QUS There is insufficient evidence to support the current use of quantitative ultrasound (QUS) as a screening tool in patients suspected of having osteoporosis or low BMD. Dense structural complexity demonstrates increased attenuation, whereas osteoporotic bone demonstrates lower velocities. The limitations of QUS are a lack of precision and sensitivity [36]. Dedicated QUS scanners are available for the calcaneus, phalanx, and tibia. However, the heel represents the only validated site for the clinical use of QUS. QUS does not measure BMD, and therefore, the WHO Osteoporosis and Bone Mineral Density classification system cannot be used and a diagnosis of osteoporosis cannot be made. Discordance between QUS and central DXA is not infrequent [37]. A recent meta-analysis conducted to assess the role of QUS in inflammatory rheumatic diseases came to the conclusion that the current literature does not support the substitution of QUS for DXA in the diagnosis and monitoring of osteoporosis in rheumatic diseases [38]. Radiography Appendicular Skeleton There is insufficient evidence to support the current use of radiography as a screening tool in patients suspected of having osteoporosis or low BMD. Radiography is a projectional X-ray-based technology that is widely used in current medical practice for rapid image acquisition for an extensive number of indications. Radiography use differences in electron density to generate contrast between different tissues, including bone. Although there are several standards used to identify demineralized bone on radiographs, radiography has a substantially lower sensitivity to bone loss than DXA. Osteopenia is not a reliable finding until 30% to 40% of the bone has been lost [39]. Patients who have radiographic evidence of osteopenia and/or fragility fractures should be referred to DXA for further characterization.
Osteoporosis and Bone Mineral Density. QUS There is insufficient evidence to support the current use of quantitative ultrasound (QUS) as a screening tool in patients suspected of having osteoporosis or low BMD. Dense structural complexity demonstrates increased attenuation, whereas osteoporotic bone demonstrates lower velocities. The limitations of QUS are a lack of precision and sensitivity [36]. Dedicated QUS scanners are available for the calcaneus, phalanx, and tibia. However, the heel represents the only validated site for the clinical use of QUS. QUS does not measure BMD, and therefore, the WHO Osteoporosis and Bone Mineral Density classification system cannot be used and a diagnosis of osteoporosis cannot be made. Discordance between QUS and central DXA is not infrequent [37]. A recent meta-analysis conducted to assess the role of QUS in inflammatory rheumatic diseases came to the conclusion that the current literature does not support the substitution of QUS for DXA in the diagnosis and monitoring of osteoporosis in rheumatic diseases [38]. Radiography Appendicular Skeleton There is insufficient evidence to support the current use of radiography as a screening tool in patients suspected of having osteoporosis or low BMD. Radiography is a projectional X-ray-based technology that is widely used in current medical practice for rapid image acquisition for an extensive number of indications. Radiography use differences in electron density to generate contrast between different tissues, including bone. Although there are several standards used to identify demineralized bone on radiographs, radiography has a substantially lower sensitivity to bone loss than DXA. Osteopenia is not a reliable finding until 30% to 40% of the bone has been lost [39]. Patients who have radiographic evidence of osteopenia and/or fragility fractures should be referred to DXA for further characterization.