In Vivo Measurement of Bone Mass

Abstract
In a sensitive method for measuring both cortical and trabecular bone mass in the radius, bone mass is determined by measuring the photon energy absorbed by bone from a monochromatic gamma-ray source,125I. The method is quite reproducible, with a coefficient of variation of about 2.5%. Measurements of bone mass were performed on 169 white women older than 50 years of age who were divided into two groups: those with (56 women) and those without collapsed vertebrae (113 women). Measurements of both trabecular and cortical bone mass were significantly less in the group with collapsed vertebrae. This method is capable of providing objective, reproducible measurements of bone mass in man. It appears to be a very promising tool for the study of the natural history of diseases of demineralization and for providing data on the response to therapy.