核酸检测阴性新型冠状病毒肺炎的CT表现特点

The CT features of COVID-19 with negative nucleic acid tests

目的:总结核酸检测阴性新型冠状病毒肺炎(COVID-2019)的CT表现特点,提高对该病早期病变的认识。方法:从3次核酸检测最终确诊为COVID-2019的217例患者中,选取之前核酸检测阴性的56例患者为研究对象,回顾性分析其胸部CT表现。结果:56例核酸检测阴性患者中,首次胸部CT有2例(3.57%)未见异常,54例(96.43%)可见异常。54例胸部CT有异常患者的病变分布特点:累及单肺叶12例(22.22%),其中病变位于左下叶6例;累及多肺叶42例(77.78%),其中37例累及3~5个肺叶。病灶形态:表现为类圆形15例(27.78%),楔形9例(16.67%),不规则形30例(55.56%)。病变密度:表现为磨玻璃影(GGO)36例(66.67%),GGO+实变13例(24.07%),以实变为主5例(9.26%)。间质性改变:小叶核心间隔增厚(铺路石征)28例(51.85%),小叶间隔增厚16例(29.63%),细支气管充气征25例(46.30%)。CT分期情况:早期26例(48.15%),进展期23例(42.59%),重症期4例(7.41%),转归期1例(1.85%)。结论:96.43%的核酸检测阴性COVID-2019患者首次胸部CT可见阳性表现,CT分期主要为早期(48.15%)和进展期(42.59%),重症少见(7.41%),对胸部CT出现阳性表现即使核酸检测阴性者需高度重视,及时复查。

Objective:To summarize the CT features of the novel coronavirus pneumonia(COVID-19)with negative nucleic acid tests,and to improve the understanding of the early lesions of the disease.Methods:From 217 patients with COVID-19 finally confirmed by 3 nucleic acid tests,56 patients who were negative in the first nucleic acid test were selected as study subjects,and their chest CT manifestations were analyzed retrospectively.Results:Among the 56 patients with negative nucleic acid test,2 cases(3.57%)showed no abnormalities on the first chest CT,and 54(96.43%)showed abnormalities.Distribution of lesions:12 cases(22.22%)involved single lobe,of which 6 cases were located in the left lower lobe;42 cases(77.78%)involved multiple lobes,of which 37 cases involved 3~5 lobes.Shape of lesions:15 cases(27.78%)were round,9 cases(16.67%)were wedge-shaped,and 30 cases(55.56%)were irregular.Lesion density:36 cases(66.67%)showed ground glass opacity(GGO),13 cases(24.07%)showed GGO+consolidation,and 5 cases(9.26%)showed consolidation.Interstitial changes:crazy paving in 28 cases(51.85%),16 cases(29.63%)with interlobular septal thickening,and 25 cases(46.30%)with air bronchogram.CT staging:26 cases(48.15%)in the early stage,23 cases(42.59%)in the advanced stage,4 cases(7.41%)in the severe stage,and 1 case(1.85%)in the absorption stage.Conclusion:96.43%of COVID-2019 patients with negative nucleic acid test showed positive manifestations for the first time on chest CT.CT staging was mainly in the early stage(48.15%)and the advanced stage(42.59%),and severe cases were rare(7.41%).We should pay more attention to the positive manifestations of chest CT even if the nucleic acid test was negative,and recheck it in time.