摘要INTRODUCTION:The radiological phenotype represents the radiological characteristics of coronavirus disease 2019(COVID-19)pneumonia.Radiological outcomes initially interpreted as post-COVID-19 lung fibrosis have been detected in short-term follow-up of recovered COVID-19 cases,but long-term radiological evaluation suggests that these abnormalities should be defined as post-COVID-19 sequelae.The present study aimed to evaluate the radiological phenotypes of post-COVID-19 residual radiological lung abnormalities(RLAs)in recovered COVID-19 cases.METHODS:This prospective,observational study included 3000 patients with polymerase chain reaction-confirmed COVID-19,with documented lung involvement and radiological severity categorized as mild,moderate,or severe by high-resolution computed tomography(HRCT)at admission.Final radiological outcomes were based on radiological assessments at 6 months and 1 year after hospital discharge.Final radiological phenotypes were defined as RLAs and categorized as resolving,persistent,or progressive,based on HRCT imaging at 1 year of follow-up.A total of 622 cases with RLAs were finally included.The final outcome phenotypes were evaluated in relation to age,sex,comorbidities,laboratory parameters,and interventions,including oxygen and ventilator-support requirements during hospitalization.The data were analyzed using Chi-square tests.RESULTS:RLAs were documented in 622 of the 3000 COVID-19 pneumonia cases(20.73％).The final radiological outcomes were defined as resolving in 77.17％(480/622),persistent in 15.43％(96/622),and progressive in 7.39％(46/622).Radiological outcome phenotypes and RLAs were significantly associated with the duration of illness at admission(P＜0.00001),laboratory parameters(D-dimer,C-reactive protein,and interleukin-6)at admission(P＜0.00001),radiological severity on computed tomography(P＜0.00001),and inpatient interventions(P＜0.00001).Radiological outcome phenotypes and RLAs were also significantly associated with age,sex,diabetes mellitus,ischemic heart disease,hypertension,chronic obstructive pulmonary disease,obesity,and lung functions assessed by spirometry at 1-year follow-up(P＜0.00001).CONCLUSIONS:Radiological outcome phenotypes have a crucial role in assigning final radiological outcomes in patients with COVID-19 pneumonia and differentiating between post-COVID-19 lung fibrosis and post-COVID-19 lung sequelae.RLAs,categorized as resolving,persistent,and progressive,provide a novel radiological classification of post-COVID-19 lung sequelae.Final phenotypic classification may play an important role in further workups and treatment planning for RLAs;some patients with progressive phenotypes may have underlying rheumatological predispositions and many cases may have resolving phenotypes requiring no further treatment,whereas cases with persistent RLAs require further follow-up.