Assessment of dose reduction and image quality by barium composite shielding in head and chest CT

Abstract

The purpose of this study was to evaluate the dose and image to assess a shielding made of barium sulfate for the protection of supersensitive radiation eye lens and superficial breast during CT scanning. Doses were measured by CT scan of the head and chest phantoms with a polymethylmethacrylate (PMMA) phantom consisting of holes (designated in sequence at 0°, 90°, 180°, and 270°). Dose measurement of the eye lens was performed using a 16 cm head phantom and chest breast dose measurement was performed using a 32 cm PMMA body phantom. The dose was measured using a barium shield and the dose reductions in the head and chest phantoms were calculated by comparing the doses of the reference. For image evaluation, HU and noise on the left and right sides were measured by dividing them into the anterior, lateral (90°, 270°), and posterior positions. To evaluate the barium shielding image, the image was evaluated by selecting a surface plot using the ImageJ program. The head phantom dose decreased by 12.4% maximum in the anterior position (0°) and the chest phantom showed a decrease of 31.37% in the anterior (0°) and 33.63% in the lateral (90°) positions. In the comparison of noise of the image, the head phantom showed an increase of 50.43% in the anterior position. There was a significant difference in dose at positions other than the lateral (270°) and posterior (180°) positions (p < 0.05). Scanning the chest phantom in the anterior position increased the noise by up to 90.66% in the noise comparison (270°) and the posterior (180°) position showed significant differences in image (p < 0.05). In the CT scan using a barium-based shielding agent, the dose was reduced by 3.3–12.4% in the head and 3.62–33% in the chest. The barium shielding agent should be used for the examination by reducing the dose and maintaining the image quality by applying it efficiently during CT examination.