I've done a little more research and found out:
- something called Bone Scan to determine density of bone was approved in 2022 (bonescan.com) and it probes the tibia to determine tissue resistance to microindention. Small risk of infection. They claim this isn't conclusive, which sounds like they mean it's a clue.
Mayo Clinic has it available, which seems like a bit of an imprimatur.
- REMS Echolight includes TBS (trabecular bone scan) which is supposed to be more accurate in calculating bone quality as opposed to just quantity. Ultrasound, not radiation, and not very expensive.
- some standard DEXA scans include the TBS software. Ask.