Metabolite T1 relaxation times differ across the adult lifespan

This work investigates the age-dependence of metabolite T1 relaxation times at 3T. T1 relaxation times were estimated by modeling the residual metabolite amplitudes in macromolecular spectra, acquired with pre-inversion. Posterior cingulate (PCC) and centrum semiovale (CSO) spectra were acquired in 102 healthy volunteers across five decades of adult life (20 to 69 years). T1 relaxation times of both tNAA2.0 and tCr3.0 significantly negatively correlated with age in CSO, and not in PCC. This has important implications for MRS studies of aging which tend to assume T1 relaxation times are constant as a function of age.