ROLE OF CHEST HIGH RESOLUTION COMPUTED TOMOGRAPHYEVALUATING POST-COVID19 FIBROSIS CORRELATED WITH TREATMENT RESPONSE

Accurate imaging, especially high-resolution CT (HRCT), is essential for early diagnosis of diffuse or focal lung diseases, allowing detailed visualization of lung anatomy, including lobules and acini. Initially based on cadaveric studies, lung anatomy understanding has advanced with modern CT techniques. The lungs are divided into lobes and broncho-pulmonary segments, with distinct imaging windows aiding in disease detection. Pulmonary fibrosis, including idiopathic pulmonary fibrosis (IPF) and post-COVID-19 pulmonary fibrosis (PCPF), involves irreversible scarring and impaired gas exchange. COVID-19 has been linked to fibrotic damage via mechanisms involving ACE2 receptors, immune responses, macrophage activation, and epithelial–mesenchymal transition (EMT). Risk factors include age, comorbidities, severe COVID-19, mechanical ventilation, and smoking. CT features of fibrosis include ground-glass opacities, consolidation, and honeycombing. COVID-19 also causes multi-organ complications, including respiratory failure, cardiac and renal injury, and multisystem inflammatory syndrome in children (MIS-C). Imagingtools like CT severity scoring and CO-RADS support clinical evaluation and diagnosis.AIM OF THE WORK:To evaluate the role of chest HRCT in evaluating post-COVID-19 lung fibrosis in correlation with patients' response to treatment.