双层探测器光谱CT胸部虚拟平扫与常规CT平扫影像质量比较分析  

Image quality of dual-layer spectral chest CT:virtual non-contrast in comparison to true non-contrast images

作　　者：穆荣华 李鑫 黄光仪 杨旭日 邓梅梅 朱西琪 MU Ronghua;LI Xin;HUANG Guangyi;YANG Xuri;DENG Meimei;ZHU Xiqi(Department of Radiology,Nanxishan Hospital of Guangxi Zhuang Autonomous Region,Guilin 541004,China)

机构地区：[1]广西壮族自治区南溪山医院放射科,桂林541002

出　　处：《国际医学放射学杂志》2023年第4期383-389,共7页International Journal of Medical Radiology

基　　金：广西壮族自治区卫生健康委员会自筹经费科研课题(Z20201422)。

摘　　要：目的探讨双层探测器光谱CT(DLCT)虚拟平扫(VNC)在肺鳞癌与腺癌中的应用价值。方法回顾性收集经手术病理证实为肺鳞癌或腺癌病人98例,男46例,女52例,平均年龄(55.4±7.7)岁。所有病人均于术前1周行胸部DLCT平扫及增强扫描检查,分别获得CT真实平扫(TNC)、动脉期VNC(VNCA)及静脉期VNC(VNCV)影像。2名放射诊断医师分别在3种影像上测量病灶、肺动脉干、胸主动脉、左心房、竖脊肌、胸壁皮下脂肪的CT值及SD值,并计算相应影像的对比噪声比(CNR)。对3种影像的影像质量采用5分法进行主观评价。分别记录平扫及增强扫描的辐射剂量。采用单因素方差分析对3种影像的客观评价指标进行比较,以TNC影像是的CT值为因变量,通过简单线性回归分析对双期VNC影像的CT值进行校正,然后绘制Bland-Altmanplot散点图进行一致性分析。采用FriedmanH检验比较3种影像的影像质量的主观评分。采用Kappa检验分析2名医师对3种影像主观评分的一致性。结果VNCA及VNCV影像上病灶、肺动脉干、胸主动脉、左心房、竖脊肌及胸壁皮下脂肪的CT值均高于TNC影像(均P<0.05),VNCA影像上肺动脉干、胸主动脉、左心房的CT值均高于VNCV影像(均P<0.05),VNCA影像上胸壁皮下脂肪的背景噪声高于TNC影像(P<0.05);经线性回归校正后,动脉期肺动脉干、胸主动脉、左心房、竖脊肌以及静脉期病灶、胸主动脉、左心房、竖脊肌、胸壁皮下脂肪VNC与TNC影像中CT值的差值在一致性界限外的数据点比例均≤5%,在上述各组织中2种影像方法具有良好的一致性。2名医师对3种影像的主观评分差异无统计学意义(P>0.05)。VNC较TNC影像的总辐射剂量减少4.73mSv,降低约33.4%。结论DLCT的VNC技术在肺部具有较好的碘抑制能力,VNC影像可替代TNC影像进行肺癌诊断。Objective To explore the diagnostic value of dual-layer detector spectral CT(DLCT)virtual non-contrast(VNC)in lung squamous cell carcinoma and adenocarcinoma.Methods We conducted a retrospective analysis of 98 patients(46 males,average age 55.4±7.7 years)who underwent DLCT imaging of the lungs,including unenhanced and enhanced scans,one week prior to surgery.The imaging protocol resulted in three types of images:true non-contrast(TNC),arterial phase VNC(VNCA),and intravenous VNC(VNCV).Two radiologists recorded CT and standard deviation(SD)values of lesions,as well as those of the pulmonary trunk,thoracic aorta,left atrium,erector spinae muscles,and subcutaneous fat in all three image types.Contrast-noise ratio(CNR)was calculated for various images,and image quality was subjectively evaluated using a five-point scale.The radiation dose during the plain and enhanced scan periods was recorded separately.One-way analysis of variance was used to compare the objective evaluation indices of each tissue among the three image types,with the CT values of TNC images serving as the dependent variable.Simple linear regression analysis was performed to correct the CT values of dual-stage VNC images,and a Bland-Altman scatter diagram was used to assess consistency.The Friedman H test was employed to compare subjective ratings of image quality among the three image types.The Kappa test was used to analyze the consistency between the subjective image ratings of the two radiologists.Results Our results showed that the CT values of lesions,pulmonary artery,thoracic aorta,left atrium,erector spinae muscles,and subcutaneous fat on VNCA and VNCV images were significantly higher compared to those on TNC images(all P<0.05).On VNCA images,the CT values of pulmonary artery,thoracic aorta,and left atrium were higher than those on VNCV images(all P<0.05).The noise of subcutaneous fat on VNCA image was more prominent than that of TNC image(P<0.05).However,after linear regression correction,the proportion of data points outside the limits of

关 键 词：双层探测器光谱CT 肺癌 虚拟平扫 影像质量 辐射剂量 

分 类 号：R814.4[医药卫生—影像医学与核医学]