摘要OBJECTIVE:The objective of the study was to investigate magnetic resonance imaging(MRI)findings of the upper respiratory tract(URT;a main harbor site for infection)in patients with coronavirus disease 2019(COVID-19),and their association with pneumonia severity.MATERIALS AND METHODS:URT MRI of 128 patients with confirmed COVID-19 was evaluated.URT lymphoid tissue hyperplasia as an overall score of adenoid mass,tonsil enlargement,and cervical adenopathy was analyzed,along with quantitative pneumonia data on chest computed tomography(CT).RESULTS:Effusion of the posterior laryngopharyngeal wall(98％)was the most common,followed by the nasopharyngeal(80％)and the posterior oropharyngeal(70％)walls.There was also evidence of(Ⅰ)swelling of the epiglottis(99％)and vocal cord(58％),(Ⅱ)mild or no(15％),moderate(42％),and severe(37％)nasopharyngeal roof thickness,(Ⅲ)mild(50％),moderate(21％),and severe(3％)tonsil enlargement,and(Ⅳ)mild(22％),moderate(54％),and severe(20％)cervical lymph node enlargement.Ethmoid sinusitis was the most common(98％),which was followed by maxillary sinusitis(81％).Mastoiditis was present in 32％of patients.At follow-up(n=22),nasopharyngeal wall thickening was improved in four patients.Chest CT images showed pneumonia in 57％of patients.There were also more focal adenoid masses,and tonsil and cervical lymph node enlargement.Furthermore,the URT lymphoid tissue hyperplasia scores were higher in patients without pneumonia than in those with pneumonia,while the four indexes were negatively correlated with CT pneumonia quantification at the peak time(r=-0.26 to-0.49,P＜0.001).CONCLUSIONS:URT lymphoid tissue hyperplasia assessed by MRI may be a protective factor against COVID-19 pneumonia.