Performance of an extrapolation chamber in computed tomography standard beams
DOI:
https://doi.org/10.15392/bjrs.v8i3B.376Keywords:
Extrapolation chamber, computed tomography, dosimetry.Abstract
Among the medical uses of ionizing radiations, the computed tomography (CT) diagnostic exams are responsible for the highest dose values to the patients. The dosimetry procedure in CT scanner beams makes use of pencil ionization chambers with sensitive volume lengths of 10 cm. The aim of its calibration is to compare the values that are obtained with the instrument to be calibrated and a standard reference system. However, there is no primary standard system for this kind of radiation beam. Therefore, an extrapolation ionization chamber, built at the Calibration Laboratory (LCI), was used to establish a CT primary standard. The objective of this work was to perform some characterization tests (short- and medium-term stabilities, saturation curve, polarity effect and ion collection efficiency) in the standard X-ray beams established for computed tomography at the LCI.
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BOONE, J. M. The trouble with CTDI100. Med. Phys. 34(4) 1364-1371, 2007.
DIAS, S.K.; CALDAS, L V E. Development of an extrapolation chamber for the calibration of beta-ray applicators. IEEE Trans. Nucl. Sci. 45, 1666-1669, 1998.
DIAS, S.K.; CALDAS, L V E. Extrapolation chamber response in low-energy radiation standard beams. J. Appl. Phys. 89, 669-671, 2001.
NEVES, L P; SILVA, E A B; PERINI, A P; MAIADANA, N L; CALDAS, L V E. Characterization of an extrapolation chamber for low-energy X-rays: Experimental and Monte Carlo preliminary results. Appl. Radiat. Isot. 70, 1388-1391, 2012.
FIGUEIREDO, M.T.T; SILVA, T.A. Determination of the effective volume of an extrapolation chamber for X-ray dosimetry, In: X CONGRESO REGIONAL LATINOAMERICANO IRPA DE PROTECTIÓN Y SEGURIDAD RADIOLÓGICA, 2015, Buenos Aires. Annals 2015.
IEC – International Electrotechnical Commission. Medical Diagnostic X-ray Equipment. Radiation Conditions for Use in the Determination of Characteristics. IEC 61267. 2nd ed. Ge-nève IEC, 2005.
IAEA – International Atomic Energy Agency. Calibration of Radiation Protection Monitoring Instruments. SRS 16, Vienna IAEA, 2001.
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