I’m not a ccsvi expert, but I’ve had the treatment 4 times, so I know where you can get it done. It will probably involve travel, if you want to go to one of the doctors with experience. If you must go with a local interventional radiologist, look for one who has specialized in treating diabetics, specifically central vein stenosis, diabetics also get stenosis in places like the jugulars.
If you want to get a Zamboni style doppler before going in for a procedure, you can check with http://ccsvi.azdoppler.com/ and see if they are travelling to a city near you, or go to AZ.
Lastly, if you can travel, you could go to the Hubbard Foundation in San Diego, and there you can get very good CCSVI MRI. The have several associated IRs. Dr Haacke also has an MRI facility in Las Vegas, and works with IRs.
My last 2 treatments were with Dr McGuckin, he has done 500 procedures now, and has extensive experience treating diabetics. He is quite the master at treating veins, has very good results. His CCSVI program specialist has an educational blog, http://thinkccsvi.com with a map of clinics around the country he travels to, and tons of info on CCSVI. You can talk to the intake nurse. Get their instructions first on referrals if needed, and they will handle the insurance part.