THE ULTRASONIC ASSESSMENT OF OSTEOPENIA AS DEFINED BY DUAL X-RAY ABSORPTIOMETRY

Dual X-ray absorptiometry (DXA) studies of bone mineral density (BMD) of the lumbar spine and femoral neck were compared with measurements o f broadband ultrasonic attenuation (BUA) and velocity of ultrasound (V OS) in the calcaneus in 300 pre- and postmenopausal women (mean age 53 years). The women were referred for evaluation of possible osteopenia as defined by DXA. The ability of ultrasound measurements to predict osteopenia in women was compared with the ability of lumbar spine and femoral neck DXA scans to predict osteopenia in the hip and spine. A n ew ultrasound parameter obtained by combining BUA and VOS (combined at tenuation and velocity (CAV)) was also evaluated. Linear regression an alysis of the three ultrasound parameters and lumbar spine and femoral neck BMD gave weak but statistically significant correlations (r = 0. 45-0.54). The correlation between spine and femoral neck BMD was stati stically significantly better (r = 0.72). Receiver-operating character istic (ROC) analysis was used to investigate the sensitivity and speci ficity of ultrasound measurements in predicting patients with osteopen ia. The areas under the ROC curves ranged from 0.64 to 0.75 and ultras ound parameters were shown to be poor at predicting osteopenia as defi ned by DXA. The ability of lumbar spine and femoral neck DXA measureme nts to predict osteopenia in the hip and spine, respectively, was stat istically significantly better than any of the ultrasound parameters. Ultrasound measurements in the calcaneus did not appear to identify ac curately patients with osteopenia defined by DXA. measurements of bone density in the axial and appendicular skeleton.