title: High-resolution CT features of severe asthma and bronchiolitis obliterans.
abstract: OBJECTIVE
  To evaluate the high-resolution CT findings of severe asthma (SA) and bronchiolitis obliterans (BO) and determine whether any reliable discriminating HRCT features exist.
  
  
  METHODS
  HRCT examinations of the chest of 30 patients with SA and 14 patients with BO were analysed. Images were scored for the presence and extent of 21 CT findings.
  
  
  RESULTS
  The most consistent HRCT features in SA were bronchial wall thickening in 30 (100%), expiratory air trapping in 19 of 22 examinations with expiratory images (87%), inspiratory decreased attenuation in 18 (60%), and bronchial luminal narrowing in 12 (40%). The most consistent HRCT features in BO were expiratory air trapping in 10 of 10 examinations with expiratory images (100%), bronchial wall thickening in 13 (93%), inspiratory decreased attenuation in 11 (79%), ground glass opacity in seven (50%), and mosaic pattern of attenuation in seven (50%). Decreased attenuation was more extensive in BO than in SA on both inspiratory and expiratory images. The mosaic pattern of attenuation was present in seven (50%) BO patients but in only one (3%) SA patients (P=0.0006).
  
  
  CONCLUSIONS
  Mosaic pattern of attenuation, when present, is highly suggestive of BO, but SA and BO may be indistinguishable.
authors.affiliation: National Jewish Medical and Research Center, 1400 Jackson Street, Room A011, Denver, Colorado 80206, USA.
authors.forename: S P
authors.initials: SP
authors.lastname: Jensen
authors.forename: D A
authors.initials: DA
authors.lastname: Lynch
authors.forename: K K
authors.initials: KK
authors.lastname: Brown
authors.forename: S E
authors.initials: SE
authors.lastname: Wenzel
authors.forename: J D
authors.initials: JD
authors.lastname: Newell
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001249:Asthma / Q000000981:diagnostic imaging*; D001989:Bronchiolitis Obliterans / Q000000981:diagnostic imaging*; D002648:Child; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed / Q000379:methods*