Characterizing blood and cerebrospinal fluid flow by D* tensor derived from intravoxel-incoherent-motion-diffusion-tensor-imaging

Motivation: A deeper understanding of brain physiology and pathology can be provided with an intravoxel-incoherent-motion-diffusion-tensor-imaging (IVIM-DTI) MR scan, which simultaneously measures blood and cerebrospinal fluid (CSF) flow and flow directions; parenchymal anisotropy; and microvascular perfusion. Goal(s): To demonstrate the feasibility of IVIM-DTI to provide a proxy for blood and CSF flow. Approach: A tensor of the pseudo-diffusion component (D*) was derived from IVIM-DTI and related to arterial and ventricular physiology. Results: D* ellipsoids align well with arterial blood and CSF flow. D*’s magnitude and anisotropy correspond to the expected flow in arteries and ventricles, indicating the technique's ability of characterizing flow dynamics. Impact: Assessing blood and cerebrospinal fluid flow with intravoxel-incoherent-motion-diffusion-tensor-imaging (IVIM-DTI) alongside traditional IVIM and DTI measures can provide comprehensive pathophysiological insights into neurological conditions. The finding that these physiological processes contribute to IVIM-derived f and D* is important for their interpretation.