Osteoporosis and bone density measurement methods.

Recent technologic advances in bone mineral densitometry have resulted in increasingly precise and accurate methods of estimating bone mineral density. Dual-photon absorptiometry has been made obsolete by the introduction of dual-energy radiography, a development that is likely to result in more widespread use of densitometry. The technique allows a reproducible, low dose examination of the spine, hip, and total body. Although capable of selectively measuring trabecular bone, quantitative computed tomography is currently limited to the spine, and the reliability of the technique varies from center to center. Single-photon absorptiometry and ultrasound experimental methods are of limited value because only peripheral skeletal sites can be examined by these techniques. Although invaluable in epidemiologic research and in limited clinical situations, the role of densitometry in the management and prevention of involutional osteoporosis has not been established. The evidence indicates that densitometry is unlikely to be effective as a selective screening procedure. Long-term prospective studies are needed to clarify the role of densitometry in osteoporosis management.