Brain relaxometric properties are widely used by the NMR community. While brain tissue relaxivities are well established, much less work has been done on CSF relaxivities. To clarify this point, we characterized the CSF relaxometric properties at various field strengths in vivo and in vitro. Our results suggest that low field is more optimal to quantify CSF T2 due to smaller residual gradients. There is a significant difference between in vitro CSF T2 vs saline T2 that is mostly explained by the glucose relaxivity. This finding was confirmed in vivo, opening the possibility of studying glucose regulation of CSF at the resolution of MRI.