We evaluated the relationship between cerebral blood flow (CBF) and T2 of peripheral CSF. The rationale behind this hypothesized association is the presumed dependency of T2 on oxygenation. The T2 of CSF was related to CBF and cognition in a group with cognitive decline. In contrast, no relationship was found between the T2 and CBF in a healthy aging cohort suggesting no relation between the T2 of CSF and oxygenation. Further investigation regarding the relation between T2 of CSF and cognition in the healthy aging cohort are ongoing and could shed light on the value of T2 as a biomarker.