Noninvasive bone mineral assessment

With increased public awareness of the hazards--and possible prevention--of osteoporotic fractures, the demand for bone mineral measurement procedures has also increased. The early methods for assessing bone mass noninvasively were based on radiography; recently, radioisotope and computed tomography techniques have been developed to overcome the technical limitations of plain radiographs. The available technologies can be distinguished by their ability to measure either the vertebrae or limbs, areas of the body with markedly different bone physiology. Now, the selection of a bone mineral assessment modality for a particular individual depends upon the importance the physician places on the need to measure the potential fracture site directly. In those instances in which the examination of the forearm provides sufficient information, such as in screening the elderly, single photon absorptiometry is likely to be chosen. Where a more direct measurement of vertebral or femoral bone mineral content is required, such as for diagnosis of disease or monitoring therapy, either dual photon absorptiometry or quantitative computed tomography will be the final choice, depending on which is ultimately proven the better predictor of hip and spinal fractures.