indispensable clinical tool / high photon energy / metal / x-ray photon energy / dual energy x-ray absorptiometry work / maximum energy / average x-ray photon energy increases / low cost technology / x-ray energy / electron kinetic energy / separate energy peaks / energy x-ray absorptiometry work / photon energy / average photon energy / energy x-ray / metal target / energy x-ray beam / metal filter / patient management / average x-ray photon energy / high and low energy parts e.g. / energy / /