From the Guidelines
Bilateral viral pneumonia on radiological imaging typically appears as diffuse, patchy ground-glass opacities affecting both lungs, often with a peripheral and lower lobe predominance, as reported by Yoon et al. 1. These findings represent alveolar inflammation and interstitial involvement. Unlike bacterial pneumonia, viral pneumonia rarely shows lobar consolidation and usually lacks air bronchograms. In COVID-19 specifically, a "crazy paving" pattern (ground-glass opacities with superimposed interlobular septal thickening) may be visible, along with vascular enlargement within lesions, as demonstrated by Shi et al. 1. CT scans are more sensitive than chest X-rays for detecting early or subtle viral pneumonia changes, with a sensitivity of 98% compared to 71% for RT-qPCR, as shown by a recent study 1. The radiological pattern often evolves over time, with initial ground-glass opacities potentially progressing to consolidations in more severe cases. Some key radiological findings of bilateral viral pneumonia include:
- Bilateral, patchy ground-glass opacities
- Peripheral and lower lobe predominance
- "Crazy paving" pattern
- Vascular enlargement within lesions
- Linear opacities and interlobular thickening
- Pleural effusion may be present in some cases, but is not a typical finding, as reported by Yoon et al. 1 and another study 1. While these findings suggest viral etiology, they are not pathognomonic, and clinical correlation with symptoms, laboratory tests, and PCR testing is necessary for definitive diagnosis, as emphasized by De Simone et al. 1. Radiological improvement typically lags behind clinical recovery, with some changes potentially persisting for weeks to months after the acute infection resolves.
From the Research
Radiological Findings of Bilateral Viral Pneumonia
The radiological findings of bilateral viral pneumonia can vary depending on the virus and the severity of the disease. Some common findings include:
- Bilateral, peripheral ground-glass opacities (GGO) and consolidation 2
- Inter-/intra-lobular septal thickening 2
- Subpleural lines and traction bronchiectasis, which can indicate the presence of interstitial fibrosis 2
- Images of severe cases can be similar to those in advanced stage of nonspecific interstitial pneumonia (NSIP) and organizing pneumonia (OP) 2
CT Findings
High-resolution CT (HRCT) is the best radiological approach for the diagnosis and differential diagnosis of COVID-19, and to assess the presence of interstitial lung disease (ILD) 2. Periodical CT follow-up is recommended for patients who present interstitial manifestations.
Other Radiological Features
Other radiological features of bilateral viral pneumonia can include: