While I think that a bone scan is a good idea, what about a QRST test? I had one and it plainly showed my RSD. While it hurt some, it is noninvasive and seemed to settle the "question" of what it was that I had. Never saw muchh of this on the board, but have been away for a bit. It is a quantitative reactive sweat test. Essentially, they put these little suction cup things on your RSD and non-RSD areas and give a small electrical impulse along with the cup being filled with acetylcholine. It them measures your sweat response (don't ask me how-no idea). However, the differences were substantial between my RSD leg and my non-RSD leg. I will say that my RSD leg was very uncomfortable during the stim, but it was about 2 minutes long and I figured that if I can survive a flare for no good reason, I could survive this for a study to prove that I wasn't crazy. Anyone else out there have them? Not sure what the rate of false negatives are, so I'm not saying they are the be-all, end-all diagnostic, but it's out there.