Potential roles for quantitative ultrasound in the management of osteoporosis.
OBJECTIVE: To assess the validity of four models for the role of quantitative ultrasound (QUS) in the management of osteoporosis. DESIGN: Cross-sectional survey and review of literature. SETTINGS: Nuclear medicine departments of three teaching hospitals in Sydney. SUBJECTS: 1000 women aged 22 to 88 years (mean, 59 years) referred for assessment of osteoporotic fracture risk. MAIN OUTCOME MEASURES: BMD categories as defined by dual-energy x-ray absorptiometry (DEXA) of the lumbar spine and proximal femur, and QUS category as defined by calcaneal ultrasound stiffness; prevalence of DEXA-defined osteoporosis in the different QUS categories. RESULTS: In women with QUS Achilles stiffness < or = 70 the prevalence of axial osteoporosis was 51%, whereas in the group with stiffness > 70 the prevalence of axial osteoporosis was 8%. In women 65 years and over the corresponding values were 59% and 17%. CONCLUSIONS: Of the four possible models for QUS, the use of QUS for the estimation of BMD, or in a "standalone" model, can not be recommended at the current time. The model of QUS as a "prescreening" modality may be acceptable assuming adequate education of clinicians and patients of its limitations, particularly the risk of false negatives. The model of QUS as one factor in a composite risk factor assessment of patients is promising but more data are required.