低管电压结合迭代重建在超重患者支气管动脉CTA的应用研究

Application Study of Low Tube Voltage Combined with Iterative Reconstruction in Bronchial Artery CTA for Overweight Patients

目的探讨低管电压结合迭代重建对超重患者支气管动脉CTA成像质量及辐射剂量的影响。方法前瞻性选择2018年6月至2019年10月我院行支气管动脉CTA的62例超重患者,并随机分为A、B两组,各31例。A组采用80 kV管电压扫描,图像行正弦图确定迭代重建,强度3级;B组采用120 kV管电压扫描,图像行滤波反投影重建。扫描结束后重组图像,比较两组图像质量及辐射剂量的差异。结果两组图像主观评分、优良率及合格率均无统计学差异(P>0.05)。另外,A组动脉CT值、SNR、CNR均高于B组(P<0.05),而噪声、容积CT剂量指数、剂量长度乘积、有效辐射剂量(Effective Dose,ED)显著低于B组(P<0.05),且A组ED较B组降低57.93%。结论采用低管电压(80 kV)结合迭代重建对超重患者行支气管动脉CTA既能优化图像质量,又可大幅降低辐射剂量。

Objective To investigate the effect of low tube voltage combined with iterative reconstruction on image quality and radiation dose in bronchial artery CTA for overweight patients.Methods A total of 62 overweight patients with bronchial artery CTA in our hospital from June 2018 to October 2019 were chosen prospectively and divided into A group and B group randomly,and there were 31 cases in each group.In A group,80 kV tube voltage scanning was used,and the image was reconstructed with sinogram affirmed iterative reconstruction of strength grade 3,while the patients in B group were scanned with 120 kV tube voltage,and the images were reconstructed by filtered back projection.After scanning,the images were reconstructed and the differences of image quality and radiation dose between the two groups were compared.Results There was no significant difference in subjective score,excellent rate and qualified rate between the two groups(P>0.05).In addition,the arterial CT value,SNR and CNR in A group were higher than those in B group(P<0.05),while noise,volume CT dose index,dose length product and effective dose(ED)in A group were significantly lower than those in B group(P<0.05),and ED in A group was 57.93%lower than that in B group.Conclusion Low tube voltage(80 kV)combined with iterative reconstruction in bronchial artery CTA for overweight patients not only can optimize image quality,but also reduce radiation dose significantly.