Early Alterations in Neurite Orientation Dispersion and Density After Acute Ischemic Stroke

Background: Advanced diffusion imaging approaches that model intracellular and extracellular diffusion components such as neurite orientation dispersion and density imaging (NODDI) may provide additional insight into evolution of acute ischemic stroke (AIS) injury over standard diffusion tensor imaging approaches (DTI). Methods: NODDI was acquired at discharge in a prospective study of acute ischemic stroke patients with advanced white matter disease (N=36). Neurite density (ND), and orientation dispersion (OD) were calculated along with model-free diffusion parameters: mean kurtosis (MK), axial kurtosis (AK), radial kurtosis (RK), mean diffusivity (MD), axial diffusivity (AD), radial diffusivity (RD) and fractional anisotropy (FA). Follow-up (FU) infarct volumes were drawn on discharge FLAIR. MD, AD, RD, FA, MK, AK, RK, OD and ND values were compared (1-way ANOVA) in infarct core (abnormal acute DWI), Growth (normal acute DWI, abnormal FU) and normal contralateral gray matter (nGM) and white matter (nWM)...