Coherent and incoherent scatterings for measurement of mandibular bone density and stable iodine content of tissue

摘要

The aim of present study is to investigate the feasibility of gamma ray scattering for measurements of mandibular bone density and stable iodine content of tissue. Scattered spectra from solutions of K2HPO4 in distilled water (a phantom simulating the mandibular bone) and KI in distilled water filled in a thin plastic vial (a phantom simulating the kinetics of thyroid iodine) are recorded for 59.54 and 145 keV incident gamma rays, respectively. A high-purity germanium detector is placed at various angular positions to record the scattered spectra originating from interactions of incident gamma rays with the phantom. The measured intensity ratio of coherent to incoherent scattered gamma rays, corrected for photo-peak efficiency of HPGe detector, absorption of gamma rays in air column present between phantom and detector, and self-absorption in the phantom, is found to be increasing linearly with increase in concentration of K2HPO4 and KI in distilled water within experimental estimated error of <6%. The regression lines, obtained from experimental data for intensity ratio, provide the bone density and stable iodine contents of thyroid. The present non-destructive technique has the potential for a measure of mandibular bone density and stable iodine contents of thyroid.Keywords: Coherent and incoherent scatterings, intensity ratio, phantom