光谱CT胸部增强静脉期虚拟血管成像替代三期扫描的可行性研究  

Feasibility study of spectral CT chest enhancement venous phase virtual angiography as an alternative to three phase scanning

作　　者：栗瑞鸿 谢晓洁[1] 尹辰琳 韩丹[1] Li Ruihong;Xie Xiaojie;Yin Chenlin;Han Dan(Department of Medical Imaging,First Affiliated Hospital of Kunming Medical University,Kunming 650032,China)

机构地区：[1]昆明医科大学第一附属医院医学影像科,昆明650032

出　　处：《中华放射学杂志》2023年第8期861-869,共9页Chinese Journal of Radiology

基　　金：国家自然科学基金(81960310)。

摘　　要：目的探讨采用光谱CT胸部增强静脉期图像获得虚拟平扫、虚拟动脉期图像实现一期扫描替代三期扫描的可行性。方法回顾性分析2022年1至5月在昆明医科大学第一附属医院接受光谱CT胸部平扫及双期增强扫描的100例患者的影像资料。对所有患者的静脉期图像进行后处理,获得虚拟平扫(VNC)及40 keV虚拟单能量图像(VMI)用于模拟动脉期图像(Vart)。采用配对t检验、Wilcoxon检验、McNemar检验对比真实平扫(TNC)与VNC、常规动脉期(CIart)与Vart的图像质量和病灶检出情况。图像质量的客观评价指标包括胸主动脉、各级肺动脉、T4椎体骨松质、胸壁脂肪的CT值、背景噪声、信噪比(SNR)、对比噪声比(CNR);图像质量的主观评分采用5分制双盲法评估。病灶情况的评估包括钙化灶检出率以及肺结节的大小、密度、体积、实性成分占比和影像特征。结果除胸壁脂肪和T4椎体骨松质外,其他部位CT值在VNC与TNC图像上差异无统计学意义(P>0.05);除右上肺动脉、右下肺动脉外,其他部位背景噪声值、SNR在TNC图像与VNC图像差异均有统计学意义(P<0.05)。相较于CIart图像,Vart图像中胸壁脂肪CT值降低(P<0.05),其余部位的CT值均明显升高(P<0.05);Vart图像上所有部位的背景噪声值均小于CIart图像,SNR、CNR值均高于CIart图像(P<0.05)。TNC与VNC图像质量、CIart与Vart图像质量的主观评分差异均无统计学意义(P>0.05)。TNC为标准,VNC对钙化的总检出率为88.53%(301/340);除部分实性结节的短径外,其余肺结节的定性及定量评估指标在TNC与VNC图上差异无统计学意义(P>0.05)。结论光谱CT胸部静脉期40 keV VMI可在血管性病变诊断方面模拟动脉期图像,静脉期VNC基本达到常规平扫标准,在一定范围内替代平扫、动脉期及静脉期三期图像具有可行性。Objective To investigate the feasibility of using spectral CT chest enhancement venous phase images to obtain virtual non-contrast(VNC)images and virtual arterial phase images to achieve one phase scan instead of three phase scans.Methods Imaging data of 100 patients who underwent spectral CT chest plain and dual-phase enhancement scans at the First Affiliated Hospital of Kunming Medical University from January to May 2022 were analyzed retrospectively.The venous phase images of all patients were post-processed to obtain virtual non contrast(VNC)and 40 keV virtual mono-energy images(VMI)for simulated arterial phase images(Vart).Image quality and lesion detection were compared between true non-contrast(TNC)and VNC images,and conventional arterial phase(CIart)and Vart images by paired t-test,Wilcoxon test and McNemar test.Objective evaluation indexes of image quality included thoracic aorta,all levels of pulmonary artery,T4 vertebral bone cancellous,chest wall fat CT value,background noise,signal-to-noise ratio(SNR),and contrast-to-noise ratio(CNR);the subjective score of image quality was assessed by double-blind method on a 5-point scale;the assessment of lesion detection included the detection rate of calcified foci and pulmonary nodules size,density,volume,percentage of solid components and imaging characteristics.Results Except for chest wall fat and T4 vertebral bone cancellous,the differences in CT values between VNC and TNC images were not statistically significant(P>0.05);Except for right upper pulmonary artery and right lower pulmonary artery,the differences in background noise values and SNR between TNC images and VNC images were statistically significant(P<0.05).Compared with CIart images,the CT values of chest wall fat were lower in Vart images(P<0.05),and the CT values of the remaining sites were significantly higher(P<0.05);the background noise values of all sites on Vart images were smaller than those on CIart images,and the SNR and CNR values were higher than those on CIart images(P<0.05).The diffe

关 键 词：体层摄影术 X线计算机 虚拟单能量成像 虚拟平扫 胸部 

分 类 号：R816.2[医药卫生—放射医学] R543.6[医药卫生—临床医学]