@mark2471
There actually is a definitive test for both PMR and GCA (Giant Cell Arterits). It's called "Color Doppler Ultrasound," "Doppler Power Ultrasound," or "Musculoskeletal Ultrasound." They use it on your shoulders for PMR, and your head/temples and other spots to check for GCA.
They can see if there is fluid in the subacromial Bursa and other indicators of PMR in the shoulders.
I'm not sure what they look for to confirm GCA, but I got checked for GCA at same time as shoulders for PMR.
It's different from a standard Ultrasound machine from what I understand.
I'm not sure if they're easy to get in rural areas, but hopefully should be in many areas. It gave me definitive answers re having PMR and not having GCA.
Hope this information will help anyone who would like a definitive test.
Only wish none of us needed or wanted confirmation!!
Blessings to all of us.