基于能谱纯化结合迭代重建算法在继发性肺结核患者低剂量CT检查中的应用

目的:探讨基于能谱纯化结合迭代重建算法在继发性肺结核患者低剂量CT检查中的应用。方法:选取2019年4月至6月武汉市肺科医院确诊的70例继发性肺结核患者作为研究对象。初检采用常规剂量组:管电压110 kV，参考管电流52 mAs，滤波反投影（FBP）重建图像；复检采用低剂量组（能谱纯化）:管电压Sn 110 kV，参考管电流73 mAs，正弦图迭代重建（SAFIRE）。比较两组图像主观评分、升主动脉CT值、图像噪声、SNR及辐射剂量差异。结果:两组图像主观评分相比无差异，满足临床诊断要求。两组升主动脉CT值无差异；低剂量组图像SNR低于常规剂量组。低剂量组ED（0.36±0.15）mSv与常规剂量组（2.35±0.73）mSv相比降低约84.7％。结论:能谱纯化结合迭代重建算法在继发性肺结核患者检查中能够显著降低患者所受辐射剂量，同时图像质量也能满足临床诊断要求。 

Application of Energy Spectrum Purification Combined with Iterative Reconstruction Algorithm in Low-dose CT Examination of Patients with Secondary Pulmonary Tuberculosis

Objective: To explore the application of energy spectrum purification combined with iterative reconstruction algorithm in low-dose CT examination of patients with secondary pulmonary tuberculosis. Methods: 70 patients with secondary pulmonary tuberculosis diagnosed in Wuhan Pulmonary Hospital from April to June 2019 were selected as the research subjects. We performed initial detection on group of conventional dose: tube voltage of 110 kV, reference tube current 52 mAs, FBP image reconstruction; then we performed reinspection on the low-dose group (spectral filtration): tube voltage Sn of 110 kV, reference tube current of 73 mAs, SAFIRE level 3 image reconstruction. Subjective image score, CT value of ascending aorta, image noise, SNR and radiation dose were compared between the two groups. Results: There was no statistically significant difference in subjective scores between the two groups, which met the requirements of clinical diagnosis. there was no significant difference in CT value between the two groups; image SNR of the low-dose group was lower than that of the conventional dose group; the ED (0.36±0.15) mSv in the low dose group was 84.7% lower than that in the conventional dose group (2.35±0.73) mSv. Conclusion: Energy spectrum purification combined with iterative reconstruction algorithm can significantly reduce the radiation dose applied in patients with secondary pulmonary tuberculosis while the image quality can meet the requirements of clinical diagnosis.