Bone Mineral Measurements

The accurate measurement of bone mineral density using noninvasive methods can be of value in the detection and evaluation of primary and secondary causes of decreased bone mass. This includes primary osteoporosis and secondary disorders, such as hyperparathyroidism, osteomalacia, multiple myeloma, diffuse metastases, and glucocorticoid therapy or intrinsic excess.By far, the largest patient population is that encompassed by primary osteoporosis with increased susceptibility to fractures in the absence of other recognizable causes of bone loss.Primary osteoporosis is a common clinical disorder and a major public health problem because of the significant number of related bone fractures occurring annually. Because the risk of vertebral and femoral neck fractures rises dramatically as bone mineral density falls, fracture risk in individual patients may be estimated. Furthermore, in estrogen-deficient women, bone mineral density values may be used to make rational decisions about hormone replacement therapy, or other bone mineral therapies, and as follow-up in assessing the success of such treatment.In this article, we discuss different methods of bone densitometry and will focus on dual-energy x-ray absorptiometry (DXA) with discussing the factors which should be considered for interpretation of DXA scan.