Influenza A (H1N1) virus-associated pneumonia: high-resolution computed tomography-pathologic correlation

Area of Science:

• Pulmonary Medicine
• Infectious Diseases
• Radiology

Background:

• Influenza A (H1N1) virus can cause severe pneumonia.
• Understanding the imaging features of fatal cases is crucial for diagnosis and management.

Purpose of the Study:

• To describe high-resolution computed tomography (HRCT) features in fatal Influenza A (H1N1) virus-associated pneumonia.
• To correlate HRCT findings with pathological findings.

Main Methods:

• Retrospective analysis of HRCT scans from six adult patients with fatal Influenza A (H1N1) pneumonia.
• Consensus review of HRCT images by two chest radiologists.
• Correlation of HRCT findings with histopathologic data reviewed by two lung pathologists.

Main Results:

• Predominant HRCT findings included airspace consolidation (6/6) and ground-glass opacities (3/6).
• Pathological features revealed diffuse alveolar damage with hyaline membrane formation (5/6), congestion, edema, hemorrhage, and bronchiolitis.
• Organizing pneumonia was observed in a patient with longer survival.

Conclusions:

• Fatal Influenza A (H1N1) pneumonia presents on CT with consolidation and/or ground-glass opacities.
• These imaging findings correlate with diffuse alveolar damage.
• Organizing pneumonia may indicate longer survival in these patients.