title: Chlamydia pneumoniae: comparison with findings of Mycoplasma pneumoniae and Streptococcus pneumoniae at thin-section CT.
abstract: OBJECTIVE
  To retrospectively compare thin-section computed tomographic (CT) findings of Chlamydia pneumoniae pneumonia with those of Streptococcus pneumoniae pneumonia and Mycoplasma pneumoniae pneumonia.
  
  
  METHODS
  Institutional review board and patient informed consent were not required. Twenty-four patients with C pneumoniae pneumonia (17 men, seven women; age range, 19-89 years) underwent thin-section CT; 41 patients with S pneumoniae pneumonia (28 men, 13 women; age range, 19-91 years) and 30 patients with M pneumoniae pneumonia (20 men, 10 women; age range, 16-67 years) were also enrolled. Thin-section CT scans of each patient were retrospectively and independently assessed by two chest radiologists for consolidation, ground-glass opacity (GGO), bronchovascular bundle thickening, nodules, pleural effusion, lymphadenopathy, reticular or linear opacity, airway dilatation, pulmonary emphysema, and bilateral lung involvement. Consensus was reached for disagreements. The frequency of each finding was compared among the three types of pneumonia by using the chi2 test.
  
  
  RESULTS
  For C pneumoniae pneumonia, CT demonstrated consolidation in 20 patients, GGO in 13, bronchovascular bundle thickening in 17, nodules in 18, pleural effusion in six, lymphadenopathy in eight, reticular or linear opacity in 15, airway dilatation in nine, pulmonary emphysema in 11, and bilateral lung involvement in 12. Bronchovascular bundle thickening (P = .022) and airway dilatation (P = .034) were significantly more frequent in patients with C pneumoniae pneumonia than in those with S pneumoniae pneumonia. Reticular or linear opacity (P = .017), airway dilatation (P = .016), and associated pulmonary emphysema (P = .003) were significantly more frequent in patients with C pneumoniae pneumonia than in those with M pneumoniae pneumonia.
  
  
  CONCLUSIONS
  C pneumoniae pneumonia demonstrates a wide spectrum of thin-section CT findings that are similar to those of S pneumoniae pneumonia and M pneumoniae pneumonia; airway dilatation and bronchovascular thickening were significantly more frequent in patients with C pneumoniae pneumonia.
authors.affiliation: Department of Radiology, Kofu Municipal Hospital, Kofu, Yamanashi prefecture, Japan. nambu-a@gray.plala.or.jp
authors.forename: Atsushi
authors.initials: A
authors.lastname: Nambu
authors.forename: Akitoshi
authors.initials: A
authors.lastname: Saito
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Araki
authors.forename: Katsura
authors.initials: K
authors.lastname: Ozawa
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Hiejima
authors.forename: Masaki
authors.initials: M
authors.lastname: Akao
authors.forename: Zennosuke
authors.initials: Z
authors.lastname: Ohki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamaguchi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016009:Chi-Square Distribution; D023521:Chlamydophila Infections / Q000000981:diagnostic imaging*; D016993:Chlamydophila pneumoniae; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011008:Pneumococcal Infections / Q000000981:diagnostic imaging*; D018410:Pneumonia, Bacterial / Q000000981:diagnostic imaging*; D011019:Pneumonia, Mycoplasma / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*