Hello Sarah. I don't have RSD but I have had bone scans in the past, and they were all performed with me lying flat on their table.

When I first got there, they took a quick scan without any dye...... then injected the dye and did another very quick set of films.

I was then sent away and told to come back 3 hours later. This was to give the bones sufficient time to absorb all the dye.

This final scan was much slower than the others, but all the films were taken with me lying flat on my back.

With the concerns that you have, why don't you ask your doctor if you could have some erect films taken. Most tables in the XRays dept will tilt (I don't know about this scanner though), and some will even allow a patient to stand, but I doubt the Radiographer would change from their norm without a doctor's permission.

.... just a thought.