The bone scan can show positive for RSD. But... Please be aware that it can be negative and your child could still have RSD. Bone scans are not definitive. I had a negative one early on, and it kept me from getting proper treatment for a long time.

You can look up triple phase bone scans and CRPS RSD studies online for more info on their usefulness in diagnosis.

Excellent for your son that this was diagnosed so soon, if it is indeed RSD, and also that he is young... Young people have a much better chance of remission.