Evidence of An Association Between Cerebral Blood Flow and Microstructural Integrity in Normative Aging Using a Holistic MRI Approach

Background Cerebral tissue integrity decline and cerebral blood flow (CBF) alteration are major aspects of motor and cognitive dysfunctions and neurodegeneration. However, little is known about the association between blood flow and brain microstructural integrity, especially in normal aging. Purpose To assess the association between CBF and cerebral microstructural integrity. Study Type Cross sectional. Population A total of 94 cognitively unimpaired adults (mean age 50.7 years, age range between 22 and 88 years, 56 Men). Field Strength/Sequence A 3 T; pseudo‐continuous arterial spin labeling (pCASL), diffusion tensor imaging (DTI), Bayesian Monte Carlo analysis of multicomponent driven equilibrium steady‐state observation of T1 and T2 (BMC‐mcDESPOT). Assessment Lobar associations between CBF derived from pCASL, and longitudinal relaxation rate (R1), transverse relaxation rate (R2) and myelin water fraction (MWF) derived from BMC‐mcDESPOT, or radial diffusivity (RD), axial diffusivity (AxD), mean diffusivity (MD) and fractional anisotropy (FA) derived from DTI were assessed. Statistical Tests Multiple linear regression models were used using the mean region of interest (ROI) values for MWF, R1, R2, FA, MD, RD, or AxD as the dependent variable and CBF, age, age2, and sex as the independent variables. A two‐sided P value of