Ping Li MD, Presenter: Nothing to Disclose

Zairen Zhang BA, Abstract Co-Author: Nothing to Disclose

Jifeng Zhang, Abstract Co-Author: Nothing to Disclose

Xudong Xia, Abstract Co-Author: Nothing to Disclose

Bailu Liu, Abstract Co-Author: Nothing to Disclose

Yanying Li, Abstract Co-Author: Nothing to Disclose

 To review the changes on the serial high-resolution CT (HRCT) findings of patients with novel swine-origin influenza A (H1N1) virus (S-OIV) infection.

 HRCT findings of 70 patients with presumed/laboratory-confirmed novel S-OIV (H1N1) infection were reviewed. All scans were categorized and compared according to the time between the date of onset of symptoms and the date on which the scan was obtained 1, 2, 3, 4, and longer than 4 weeks after onset of symptoms. The patterns, distribution and extent of abnormality of the lesions on the HRCT were evaluated at the weeks. The extent of involvement of each abnormality was assessed by summation of scores provided overall lung involvement. To assess changes that occurred over time, the CT scans in 56 patients were examined in sequence. 

The most common MDCT findings in patients with H1N1 are subsegmental patchy peribronchovascular ground-glass opacities throughout all regions of the bilateral lungs at the 1st week after the onset of symptoms.The abnormalities peaked at the 2nd week and resolved after that time, which resulted in substantial residual disease at 4 weeks or longer.The extent of abnormalities was greater in group 1 patients requiring advanced mechanical ventilation, and the scores ( 15.6±29) in group 1 patients is higher than group 2 patients (10.8±41.1) at the first week (P < 0.05, χ2 test).The findings of fibrosis were noted in the first week after onset of symptoms and increased to peak at 3rd week of illness (34.7%).The sign of air trapping was seen only in 9 patients who had received prolonged ventilation.The mean time of air trapping being noted after the onset of symptoms was 55.5±20.6 days.Comparing to the findings of initial CT, most (54 of 56 patients, 96.4%) the results of follow-up chest CT findings had improved (P < 0.01).Changes in score between the first and last thin-section CT examinations were significant (P < 0.01).

The abnormalities of ground-glass opacities and/or consolidation on initial CT scans of the patients with H1N1 tended to resolve to fibrosis, which resolved completely or substantial residual disease. Air trapping was only observed in ICU patients who received long-term mechanical ventilation and persisted.This suggests an important role for CT in the evaluation of severe S-OIV.

 MSCT play an important role in the evaluation of pneumonia in severe S-OIV.

Li, P, Zhang, Z, Zhang, J, Xia, X, Liu, B, Li, Y, Serial Evaluation of High-Resolution Computed Tomography Findings in Patients with Pneumonia in Novel Swine-origin Influenza A (H1N1) Virus Infection .  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9009152.html