256层iCT第4代混合迭代重建技术在胸部低剂量扫描中的应用评价
Evaluation of the application of hybrid iterative reconstruction method (iDOSE4) to low-dose chest scan with 256 slices computed tomography

目的 比较低剂量iCT、常规剂量iCT及64排常规剂量CT胸部扫描图像质量，探讨第4代混合迭代重建（iDOSE4）技术在低剂量扫描中的应用价值。方法 收集排除胸部病变的150名男性健康体检者的胸部螺旋CT扫描图像资料，分为256层iDOSE4低剂量组（iDOSE4低剂量组，n=50）、256层iDOSE4常规剂量组（iDOSE4常规剂量组，n=50）、64排常规剂量组（n=50），对CT图像质量（肺纹理、纵隔大血管轮廓、支气管形态、腋窝淋巴结）进行评分和比较分析。结果 在iDOSE4低剂量组与常规剂量组，2组间肺纹理、纵隔大血管轮廓、支气管形态等评分的差异无统计学意义（P=0.633，P=0.814，P=0.543），iDOSE4低剂量组腋窝淋巴结评分和4项总分低于常规剂量组(P=0.000，P=0.000)；在iDOSE4低剂量组与64排常规剂量组，2组间肺纹理、纵隔大血管轮廓、支气管形态评分的差异无统计学意义（P=0.466, P=0.820, P=0.377），iDOSE4低剂量组腋窝淋巴结评分和4项总分低于64排常规剂量组（P=0.000，P=0.000）；iDOSE4常规剂量组与64排常规剂量组的CT图像质量无明显差异。各组辐射剂量值（CTDIvol）从高到低依此为64排常规剂量组（13.6 mGy）、iDOSE4常规剂量组（9.7mGy）和iDOSE4低剂量组（3.4 mGy）。结论 256层iCT的iDOSE4胸部低剂量扫描技术能获取可靠的图像质量，仅腋窝淋巴结显示能力略低于常规剂量，但能够显著减少辐射剂量。
： Objective To compare the quality of chest images scanned by iCT with low radiation dose and with regular radiation dose and by CT with regular radiation dose, and explore the application value of iDOSE4 in low radiation dose scan. Methods Chest spiral CT scan images of 150 healthy males without chest disorders were enrolled and randomly assigned to the 256 slices iDOSE4 low-dose group (iDOSE4 low dose group, n=50), 256 slices iDOSE4 regular dose group (iDOSE4 regular dose group, n=50), and 64 rows regular dose group (n=50). The quality of CT images (lung markings, mediastinum artery outline, bronchial morphology, and axillary lymph nodes) was scored, compared, and analyzed. Results The differences in lung markings, mediastinum artery outline, and bronchial morphology scores between the iDOSE4 low dose group and the iDOSE4 regular dose group were not statistically significant (P=0.633, P=0.814, P=0.543). Axillary lymph nodes score and the total score in the iDOSE4 low dose group were lower as compared with the iDOSE4 regular dose group (P=0.000, P=0.000). The differences in lung markings, mediastinum artery outline, and bronchial morphology scores between the iDOSE4 low dose group and the 64 rows regular dose group were not statistically significant (P=0.466, P=0.820, P=0.377). Axillary lymph nodes score and the total score in the iDOSE4 low dose group were lower as compared with the 64 rows regular dose group (P=0.000, P=0.000). There was no significant difference in the quality of CT images between the iDOSE4 regular dose group and the 64 rows regular dose group. The 64 rows regular dose group had the highest radiation dose (13.6 mGy), followed by the iDOSE4 regular dose group (9.7mGy) and the iDOSE4 low dose group (3.4 mGy). Conclusion The 256 slices low-dose chest CT scan with iDOSE4 method can obtain images with reliable quality and can significantly reduce the radiation dose