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

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.