摘要
背景肝癌经导管动脉化疗栓塞(TACE)术后常规CT检查中碘油易产生较重的线束硬化伪影,双源CT虚拟新单能量重建技术可以减小碘油线束硬化伪影,对正确评价肝癌TACE术后疗效具有重要的临床意义。目的探讨双源CT新虚拟单能量重建技术在肝癌TACE术后的临床应用价值,探讨该技术在降低碘油沉积灶伪影方面的效果。方法回顾性分析2015年9月-2017年10月在咸宁市中心医院TACE术后完成双源双能量CT扫描的31例肝癌患者的临床资料。对肝癌TACE术后患者进行双源CT双能量扫描,并以10 keV为间隔重组16组(40、50、60、70、80、90、100、110、120、130、140、150、160、170、180、190 keV)新单能量重建图像,在线性融合图像(M=0.5)及16组新单能量重建图像上,选择碘油沉积最明显的层面,测量碘油硬化伪影区及同层面正常肝实质CT值。通过比较线性融合图像和各组新单能重建图像的客观指标伪影指数(AI)及对比噪声比(CNR),从图像硬化伪影、图像噪声及碘油形态显示情况三个方面进行观察,并对整体图像质量进行综合主观评分,获得单能量去碘油硬化伪影最佳的图像keV。结果碘油硬化伪影:在虚拟单能量图像中碘油硬化伪影随能级升高呈降低趋势。图像噪声:随着能级的升高,图像噪声在40~80 keV图像上逐渐下降,随后呈缓慢上升趋势。碘油形态显示:以60~80 keV新单能重建图像上碘油沉积灶显示较为清晰。线性融合图像与70~100 keV新单能量重建图像质量综合主观评分比较,线性融合图像与60~190 keV新单能量重建图像AI值比较,线性融合图像与120~190 keV新单能量重建图像CNR比较,差异无统计学意义(P>0.05)。70、80 keV新单能量重建图像可在保证图像CNR的同时有效减少线束硬化伪影,碘油形态显示满意,AI值与线性融合组相近,与线性融合图像的图像质量相似。结论双源CT新虚拟单能量重建技术可以减少肝癌TACE术后碘油沉积的硬化伪影,以70 keV及80 keV的虚拟单能量图像重建效果最佳,可在保证图像CNR的同时有效减少线束硬化伪影,碘油形态显示满意,AI与线性融合组相近,与线性融合的图像质量相似。
Background In the evaluation of the efficacy of transarterial chemoembolization(TACE) for hepatocellular carcinoma(HCC),conventional CT examination is prone to producing heavy beam-hardening artifacts in images due to use of iodized oil,but dual-energy CT with advanced virtual monoenergetic reconstruction technique can reduce the beamhardening artifacts,which is of great significance in accurately evaluating TACE efficacy.Objective To analyze the clinical value of advanced virtual monoenergetic reconstruction technique in dual-energy CT for evaluating TACE efficacy in HCC to explore the effect of this technique in reducing iodized oil-induced artifacts in images.Methods The clinical data of 31 patients with HCC who underwent dual-source dual-energy CT examination after TACE in Xianning Central Hospital from September 2015 to October 2017 were retrospectively analyzed.The third generation Flash dual-source CT dual-energy scan was performed.Each patient’s linear blending images(M=0.5) and 16 groups of monoenergetic images reconstructed in 10-keV intervals(40,50,60,70,80,90,100,110,120,130,140,150,160,170,180,and 190 keV) were obtained,respectively.CT images influenced most by iodine deposition were selected in which iodized oil-induced artifacts and the normal areas were measured.The objective indices,including image artifact indices,contrast to noise ratio(CNR),the beam-hardening artifacts,image noise,contour of iodized oil deposition,and comprehensive subjective score were compared between the linear blending images and keV images.After comparative analysis,the best monoenergetic keV images with beam-hardening artifacts removed were identified.Results Iodized oil-induced beam-hardening artifacts:In virtual monoenergetic images,beam-hardening artifacts from iodized oil tended to decrease with the increase of energy levels.Image noise:With the increase of energy,the image noise in the 40-80 keV images decreased gradually,and then increased slowly.Contour of iodized oil deposition:Iodized oil deposits were clearly displayed on 60-80 keV images.There was no significant difference between linear blending images and 70-100 keV images in comprehensive subjective score(P>0.05).There was no significant difference between linear blending images and 40-50 keV images in artifact indices(P>0.05).And there was no significant difference between linear blending images and 120-190 keV images in CNR(P>0.05).Statistical analysis with comprehensive indices indicated that 70 keV and 80 keV were the optimal monoenergetic parameters for dual-energy CT scan with advanced virtual monoenergetic reconstruction technique,which could ensure that the images have appropriate CNR,with reduced beam-hardening artifacts,ideal iodine’s contour,and AI and overall quality similar to those of linear blending images.Conclusion In evaluating TACE efficacy in HCC,using advanced virtual monoenergetic reconstruction technique in dual-energy CT scan can reduce the incidence of iodized oil-induced beamhardening artifacts in images.Under the conditions of 70 keV and 80 keV,the quality of images are best,the CNR of the images can be guaranteed,beam-hardening artifacts can be reduced,iodine’s contour can be displayed well,AI and overall quality similar to those of linear blending images can be achieved.
作者
程国涛
杨涛
孔曙兵
郑义
CHENG Guotao;YANG Tao;KONG Shubing;ZHENG Yi(Department of Radiology,Xianning Central Hospital/the First Affiliated Hospital of Hubei University of Science and Technology,Xianning 437100,China)
出处
《中国全科医学》
CAS
北大核心
2019年第30期3736-3741,共6页
Chinese General Practice
基金
咸宁市中心医院湖北科技学院附属第一医院科研基金资助(2016XYA0010)
关键词
肝肿瘤
体层摄影术
螺旋计算机
双能量CT
线束硬化伪影
经导管动脉化疗栓塞
虚拟新单能量图像
Liver neoplasms
Tomography,spiral computed
Dual-energy CT
Beam-hardening artifact
Transcatheter hepatic arterial Chemoembolization
Monoenergetic plus images
