title: Chest CT features of community-acquired respiratory viral infections in adult inpatients with lower respiratory tract infections.
abstract: OBJECTIVE
  The appearance of respiratory virus infection on thoracic computed tomography (CT) has been described only to a limited extent in the current literature, and viral pneumonias may be under-recognized by radiologists. Our objective was to describe thoracic CT findings in a broad range of adult inpatients with respiratory virus infections.
  
  
  METHODS
  A retrospective analysis of chest CTs was performed on symptomatic adult inpatients presenting with positive nucleic acid-based assays for 1 of 4 common community-acquired respiratory viruses. Forty-two patients with viral respiratory tract infections who underwent chest CT imaging were evaluated. The reviewer was blinded to virus type and patient information. CT findings were compared with CT reports produced at the time of the original study and correlated with clinical outcome measures.
  
  
  RESULTS
  Influenza (n=21), adenovirus (n=9), respiratory syncytial virus (n=8), and parainfluenza (n=4) were represented among the cohort. Three patterns of the disease were seen with viral infection: (1) limited infection with normal imaging (21%), (2) bronchitis/bronchiolitis characterized by bronchial wall thickening and tree-in bud opacities (31%), and (3) pneumonia characterized by multifocal consolidation or ground-glass opacities (36%). Viral infection was suggested in only 4/42 (10%) of the original radiology reports, all of which had evidence of bronchitis/bronchiolitis on chest CT. Viral pneumonia, characterized by multifocal ground-glass opacities or multifocal consolidations, was interpreted as aspiration pneumonia or bacterial pneumonia in 15/16 (94%) of the original CT reports.
  
  
  CONCLUSIONS
  CT scans of the inpatients with community-acquired viral infections most commonly show 1 of 2 patterns: consolidation and ground-glass opacities or bronchial wall thickening and tree-in-bud opacities. It is important that physicians interpreting CTs with multifocal consolidations and/or multifocal ground-glass opacities consider viral pneumonia when these findings are observed and recommend appropriate diagnostic testing when clinically warranted.
authors.affiliation: Division of Infectious Diseases, Hospital of the University of Pennsylvania, Silverstein Pavilion, 3rd Floor, Suite D, 3400 Spruce Street, Philadelphia, PA 19104, USA. shileyk@uphs.upenn.edu
authors.forename: Kevin T
authors.initials: KT
authors.lastname: Shiley
authors.forename: Vivianna M
authors.initials: VM
authors.lastname: Van Deerlin
authors.forename: Wallace T
authors.initials: WT
authors.lastname: Miller
mesh_terms: D000258:Adenovirus Infections, Human / Q000000981:diagnostic imaging / Q000821:virology; D001988:Bronchiolitis / Q000000981:diagnostic imaging / Q000821:virology; D001991:Bronchitis / Q000000981:diagnostic imaging / Q000821:virology; D015331:Cohort Studies; D017714:Community-Acquired Infections / Q000150:complications / Q000000981:diagnostic imaging / Q000821:virology; D003287:Contrast Media; D005260:Female; D006801:Humans; D007251:Influenza, Human / Q000000981:diagnostic imaging / Q000821:virology; D007297:Inpatients / Q000706:statistics & numerical data; D007472:Iohexol; D007902:Length of Stay / Q000706:statistics & numerical data; D008168:Lung / Q000000981:diagnostic imaging* / Q000821:virology; D008297:Male; D008875:Middle Aged; D018184:Paramyxoviridae Infections / Q000000981:diagnostic imaging / Q000821:virology; D011856:Radiographic Image Enhancement / Q000379:methods; D018357:Respiratory Syncytial Virus Infections / Q000000981:diagnostic imaging / Q000821:virology; D012141:Respiratory Tract Infections / Q000150:complications / Q000000981:diagnostic imaging* / Q000821:virology; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014777:Virus Diseases / Q000150:complications / Q000000981:diagnostic imaging*
chemical_list: D003287:Contrast Media; D007472:Iohexol