The actual study requires analysis of "free water" changes in the substantia nigra over the course of a full year so this kind of diagnosis will take a LONG TIME to get feedback on.

Of course none of this gets us much more understanding of treating PD.

Still it's interesting to see imaging technology can be used, though if my doc told me we could do this test and in a year get a result I wouldn't be interested.

I would be vastly more interested in analyzing systemic problems that could be contributing/causing PD and treating them post haste. Genetic testing and gut bacterial profiling (both available to anyone for only a $100 or so each) would, I think, be good places to start. I don't know about you but I can easily imagine my doc not wanting to do either of these kinds of tests.