Endocrinology

The relatively recent ability to quantitate bone mass or density with precision has made osteoporosis a much more satisfying disorder to deal with from the standpoint of clinicians and investigators. Prior to the introduction of current methodology, assessing the degree of osteoporosis from skeletal roentgenograms was somewhat akin to measuring blood pressure by feeling the strength of the pulse. Now bone mass or density can be measured in the total skeleton by neutron activation analysis or dual-photon methodology. Bone mass in the appendicular skeleton (radius and calcaneus) can be measured by single-photon methods and in the axial skeleton (lumbar vertebrae and proximal femur) by dual-photon or computed tomographic methods. Neutron activation analysis is available in only two centers and is impractical for clinical use but the other methods, particularly those for measuring regional bone density, are in widespread use, and much clinically useful information is being collected.¹ Which of