Quantitative Ultrasound Methods to Assess Bone Mineral Status in Children: Technical Characteristics, Performance, and Clinical Application

Abstract

Measurement of bone mineral status may be a useful tool in identifying the children who could be exposed to an increased risk of osteoporosis in adulthood. Dual energy x-ray absorptiometry and peripheral quantitative computed tomography may be used to this purpose, but the exposure to ionizing radiation is a limiting factor for preventive studies in large populations of children. In the last years, quantitative ultrasound (QUS) methods have been developed to assess bone mineral status in some peripheral skeletal sites such as calcaneus, phalanges of the hand, and tibia. QUS techniques are safe, easy to use, radiation-free, and devices are portable, so that they are particularly indicated to assess bone mineral status in children. This review will concentrate on the main methodological principles of ultrasounds and the QUS variables derived from their application to bone tissue, technical differences and performance of QUS methods, factors influencing QUS measurements, normative data and results obtained in children with disturbances of growth or affected by disorders of bone and mineral metabolism, including the assessment of fracture risk, and comparison among QUS, dual energy x-ray absorptiometry, and peripheral quantitative computed tomography methods. (Pediatr Res 63: 220-228, 2008) I n the last years, the demand for measurement of bone mineral status to identify children who could be exposed to an increased risk of osteoporosis in adulthood is rapidly increased. Several disorders, by various mechanisms, may be associated with a reduced bone mineral status; in particular, patients with chronic or genetic diseases, malignancies, acute or chronic disabilities caused by neuromuscular disorders, and patients receiving prolonged glucocorticoid treatment are at risk of fractures by minimal trauma caused by a severe reduction in bone mineral status (1).Moreover, there is a growing demand for assessing the effects of some environmental factors on bone health, such as dietary habits and various degrees of physical activity by using radiationfree techniques. DENSITOMETRIC TECHNIQUES FOR ESTIMATING BONE MINERAL STATUS IN CHILDRENSome densitometric techniques to assess bone mineral status developed for adults have been adapted for the use in children. Dual energy x-ray absorptiometry (DXA) is the most commonly used technique for bone mineral status assessment worldwide. The main advantages of DXA are its wide availability and short scanning times, but the subject is exposed to ionized radiation that varies according to the machinery and the examined skeletal site; anyway, radiation dose to patient from DXA is minimal (0.08 -4.6 Sv and 6.7-31 Sv for pencil beam and fan beam methods, respectively) compared with that given by many other investigations involving ionizing radiation (2). Nevertheless, an important shortcoming of DXA is that it measures bone in two dimensions providing only an estimation of bone density. Indeed, DXA measures an integral areal density that is calculated as bone mineral content/bone su...

Bone status in adolescents with type 1 diabetes

“…The present study was based on QUS, which has been found to correlate with DXA results in adults [10]. It needs to be underlined that QUS and DXA do not measure identical properties of bone tissue.…”

“…Dual x-ray absorptiometry (DXA) remains a gold standard in bone densitometry. However, it may not be appropriate for assessing a maturing skeleton, as it allows only two-dimensional measurements and depends on bone size, therefore making the results potentially inaccurate [10]. Measurements made by quantitative ultrasound (QUS) are less influenced by bone size [11][12][13].…”

“…Importantly, when considering the paediatric population, no radiation is used and costs are relatively low. Prospective studies using QUS have revealed similar prognostic values for osteoporotic fractures as DXA in adults [10], and it has been shown to be similar to DXA in detecting low bone mineral status in young patients with fragility fractures [14,15]. Although phalangeal QUS seems to be a very promising tool in the assessment of skeletal status in children and adolescents, the use of QUS remains the subject of much controversy.…”

Measurement properties of radial and tibial speed of sound for screening bone health and fragility in 10[ndash]12 years old boys and girls

“…The screening of bone health around 10-14 years of age in girls and 12-16 years of age in boys seems to be particularly important in the prevention of osteoporosis because about 40% of peak bone mineral mass is acquired during the four year period surrounding peak height velocity, which is around the 12 nd and 14 th years of life in girls and boys, respectively [4][5][6]. Beyond DXA, other equipments have been applied in both pediatrics and adults to assess bone mineral status, as the quantitative ultrasonography (QUS), which quantifies the ultrasound velocity and attenuation parameters at the distal regions of the appendicular skeleton [7][8][9]. In children and adolescents, the tibia (midshaft) and the radius (distal third) with cortical axial transmission of ultrasound have been the skeletal sites most often assessed by the multisite QUS device [7].…”

“…Beyond DXA, other equipments have been applied in both pediatrics and adults to assess bone mineral status, as the quantitative ultrasonography (QUS), which quantifies the ultrasound velocity and attenuation parameters at the distal regions of the appendicular skeleton [7][8][9]. In children and adolescents, the tibia (midshaft) and the radius (distal third) with cortical axial transmission of ultrasound have been the skeletal sites most often assessed by the multisite QUS device [7]. However, poor or inconsistent associations between QUS and DXA both in growing patients with pathology [10][11][12] as in healthy children [13][14] …”