能谱纯化技术在成人胸部双能量CT扫描中的应用

Application of Selective Photon Shield Technology in Chest Dual-energy CT Scan of Adult

目的探讨双源CT能谱纯化(SPS)技术在成人胸部双能量CT成像中的应用价值。方法收集30例成年患者初次和随访2次扫描图像数据,2次扫描均采用自动管电流调节(CARE Dose 4D)技术、双能量模式,初次扫描管电压80 kV/140 kV,随访扫描采用80 kV/Sn140kV,分别获得肺窗、纵隔窗图像。比较2次间辐射剂量指标及图像客观评价指标、图像质量主观评分的差异。结果随访组CT剂量指数(CTDIvol)、剂量长度乘积(DLP)及有效剂量(ED)均较初次组下降(P均<0.01)。2次图像间肺窗及纵隔窗各感兴趣区(ROI)图像噪声(OIN)、信噪比(SNR)及噪声比(CNR)差异均有统计学意义(P均<0.05)。2次图像间肺窗及纵隔窗图像质量评分差异有统计学意义(P均<0.05),随访图像肺窗及纵隔窗图像质量评分分别为(3.65±0.37)分和(3.05±0.18)分,均可满足诊断要求。结论在成人胸部双能量CT检查中,采用能谱纯化结合技术能在图像满足诊断要求的同时大幅度降低辐射剂量。

Objective To explore the application value of selective photon shield(SPS)technique in adult chest dual-energy CT imaging.Methods The initial and follow-up scan images of 30 adult patients were collected.Both scans were performed with CARE Dose 4D technique and dual energy mode.The initial scan tube voltage was 80 kV/140 kV,and the follow-up scan was 80 kV/Sn 140kV.The lung window and mediastinal window images were obtained respectively.The differences between the radiation dose index and the objective evaluation index of the image and the subjective score of the image quality were compared between the two scans.Results The CT dose index(CTDIvol),dose length product(DLP)and effective dose(ED)of the follow-up scan were significantly lower than the initial scan(P all<0.01).All of the ROI image noise(OIN),signal-to-noise ratio(SNR)and noise ratio(CNR)of the lung window and mediastinal window were statistically significant between the two scans(P all<0.05).Also there were significant differences in image quality scores between the two scans(P all<0.05),the image quality scores of the lung window and mediastinum in the follow-up scan were(3.65±0.37)and(3.05±0.18)respectively,which can meet the diagnostic requirements.Conclusion In the adult chest dual-energy CT examination,the selective photon shield technique can greatly reduce the radiation dose while the image meets the diagnostic requirements.