A five-year study of COVID-19 pneumonia survivors found that 35.6% still have residual lung lesions and 25.5% have abnormal diffusing capacity, with advanced imaging techniques revealing ventilation defects that conventional CT scans often miss.
- Persistent abnormalities: 35.6% of COVID-19 pneumonia survivors had residual lung lesions five years after infection, with 25.5% showing abnormal diffusing capacity.
- Advanced imaging needed: Functional imaging like xenon-129 MRI and quantitative CT detected lung disease that conventional CT alone missed in long-term follow-up.
- Stabilization after two years: While respiratory symptoms and chest CT abnormalities remained stable between years two and five, ventilation defects persisted, particularly in severe cases.
- Severity matters: Survivors of severe COVID-19 pneumonia showed significantly greater lung abnormalities compared to those with nonsevere disease and healthy controls.
- Research gap filled: This study extends long-term imaging data beyond two years, addressing a significant gap in COVID-19 recovery research.
CT and MRI scans show that survivors of COVID-19 pneumonia have persistent respiratory symptoms, abnormal diffusing capacity, and ventilation defects five years after infection, researchers in Wuhan, China, have reported.
The finding is from a comparison among 104 COVID-19 patients and 39 healthy controls who underwent advanced imaging such as quantitative CT and xenon-129 ventilation MRI and suggests that functional imaging captures long-term lung disease burden that conventional CT alone may miss, according to the group.
“These findings support combined structural and functional assessment in long-term follow-up of COVID-19 pneumonia survivors,” noted lead authors Xiaohu Han, MD, PhD, and Yiwan Guo, MD, PhD, of the Huazhong University of Science and Technology. The study was published September 22 in Radiology.
Long-term imaging data beyond two years in COVID-19 patients has remain limited, and prior studies have relied mainly on conventional CT without quantitative or functional techniques, the authors noted. The group's own two-year follow-up found residual CT abnormalities in 39% of participants associated with respiratory symptoms and impaired diffusion, and the present study extended that cohort to five years, they added.
In the study, the group recruited 83 survivors of severe COVID-19 pneumonia, 21 survivors of nonsevere COVID-19 pneumonia, and 39 healthy controls from September to December 2025. In addition to serial chest CT from the acute phase through four prior follow-ups (acute phase, six month, one year, and 2 years), participants underwent inspiratory-expiratory quantitative CT, pulmonary function testing, and hyperpolarized xenon-129 (Xe-129) ventilation MRI at five years.
After five years, residual lesions persisted in 35.6% of survivors (37 of 104), and abnormal diffusing capacity remained present in 25.5% (26 of 102). A comparison between two-year and five-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.
Representative longitudinal chest CT images and five-year parametric response mapping (PRM), pulmonary vascular CT reconstructions, and hyperpolarized xenon-129 (Xe-129) ventilation MRI scans from survivors of nonsevere and severe COVID-19 pneumonia. (A–F) Images in a 68-year-old male survivor of nonsevere COVID-19 pneumonia, (G–L) 62-year-old male survivor of severe COVID-19 pneumonia, and (M–R) 55-year-old male survivor of severe COVID-19 pneumonia. For each participant, the first three columns show coronal chest CT images from the acute phase (A, G, M), two-year follow-up (B, H, N), and five-year follow-up (C, I, O) (left to right). The fourth column (D, J, P) shows a coronal PRM image for each participant at five-year follow-up derived from paired inspiratory and expiratory CT scans, showing the spatial distribution of lung functional categories. Green indicates normal lung tissue, yellow indicates functional small airway disease, and red indicates emphysema. The second-to-last column shows volume-rendered small pulmonary vessel visualization (red) at five-year follow-up per participant (E, K, Q). The column on the far right (F, L, R) shows a hyperpolarized Xe-129 MRI ventilation defect percentage (VDP) map at five-year follow-up per participant. Dark blue represents high Xe-129 signal intensity, corresponding to well-ventilated lung regions, whereas red represents no Xe-129 signal intensity, corresponding to ventilation defects. At five-year follow-up, the 68-year-old survivor of nonsevere COVID-19 pneumonia (top row) showed near-complete radiologic resolution, no respiratory symptoms, and preserved pulmonary function. In contrast, the 62-year-old survivor of severe COVID-19 pneumonia (middle row) showed persistent fibrotic linear opacities without respiratory symptoms and mildly reduced pulmonary function. The 55-year-old survivor of severe COVID-19 pneumonia (bottom row) showed persistent scattered fibrotic linear opacities and focal emphysematous changes in both lungs, with dyspnea and impaired gas exchange function. The VDP values obtained from F, L, and R were 7.7%, 7.1%, and 6.3%, respectively. RSNA
“Five years after COVID-19 pneumonia, some survivors showed persistent respiratory symptoms, abnormal diffusion capacity, and ventilation defects, with stabilization of pulmonary function and chest CT abnormalities between two and five years,” the group wrote.
Ultimately, the findings support integrating quantitative CT and Xe-129 MRI alongside conventional imaging for long-term COVID-19 surveillance, particularly for survivors of severe disease, the group suggested.
Whether these abnormalities are specific to COVID-19 or reflect severe respiratory illness more broadly, and how the findings apply to patients infected with later SARS-CoV-2 variants, remain open questions, the authors concluded.
Read the full study here.
