title: Follicular bronchiolitis: thin-section CT and histologic findings.
abstract: OBJECTIVE
  To evaluate the thin-section computed tomographic (CT) findings of follicular bronchiolitis and compare them with the histologic findings.
  
  
  METHODS
  Thin-section CT scans obtained in 12 patients (age range, 24-77 years; mean age, 47 years) with follicular bronchiolitis proved at open lung biopsy were reviewed by two observers. Underlying conditions included rheumatoid arthritis (n = 8), mixed collagen vascular disorders (n = 2), autoimmune disorder (n = 1), and acquired immunodeficiency syndrome (n = 1). All patients had thin-section CT scans (1.0-1.5-mm collimation, 11 patients; 3.0-mm collimation, one patient; high-spatial-frequency reconstruction algorithm) obtained at 10-mm intervals through the chest.
  
  
  RESULTS
  The main CT findings included bilateral centrilobular (n = 12) and peribronchial (n = 5) nodules. All 12 patients had nodules smaller than 3 mm in diameter; six patients also had nodules 3-12 mm in diameter. Areas of ground-glass opacity were present in nine (75%) patients. Histologically, all patients had lymphoid hyperplasia along the bronchioles; eight had peribronchiolar lymphocytic infiltration.
  
  
  CONCLUSIONS
  The cardinal CT feature of follicular bronchiolitis consists of small centrilobular nodules variably associated with peribronchial nodules and areas of ground-glass opacity.
authors.affiliation: Department of Radiology, Vancouver Hospital and Health Sciences Centre, University of British Columbia, Canada.
authors.forename: S J
authors.initials: SJ
authors.lastname: Howling
authors.forename: D M
authors.initials: DM
authors.lastname: Hansell
authors.forename: A U
authors.initials: AU
authors.lastname: Wells
authors.forename: A G
authors.initials: AG
authors.lastname: Nicholson
authors.forename: J D
authors.initials: JD
authors.lastname: Flint
authors.forename: N L
authors.initials: NL
authors.lastname: Müller
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000000981:diagnostic imaging / Q000473:pathology; D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging / Q000473:pathology; D001327:Autoimmune Diseases / Q000000981:diagnostic imaging / Q000473:pathology; D001980:Bronchi / Q000473:pathology; D001988:Bronchiolitis / Q000000981:diagnostic imaging* / Q000473:pathology; D001995:Bronchography; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D008947:Mixed Connective Tissue Disease / Q000000981:diagnostic imaging / Q000473:pathology; D019310:Pseudolymphoma / Q000000981:diagnostic imaging* / Q000473:pathology; D014057:Tomography, X-Ray Computed