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.
- Views: 176
- PDF Downloads: 110
Downloads
References
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.
Published
How to Cite
Issue
Section
License
Copyright (c) 2021 Brazilian Journal of Radiation Sciences
This work is licensed under a Creative Commons Attribution 4.0 International License.
Licensing: The BJRS articles are licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/
