窗宽和层厚在COVID-19磨玻璃征象中的诊断价值

Diagnostic value of window width and slice thickness in ground glass opacity of COVID-19

目的:探讨并筛选适合观察新型冠状病毒肺炎(COVID-19)中磨玻璃影及各征象的最佳窗宽及层厚设置方案。方法:回顾性分析11例COVID-19患者的影像资料,分别选取30个磨玻璃影、铺路石征、血管影增粗及空气支气管征的COVID-19病灶进行分析对照,两名具有15年以上诊断经验的胸部影像医生对固定窗位下不同窗宽及层厚下的磨玻璃影及其他各征象的显示程度进行主观评分,得出图像质量评分。结果:对磨玻璃影显示为3分的占比最大的窗宽值为1000 HU(76.7%),对铺路石征显示为3分的占比最大的窗宽值为1400 HU(80.0%),对血管影增粗显示为3分的占比最大的窗宽值为1400 HU(83.3%),对空气支气管征显示为3分的占比最大的窗宽值为1000 HU(83.3%),以上结果与其他窗宽组的显示结果比较均具有显著统计学意义(P<0.001)。对磨玻璃影、铺路石征、血管影增粗及空气支气管征显示为3分的占比最多的层厚均为1mm(100%);与其他层厚组比较,差异均具有显著统计学意义(P<0.001)。结论:在COVID-19的影像诊断过程中,1000 HU是观察磨玻璃影及空气支气管征的最佳窗宽值,1400 HU是观察铺路石征及血管影增粗的最佳窗宽值;1 mm是观察磨玻璃影及各征象的最佳层厚值。

Objective To explore and select the best setting scheme of window width and slice thickness which is suitable for observing the ground glass opacity and various signs of corona virus disease 2019(COVID-19).Methods The imaging data of11 patients with COVID-19 were analyzed retrospectively;and 30 COVID-19 lesions with ground glass opacity,paving stone sign,vascular thickening and air bronchogram sign were selected for analysis and comparison.The display degrees of ground glass opacity and the other signs under different window widths and slice thicknesses at the fixed window level were subjectively scored by two chest imaging doctors with more than 15 years of diagnostic experience for obtaining the image quality score.Results The window widths with the highest percentage for the ground glass opacity with a score of 3,the paving stone sign with a score of3,vascular thickening with a score of 3 and air bronchogram sign with a score of 3 were 1000 HU(76.7%),1400 HU(80.0%),1400 HU(83.3%)and 1000 HU(83.3%),respectively,and there were statistical differences between the above results and those in other groups(P<0.001).For the signs(ground glass opacity,paving stone sign and vascular thickening and air bronchogram sign)with the highest score,the slice thickness with the highest proportion was 1 mm(100%),and the results were significantly different from those in other groups(P<0.001).Conclusion During the imaging diagnosis of COVID-19,the best window width for observing ground glass opacity and air bronchogram sign is 1000 HU,and that for observing paving stone sign and vascular thickening is 1400 HU.Moreover,1 mm is the best slice thickness for observing ground glass opacity and various signs.