Bone mineral density measurement

A variety of bone mineral density measurement techniques are available and these have been applied to various anatomical sites:

• dual energy X-ray absorptiometry (DXA) - the most widely used technique (1)
• peripheral dual energy X-ray absorptiometry
• single energy X-ray absorptiometry
• quantitative ultrasound (QUS)
• quantitative computed tomography (QCT) (1)

Site-specific measurements are more predictive than measurements at other sites (relative risk 2.0-2.8 vs 1.5-2.2).

Measurements taken at different sites or with different technologies are not well correlated. Hence the proportion of individuals classified as having osteoporosis (on a T score <-2.5) will vary considerably on the site and method of measurement

Because of these considerations it has been suggested that bone density measurement should be standardised to total hip bone mineral density measured by DEXA.

Reference:

• (1) International Osteoporosis Foundation and National Osteoporosis Foundation 2011. Osteoporosis: burden, health care provision and opportunities in the EU. A report prepared in collaboration with the International Osteoporosis Foundation (IOF) and the European Federation of Pharmaceutical Industry Associations (EFPIA)