Artery-pulsation dependence of the paravascular cerebrospinal fluid flow measured by dynamic diffusion tensor imaging in human brain

Motivation: There is still lack non-invasive methods to quantitative measure the paravascular cerebrospinal fluid (pCSF) flow speed and directions pulsations of arterial vessel . Goal(s): To explore whether dynamic DTIlow-b could capture the artery-pulsation dependence of pCSF flow in human and how DTIlow-b metrics are modulated by artery pulsation. Approach: Six-direction dynamic DTIlow-b was acquired simultaneously with finger pulse oximeter recording on eight subjects. Results: Both the axial and radial diffusivity of pCSF and whole-brain white matter is increased by artery dilation. DTIlow-b signal of pCSF at b = 0 mm2/s also shows artery-pulsation dependence but lags from diffusivity changes. Impact: The proposed dynamic DTIlow-b with ultra-long TE could potentially capture the volume and flow dynamics of MRI-visible and -invisible pCSF in artery pulsation.