The Effect of silicone rubber-lead (SR-Pb) as an additional filter on radiation dose and image quality in computed radiography (CR)

Abstract

Abstract This study aims to determine the validity of the Silicone Rubber-Lead (SR-Pb) as an additional filter on the computed radiography (CR) using the tube voltage of 70 kVp and current-time of 6.3 mAs with a Pb percentage of 5 wt%. In addition, the thickness variations of the SR-Pb were 2, 4mm, 6mm, 8mm, and 10 mm, were compared to the Aluminum (Al) filter, of 0.5 mm, 1.0 mm and 1.5 mm. The effect of both SR-Pb and Al filters on radiation dose and image quality was studied. The radiation dose was measured using the Piranha detector, while the image quality was quantified using the signal to noise ratio (SNR) and the contrast to noise ratio (CNR) from images of the CDR TOR phantom. It was found that the dose decreased with an increase in the thickness of SR-Pb filter. At 77% and 53%, the thickness increased to 10 mm and 6 mm, respectively, which is equivalent to a 1.5 mm Al filter. The result showed that when CNR decreases, SNR increases with a rise in thickness values of SR-Pb filter. The decrease in CNR value at 6 mm SR-Pb filter was greater than 1.5 mm Al which is 45.3% and 11.04%, respectively. In addition, the use of SR-Pb filter led to an increase in SNR value by 45.9%, while the 1.5 mm Al filter increased SNR value of about 47.5% In conclusion, the SR-Pb filter has the potential to be used as an alternative additional filter for the CR examination.