Bone densitometry in the follow-up of metabolic bone diseases

Bone densitometry is commonly considered the mainly reliable technique for osteoporosis diagnosis; it allows to estimate the absolute and lifetime risk of osteoporotic fracture. It is essential, both in controlled clinical studies and in follow-up of a single patient, to use techniques with high accuracy and precision: accuracy is essential to correctly diagnose osteoporosis and to detect fracture risk, while an high precision guarantees the reproducibility of the measure. The most common factors and mistakes influencing accuracy and precision are discussed below. Nowadays the DXA is considered the best cost-effective technique, while ultrasound technique presents some technical problems that at the moment Limit its diagnostic use. Vertebral morphometry applied to DXA promise to give us in the future important information about vertebral fractures both in epidemiological and in longitudinal drug efficacy studies.