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Generation of the additional fluorescence radiation in the elastomeric shields used in computer tomography (CT).

Szajerski P, Zaborski M, Bem H, Baryn W, Kusiak E - J Radioanal Nucl Chem (2013)

Bottom Line: To measure the radiation reduction ability of the protective shields, the dose reduction factor (DRF) has been determined.The results clearly indicate that among the examined compositions, the highest values DRF have been achieved with preparations containing Bi+W, Bi+W+Gd and Bi+W+Sb mixtures with gradually decreasing content of heavy metal additives in the following order: Bi, W, Gd and Sb.The respective values of DRF obtained for the investigated composites were 21, 28 and 27 % dose reduction for a 1 mm thick shield and 39 and ~50 % for a 2 mm thick layer (M1-M4).

View Article: PubMed Central - PubMed

Affiliation: Institute of Applied Radiation Chemistry, Lodz University of Technology, Wroblewskiego 15, 90-924 Lodz, Poland.

ABSTRACT

Two commercially available (EP, Z) and eight new elastomeric composites (M1-M4, G1-G4, of thickness ≈1 mm) containing mixtures of differing proportions of heavy metal additives (Bi, W, Gd and Sb) have been synthesised and examined as protective shields. The intensity of the X-ray fluorescence radiation generated in the typical elastomeric shields for CT, containing Bi and other heavy metal additives influence on the practical shielding properties. A method for assessing the radiation shielding properties of elastomeric composites used in CT examination procedures via X-ray spectrometry has been proposed. To measure the radiation reduction ability of the protective shields, the dose reduction factor (DRF) has been determined. The lead equivalents for the examined composites were within the ranges of 0.046-0.128 and 0.048-0.130 mm for 122.1 and 136.5 keV photons, respectively. The proposed method, unlike to the common approach, includes a dose contribution from the induced X-ray fluorescence radiation of the heavy metal elements in the protective shields. The results clearly indicate that among the examined compositions, the highest values DRF have been achieved with preparations containing Bi+W, Bi+W+Gd and Bi+W+Sb mixtures with gradually decreasing content of heavy metal additives in the following order: Bi, W, Gd and Sb. The respective values of DRF obtained for the investigated composites were 21, 28 and 27 % dose reduction for a 1 mm thick shield and 39 and ~50 % for a 2 mm thick layer (M1-M4).

No MeSH data available.


Schematic diagram of the experimental setup
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Fig1: Schematic diagram of the experimental setup

Mentions: For a radiation source that mimics the X-ray tube radiation used in CT, a Co-57 closed isotopic source has been applied providing γ-rays of 122.1 (85.6 %) and 136.5 (10.7 %) keV., which closely approximates the typical X-ray tube voltages applied in CT examinations. The intensity of the excited X-ray photons was measured using a γ-ray spectrometry system with a high-resolution REGe detector placed in a 5 cm thick lead shielding housing lined with a 5 mm thick Zn plate cylinder. The resolution of the detector was 0.9 keV for the 122 keV peak, and its relative efficiency was 20 % for the 1.33 MeV peak. The data were processed using a model S404 Inspector Spectroscopy System (Canberra). Details of the detection system are described elsewhere [20]. A schematic diagram of the measuring system is shown in Fig. 1.Fig. 1


Generation of the additional fluorescence radiation in the elastomeric shields used in computer tomography (CT).

Szajerski P, Zaborski M, Bem H, Baryn W, Kusiak E - J Radioanal Nucl Chem (2013)

Schematic diagram of the experimental setup
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4514613&req=5

Fig1: Schematic diagram of the experimental setup
Mentions: For a radiation source that mimics the X-ray tube radiation used in CT, a Co-57 closed isotopic source has been applied providing γ-rays of 122.1 (85.6 %) and 136.5 (10.7 %) keV., which closely approximates the typical X-ray tube voltages applied in CT examinations. The intensity of the excited X-ray photons was measured using a γ-ray spectrometry system with a high-resolution REGe detector placed in a 5 cm thick lead shielding housing lined with a 5 mm thick Zn plate cylinder. The resolution of the detector was 0.9 keV for the 122 keV peak, and its relative efficiency was 20 % for the 1.33 MeV peak. The data were processed using a model S404 Inspector Spectroscopy System (Canberra). Details of the detection system are described elsewhere [20]. A schematic diagram of the measuring system is shown in Fig. 1.Fig. 1

Bottom Line: To measure the radiation reduction ability of the protective shields, the dose reduction factor (DRF) has been determined.The results clearly indicate that among the examined compositions, the highest values DRF have been achieved with preparations containing Bi+W, Bi+W+Gd and Bi+W+Sb mixtures with gradually decreasing content of heavy metal additives in the following order: Bi, W, Gd and Sb.The respective values of DRF obtained for the investigated composites were 21, 28 and 27 % dose reduction for a 1 mm thick shield and 39 and ~50 % for a 2 mm thick layer (M1-M4).

View Article: PubMed Central - PubMed

Affiliation: Institute of Applied Radiation Chemistry, Lodz University of Technology, Wroblewskiego 15, 90-924 Lodz, Poland.

ABSTRACT

Two commercially available (EP, Z) and eight new elastomeric composites (M1-M4, G1-G4, of thickness ≈1 mm) containing mixtures of differing proportions of heavy metal additives (Bi, W, Gd and Sb) have been synthesised and examined as protective shields. The intensity of the X-ray fluorescence radiation generated in the typical elastomeric shields for CT, containing Bi and other heavy metal additives influence on the practical shielding properties. A method for assessing the radiation shielding properties of elastomeric composites used in CT examination procedures via X-ray spectrometry has been proposed. To measure the radiation reduction ability of the protective shields, the dose reduction factor (DRF) has been determined. The lead equivalents for the examined composites were within the ranges of 0.046-0.128 and 0.048-0.130 mm for 122.1 and 136.5 keV photons, respectively. The proposed method, unlike to the common approach, includes a dose contribution from the induced X-ray fluorescence radiation of the heavy metal elements in the protective shields. The results clearly indicate that among the examined compositions, the highest values DRF have been achieved with preparations containing Bi+W, Bi+W+Gd and Bi+W+Sb mixtures with gradually decreasing content of heavy metal additives in the following order: Bi, W, Gd and Sb. The respective values of DRF obtained for the investigated composites were 21, 28 and 27 % dose reduction for a 1 mm thick shield and 39 and ~50 % for a 2 mm thick layer (M1-M4).

No MeSH data available.