High-resolution Computed Tomography Thorax Volumetric Assessment in Coronavirus Disease 2019 Patients and Correlation with Pulmonary Function Tests

Abstract

Introduction: Years after SARS coronavirus disease 2019 (COVID-19) recovery, residual pulmonary abnormalities may still exist. This brings on the question of whether or not COVID-19 could have comparable late consequences. Structural changes in the lungs after recovery can be better visualized using computed tomography (CT) thorax. Computed Tomography Lung Parenchymal changes during hospitalization by COVID-19 and after 4 months of follow-up to correlate with the volumetric high-resolution computed tomography thorax indices, Pulmonary function tests (PFTs) indices, SpO2, and 6 min Walking Test (6MWT). Materials and Methods: This is a Hospital based cross-sectional study, with a follow-up among 100 Patients from 2020 to 2022. Each patient’s different CT parameters and HRCT volumetric indices Normal Lung (NL), Normal Lung Percentage (NL%), Whole Lung (WL) were correlated with the PFT indices (Forced expiratory volume in 1s [FEV1], forced vital capacity [FVC], FEV1/FVC), Oxygen Saturation (SpO2) and 6-Minute Walking Test (6MWT). Results: The mean NL (L) and NL% during COVID were significantly lower than the mean values 4 months post-COVID. Architectural distortion, bronchiolar dilatation, interstitial thickening, and parenchymal bands were reduced considerably after 4 months post-COVID, compared to during COVID. PFTs results, such as PFT indices, were not significantly different after 4 months post-COVID, compared to during COVID. SpO2 (%) and 6 MWT (m) were significantly increased. During COVID and post-COVID, the values of NL (L) and NL (%) had a significant positive correlation with PFT indices, SpO2, and 6MWT (m). Conclusion: Hence, the different CT indices (NL and NL%) can be used as a surrogate for functional recovery of COVID patients since it correlates with the PFT indices (FEV1 and FEV1/FVC), SpO2, and 6MWT post-COVID.