PMC10229443_01
Chest CT findings on the first admission, second admission, and at one year later. (A and D) On the first admission (day 1), chest CT showed a slight increase in lung densities in the lower lobes. (B and E) On the second admission, chest CT showed opacities in the left lung. (C and F) One year after COVID-19, the emphysematous lesions in the left lung significantly shrank (arrow). CT, computed tomography; COVID-19, coronavirus disease 2019.
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Chest CT showed a slight increase in lung density in the lower lobes in the background of severe emphysematous changes (Fig. 1 A and D). CT showed opacities in the left lung (Fig. 1 B and E). Chest CT performed 1 year after COVID-19 showed shrinkage of emphysematous lesions in the left lung compared to before COVID-19 when severe organizing pneumonia due to COVID-19 had been identified (Fig. 1 C and F).
CT densitometry analysis before and after COVID-19. (A) TLC-CT decreased after COVID-19 in the left lung. (B) The fraction of low attenuation volume below -950 HU to TLC-CT (LAV%) decreased after COVID-19 in the left lung. Both reductions lasted at least a year after recovery. HU, Hounsfield unit; TLC-CT, total lung capacity measured using computed tomography.
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Both total lung capacity measured using CT (TLC-CT) and the fraction of low attenuation volume below -950 HU to TLC-CT (LAV%) decreased after COVID-19 in the left lung (Fig. 2), and the reduction persisted for approximately 1 year after recovery.