QUANTITATIVE CT-BASED PREDICTION OF EARLY FIBROSIS-LIKE LUNG REMODELING IN ACUTE COVID-19: INTEGRATION WITH CLINICAL...

Fibrosis-like lung remodeling is increasingly recognized as a clinically relevant consequence of coronavirus disease 2019 (COVID-19), yet factors associated with early structural remodeling during the acute phase remain incompletely characterized. We hypothesized that acute fibroinflammatory remodeling reflects an interaction between systemic inflammatory-coagulation activation and quantifiable parenchymal alterations detectable by automated CT morphometry. In this retrospective cohort study, 77 hospitalized patients with RT-PCR-confirmed COVID-19 pneumonia and fibrosis-like abnormalities on high-resolution CT were evaluated. Fibrosis severity was graded qualitatively (Grades 1-4) using a CT-adapted fibrosis scale. Automated lung segmentation and density-based analysis quantified regional fibrotic involvement and total lung volumes. Clinical characteristics and laboratory biomarkers were integrated with quantitative imaging metrics to assess associations with the severity of fibrosis-like remodeling across CT grades. Increasing fibrosis grade was associated with older age (p=0.012), elevated absolute neutrophil count (p=0.038), and higher fibrinogen levels (p=0.046), supporting an association between inflammatory-coagulation pathways and early structural remodeling. In contrast, admission oxygenation, symptom burden, comorbidity prevalence, and in-hospital mortality were not significantly associated with fibrosis severity. Among qualitative CT findings, pleural effusion was observed exclusively in higher grades (p=0.003). Quantitative morphometry demonstrated a stepwise increase in high-attenuation fibrotic lung burden (right lung: 14.3% to 35.3%, p=0.002; left lung: 15.0% to 38.8%, p=0.001), accompanied by progressive lung volume reduction (p≤0.002). These objective imaging biomarkers revealed structural differences across fibrosis grades that were not fully captured by clinical severity indices. Early fibrosis-like remodeling in acute COVID-19 was associated with older age and markers of systemic inflammatory-coagulopathic activation rather than with initial clinical severity alone. Quantitative CT morphometry provides reproducible structural biomarkers that may enhance evaluation of the severity of fibrosis-like lung remodeling and mechanistic understanding of post-viral lung remodeling. Prospective multicenter studies are required to further validate these imaging biomarkers.