Evaluating the influence of the aluminum purity at mammographic HVL procedures

This paper intends to evaluate the influence of the Aluminum's purity over the mammographic HVL procedures. It was measured the HVL of a GE Senographe 700 T using 7 groups of commercial filters, and its purity and thickness were determined. As the results shows, the first HVL inherent procedure's uncertainty is about 3%; the best local prototype's deviation over the worst commercial device is about 5%; and, according to the procedure's uncertainty, as to the commercial device's response variability, it may be possible using local Al filters, although it is necessary to extend this study over more equipment in order to set up a correction factor, which was found to be about 5% to 8% over Al filters about 99% purity, on this study. (author)