Chronic Pulmonary Manifestations of COVID-19 Infection: Imaging Evaluation

Abstract

This case presents a patient with severe COVID-19 pneumonia requiring intensive care unit admission and a prolonged hospital stay. The infection resulted in long-term morbidity, functional decline, and abnormal chest CT findings. The mechanisms for long-term lung injury after COVID-19 infection, imaging appearances, and the role of imaging in follow-up are discussed.

Dr Murphy completed radiology residency in the Mater Misericordiae University Hospital in Dublin, Ireland. He is currently undertaking a fellowship in cardiothoracic imaging and intervention at Massachusetts General Hospital, Boston, where he was awarded a Ralph Schlaeger grant for research activities.

Dr Little is a cardiothoracic radiologist at Mayo Clinic, Florida. His clinical and research interests include imaging of COVID-19 and other infections, diffuse lung disease, and lung cancer screening. He also has a longstanding interest in radiology teaching and education.

Figure 1:

A 51-year-old man with COVID-19 infection. Anteroposterior chest radiograph shows extensive pulmonary opacities bilaterally with a lower lung and peripheral predominance.

Figure 2:

A 51-year-old man with COVID-19 infection. Axial contrast-enhanced CT image obtained the week of initial presentation after intensive care unit transfer. There is dense consolidation within the dependent portions of the lungs bilaterally (dashed arrows) and multifocal ground-glass opacity within the nondependent portions of the lungs (solid arrows). These findings are suggestive of a diffuse alveolar damage pattern of lung injury.

Figure 3:

A 51-year-old man with COVID-19 infection. Axial contrast-enhanced CT image obtained 1 month after initial presentation. There is improved aeration of the dependent portions of the lungs; however, there is residual consolidation with contraction and architectural distortion (solid arrows). There is also persistent ground-glass opacity (dashed arrows) and new bronchial dilatation bilaterally. This appearance is suggestive of the organizing phase of acute lung injury. There is pneumomediastinum (round arrow) likely secondary to barotrauma from mechanical ventilation.

Figure 4:

A 51-year-old man 6 months after COVID-19 infection. Axial contrast-enhanced CT images from a series obtained at (A, B) inspiration and (C) expiration. (A) Persistent faint ground-glass opacities scattered throughout the lung parenchyma (solid arrows) have decreased in attenuation since prior imaging but remain extensive (tinted sign). Subpleural curvilinear opacities represent parenchymal bands and perilobular opacities (dashed arrows). (B) Mild anterior varicose bronchiectasis appreciated anteriorly in the right middle lobe (round arrows). Faint persistent ground-glass opacities (solid arrows). (C) Lobular and regional areas of persistent low attenuation (dashed arrows) on expiratory images consistent with air trapping, suggestive of small airway disease.

Figure 5:

A 51-year-old man 6 months after COVID-19 infection with shortness of breath. Axial CT pulmonary angiograms obtained with (A) soft-tissue and (B) lung window settings at second acute presentation to the emergency department. There are filling defects within several pulmonary artery branches (solid white arrows), consistent with acute pulmonary emboli. Multifocal patchy and linear ground-glass opacities and consolidation (solid black arrows) are new from 2 weeks prior. New bronchial wall thickening (dashed black arrows) and bilateral small pleural effusions (dashed white arrows). These findings suggest a superimposed acute process.

Figure 6:

A 51-year-old man 9 months after COVID-19 infection. Axial contrast-enhanced CT image shows mild persistent anterior varicose bronchiectasis and architectural distortion best appreciated in the right middle lobe (dashed arrows). Faint patchy ground-glass opacities and reticulation are improved from 6-month imaging and barely perceptible (round arrows). Faint linear parenchymal bands have greatly improved (solid arrow). This may reflect the patient's new baseline.

Figure 7:

A 60-year-old woman with a history of hospitalization for moderate COVID-19 pneumonia requiring supplemental oxygen but not mechanical ventilation. Axial noncontrast CT image obtained 25 months after presentation for COVID-19 pneumonia shows bilateral thin parenchymal bands (white arrows), peripheral reticulation (black arrows), patchy ground-glass attenuation and reticulation, and traction bronchiectasis with architectural distortion (dashed black arrows). The fibrotic-like findings shown here appear to represent a new baseline given the 2-year period and have a pattern suggesting fibrotic sequelae of organizing lung injury in the setting of COVID-19. In other cases, parenchymal bands, ground-glass opacities, reticulation, and bronchial dilatation improve or resolve at follow-up imaging and cannot be interpreted as irreversible fibrosis without follow-up imaging.

Figure 8:

Commonly seen chronic CT findings after COVID-19 infection.

Figure 9:

Flowchart shows the timing of imaging follow-up and the role of imaging modalities after COVID-19 infection. CTPA = CT pulmonary angiography, PE = pulmonary embolus, V/Q = ventilation-perfusion.