256层iCT胸部低剂量扫描和不同重建层厚对小于10 mm肺结节图像质量影响的研究

The Effect of 256-slice Spiral CT Low-dose Chest Scan and Different Reconstruction Thickness on the Image Quality of Pulmonary Nodules Less than 10 mm

目的:比较胸部低剂量扫描与常规剂量扫描对小于10 mm肺结节图像质量的差异及不同重建层厚对图像质量和结节检出率的影响。方法:在肺结节复查的98名患者中,随机分成两组,分别进行低剂量扫描和常规剂量扫描,低剂量扫描采用管电流80 mA,常规剂量组采用120 mA。低剂量组进行iDose迭代重建,常规剂量组进行FBP重建,比较两种方法辐射剂量、噪声及图像质量的差别。对低剂量组分别进行0.625 mm、1~5 mm层厚重建,比较不同层厚图像质量及肺结节检出率的影响。结果:低剂量组与常规剂量组比较,辐射剂量差异有统计学意义,图像噪声和图像质量差异无统计学意义。低剂量组不同重建层厚对图像质量及肺结节检出率差异有统计学意义。结论:胸部低剂量扫描在降低辐射剂量的同时,可以保证图像质量,选择合适的重建层厚,有助于肺结节诊断。

Objective:To compare the difference of image quality of pulmonary nodules less than 10mm between low-does chest scanning and routine dose scan,and the effect of different reconstruction layer thickness on image quality and nodule detection rate.Methods:A total of 98 patients who were re-examined for pulmonary nodules were randomly divided into two groups for low-dose scanning and routine dose scanning.Tube current was 80 mA for low-dose scanning and 120 mA for routine dose scanning.Dose iterative reconstruction was carried out in the low-dose group,while FBP reconstruction was carried out in the conventional dose group.The differences of injection dose,noise and image quality between the two methods were compared.In the low-dose group,the thickness of 0.625 mm,1~5 mm layers were constructed respectively,and the influences of image quality of different layers thickness and detection rate of pulmonary nodules were compared.Results:There were statistically significant differences in radiation dose between the low-dose group and the conventional dose group,but no statistically significant differences in image noise and image quality.There were statistically differences in image quality and pulmonary nodule detection rate between the low-dose group and the low-dose group.Conclusion:Low dose scan can ensure the quality and choose the right thickness,which is helpful for the diagnosis of pulmonary nodules.