Imaging manifestations and pathological analysis of severe pneumonia caused by human infected avian influenza (H7N9)

Objective: To investigate the imaging and pathological findings of severe pneumonia caused by human infected avian influenza (H7N9), and therefore to further understand and improve diagnostic accuracy of severe pneumonia caused by human infected avian influenza (H7N9). Methods: The relevant clinical and imaging data of 19 cases, including 10 males and 9 females, with pneumonia caused by human infected avian influenza (H7N9) was retrospectively analyzed. One of the cases had received percutaneous lung biopsy, with the clinical, imaging and pathological changes possible to be analyzed. Results: The lesions were mainly located at lower lobes and dorsal of lungs, involving multiple lobes and segments. Ground-glass opacities and/or pulmonary opacities were the more often imaging manifestations of severe pneumonia caused by human infected avian influenza (H7N9) in early and evolving phases (19/19,100%). By biopsy following percutaneous lung puncture, exudation of slurry, cellulose, RBC and neutrophils, formation of hyaline membrane, squamous metaplasia and organizing exudates were observable at the alveolar space. Some of alveoli collapsed, and some responded to show compensatory emphysema. Conclusion: The imaging features of severe pneumonia caused by human infected avian influenza (H7N9) include obvious ground-glass opacity and pulmonary consolidation, mainly at lower lobes and dorsal of lungs, with rapid changes. The cross-analysis of imaging and pathology preliminary can elucidate the pathological mechanisms of ground-glass opacities and pulmonary consolidation of severe pneumonia. Such an intensive study is beneficial to prompt clinicians to observe and evaluate the progress of the disease. In addition, it is also in favor of managing the symptoms and reducing the mortality rate