DETERMINING BODY COMPOSITION USING FAN BEAM DUAL-ENERGY X-RAY ABSORPTIOMETRY

摘要

True body composition is estimated using a dual-energy, fan-shapeddistributionof x-rays and signal processing that corrects for mass magnification and othereffectsdue to the geometry of the measurement system. To avoid inaccuracies due tobeamhardening and certain other effects, the thickness of attenuating materialalongrespective raypaths is obtained through using a four-dimensional look-up tablederivedexperimentally from step-wedge measurements. To correct for mass magnificationeffects due to using a fan-shaped distribution of x-rays, another look-uptable andinterpolation between table entries are used to convert projected mass to truemass.