Five-year Quantitative Chest CT and Hyperpolarized Xenon 129 Ventilation MRI Findings in Survivors of COVID-19 Pneumonia.

Background Whether pulmonary sequelae persist 5 years after COVID-19 pneumonia remains unknown. Purpose To evaluate 5-year pulmonary abnormalities in survivors of COVID-19 pneumonia with use of longitudinal chest CT, inspiratory-expiratory quantitative CT, pulmonary function testing, and hyperpolarized xenon 129 (129Xe) ventilation MRI and to compare findings with those in matched healthy controls. Materials and Methods This prospective longitudinal study performed a 5-year follow-up from September to December 2025, enrolling survivors of severe and nonsevere COVID-19 pneumonia along with age-, sex-, and body mass index-matched healthy controls. Survivors underwent serial chest CT during the acute phase and at 6-month, 1-year, 2-year, and 5-year follow-ups. At 5 years, participants underwent inspiratory-expiratory CT, pulmonary function testing, symptom assessment, and hyperpolarized 129Xe ventilation MRI. Quantitative CT and ventilation parameters were compared among controls and both survivor groups with use of covariate-adjusted linear regression models, and associations of these parameters with pulmonary function and symptoms were determined with adjusted regression models. Results This study included 143 participants (mean age, 62 years ± 11.0 [SD]; 74 male; 83 survivors of severe COVID-19 pneumonia, 21 survivors of nonsevere COVID-19 pneumonia, and 39 healthy controls). After 5 years, residual lesions persisted in 35.6% of survivors (37 of 104), and abnormal diffusing capacity remained present in 25.5% (26 of 102). Prespecified comparison between 2- and 5-year follow-ups showed no evidence of change in respiratory symptoms (all P ≥ .88), pulmonary function (all P ≥ .67), or conventional CT abnormalities (all P ≥ .81) among survivors. At 5 years, ventilation defect percentage as well as parametric response mapping measures of functional small airway disease and emphysema differed among controls and both survivor groups (all P ≤ .01), with greater abnormalities generally observed in survivors of severe COVID-19 pneumonia (all P ≤ .005 vs controls). Conclusion Five years after COVID-19 pneumonia, some survivors showed persistent respiratory symptoms, abnormal diffusion capacity, and ventilation defects, with stable pulmonary function and no change in CT abnormalities between 2 and 5 years. Clinical trial registration no. ChiCTR2000038609 © RSNA, 2026 Supplemental material is available for this article.