title: High-resolution CT findings of bronchiolitis obliterans syndrome after hematopoietic stem cell transplantation.
abstract: OBJECTIVE
  To describe the high-resolution computed tomography (CT) findings occurring in bronchiolitis obliterans syndrome (BOS) after hematopoietic stem cell transplantation (HSCT) and to determine the relationship between pulmonary function tests (PFTs) and air trapping detected on expiratory CT.
  
  
  METHODS
  The high-resolution CT scans of 33 patients who underwent HSCT and subsequently developed BOS were evaluated by 2 observers blinded to PFT results. Scans were ranked for degree of air trapping and scored for findings of bronchial wall thickening, bronchiectasis, and centrilobular opacities. Air-trapping rank was correlated with the degree of airflow obstruction as determined by PFTs.
  
  
  RESULTS
  The ranking of air trapping correlated significantly with 1-second forced expiratory volume (P=0.001), 1-second forced expiratory volume/forced vital capacity (P<0.001), residual volume (P<0.001), carbon monoxide diffusion capacity (P=0.023), but not forced vital capacity (P=0.14) or total lung capacity (P=0.07). Bronchial wall thickening occurred in 73.0%, predominantly in lower lobes (P=0.007), but was mild. Bronchiectasis occurred in 42.4% and centrilobular opacities in 39.4%.
  
  
  CONCLUSIONS
  In BOS developing after HSCT, air trapping is the principal finding on CT, and its severity correlates with PFTs. Bronchial wall thickening is common, but almost always mild; bronchiectasis and centrilobular opacities occur in less than half of cases and are also mild.
authors.affiliation: Department of Radiology, University of Washington, Fred Hutchinson Cancer Research Center, Seattle, Washington 98104, USA. marting@u.washington.edu
authors.forename: Martin L D
authors.initials: ML
authors.lastname: Gunn
authors.forename: J David
authors.initials: JD
authors.lastname: Godwin
authors.forename: Jeffrey P
authors.initials: JP
authors.lastname: Kanne
authors.forename: Mary E
authors.initials: ME
authors.lastname: Flowers
authors.forename: Jason W
authors.initials: JW
authors.lastname: Chien
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001987:Bronchiectasis / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D001989:Bronchiolitis Obliterans / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D002648:Child; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects*; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D013902:Radiography, Thoracic / Q000379:methods*; D012129:Respiratory Function Tests; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed / Q000379:methods*