title: Computed tomography findings of influenza A (H1N1) pneumonia in adults: pattern analysis and prognostic comparisons.
abstract: OBJECTIVE
  The aim of this study was to evaluate retrospectively the chest computed tomography findings of influenza A (H1N1) pneumonia and their relationship with clinical outcome.
  
  
  METHODS
  Chest computed tomography findings and clinical outcomes of 76 patients with influenza A (H1N1) pneumonia were assessed. Computed tomography findings were evaluated for the presence and distribution of parenchymal abnormalities, which were then classified into 3 patterns: bronchopneumonia, cryptogenic organizing pneumonia (COP), and acute interstitial pneumonia (AIP) patterns. Clinical courses were divided into 2 groups on the basis of necessitating admission to intensive care unit or mechanical ventilation therapy (group 1) or not (group 2).
  
  
  RESULTS
  Lung abnormalities consisted of ground-glass opacity (93%, 71 patients), consolidation (66%, 50 patients), small nodules (61%, 46 patients), and tree-in-bud sign (22%, 17 patients). Lesions were classified into bronchopneumonia (49%, 37 patients), COP (30%, 23 patients), AIP (18%, 14 patients), and unclassifiable (3%, 2 patients) patterns. Patients with AIP pattern had a tendency to belonging to group 1, accounting for 40% (8 of 20 patients) of group 1 course and only 11% (6 of 56 patients) of group 2 course (P = 0.004).
  
  
  CONCLUSIONS
  Computed tomography findings of influenza A (H1N1) pneumonia in adults can be classified into COP, AIP, and bronchopneumonia patterns. Patients presenting with AIP pattern have a tendency to show poor prognosis.
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Hee
authors.initials: H
authors.lastname: Kang
authors.forename: Kyung Soo
authors.initials: KS
authors.lastname: Lee
authors.forename: Yeon Joo
authors.initials: YJ
authors.lastname: Jeong
authors.forename: Ho Yun
authors.initials: HY
authors.lastname: Lee
authors.forename: Kun Il
authors.initials: KI
authors.lastname: Kim
authors.forename: Kyung Jin
authors.initials: KJ
authors.lastname: Nam
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001996:Bronchopneumonia / Q000000981:diagnostic imaging / Q000209:etiology / Q000628:therapy; D003287:Contrast Media; D003422:Critical Care / Q000379:methods; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000150:complications* / Q000628:therapy; D007479:Iopamidol / Q000031:analogs & derivatives; D008168:Lung / Q000000981:diagnostic imaging; D017563:Lung Diseases, Interstitial / Q000000981:diagnostic imaging / Q000209:etiology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D011024:Pneumonia, Viral / Q000000981:diagnostic imaging* / Q000628:therapy / Q000821:virology*; D011379:Prognosis; D011856:Radiographic Image Enhancement / Q000379:methods; D012121:Respiration, Artificial / Q000379:methods; D012189:Retrospective Studies; D036542:Tomography, Spiral Computed / Q000379:methods*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D003287:Contrast Media; C057937:iomeprol; D007479:Iopamidol