For homogeneous and isotropic probes, different MR relaxometry methods are expected to yield consistent results. For tissues, however, wide-spread T1 and T2 relaxation times are reported in the literature. Especially in the brain, we hypothesize that the microstructure, e.g. the presence of myelin, affects the apparent observed T1, as assessed by different imaging sequences. As a result, apparent differences in T1 might reflect valuable information on the underlying tissue microstructure, such as myelination.