深度学习图像重建在虚拟平扫CT尿路成像中的应用价值  

The application of deep learning image reconstruction in dual⁃energy CT virtual non⁃contrast CT urography

作　　者：钱佳乐 范婧 朱宏[1] 王落桐 孔德艳 QIAN Jiae;FAN Jing;ZHU Hong;WANG Luotong;KONG Deyan(Department of Radiology,Ruijin Hospital,Shanghai Jiao Tong University School of Medicine,Shanghai 200025,China;GE CT Imaging Research Center,Shanghai 201203,China)

机构地区：[1]上海交通大学医学院附属瑞金医院放射科,上海200025 [2]GE(中国)CT影像研究中心,上海201203

出　　处：《诊断学理论与实践》2024年第2期139-145,共7页Journal of Diagnostics Concepts & Practice

摘　　要：目的:探究深度学习图像重建(deep learning image reconstruction, DLIR)在基于能谱CT虚拟平扫(virtual non-contrast scan, VNC)的CT尿路成像(CT urography, CTU)中的图像质量和肾结石测量精度。方法:回顾性分析2022年9月至2023年4月期间于我院行腹盆平扫和CTU的90例患者的临床和影像学资料。所有患者均在常规行腹盆CT平扫后,进行能谱模式的多期CTU扫描。真实平扫采用ASIR-V 70%权重进行重建(TNC-AR70组)。基于基于实质期及排泌期数据分别获得2组VNC图像,再分别结合DLIR中档和高档权重重建得到4组VNC图像,即实质期-VNC-DLIR中档(venous phase-VNC-DLIR medium, VP-VNC-DM)组、实质期-VNC-DLIR高档(venous phaseVNC-DLIR high, VP-VNC-DH)组、排泌期-VNC-DLIR中档(delay phase-VNC-DLIR medium, DP-VNC-DM)组、排泌期-VNC-DLIR高档(delay phase-VNC-DLIR high,DP-VNC-DH)组。记录平扫、实质期及排泌期的辐射剂量。在5组图像上分别测量CT值、噪声(SD)、信噪比(signal-to-noise ratio, SNR)和对比噪声比(contrast-to-noise ratio, CNR),并进行组间比较。由2位资深放射诊断医师,用李克特五级量表法(Likert Scale)计分方法对图像质量和病灶显示度进行主观评价。此外,以TNC作为标准,采用Bland-Altman分析VNC上肾结石的CT值和体积的测量差异。结果:在客观图像质量评价上,VNC-DH组图像质量优于TNC-AR70,且5组图像间的CT值差异无统计学意义(P>0.05);DP-VNCDH组的图像噪声最低,SNR、CNR最高。在主观评价方面,DP-VNC-DH组的图像质量评分最高,而VP-VNC-DH组在病灶显示度方面表现最佳。在结石的CT值和体积测量上,4组VNC重建图像与真实平扫之间均无统计学差异(P>0.05)。结论:在CTU检查中,基于DLIR重建技术的VNC图像质量优于基于ASIR-V 70%重建的真实平扫,推荐结合使用实质期和排泌期的DLIR-H重建VNC图像代替真实平扫,以减少CTU扫描的辐射剂量。Objective To investigate the effect of dual-energy CT(DECT)virtual non-contrast(VNC)images recon-structed by deep learning image reconstruction(DLIR)on the image quality and measurements of renal calculus in CT urog-raphy(CTU).Methods The clinical and imaging data of 90 patients who underwent abdominal and pelvic non-contrast CT examination followed by a nephrographic-phase DE CTU during September 2022 to April 2023 were retrospectively ana-lyzed.The non-contrast CT images were reconstructed with ASIR-V with 70%weight(TNC-AR70).Four groups of VNC im-ages were reconstructed based on medium level and high level DLIR for venous phase and delay phase,namely venous phase-VNC-DLIR medium(VP-VNC-DM),venous phase-VNC-DLIR high(VP-VNC-DH),delay phase-VNC-DLIR medium(DP-VNC-DM),and delay phase-VNC-DLIR high(DP-VNC-DH).The radiation doses of TNC and VNC in venous phase and delay phase were recorded.The mean CT value,image noise(SD),signal-to-noise ratio(SNR)and contrast-to-noise(CNR)were recorded and compared among the five groups.Two radiologists independently assessed the overall image qua-lity and lesion visibility with 5-point Likert scale.Additionally,according to results of TNC,Bland-Altman was used to ana-lyze the measurement differences between VNC and TNC in mean CT value and mean size of renal calculus.Results In the objective assessments,the image quality of the VNC-DH group was better than that of TNC-AR70,and there was no statisti-cally significant difference in CT value among the five groups of images(P>0.05).DP-VNC-DH showed the lowest SD and the highest SNR and CNR values.In the subjective assessments,DP-VNC-DH achieved the best subject scores on image qua-lity,and VP-VNC-DH achieved the best subject scores on lesion visibility.Furthermore,Bland-Altman analysis showed that there was a strong overall agreement between VNC and TNC for renal calculus characterization(all P>0.005).Conclu-sions VNC generated by DLIR may provide high-quality image compared with the non-contrast images reconstructed with ASIR-V 70%

关 键 词：CT尿路成像 能谱CT 深度学习 虚拟平扫 肾结石 

分 类 号：R814.42[医药卫生—影像医学与核医学] R694.4[医药卫生—放射医学]