Bone densitometry measurement

Espallargues M, Sampietro-Colom L, Estrada MD, Sola M, del Rio L, Setoain J, Granados A. Identifying bone-mass-related risk factors for fracture to guide bone densitometry measurements a systematic review of the literature. Osteoporos Int 2001 12(10) 811-22. 

An estimated 75 million people are affected by osteoporosis to some degree in the United States, Europe, and Japan. Osteoporosis is a systematic skeletal disease characterized by bone mass and microarchitectural deterioration with a consequent increase in bone fragility and susceptibility to fracture. Operationally, osteoporosis can be defined as a certain level of bone mineral density. The definition of osteoporosis is somewhat arbitrary and is based on epidemiological data relating fracture incidence to bone mass. Uncertainty also is introduced due to variability in bone densitometry measurements. Other clinical measures to assess the skeleton include collagen cross-links (measure of bone resorption) and levels of bone-specific alkaline phosphatase and osteocalcin (bone formation). A list of biochemical markers of bone remodeling is provided in Table 37-3. Measurement of total serum alkaline phosphatase level and urinary hydroxyproline or calcium levels is of limited value. 

In this study a new phantom with capabilities of easily supporting wide range of densities and using in both DEXA and QCT techniques is designed. Performing bone densitometry measurement in large amount of densities by this phantom, make it more accurate to assess the sensitivity and error of systems especially in low densities. 

Peripheral bone mineral density measurements cannot be used for diagnosis because they do not correlate with central measurements. However, they are useful in identifying patients who are candidates for central DXA and who are at increased risk of fracture.5 It also may be useful in patients who have had multiple fractures or in low-risk patients. Additionally, peripheral measurement of bone mineral density generally is less expensive than central DXA and is easily accessible. Instruments used for peripheral bone densitometry are portable, which allows bone density to be measured in pharmacies and health-fair screening booths. 

Women older than 65 years of age or yonnger with risk factors for osteoporosis shonld have their bone mineral density measured. Although bone densitometry has been shown to predict fractures, at present there are no guidelines for follow-up bone mineral density testing. However, in women with significant bone loss, repeat testing should be performed as clinically indicated. 

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