Chapter 19 - Linking diffusion tensor imaging, microstructures and Parkinson's disease

Abstract

Diffusion tensor imaging allows measuring fractional anisotropy and similar microstructural indices of brain white matter, in which lower than normal fractional anisotropy is associated with loss of microstructural integrity and degeneration. It has been argued whether anisotropy is higher or lower than normal in early Parkinson's disease and to what extent the abnormal anisotropy is detected. This study, by analyzing imaging datasets from the Parkinson's progression markers initiative, reveals a complex pattern of vulnerable microstructural alterations in early Parkinson's disease. Also, the abnormal reduction and elevation of fractional anisotropy coexist across the brain. The divergency of these abnormalities depends on the stage of disease and the age at disease onset. This chapter also discusses the utilities of diffusion tensor imaging in detecting microstructural changes in dopaminergic sites and pathway, and the roles of diffusion tensor imaging in tracking disease progression and medication effects.