Radiological determination of changes in bone mineral content.

It is possible to obtain reliable data of changes in bone mineral content using simple radiographic techniques. Methods available include morphometry and densitometry. Of these morphometry of the third metacarpal is most accurate in our hands and cortical width is the most reliable of such morphometric data. Densitometry produces more variable results and shows no advantage over straight measurement of cortical width. The only acceptable alternative method of obtaining information about bone status is photon absorptiometry. Results of these methods are shown in a trial of oestrogen therapy for the prevention of post-menopausal osteoporosis. The data suggest that oestrogens prevent post menopausal bone loss when this is estimated by measurement of cortical width or photonabsorptiometry.