Here it is - just change MRI (Magnetic Resonance Imaging) to MRS (SPectroscopy) and we have solved our problem of diagnosing PD. I hope it is that easy! (Note the word "claim" when we would have preferred "proven"):

A team of American scientists claim that a new method of testing for neurological diseases could provide doctors with a rapid and non-invasively method of diagnosing degenerative disorders. The research, published in The journal of Comparative Neurology, reveals that Magnetic Resonance Spectroscopy (MRS) can distinguish between different disorders in patients, allowing earlier diagnosis.

http://www.sciencecentric.com/news/1...disorders.html