Quantitative Ultrasound in Diagnosis of Metabolic Bone Diseases

Currently, the diagnosis of osteoporosis is based on bone mineral density measurements using Dual Energy Xray Absorptiometry (DXA). DXA provides information about quantitative content of calcium hydroxyapatite in the skeleton. From about 20 years Quantitative Ultrasound (QUS) measurements are used. QUS reveals both quantitative and qualitative (elasticity and microstructure) features of bone tissue and was used in several pathologic and physiologic conditions. The most important are results of prospective studies showing the ability of QUS measurements to predict osteoporotic fractures. QUS was used in monitoring skeletal changes during therapy on osteoporosis. In several studied QUS measurements showed an ability to detect skeletal changes in children and adolescents and involutional changes at the skeleton. QUS measurements were also used in order to follow bone changes during pregnancy and lactation, glucocorticosteroid therapy, renal osteodystrophy, oncologic and rheumatic diseases, and prolonged immobilization. Advantages of QUS are: lack of ionizing radiation, portability of devices and their relatively low cost. Disadvantages of QUS include the lack of precise determination of measured bone features, measurements limited to peripheral skeleton, relatively poor precision and the lack of unification of several devices. Currently, despite these limitations QUS is a validated method in diagnostic armentarium in metabolic bone diseases.