title: Acute parenchymal lung disease in immunocompetent patients: diagnostic accuracy of high-resolution CT.
abstract: OBJECTIVE
  The purpose of this study was to determine whether acute parenchymal lung diseases can be differentiated on the basis of the pattern and distribution of abnormalities revealed on high-resolution CT.
  
  
  METHODS
  High-resolution CT scans of 90 patients with acute parenchymal lung diseases (19 with bacterial pneumonia, 13 with mycoplasmal pneumonia, 21 with acute interstitial pneumonia, 18 with hypersensitivity pneumonitis, 10 with acute eosinophilic pneumonia, and nine with pulmonary hemorrhage) were independently assessed by two observers who had no knowledge of clinical or pathologic data. The observers recorded abnormalities, their first-choice diagnosis, and their degree of confidence in their first-choice diagnosis.
  
  
  RESULTS
  The two observers made a correct first-choice diagnosis in an average of 55 (61%) of 90 cases. Correct first-choice diagnosis was made in 50% of cases of bacterial pneumonia, 62% of mycoplasmal pneumonia, 90% of acute interstitial pneumonia, 72% of hypersensitivity pneumonitis, 30% of acute eosinophilic pneumonia, and 28% of pulmonary hemorrhage. CT findings allowed distinction between infectious and noninfectious causes in 81 (90%) of 90 cases.
  
  
  CONCLUSIONS
  High-resolution CT is helpful in the differential diagnosis of infectious from noninfectious acute parenchymal lung disease. However, high-resolution CT is of limited value in making a specific diagnosis.
authors.affiliation: Department of Radiology, Vancouver General Hospital and University of British Columbia, Canada.
authors.forename: N
authors.initials: N
authors.lastname: Tomiyama
authors.forename: N L
authors.initials: NL
authors.lastname: Müller
authors.forename: T
authors.initials: T
authors.lastname: Johkoh
authors.forename: O
authors.initials: O
authors.lastname: Honda
authors.forename: N
authors.initials: N
authors.lastname: Mihara
authors.forename: T
authors.initials: T
authors.lastname: Kozuka
authors.forename: S
authors.initials: S
authors.lastname: Hamada
authors.forename: H
authors.initials: H
authors.lastname: Nakamura
authors.forename: M
authors.initials: M
authors.lastname: Akira
authors.forename: K
authors.initials: K
authors.lastname: Ichikado
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D006470:Hemorrhage / Q000000981:diagnostic imaging; D006801:Humans; D007109:Immunity; D008168:Lung / Q000000981:diagnostic imaging; D008171:Lung Diseases / Q000000981:diagnostic imaging* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000000981:diagnostic imaging / Q000276:immunology; D014057:Tomography, X-Ray Computed