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

Sharma A, Singh M, Singh B, Sandhu BS - J Med Phys (2009)

Bottom Line: 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 K(2)HPO(4) and KI in distilled water within experimental estimated error of <6%.The present non-destructive technique has the potential for a measure of mandibular bone density and stable iodine contents of thyroid.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, Punjabi University, Patiala-147002, India.

ABSTRACT
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 K(2)HPO(4) 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 K(2)HPO(4) 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.

No MeSH data available.


Related in: MedlinePlus

(a) A typical observed spectra at a scattering angle of 130° for a phantom (K2HPO4 concentration 30 g in 100 mL) when irradiated by 59.54 keV incident photons for 5 ks duration, (b) zoom in spectra of region of coherent peak, and (c) a typical observed spectra at a scattering angle of 50° for a phantom (KI concentration, 2 g in 10 mL of water) when irradiated by 145 keV incident gamma rays
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Figure 0002: (a) A typical observed spectra at a scattering angle of 130° for a phantom (K2HPO4 concentration 30 g in 100 mL) when irradiated by 59.54 keV incident photons for 5 ks duration, (b) zoom in spectra of region of coherent peak, and (c) a typical observed spectra at a scattering angle of 50° for a phantom (KI concentration, 2 g in 10 mL of water) when irradiated by 145 keV incident gamma rays

Mentions: A typical observed spectrum, corrected for background events, from phantom (30 g of K2HPO4 in 100 mL distilled water) when irradiated by 59.54 keV gamma rays (at scattering angle of 130°) is shown in [Figure 2a]. The coherent and incoherent peaks are observed at 59.54 and 50.5 keV, respectively. The intensity of coherent peak is much smaller in comparison to incoherent peak owing to low effective atomic number of the phantom and lesser probability for coherent process to occur at large scattering angles. [Figure 2b] shows zoom in the spectrum of region of coherent peak [Figure 2a] showing its presence, which otherwise is not clearly visible because of observed higher counting rate under the incoherent peak. [Figure 2c] shows a typical observed spectrum, corrected for background events, from phantom (2 g of KI in 10 mL distilled water) when irradiated by 145 keV gamma rays (at scattering angle of 50°). The Rayleigh and Compton peaks are clearly visible at energies of 145 and 131.6 keV, and distinguished from each other in the scattered spectra. The intensity of Rayleigh peak is considerably smaller in comparison to Compton peak owing to lesser probability for Rayleigh process to occur in comparison to Compton scattering at the chosen scattering angle for a given incident energy. The observed spread in the coherent peak is caused by inherent energy resolution of the HPGe detector. The spread in the observed incoherent peak is caused by finite angular aperture of the source and detector collimators, Doppler broadening of incoherent peak and intrinsic energy resolution of the HPGe detector.


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

Sharma A, Singh M, Singh B, Sandhu BS - J Med Phys (2009)

(a) A typical observed spectra at a scattering angle of 130° for a phantom (K2HPO4 concentration 30 g in 100 mL) when irradiated by 59.54 keV incident photons for 5 ks duration, (b) zoom in spectra of region of coherent peak, and (c) a typical observed spectra at a scattering angle of 50° for a phantom (KI concentration, 2 g in 10 mL of water) when irradiated by 145 keV incident gamma rays
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2807686&req=5

Figure 0002: (a) A typical observed spectra at a scattering angle of 130° for a phantom (K2HPO4 concentration 30 g in 100 mL) when irradiated by 59.54 keV incident photons for 5 ks duration, (b) zoom in spectra of region of coherent peak, and (c) a typical observed spectra at a scattering angle of 50° for a phantom (KI concentration, 2 g in 10 mL of water) when irradiated by 145 keV incident gamma rays
Mentions: A typical observed spectrum, corrected for background events, from phantom (30 g of K2HPO4 in 100 mL distilled water) when irradiated by 59.54 keV gamma rays (at scattering angle of 130°) is shown in [Figure 2a]. The coherent and incoherent peaks are observed at 59.54 and 50.5 keV, respectively. The intensity of coherent peak is much smaller in comparison to incoherent peak owing to low effective atomic number of the phantom and lesser probability for coherent process to occur at large scattering angles. [Figure 2b] shows zoom in the spectrum of region of coherent peak [Figure 2a] showing its presence, which otherwise is not clearly visible because of observed higher counting rate under the incoherent peak. [Figure 2c] shows a typical observed spectrum, corrected for background events, from phantom (2 g of KI in 10 mL distilled water) when irradiated by 145 keV gamma rays (at scattering angle of 50°). The Rayleigh and Compton peaks are clearly visible at energies of 145 and 131.6 keV, and distinguished from each other in the scattered spectra. The intensity of Rayleigh peak is considerably smaller in comparison to Compton peak owing to lesser probability for Rayleigh process to occur in comparison to Compton scattering at the chosen scattering angle for a given incident energy. The observed spread in the coherent peak is caused by inherent energy resolution of the HPGe detector. The spread in the observed incoherent peak is caused by finite angular aperture of the source and detector collimators, Doppler broadening of incoherent peak and intrinsic energy resolution of the HPGe detector.

Bottom Line: 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 K(2)HPO(4) and KI in distilled water within experimental estimated error of <6%.The present non-destructive technique has the potential for a measure of mandibular bone density and stable iodine contents of thyroid.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, Punjabi University, Patiala-147002, India.

ABSTRACT
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 K(2)HPO(4) 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 K(2)HPO(4) 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.

No MeSH data available.


Related in: MedlinePlus