title: Cryptogenic organizing pneumonia: CT findings in 43 patients.
abstract: OBJECTIVE
  Description of the CT findings of cryptogenic organizing pneumonia has been limited to a small number of cases. This study was performed to characterize the CT findings of this disease in a larger number of cases and to compare the findings in immunocompetent and immunocompromised patients.
  
  
  METHODS
  The CT scans of 43 (32 immunocompetent and 11 immunocompromised) patients who had biopsy-proved cryptogenic organizing pneumonia were reviewed. The scans were obtained by using contiguous 8- or 10-mm collimation and selected thin (1.5 or 2.0 mm) section (n = 23), thin-section collimation at 10-mm intervals (n = 12), or 8- or 10-mm collimation only (n = 8). The scans were analyzed by three observers, and final decisions were reached by consensus.
  
  
  RESULTS
  The most common pattern seen was consolidation, which was present alone or as part of a mixed pattern in 34 cases (79%). The consolidation had a predominantly subpleural and/or peribronchovascular distribution in 27 cases (63%). Ground-glass attenuation and nodules were seen in 26 patients (60%) and 13 patients (30%), respectively, and were usually random in distribution. Consolidation was present in 91% (29/32) of immunocompetent and 45% (5/11) of immunocompromised patients (p < .01). Ground-glass attenuation was present in 56% (18/32) of immunocompetent and 73% (8/11) of immunocompromised patients (p > .25). Nodules were present in seven (22%) of 32 immunocompetent patients and six (55%) of 11 immunocompromised patients (p < .025).
  
  
  CONCLUSIONS
  We conclude that in immunocompetent patients the CT findings in cryptogenic organizing pneumonia most commonly consist of bilateral areas of consolidation involving mainly the subpleural and/or peribronchovascular regions. In the immunocompromised patient, the CT findings are variable.
authors.affiliation: Department of Radiology, University of British Columbia, Vancouver, Canada.
authors.forename: K S
authors.initials: KS
authors.lastname: Lee
authors.forename: P
authors.initials: P
authors.lastname: Kullnig
authors.forename: T E
authors.initials: TE
authors.lastname: Hartman
authors.forename: N L
authors.initials: NL
authors.lastname: Müller
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001989:Bronchiolitis Obliterans / Q000150:complications / Q000000981:diagnostic imaging* / Q000276:immunology; D005260:Female; D006801:Humans; D016867:Immunocompromised Host; D008168:Lung / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000150:complications / Q000000981:diagnostic imaging* / Q000276:immunology; D014057:Tomography, X-Ray Computed