Radiology of viral pneumonia

Objective: to evaluate the clinical and radiological features of viral pneumonia caused by influenza A (H1N1) in 2015–2016.

Material and methods. The study involved 22 patients (13 men, 9 women, 1 patient died) with viral pneumonia caused by influenza A (H1N1). The average age of patients was 39±14 years. All patients underwent conventional X-ray examinations (radiography in two projections), multi-spiral computed tomography (CT), high-resolution CT. Seven patients underwent CT angiography. Assessment of respiratory function was performed in 20 patients (except two severe patients that were unable to undergo the test).

Results. The clinical course included rapid progression, with body temperature increase up to 39 °C or above, development of intoxication and respiratory failure. X-ray patterns were identical to the previous epidemic in 10 patients. Others showed rapid process progression leading to the formation of mixed infections (3 pts), development of respiratory distress syndrome (5 pts), complicated by pneumomediastinum and pneumothorax, pulmonary embolism accession (3 pts). Long-term retention of respiratory failure was caused by the formation of two types of lung pathology: severe constrictive bronchiolitis (in 5 patients receiving mechanical ventilation) and fibrotic changes in lung tissue resembling fibrosing alveolitis (6 patients without mechanical ventilation).

Conclusion. The use of long-term mechanical ventilation in patients with severe viral lung lesions may complicate with constrictive bronchiolitis development. The formation of fibrotic changes in the lung tissue similar to idiopathic interstitial pneumonias may be the confirmation of their suspected viral nature. Development of pneumothorax and pneumomediastinum may be due to lung tissue changes caused by viral infection. Development of pulmonary embolism in viral lungs lesions requires inclusion of CT angiography in the diagnostic algorithm of complicated influenza.

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