Neuromelanin magnetic resonance imaging of locus ceruleus and substantia nigra in Parkinson's disease

We carried out an investigation to identify neuromelanin-containing noradrenergic and dopaminergic neurons in the locus ceruleus and substantia nigra pars compacta of healthy volunteers and patients with Parkinson's disease using a newly developed magnetic resonance imaging technique that can demonstrate neuromelanin-related contrast. The high-resolution neuromelanin images obtained by a 3-T scanner revealed high signal areas in the brain stem and these corresponded well with the location of the locus ceruleus and substantia nigra pars compacta in gross specimens. In Parkinson's disease patients, the signal intensity in the locus ceruleus and substantia nigra pars compacta was greatly reduced, suggesting depletion of neuromelanin-containing neurons. We conclude that neuromelanin magnetic resonance imaging can be used for direct visualization of the locus ceruleus and substantia nigra pars compacta, and may help in detecting pathological changes in Parkinson's disease and related disorders.