Broadband ultrasound attenuation of the calcaneus predicts lumbar and femoral neck density in Caucasian women: a preliminary study. 
Recent studies have demonstrated the ability of ultrasound techniques to differentiate normal and osteoporotic women.  To define the ability of broadband ultrasound attenuation (BUA) of the calcaneus to predict axial bone mass, the ultrasound value was correlated with lumbar vertebral and femoral neck density in 22 Caucasian women.  The three measures of bone mass inversely correlated with age: lumbar density (r = 0.54), femoral neck density (r = 0.65), and BUA (r = 0.73).  BUA correlated with lumbar (r = 0.83) and femoral neck (r = 0.87) density.  Lumbar vertebral density predicted femoral neck density with a standard error of estimate (SEE) of 0.07 g/cm2, and femoral neck density predicted lumbar density with a SEE of 0.09 g/cm2.  BUA of the calcaneus was as effective as either axial bone mass measure in predicting the other value: the SEE for lumbar density was 0.09 g/cm2 while that for femoral neck density was only 0.06 g/cm2.  The results of this preliminary study indicate that this rapid, radiation-free technique can accurately predict axial bone mass, and may be of value as an initial procedure to discriminate those women warranting more extensive radiologic evaluations.