Methods for measurement of pediatric bone.

Many experts believe that optimizing bone mineral accrual early in life may prevent childhood fractures and possibly delay the development of osteoporosis later in life. Adequate nutrition and physical activity are environmental factors important in determining whether or not children acquire an appropriate amount of bone for their body size. Pediatric diseases, or therapeutic interventions used in their treatment, may interfere with normal bone development. Although there are specific methods available for assessing pediatric bone, there is no one method that can adequately assess bone health and identify the specific bone deficits that may be occurring. Understanding the biological basis for bone deficits and the ability of various bone assessment methods to discriminate or measure these deficits is important in understanding normal bone development and how to prevent and treat pediatric bone disease. The purpose of this review is to briefly describe changes in bone with growth, to define "bone density" in biological terms, to discuss some of the issues with pediatric bone measurements, and to review the three main methods for assessing bone parameters in pediatric populations. These methods, including dual energy X-ray absorptiometry (DXA), quantitative ultrasound (QUS) and peripheral quantitative computed tomography (pQCT) will be described, the advantages and disadvantages discussed, and the relationship between bone parameters and fracture risk presented for each of the methods.