Frontiers in Medicine, cilt.13, 2026 (SCI-Expanded, Scopus)
Objectives – Coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2, remains a global health concern. The computed tomography (CT) severity score is widely used as an objective measure of pulmonary involvement, while increased pulmonary artery (PA) diameter has emerged as a potential marker of disease severity. This study aimed to investigate the relationship between CT severity scores, PA diameter, and the D-dimer/CRP ratio, and to determine whether these parameters are independently associated with radiological severity. Materials and methods – This retrospective case-control study included 199 PCR-confirmed COVID-19 patients who underwent chest CT and laboratory evaluation. Sociodemographic and clinical data were obtained from hospital records. Laboratory parameters, including procalcitonin, C-reactive protein (CRP), D-dimer, and the D-dimer/CRP ratio, along with CT findings such as PA diameter, were analyzed. Patients were categorized according to CT severity score (0–25). Multivariable linear regression analysis was performed to identify independent predictors of CT severity. Results – Higher CT severity scores were significantly associated with increased levels of inflammatory and laboratory markers, including procalcitonin, CRP, D-dimer, and troponin (all p < 0.05). Procalcitonin showed a significant positive association with CT severity score. Significant differences between severity groups were also observed for age, hypertension, creatinine, hemoglobin, platelet count, D-dimer/CRP ratio, and PA diameter (all p < 0.05). A modest but significant positive correlation was found between PA diameter and CT severity score (r = 0.333, p < 0.001). In multivariable analysis, PA diameter (β = 0.194, p = 0.005), D-dimer/CRP ratio (β = −0.177, p = 0.007), age (β = 0.175, p = 0.043), and troponin (β = −0.280, p < 0.001) remained independently associated with CT severity score (R2 = 0.291). Conclusion – Higher CT severity scores are associated with increased PA diameter and lower D-dimer/CRP ratios. Integrating radiological parameters with inflammatory markers may improve early risk stratification in COVID-19 patients.