title: Thin-section CT findings in hematopoietic stem cell transplantation recipients with respiratory virus pneumonia.
abstract: OBJECTIVE
  The purpose of this study was to use serial thin-section CT scans to assess the incidence of respiratory viral infection and lung abnormalities in a large patient population at high risk of pulmonary complications.
  
  
  METHODS
  The study population consisted of 26 recipients of hematopoietic stem cell transplants who had proven respiratory viral pneumonia. In all cases, thin-section CT scans were obtained before fiberoptic bronchoscopy and bronchoalveolar lavage. The study included only patients in whom bronchoalveolar lavage fluid showed no evidence of organisms other than respiratory viruses. The CT scans were assessed for the presence, extent, and anatomic distribution of ground-glass attenuation, air-space consolidation, nodules, centrilobular branching structures (tree-in-bud), thickening of the bronchovascular bundles, and pleural effusion.
  
  
  RESULTS
  Areas of ground-glass attenuation were identified in 24 (92%) of 26 patients and were the only finding in eight patients. Multiple nodules, seen in 17 (65%) of 26 patients, measured 3-10 mm in diameter or were larger than 10 mm. The nodules had a centrilobular or random distribution. A tree-in-bud appearance was seen in six of the patients with centrilobular nodules. This pattern had a bilateral distribution and involved mainly the lower lung zones. CT revealed thickening of the bronchovascular bundles in 16 (61%) of the patients. Thickening was bilateral in 14 and unilateral in two patients. Bronchial wall thickening involved the lower lobes in six patients and had a patchy random distribution in the remaining nine patients. Air-space consolidation was present in nine (35%) of the cases. It had a lobular or subsegmental distribution in eight of the patients and a segmental distribution in one patient. Areas of consolidation were randomly distributed throughout the lungs in all cases. Less common findings included bilateral pleural effusion and bronchial dilatation.
  
  
  CONCLUSIONS
  Respiratory viral infection is common among adult recipients of hematopoietic stem cell transplants, occurring over a wide time span after transplantation. The presence of respiratory viral infection must be considered in any patient with new respiratory symptoms, fever, or findings at CT such as extensive or patchy areas of ground-glass opacities or a mixture of patterns, most commonly ground-glass attenuation, thickening of the bronchial walls, and multiple small nodules.
authors.affiliation: Department of Radiology, Hospital de Sant Pau, Universitat Autónoma de Barcelona, Avda Sant Antoni Ma Claret 167, 08025 Barcelona, Spain.
authors.forename: Tomas
authors.initials: T
authors.lastname: Franquet
authors.forename: Sonia
authors.initials: S
authors.lastname: Rodriguez
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Martino
authors.forename: Ana
authors.initials: A
authors.lastname: Giménez
authors.forename: Teresa
authors.initials: T
authors.lastname: Salinas
authors.forename: Alberto
authors.initials: A
authors.lastname: Hidalgo
mesh_terms: D000328:Adult; D001992:Bronchoalveolar Lavage Fluid; D001999:Bronchoscopy; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D016867:Immunocompromised Host; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011024:Pneumonia, Viral / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000276:immunology; D014057:Tomography, X-Ray Computed