[Evaluation of post-menopausal osteoporosis using ultrasound]

Quantitative ultrasound (QUS) has recently been proposed for evaluating bone mineral density. Several QUS units are now commercially available. They measure both the attenuation and velocity of the US beam, in a transmission mode, mainly at the calcaneum and phalanges. These parameters are mainly related to bone density, but may also, in theory, be affected by non-quantitative properties of bone such as elasticity and anisotropy. Values measured at QUS are lowered in osteoporotic patients compared to normal control subjects. The predictive value for hip fracture in an elderly population is similar for QUS measurements and conventional techniques of bone mineral density measurements. The reproducibility of measurements with QUS is good, but the variation to be measured is only minimal. Thus, QUS cannot yet be recommended for follow up of patients or evaluation of response to treatment. Technical advances are to be expected. Because this technique is non-invasive and simple, it represents a promising tool for the screening of patients at risk for osteoporosis.