamar Ronen¹

In this work we employed a method we recently developed for collection and analysis of multi-echo highly truncated MRS CPMG (Carr-Purrell Meiboom-Gill) spectroscopic data in order to achieve accurate proton transverse relaxation times (T2) measurements of total creatine (tCr), total NAA (tNAA) and choline compounds (tCho) in the primary visual cortex at 7T and to investigate possible T2 changes during visual stimulation. The large echo-time range employed allowed for evaluation of deviation of amplitude-TE curves from mono-exponential decay pattern, reflecting the presence of multi-components possessing different T2, as expected for the tCr signal at 3.0 ppm.