ASiR-V迭代重建超低剂量胸部CT在体检中的应用

The application of ultra-low dose chest CT with physical examination based on ASiR-V iterative reconstruction

目的评价ASiR-V迭代重建技术对体检患者胸部图像质量及辐射剂量的影响。方法将60例拟行胸部CT体检者随机分为2组,即低剂量组及常规剂量组,每组30例。所有患者均利用Revolution CT进行胸部CT检查,常规剂量组管电压为100kV,图像重建采用滤波反投影重建算法(FBP);低剂量组管电压为80 k V,图像重建采用60%ASiR-V迭代重建。2组管电流均采用自动毫安秒(10~500 mA),比较2组图像噪声、主观图像质量及辐射剂量的差异。结果 2组图像主动脉噪声差异无统计学意义(P>0.05),低剂量组图像背部肌肉噪声较常规剂量组图像噪声略减低,差异有统计学意义(P<0.05),2组主观图像质量差异无统计学意义(P>0.05)。常规剂量组及低剂量组辐射剂量分别为(2.84±0.39)mSv、(0.77±0.16)mSv,差异有统计学意义(P<0.05),低剂量组较常规剂量组辐射剂量降低72.89%。结论利用ASiR-V迭代重建技术,不仅可以降低胸部CT图像噪声,而且可以明显降低患者的辐射剂量;在体检患者的胸部CT检查中,利用ASiR-V迭代重建技术,可以在保证图像质量的前提下实现亚毫希伏胸部CT成像。

Objective To evaluate the effect of image quality and radiation dose of physical examination of the patient＇s chest CT based on ASiR - V iterative reconstruction. Methods 60 patients undergoing chest CT examination were randomly divided into two group：low dose group and routine dose group,30 cases of each group. All the patients underwent chest CT with a 256 row wide - cover- age volumetric CT （ Revolution CT）. The routine dose group tube voltage was 100 kv. The filter back projection reconstruction algorithm place （FBP） was used to make the image reconstruction. The low dose group of tube voltage was 80 kv,60% ASiR -v iterative recon- struction was used to make the image reconstruction. Automatic tube current modulation technique was applied to each patient （ 10 ~ 500）mA. To compare the differences of the image noise, the subjective image quality and radiation dose between the two groups. Results Age, height, weight and body mass index was not statistically different between the two groups （P 〉 0.05 ）, there was no statisti- cally significant difference on image noise of aorta in two groups （P 〉 0.05 ）. Compared with conventional dose group, the low dose group of image noise on back muscles slightly reduced, there was statistically difference between the two group （ P 〈 0.05 ）. Subjective image quality score had no difference between the two group（ P 〉 0.05 ）. The ED in low dose group （ 2.84±0.39 ） mSv was lower than the conventional dose group （0.77±0. 16）mSv. Compared with the conventional dose group, the ED of low dose group was decreased by 72.89%. Conclusion ASiR - V iterative reconstruction techniques can reduce the chest CT image noise and the radiation dose of pa- tients in physical examination. In the chest CT examination, patients with ASiR - V iterative reconstruction technique can guaranteeing the image quality and achieve sub milli volts check.