Osteoporosis and bone densitometry.

Osteoporosis, a clinically detectable decrease in bone density, affects 24 million Americans, placing them at increased risk for fractures. This article describes the anatomy and physiology of bones and the detection, treatment and prevention of osteoporosis. Techniques for bone densitometry are emphasized, including conventional radiography, single photon and single energy x-ray absorptiometry, dual photon absorptiometry, dual energy x-ray absorptiometry, quantitative CT and ultrasound.