title: Human infection with a novel avian-origin influenza A (H7N9) virus: serial chest radiographic and CT findings.
abstract: BACKGROUND
  Rapidly progressive pneumonia infection with H7N9 virus is a novel disease, and limited information is available concerning serial chest radiographic and computed tomography (CT) findings. The aim of this study was to evaluate the changes in serial radiologic findings in patients with H7N9 pneumonia.
  
  
  METHODS
  The two institutional ethics review boards approved this retrospective study. This study included 10 patients with H7N9 pneumonia. All patients underwent chest radiologic examinations at different time points. Serial radiologic images were systematically analyzed.
  
  
  RESULTS
  All patients showed abnormal results on initial chest radiography and CT. The initial radiographic abnormalities were unilateral (n = 9) and bilateral (n = 1), including ground-glass opacities (GGOs) (n = 5) and consolidation (n = 5). The initial CT findings consisted of unilateral (n = 6) and bilateral (n = 4), including consolidation (n = 10), GGOs (n = 10), reticular opacities (n = 2), and pleural effusion (n = 3). Follow-up radiologic findings showed rapid development of consolidation or GGOs within two weeks after illness onset. Pneumomediastinum with secondary subcutaneous emphysema and pneumothorax were noted in two patients. Follow-up high resolution computed tomography (HRCT) after two weeks showed slow improvement in both size and opacity of the lesions. On HRCT after discharge, patients had substantial residual lesions such as irregular linear opacities, reticular opacities, parenchymal bands, traction bronchiectasis, and cystic lesions.
  
  
  CONCLUSIONS
  The most common radiologic findings at presentation are multifocal or diffuse areas of consolidation and GGOs in H7N9 pneumonia. HRCT in sequence can show more changes in rapid progression of disease and a slow decrease of both size and opacity of the lesions plays an important role in the evaluation of H7N9 pneumonia.
authors.affiliation: Department of Respiratory Medicine, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu 210008, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Dai
authors.affiliation: Department of Respiratory Medicine, Jiangsu Province Hospital of Traditional Chinese Medicine, Nanjing, Jiangsu 210029, China. Email: xianmeizjs@gmail.com.
authors.forename: Xianmei
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Critical Care Medicine, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu 210008, China.
authors.forename: Danjiang
authors.initials: D
authors.lastname: Dong
authors.affiliation: Department of Respiratory Medicine, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu 210008, China.
authors.forename: Yin
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Critical Care Medicine, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu 210008, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Gu
authors.affiliation: Department of Radiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu 210008, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Zhu
authors.affiliation: Department of Infectious Diseases, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu 210008, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Wu
authors.affiliation: Department of Respiratory Medicine, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu 210008, China. Email: caihourong2013@163.com.
authors.forename: Hourong
authors.initials: H
authors.lastname: Cai
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D064766:Influenza A Virus, H7N9 Subtype / Q000502:physiology*; D007251:Influenza, Human / Q000000981:diagnostic imaging* / Q000821:virology; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed