3-Tesla Parasagittal dural space (PSD) T2 relates to PSD volume and correlates with diurnal circadian oscillation during wakefulness

Motivation: The parasagittal dural space (PSD) has been shown to harbor meningeal lymphatic vessels and is hypothesized to play a fundamental role in CSF egress and neuroimmune functions. While PSD hypertrophy has been demonstrated with age and neurodegeneration, limited information is available on the composition of this space. Goal(s): To provide quantitative measures of PSD T2 and investigate potential relationships between T2 and diurnal variation, which is known to alter neurofluid circulation kinetics. Approach: A long-TE, multi-echo T2-weighted turbo-spin-echo sequence was repeated four times over day in 15 healthy adults. Results: PSD T2 was 240.6±57.2 ms and increased from morning to evening. Impact: The T2 relaxation times of water in the parasagittal dural (PSD) space were quantified over the circadian cycle of wakefulness at using a long-TE multi-echo turbo-spin-echo sequence. PSD T2 was 240.6±57.2 ms on average and increased from morning to evening.