Please see the following attached document.

The gold-standard technique for estimation of BMD is the DXA technique because of their reproducibility, large normative data, non-invasive nature, little time requirement for procedure, and minimal radiation exposure.

A bone density test determines the bone mineral density (BMD). Your BMD is compared to 2 norms—healthy young adults (your T-score) and age-matched adults (your Z-score).

•Bone Mineral Density (BMD)

•2.5 SD Below the Young Adult Average Value (T ).

DEXA scan is the Gold standard technique which is most widely used and available.

Quantitative CT scan is the most accurate but requires higher exposure to radiation and is also not easily available.

Quantitative Ultrasound of heel and other body parts is quite inaccurate.

For more details on the WHO standards for BMD measurements and their clinical value, you may find this useful:

https://www.bones.nih.gov/health-info/bone/bone-health/bone-mass-measure

Dear Dr Narinder Kumar

Thanks for your interesting information

The best

Hello Dr Asaad Hamid Ismail

Apologies for not joining the discussion sooner! I was going to ask do you have easy access to DXA? I take it for granted - it is in the same room from me every day about 10m a where I sit but I have realised a lot of things available to me are not the same for everybody…

Thanks dear Joseph for commment

The best

Basically due to so-called K-edge phenomenon elemental composition to some degree can be identified by obtaining X-ray attenuation at several X-ray energies. https://radiologykey.com/bone-densitometry/