ABSTRACT
Over the past decade, development of functional neuroimaging of the nigrostriatal dopaminergic system has improved our understanding of the natural history of pathophysiological changes in Parkinson’s disease (PD). PD is characterized by degeneration of the nigral dopaminergic cells and their striatal terminals, resulting in decreased striatal dopamine and a loss in dopamine transporters. Functional neuroimaging uses radioactively labeled molecules called ligands as markers in conjunction with single photon emission tomography (SPECT) and positron emission tomography (PET) imaging to evaluate neurochemical systems in the brain. These methods offer a unique advantage in PD over structural imaging, such as computed tomography or magnetic resonance imaging. PET and SPECT provide a means to visualize the neurochemistry of the brain. Ligands targeting the dopamine transporter (DAT) have been developed as markers of dopaminergic neuronal cell loss. In this chapter, the role of DAT imaging as a marker for evaluating disease progression, severity, or stage of disease, and as a diagnostic tool in parkinsonian syndrome, is reviewed.
