骨盆数字断层融合辐射剂量优化

Optimization of Radiation Dosage in Pelvis Digital Tomosynthesis

目的探讨骨盆数字断层融合(DTS)成像的最佳剂量比,以实现骨盆DTS的低剂量检查。资料与方法对18具骨盆标本进行3组骨盆DTS扫描和1组髋关节CT扫描,其中3组骨盆DTS扫描的剂量比参数值分别为6、7、10,比较4组所得图像质量评分和有效剂量。结果 4组有效剂量差异有统计学意义(F=4632.06,P<0.001),4组髋关节图像质量评分差异有统计学意义(F=1682.34,P<0.001)。4组间检查剂量依次为:6DTS剂量比组<7DTS剂量比组<10DTS剂量比组<CT组;DTS剂量比设置为6时所得图像质量低于其他3组,而DTS剂量比设置为7、10时的图像质量与CT无差别。剂量比设置为7时的DTS图像质量高而检查剂量小。结论剂量比影响骨盆DTS的检查剂量和图像质量,骨盆DTS检查的最佳剂量比为7,在此剂量比设置下,可以在保证诊断质量的前提下实现骨盆DTS的低剂量检查。

Purpose To study the optimal dose ratio of pelvis digital tomosynthesis(DTS) so as to achieve the low-dose examination in pelvis DTS. Materials and Methods Eighteen human pelvis specimens with soft tissue were examined with DTS scan and CT scan. The dose ratios of DTS were set up as 6, 7 and 10, respectively. Effective examination dose and image quality score were compared among the four groups(DTS-6, DTS-7, DTS-10, and CT group). Results The four groups were significantly different with regard to effective examination dose(F=4632.06, P<0.001) and image quality score(F=1682.34, P<0.001). Among them the examination dose from low to high was that in DTS-6 group, DTS-7 group, DTS-10 group and CT group. Image quality score in DTS-6 group was significantly lower than that in other groups. DTS-7 group showed no difference with DTS-10 group and CT group in image quality score, but had significantly lower examination dose than the other two groups. Conclusion Dose ratio affects examination dose and image quality of pelvis DTS. Dose ratio 7 is optimal in pelvis DTS, which ensures good image quality with effective low dose.