能谱CT单能量成像显示早期新型冠状病毒肺炎的价值  

The value of monochromatic imaging of spectral CT in early coronavirus disease 2019

作　　者：文雨婷 李万江[1] 帅桃[1] 潘雪琳[1] 彭礼清[1] 秦韵 李真林[1] WEN Yuting;LI Wanjiang;SHUAI Tao;PAN Xuelin;PENG Liqing;QIN Yun;LI Zhenlin(Department of Radiology,West China Hospital,Sichuan University,Chengdu,Sichuan 610041,P.R.China)

机构地区：[1]四川大学华西医院放射科,成都610041

出　　处：《华西医学》2020年第3期264-268,共5页West China Medical Journal

基　　金：四川省科学技术厅重点研发项目(2019YFS0522);四川大学华西医院学科卓越发展1·3·5工程项目(ZYGD18019)。

摘　　要：目的探讨能谱CT普通扫描不同单能量重建对新型冠状病毒肺炎(coronavirus disease 2019,COVID-19)早期病灶显示及图像质量的影响。方法回顾性分析2020年1月-2月11例于四川大学华西医院发热门诊就诊并确诊为COVID-19病例的胸部能谱CT影像学资料,11例病例总共发现炎性病灶34个。将能谱CT扫描的原始数据分别重建40~140 keV(间隔20 keV)的单能量图像和常规混合能量图像,每例患者共重建7组图像,并测量所有炎性病灶的CT值和标准差(standard deviation,SD),计算信噪比(signal-noise ratio,SNR)和对比噪声比(contrast-noise ratio,CNR);由2名诊断医师对图像质量进行主观评分,比较不同单能量组以及混合能量组图像质量的差异。结果 7组重建图像上,单能量组重建图像CT值和SD值随X线能量升高而逐渐降低,SNR和CNR逐渐升高,相邻两组间差异均有统计学意义(P<0.001);80~140 keV范围内单能量组图像SD值低于混合能量组,而SNR和CNR高于混合能量组,两两比较结果显示差异均有统计学意义(P<0.001);120 keV单能量图像主观评分最高,且与混合能量图像主观评分的差异有统计学意义(P<0.05)。结论能谱CT应用于COVID-19扫描时,不同单能量重建可显著降低COVID-19早期病灶的图像噪声,从而提高图像质量。结合图像的主客观评价,120 keV单能量重建图像对COVID-19早期病灶的显示最佳,对临床早期筛查具有重要的意义。Objective To explore the impact of different monochromatic reconstruction on image quality of early lesions of coronavirus disease 2019(COVID-19). Methods The chest spectral CT images of 11 patients confirmed as COVID-19 in West China Hospital of Sichuan University between January and February 2020 were retrospectively analyzed. A total of 34 inflammatory lesions were found in the 11 cases. Seven groups of images were reconstructed from the raw data for each patient, including the conventional polychromatic image and different monochromatic images of 40-140 keV(with intervals of 20 keV). CT and standard deviation(SD) values of all lesions were measured to calculate the signal-noise ratio(SNR) and contrast-noise ratio(CNR). The image quality was subjectively scored by two radiologists,and the differences in image quality among different monochromatic groups and the polychromatic group were compared. Results With the increase of X-ray energy, the CT values and SD values of reconstructed images in monochromatic groups gradually decreased, and the SNRs and CNRs gradually increased, and the differences between adjacent two groups were all statistically significant(P<0.001). In the range of 80-140 keV, the SD values of different monochromatic groups were lower than that of the polychromatic group, and the SNRs and CNRs were higher than those of the polychromatic group, and the pairwise comparison results showed statistically significant differences(P<0.001). The120 keV-reconstructed image had the highest subjective score, and the difference from that of the polychromatic image was statistically significant(P<0.05). Conclusions Different monochromatic reconstruction of spectral CT can significantly reduce the image noise in early COVID-19 lesions, and improve the image quality. Combining subjective and objective evaluation of images, the 120 keV-reconstructed monochromatic image shows the best early lesions of COVID-19 and is of great significance for early clinical screening.

关 键 词：能谱 计算机体层摄影术 新型冠状病毒肺炎 图像质量 

分 类 号：R816.4[医药卫生—放射医学] R563.1[医药卫生—临床医学]