Abstract:Objective To compare the difference of image quality and radiation dose in children's chest CT examination with single AP, single AP and dual AP in DoseRight technique. Methods 367 children aged 0-16 years who underwent chest CT examination were prospectively selected as the subjects of study. They were divided into group A (n=120), group B (n=120) and group C (n=127) according to their ages. According to the selection of location image, each group of children was randomly divided into single location image, single location image and double location image. The data were collected with Philips 128 iCT, and the scan range (L), CTDIVOL and DLP were recorded. The anterior and posterior chest diameters, left and right chest diameters were measured, and the effective diameters were calculated. The quality of chest CT image was evaluated subjectively and objectively. ResultsL of A1 was significantly larger than that of A2 and A3 (P＜0.05). There was no significant difference between A2 and A3 (P＞0.05). The L of B1 was significantly higher than that of B2 and B3 (P＜0.05), but there was no significant difference between B2 and B3 (P＞0.05). L of C1 was significantly higher than that of C2 and C3 (P < 0.05), but there was no significant difference between C2 and C3 (P＞0.05). The CTDI, Vol and DLP of A1 were higher than those of A2, and those of A2 were higher than those of A3 (P＜0.05). The CTDI, Vol and DLP of B1 were higher than those of B2, and those of B2 were higher than those of B3 (P＜0.05). CTDI, Vol and DLP of C1 were higher than those of C2, and those of C2 were higher than those of C3 (P＜0.05). Conclusion T In CT examination of children's chest, the use of positive and lateral double location image scanning can control the scanning range more accurately, reduce the radiation dose, and ensure the image quality.
