Computed Tomography Scan Abnormalities in Patients with Post-Acute COVID Syndrome

Rationale: Patients recovering from COVID-19 infection can have persistent respiratory symptoms. These symptoms are part of a syndrome of prolonged recovery from of COVID-19 which has been termed 'Post-Acute Covid Syndrome (PACS).' Many patients with PACS have been found to have persistent radiographic changes. It is not known whether these radiographic changes represent developing fibrosis, a developing inflammatory process such as organizing pneumonia, or both. In this study we sought to characterize the radiographic changes seen in patients with persistent pulmonary symptoms. Methods: The medical records of patients who presented to the pulmonary clinic at the Comprehensive COVID Center were reviewed. Computed tomography (CT) scans were reviewed if obtained greater than 4 weeks after COVID diagnosis. If multiple CT scans were performed, the most recent scan was included. Radiographic abnormalities were categorized as inflammatory (ground-glass opacities or consolidation), fibrotic (traction bronchiectasis, reticulation, or honeycombing), both, or neither. Results: 33 patients were evaluated. During the acute phase of COVID infection 8 (24%) were admitted to the intensive care unit, 7 (21%) required mechanical ventilation, and 12 (36%) were admitted to the floor. 20 (61%) patients had CT that fit inclusion criteria. Of the 20 CT scans reviewed, 13 (65%) were abnormal. 10 (50%) scans demonstrated evidence of fibrosis, 11 (55%) scans demonstrated inflammatory changes, and 8 (40%) scans demonstrated both fibrosis and inflammatory changes. The average time from COVID diagnosis to recovery CT was 131 days. The average time from COVID diagnosis to scans with signs of fibrosis was 151 days, whereas the average time from COVID diagnosis to scans with inflammatory changes was 127 days. Conclusion: The etiology of persistent dyspnea in PACS is an area of active investigation, and radiographic patterns of injury may suggest underlying pathologic processes. Our study demonstrates abnormal radiographic findings, including evidence of both fibrotic and inflammatory parenchymal changes, in the majority of patients seen with PACS followed greater than 4 months after initial diagnosis. It is unknown if the ground glass opacities or consolidative changes are representative of post infectious organizing injury or fibrosis that is below the level of detection of CT resolution. Further prospective observational studies are warranted to determine if these changes are progressive, or if interventions such as steroids can expedite respiratory symptom recovery in the setting of a post-acute COVID clinic.