Karl迭代技术降低64排CT肺结核患者胸部扫描辐射剂量的临床研究

Karl Iterative Reconstruction Technique for Dose Reduction in Pulmonary Tuberculosis Patients’Chest Examination Using 64-Detector CT:A Patient Study

目的探讨Karl迭代重建技术在结核病64排螺旋CT检查中的应用价值。方法将86例肺结核患者进行胸部CT检查,随机分为两组。对照组(A组)采用标准剂量(120 kV、130 mAs)进行扫描并采用滤波反投影法(FBP)进行重建,低剂量组使用120 kV和60 mAs进行图像采集,并使用Karl技术(B组)和FBP方法(C组)进行图像重建。比较三组间的图像噪声,信噪比(SNR),对比度噪声比(CNR),图像质量主观评估,体积CT剂量指数(CTDI vol)和有效剂量(ED)。结果低剂量组的有效剂量为(2.02±0.39)mSv,较标准剂量组的(5.73±1.96)mSv减少64.74%(P<0.05)。B组与A组的CT值、SNR和主观评分无显着差异(P>0.05)。B组的SNR、CNR和主观评分均高于C组,两组差异有统计学意义(P<0.05)。结论在肺结核患者的胸部CT扫描中,采用Karl迭代重建技术可有效保证降低辐射剂量后的图像质量,优于FBP技术,具有良好的临床应用价值。

Objective To assess the value of Karl iterative reconstruction technique(IRT)for dose reduction in Pulmonary Tuberculosis patients’chest examination using 64-detector CT.Methods 86 pulmonary tuberculosis patients were randomly selected into two groups(normal-dose group and low-group)and underwent chest CT scanning with two different protocols:for normal-dose group(group A),standard dose(120 kV,130 mAs)and FBP technique were used;for lowdose group,120 kV and 60mAs were used and the imaging data were reconstructed by Karl IRT(group B)or FBP(group C).The image noise,signal-to-noise Ratio(SNR),CNR,subjective score of image quality,volume CT dose index(CTDI vol)and effective dose(ED)in the three groups were measured and compared.Results In the clinical study,the ED[(2.02±0.39)mSv]in group B and C was 64.74%lower than that[(5.73±1.96)mSv]in group A.The differences were not significant,which occurred in SNR and subjective score of image quality between group A and B(P>0.05),the image noise and CNR of group B were superior to those of group A,but the SNR,CNR and subjective score image quality of group B were higher than those of group C with statistically significant differences(P<0.05).Conclusion In pulmonary tuberculosis patients’chest CT scan,Karl IRT could maintain or improve image quality while saving 64.74%radiation dose,and is superior to FBP.