Impacto da pureza dos filtros de alumínio no valor de Camada Semi-Redutora em radiologia convencional e mamografia
DOI:
https://doi.org/10.15392/bjrs.v3i2A.92Keywords:
Radiology, mammography, dosimetry.Abstract
Half Value Layer (HVL) test is an important technical information in conventional radiology once it is the only test which allows us to quantify beam quality in a complete way. This work promotes a preliminary analysis of the impact of aluminum alloy composition in the determination of HVL value taking into account a realistic geometry. Deterministic calculations and Monte Carlo Method were applied in order to make the proposed analysis. Six aluminum alloys (99% pure) commercialized and pure aluminum were used as comparative basis for both methods. Experimental data were collected in conventional radiology, using tungsten target and aluminum filter for two peak tensions (66 kVp, 81 kVp), and in mammography, using three target filter combinations( molybdenum-molybdenum, molybdenum-rhodium, tungsten-rhodium) for three peak tensions (25 kVp, 30 kVp and 35 kVp). Spectra used in the deterministic calculations were taken from Report No 78 of Institute of Physics and Engineering in Medicine, 1997. Results show that Mammography is more sensitive than conventional X-ray equipment to impurities in aluminum alloys (up to 34.65% variation for W-Rh combination with 30 kVp).
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References
AGOSTINELLI, S. et al. GEANT 4 — a simulation toolkit. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, v 506, Issue 3, p.250-303. 2003.
ALLISON, J. et al. Geant Developments and Applications. IEEE Transactions on Nuclear Science, v.53, p. 270-278, 2006.
ANVISA – Agência Nacional de Vigilância Sanitária – Ministério da Saúde – Secretaria de Vigilância Sanitária. Diretrizes de ProteçãoRadiológicaemRadiodiagnóstico Medico e odontológico. ANVISA Portaria 453.1998.
ATTIX, F. H. Introduction to Radiological Physics and Radiation Dosimetry. New York: J. Wiley;1986.
CRANLEY, K. et al. Catalogue of Diagnosis X ray Spectra and Other Data. Report 78 The Institute of Physics and Engineering in Medicine - Report 78. 1997
FREE SOFTWARE FOUNDATION. Gnumeric. Disponível em: http://www.gnumeric.org/. GNU GPL Protect. Últimoacesso: 03 de Fevereiro de 2015.
LOPES, G. A. et al. Determinação de Camada Semi-Redutora e Deci-Redutora para Barita com blindagem contra radiação X em Proteção Radiológica. International Nuclear Atlantic Conference . Recife, 2013.
NAGEL, H. D. Limitations in the determination of the total filtration of x-ray tube assemblies. Phys Med Biol, v.33. p. 271-28, 1988.
BERGER, M. J. at al XCOM: Photon Cross Sections Database. Disponível em http://physics.nist.gov/PhysRefData/Xcom/html/xcom1.html. The NationalInstituteof Standards and Technology (NIST) isanagencyofthe U.S. DepartmentofCommerce. Último Acesso: 09 de setembro de 12014. .
VILLAFANA, T. Generators, x-ray tubes, and exposure geometry in mammography. Radiographics, v.10, p.539-54,1990.
WAGNER, L. K.; ARCHER, B. R.; CERRA, F. On the measurement of half-value layer in film-screen mammography. Med Phys, v.17, p.989-97, 1990.
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