Estudo da liga de aluminio-zinco como filtração alternativa para a radiação X

AUTOR(ES)
DATA DE PUBLICAÇÃO

2000

RESUMO

The aim of this research was evaluate the effects of the alternative filtration of the aluminumlzinc alloy in dental X rays machines, in relation to the spectrum of energy , the X ray dose, the contrast alterations and the image quality. This study was accomplished comparing the conventional aluminum filter with several thickness of the aluminumlzinc alloy filter, in different percentages of zinc in the alloy (2%, 3%, 4% and 5%). It was used a conventional X ray machine, operating with 60 kVp and 70 kVp, and D and E speed films, in order to obtain images of a phantom and of a aluminum step wedge. The use of the filters Al/Zn resulted in a spectra with smaller amount of fótons, however it was not found hardening of the beam. The kerma in the air was decreased in up to 18,53%, without alteration in the contrast of the images. The quality of the images obtained with the filters Al/Zn also had a good acceptance for the examiners. The analysis of the results showed that the filter alloy Al/Zn 2%, with 1,99 mm of thickness, tension of 60 kVp, when used with film D, obtained the best performance, reducing the kerma in the air without reducing contrast, and the image quality was considered acceptable for diagnosis. This filter also didn t needed an increase in the exposition time that would cause an consequent increase in the load of the tube

ASSUNTO(S)

liga de aluminio raios x espectrometria de raio x filtros e filtração

ACESSO AO ARTIGO

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