Quantitative assessment of bone mineral by photon scattering: Accuracy and precision considerations

Abstract

A method to determine the bone mineral density of the calcaneum has been reported earlier. In this method, the calcaneum is irradiated by a 60-keV photon beam from 241Am source and both coherent and Compton scattered photons are detected by a high-purity Ge detector. The bone mineral density is determined by measuring the ratio of coherent-to-Compton scattered photons. The accuracy and the precision (in vitro) of the method are reported in this paper. The accuracy was determined to be 5%. This was obtained by comparing the bone mineral density values of cadaver calcanea measured directly by Archimedes'' volume displacement method with the values measured by the scattering method. The precision was determined to be 3% by measuring the bone mineral density of a calibration phantom intermittently over a 10 mo. period by the scattering method.