title: Chest X-ray and CT findings of early H7N9 avian influenza cases.
abstract: BACKGROUND
  The H7N9 strain of bird flu is a new type of avian flu that was identified at the end of March 2013. The disease is concerning because most patients have become severely ill.
  
  
  OBJECTIVE
  To study the X-ray and computed tomography (CT) findings of early H7N9 avian influenza cases.
  
  
  METHODS
  Chest radiography and CT were performed in six patients with H7N9 avian influenza within 1-20 days after onset. The CT examinations included conventional spiral CT and high-resolution CT. The findings on the radiography and CT images were analyzed.
  
  
  RESULTS
  Abnormal X-ray and CT findings were present in all of the patients. All of the cases had acute onset. In the early stage, the right lung was more commonly affected (particularly in the right upper and middle lobes). The lesions rapidly expanded to the entire lungs and were characterized primarily by ground-glass opacities (GGOs) combined with consolidation. Diffuse GGO was observed in all six cases (1 was symmetric, and 5 were non-symmetric). Local consolidation was found in four cases, and lobar consolidation was found in two cases. Normal lung tissue was observed between the lesions. Pleural thickening was common and was combined with pleural/pericardial effusion or mediastinal lymph node enlargement. Reticular changes, centrilobular nodules, and the tree-in-bud sign were observed in some cases, but reticular changes, bronchial wall thickening, and hyperinflation were not found.
  
  
  CONCLUSIONS
  Radiological changes associated with both acute pneumonia and acute interstitial inflammation were observed in early H7N9 avian influenza cases. Serial chest X-rays were useful for the diagnosis and severity assessment of the disease. CT may provide a more accurate assessment of the lung pathology.
authors.affiliation: Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, PR China.
authors.forename: Zhi Qian
authors.initials: ZQ
authors.lastname: Lin
authors.affiliation: Department of Radiology, Ruijin Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, PR China.
authors.forename: Xue Qin
authors.initials: XQ
authors.lastname: Xu
authors.affiliation: Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, PR China.
authors.forename: Ke Bei
authors.initials: KB
authors.lastname: Zhang
authors.affiliation: Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, PR China.
authors.forename: Zhi Guo
authors.initials: ZG
authors.lastname: Zhuang
authors.affiliation: Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, PR China.
authors.forename: Xiao Sheng
authors.initials: XS
authors.lastname: Liu
authors.affiliation: Department of Radiology, Putuo District Central Hospital, Shanghai, PR China.
authors.forename: Li Qun
authors.initials: LQ
authors.lastname: Zhao
authors.affiliation: Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, PR China.
authors.forename: Chang Yang
authors.initials: CY
authors.lastname: Lin
authors.affiliation: Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, PR China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, PR China.
authors.forename: Xiao Lan
authors.initials: XL
authors.lastname: Hua
authors.affiliation: Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, PR China.
authors.forename: Hui Lin
authors.initials: HL
authors.lastname: Zhao
authors.affiliation: Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, PR China.
authors.forename: Jia
authors.initials: J
authors.lastname: Hua
authors.affiliation: Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, PR China xujianr@hotmail.com.
authors.forename: Jian Rong
authors.initials: JR
authors.lastname: Xu
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D064766:Influenza A Virus, H7N9 Subtype; D007251:Influenza, Human / Q000000981:diagnostic imaging*; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D013902:Radiography, Thoracic / Q000379:methods*; D036542:Tomography, Spiral Computed / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: H7N9 avian influenza; X-ray; radiography; tomography