新型冠状病毒SARS-CoV-2基因检测及其影像学对照

目的研究新型冠状病毒(SARS-CoV-2)核酸基因检测及其影像学对照。方法实时荧光RT-PCR方法检测SARS-CoV-2 ORF1a/b和N基因,分析23例SARS-CoV-2核酸阳性患者临床及影像学资料。结果①无症状感染者3例,COVID-19确诊20例,潜伏期2~24天,成人轻型5例,儿童轻型1例,青年轻型1例,成年普通型13例。②23例SARS-CoV-2基因阳性患者,痰标本的病毒含量和检测效果高于鼻咽拭子标本,N基因粪便比痰和鼻咽拭子阳性持续时间长。③20例COVID-19中,30.0%(6/20)CT扫描未见异常。病毒载量与影像学无正比对应关系。④发病部位以外周带(13/14)和下叶后基底段(11/14)多见,两个或多个肺叶受累(11/14),双侧病变(11/14)。⑤14例CT异常COVID-19中,影像学主要表现为毛玻璃影(10/14)、双肺斑片状阴影(10/14)、晕征(8/14)、细网格征(5/14),以及伴发小叶间隔增厚(5/14)、支气管充气征(5/14)和小血管增粗影(5/14)。结论病毒载量与影像学无正比对应关系,SARS-CoV-2核酸检测联合CT扫描、流行病学史可以提高COVID-19的检出率,不能孤立仅仅依靠核酸PCR检查或CT检查。

Comparative observation between SARS-CoV-2 gene detection and CT imaging of patients with COVID-19

Objective To investigate the relationship between novel severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)nucleic acid detection and imaging data. Methods Real-time fluorescent RT-PCR was used to detect the SARS-CoV-2 ORF1 a/b and nucleocapsid(N)genes,and the clinical and imaging data from 23 patients with SARS-CoV-2 nucleic acid positive were analyzed. Results①There were 3 cases of asymptomatic infection,20 cases of COVID-19 confirmed with incubation period from 2 to 24 days,5 cases of adult and 1 case of children are mild type. One mild case was young,13 cases of adult general type.②Twenty-three SARS-CoV-2 gene-positive patients had higher virus content and detection effect in sputum specimens than in nasopharyngeal swab specimens,and N-gene feces had a longer duration of positive than sputum and nasopharyngeal swabs.③Among 20 cases of COVID-19,30.0%(6/20)CT scans showed no abnormalities,and 70.0%(14/20)were abnormal. There is no proportional relationship between viral load and imaging.④It is more common in the peripheral zone(13/14)and posterior basal segment(11/14)of the inferior lobe,involving two or more lung lobes(11/14),and bilateral lesions(11/14).(5)In 14 cases of CT abnormality COVID-19,the imaging findings mainly include ground glass shadow(10/14),patchy shadows of lungs(10/14),halo sign(8/14),and fine mesh sign( 5/14),accompanied by thickening of lobular septum,bronchial inflation signs,and coarse blood vessels(5/14,respectively). Conclusion There is no positive correlation between viral load and CT imaging changes. SARS-CoV-2 nucleic acid detection combined with CT scanning,epidemiological history can improve the detection rate of COVID-19.