Aim: To study the dynamic changes of COVID-19 pneumonia on chest CT imaging. To demonstrate mild/moderate/severe progression or regression of COVID-19 pneumonia, as manifested by increasing/decreasing extent and density of lung opacities on chest CT imaging. Materials and methods: This is a prospective and retrospective review of patients with RT-PCR confirmed COVID-19 pneumonia presenting to our hospital for treatment or isolation between time period of 1st July 2020 to 30th June 2021. RTPCR confirmed COVID-19 patients who had undergone chest CT during the initial or active phase of illness and at least one follow-up CT with a gap of at least 3 months between the two scans were enrolled in the study. If the patient had undergone more than one CT scan during the initial illness, then the CT with highest percentage of total lung involvement (highest CT severity score) was selected. Repeat Chest CT were followed up after minimum period of 3months and more. A scoring system was used in this study to quantitatively estimate the pulmonary involvement of all these abnormalities on the basis of the area involved. Each of the 5 lung lobes was visually scored from 1 to 5. The percentage of lung involvement was calculated from AI algorithm based CT Pneumonia Analysis prototype. The data was divided into three groups: Group 1 included the participants with complete resolution of GGO or consolidations on the follow up study, Group 2 included participants with residual GGO/Consolidation in COVID19 pneumonia on follow up study, Group 3 cases includes the follow up with residual lesions in form of either interlobular septal thickening, curvilinear or linear parenchymal bands and bronchiectasis irrespective of GGO and consolidations. Results: • In this study, age of patients was ranging from 23.00 – 87.00 years with average being 58.36 among Group 1, 70.55 years among Group 2 and 65.57 years among Group 3 respectively. • On follow up, mean No. of lung lobes involved showed a significant fall of 100.0% among Group 1, 29.0% among Group 2 and 77.3% among Group 3 from initial. • Mean percentage of lung involvement was 50.80 among Group 2 which was significantly more as compared to 32.77 among Group 3 and was more as compared to 21.33 among Group 1 but the difference was not statistically significant on initial study. After follow up, mean percentage of lung involvement showed a significant fall of 100.0% among Group 1, 79.5% among Group 2 and 89.4% among Group 3 from initial. • At initial, mean CT Severity Score was 18.18 among Group 2 which was significantly more as compared to 9.90 among Group 1 and comparable to 13.42 among Group 3 and the difference was statistically significant. After follow up, mean CT Severity Score showed a significant fall of 100.0% among Group 1, 64.5% among Group 2 and 84.1% among Group 3 from initial. • 97.1% of cases from Group 1, 100% from Group 2 and 96.8% from Group 3 had Pure GGO at Initial. On follow up % of cases with Pure GGO had significant reduction in Group 1 and Group 3 and no change in Group2. • 50.0% of cases from Group 1, 54.5% from Group 2 and 61.3% from Group 3 had Linear/curvilinear parenchymal bands at baseline. During follow up there was significant reduction among Linear/curvilinear parenchymal bands in Group 1 and significant increase among Group 2 and insignificant change in Group3 from baseline. • 38.2% of cases from Group 1 had Interlobular septal thickening which was significantly less as compared to , 81.8% from Group 2 and 58.1% from Group 3 at baseline. During follow up there was significant reduction among Interlobular septal thickening in Group 1 and insignificant reduction in Group 2 and 3 from baseline. • 7.4% of cases from Group 1 & 9.7% in Group 3 had bronchiectasis which was significantly less as compared to 81.8% from Group 2 at baseline. During follow up there was insignificant reduction among bronchiectasis in Group 2 and insignificant increase among Group 1 and 3 from baseline. Conclusion: Follow up CT scan obtained with minimal interval period of 3 months of disease onset shows there is near total resolution of ground-glass densities and consolidations in more than 2/3rd of patients in RT-PCR proven COVID-19 infection. Significant residual findings after mid term follow up were seen in older patients and had more CT severity score during the acute phase. Patients with more involvement of lungs with high severity score are prone to significant residual lesions on follow up study. Mixed pattern was predominant pattern associated with persistent lung findings on follow up, thus speculated as more advanced stage of disease.