Unfortunately the results you get from doing that are pretty variable.

Not like you shouldn't go see a doc and get imaging and do all that (you should!) but every time I've gotten imaging done I've heard "you've got degeneration which is typical for somebody your age" -- my son just got an MRI for a work injury (paid for by Workman's Comp) and got told the same thing. Often your doc gives you an order to a PT and what sort of therapy you get from a PT is complete random and not evidence based.

Imaging might turn up a specific cause (maybe a tumour) but it is usually inconclusive. Studies tend to show low correlation between degeneration seen and back pain and my doc was clear it was the same when I was having serious pain in my knee.

You're right that centralization vs peripheralization is an important sign.