Quantitative ultrasound: An indicator of osteoporosis in perimenopausal women

The key to effective treatment of osteoporosis is early detection. To asses s the utility of quantitative ultrasound (QUS) at the calcaneus in perimeno pausal women, broadband ultrasound attenuation (BUA); speed of sound (SOS); quantitative ultrasound index (QUI), an algorithm of BUA and SOS; and bone mineral density by dual X-ray absorptiometry (DXA) of the posteroanteiror spine, femoral neck, and total hip were measured in 420 women (ages 45-55 y r). Thirty (7.1%) of the women were found to be osteoporotic by DXA. All QU S measurements were predictors of osteoporosis. QUS values did not differ b etween postmenopausal women on estrogen replacement therapy (ERT) and those not on ERT. There were no differences among BUA, SOS, and QUI in the area under the receiver operating characteristic curves for predicting osteoporo tic vs nonosteoporotic cases. At a QUI of 89, ultrasound had an 80% sensiti vity for the diagnosis of osteoporosis, but only a 74% specificity. Tho hig h false-positive rate (26%) limits the utility of QUS as the sole diagnosti c technique on which to base therapeutic decisions. Nevertheless, low QUS m easurements may provide a means for targeting those women who would benefit most from more extensive evaluation (e.g., DXA).