Is DEXA technology better than ultrasound?
DEXA certainly has the advantage of having high precision at measuring BMD (1-2% in vivo) however this does not translate into it being a superior tool at predicting fracture. DEXA technology is expensive and exposes the patient to low dose ionizing radiation. Ultrasound is inexpensive and safe. In a recent trial for Raloxifene it was demonstrated in 7000 osteoporotic women that their BMD changes over 2 years were only 2.0% on doses of both 60 and 120mg Raloxifene, however their reduction in fracture rates were 30% and 50% compared to a placebo, therefore changes in BMD do not always mirror fracture rate data which is a major limitation to DEXA technology. It was assumed in this study that Raloxifene has a major effect on bone structure and not BMD.
