Outcome of Pulmonary Spherical Ground-glass Opacities on Ct in Patients With Coronavirus Disease 2019 (Covid-19): A Retrospective Analysis

Abstract Background: Pulmonary spherical ground-glass opacities (GGOs) are commonly detected on initial chest CT scan in patients with coronavirus disease 2019 (COVID-19).We aimed to investigate the evolution of spherical GGOs to better understand their clinical significance.Materials and Methods:A retrospective study of 33 consecutive patients with confirmed COVID-19 and pulmonary spherical GGOs was performed from January 21, 2020, to March 6, 2020. The initial and follow-up CT images and clinical data were reviewed. The initial CT manifestations of spherical GGOs and their subsequent changes were mainly evaluated. Results:A total of 101 pulmonary spherical GGOs, including 38 with and 63 without consolidation, were found in 33 patients. Of the 101 spherical GGOs, 71 (70.3%) and 30 (29.7%) showed progression and direct absorption on follow-up CT images, respectively. GGOs with consolidation were more likely to progress than those without (84.2% vs. 61.9%, p = 0.017). The 71 progressed lesions mainly showed an increase in size and/or density and most (70.4%) of them extended toward the pleura and developed from spherical to patchy. Internal consolidation appeared and increased in 18 (25.4%) and 22 (31.0%) lesions, respectively. During absorption, all the previous progressed and directly absorbed lesions exhibited a simultaneous decrease in size and density. On each patient’s final CT, more lesions with progression had a residual mixed GGO (40.8% vs. 6.7%, p = 0.002) and fewer had pure GGO (39.4% vs. 60.0%, p = 0.016) than those with direct absorption.Conclusion: In patients with COVID-19, most pulmonary spherical ground-glass opacities would progress, especially those with consolidation, and develop into patchy, subpleural lesions.