Imaging biomarkers
Brain imaging techniques are widely used diagnostic tools for PD
[39]. Multimodal imaging allows the visualization of structural and
functional changes in the brain and can reveal neuroanatomical and
pathophysiological mechanisms underlying the disease processes [40].
As imaging modalities are non-invasive and can be used repeatedly, they
are well suited for longitudinal investigations of, for example, the
integrity of nigrostriatal dopamine system [41].