低剂量容积数据高分辨率CT应用于肺部体检的参数优化

Optimization of the parameters of low-dose volumetric data with a high-resolution CT algorithm for lung physical examination

目的探讨低剂量容积数据高分辨率CT(VHRCT)应用于肺部体检扫描的最佳参数。方法将本院2013年10月至2015年7月500名肺部健康体检者简单随机化分成5组,各组100名,管电流分别为常规剂量220 m A和低剂量35 m A、30 m A、25 m A、20 m A,管电压均为120 k V扫描,容积数据进行薄层高分辨率算法重组,以能显示肺小叶水平上的细微结构和病变以及大血管的边界为保证诊断质量的图像。记录各组受检者的照射剂量,对不同低剂量管电流和常规剂量的VHRCT图像进行统计学分析。结果 35 m A、30 m A、25 m A、20 m A低剂量与常规剂量220 m A相比,受检者的照射剂量分别下降85.64%、87.86%、90.24%、92.53%。35 m A、30 m A、25 m A和220 m A常规剂量VHRCT图像比较差异均无统计学意义(P<0.05),20 m A和常规剂量比较差异有统计学意义(P<0.05)。结论 25 m A的管电流可作为低剂量容积数据高分辨率CT应用于肺部体检的参考条件。

Objective To study the optimal parameters low-dose volumetric data with a high-resolution CT algorithm(VHRCT) for lung physical examination. Methods A total of 500 cases of lung physical examinations in our hospital from October 2013 to July 2015 were randomly divided into 5 groups, with 100 cases in each group. The 5groups were scanned by VHRCT with the different parameters as follows: tube voltage was 120 k V; tube current were respectively regular dose of 220 m A and low-dose of 35 m A, 30 m A, 25 m A, 20 m A; thin-recon-struction of volumetric data with a high-resolution algorithm was used to ensure the quality of diagnostic images to show the small structure and lung lobules level of lesion and the boundary of the great vessels. The radiation dose of each group of subjects was recorded, and the VHRCT images of different low-dose tube currents and conventional doses were analyzed statistically.Results Compared with the low-dose of 35 m A, 30 m A, 25 m A, 20 m A, the radiation dose of the conventional dose of220 m A decreased respectively by 85.64%, 87.86%, 90.24%, 92.53%. There was no significant difference between the low-dose of 35 m A, 30 m A, 25 m A and conventional dose of 220 m A in the VHRCT image(P>0.05), while there was significant difference between the low-dose of 20 m A and conventional dose of 220 m A in the VHRCT image(P<0.05).Conclusion The 25 m A tube current scan can be used as a reference of low-dose volumetric data with a high-resolution CT algorithm for lungs physical examination.