EVALUATION OF BONE BY ULTRASOUND

The evaluation of bone by ultrasound is a new, transportable and non-i rradiating method. It measures attenuation of ultrasound (BUA), as wel l as velocity (SOS) of ultrasound in a given tissue. For the measureme nt of bone, the most frequently used bone is the calcaneus. We have us ed this technique (Achilles, Lunar) to evaluate the reproducibility of measurements in healthy volunteers and to determine the correlations between the results of ultrasound measurements and those of convention al densitometry (DXA) in a population of postmenopausal females who co nsulted for screening or diagnosis of osteoporosis, Although several p ublications have already dealt with the same questions; it is importan t to reexamine them locally before the technique is uncritically used even in unspecialized centers. The coefficients of variation correspon ded to that reported by others: 1.8% for BUA and 0.3% for SOS. The cor relations between the ultrasound measurements and the results of DXA a t lumbar spine, femoral neck and calcaneus in 57 postmenopausal women aged +/- 59 (43-78) years and in part osteoporotic (DXA results below 2.5 SD - T-score) (Hologic QDR 2000) were all significant (p <0.001). The best correlation between the two techniques (DEXA and ultrasound) is found when applied to the same site, i.e. the calcaneus (r >0.8). T hese results also agree with the literature. Low ultrasound values (BU A <100 dB/MHz, SOS <1495 m/s) are highly suggestive of osteoporosis, w hile high ultrasound values are almost exclusively found in non-osteop orotic women. This information provides the basis for further investig ations, such as correlation with fracture risk, in cross-sectional and longitudinal studies.