256层iCT联合iDose~4迭代重建在胸部低剂量CT中的应用价值

目的评价256层i CT联合i Dose4迭代重建技术在胸部低剂量CT扫描中的应用价值。方法将150名健康体检者随机分为常规剂量组(100m As)、低剂量50m As组和低剂量25m As组,分别采用100、50、25m As进行胸部CT扫描,100m As采用FBP重建作为常规对照组,两组低剂量扫描组均采用FBP及i Dose4对图像进行重建。比较不同毫安秒和重建算法的辐射剂量、CT图像噪声(MSD)、对比信噪比(CNR)、信噪比(SNR)以及主观图像质量。结果低剂量采用i Dose4组与常规对照组主观图像质量比较差异无统计学意义。50m As采用i Dose4重建图像的MSD、CNR及SNR与常规对照组差异有统计学意义(P0.05);25m As采用i Dose4与对照组比较差异无统计学意义。50m As组较常规对照组辐射剂量降低约53.3%,25m As相比对照组剂量降低76.4%。结论与常规剂量FBP重建相比,50和25 m As采用i Dose4重建能有效降低辐射剂量,同时不影响图像质量。

Application Value of 256-slice iCT Associated with iDose4 Iterative Reconstruction Technique in Chest Low dose CT

Objective To evaluate application value of 256-slice iCT associated with iDose4 iterative reconstruction technique in chest low dose CT. Methods 150 patients were randomly assigned into three groups: 100 mAs group as control group (n=50),50 mAs group (n=50), and 25 mAs group (n=50). Images from control group were reconstructed by FBP, and low dose groups were reconstructed by FBP and iDose4. Quantitative noise, SNR, CNR, subjectively image quality, and radiation dose were compared and analyzed statistically. Results The subjectively image quality of low dose groups have no statistical significance compared with control group. MSD, CNR and SNR in 50 mAs with iDose4 were improved compared with control group(P<0.05). MSD, CNR and SNR in 25 mAs with iDose4 have no statistical significance compared with control group. Radiation dose were respectively reduced by 53.3%and 76.4%In 50mAs and 25 mAs. Conclusion Compared with FBP, 50mAs and 25 mAs groups with iDose4 could maintain or improve image quality on chest CT while reducing radiation dose effectively.