Hi, @katwhisperer When I had my last DXA my endocrinologist did mention an additional test I could have and I believe that was the TBS. Unfortunately I didn't decide until it was too late to add that to the DXA. She did not push it, I think because she was not sure it would be covered by insurance, but I regret not getting it.
Keep in mind, that doctors want you to have DXAs at the same facility on the same machine each time you get them. I guess the machines are quirky and there can be differences in the results. If you think at some point you might want a TBS I would choose a facility for your DXA that can do that test.