title: Human metapneumovirus infection in hematopoietic stem cell transplant recipients: high-resolution computed tomography findings.
abstract: OBJECTIVE
  To review the high-resolution computed tomography (CT) findings in hematopoietic stem cell transplant (HCT) recipients who had proven human metapneumovirus (HMPV) pneumonia.
  
  
  METHODS
  The study included 5 HCT recipients who had proven HMPV pneumonia. The patients included 4 men and 1 woman ranging in age from 23 to 58 years (mean age = 42 years). The CT scans were assessed for the presence, appearance, size, and distribution of parenchymal abnormalities.
  
  
  RESULTS
  Human metapneumovirus was isolated in all 5 patients in this series. None of these patients had any other infectious organism identified in cultures or bronchoalveolar lavage. The predominant CT findings were bilateral abnormalities in all patients, consisting primarily of a mixture of patterns, including, most commonly, ground-glass attenuation and nodular opacities. Areas of ground-glass opacification had no zonal predominance and were bilateral, asymmetric, and patchily distributed. Multiple nodules were identified in 4 (80%) of 5 patients. Nodules were multiple; less than 5 nodules were identified in 1 case, and 5 to 10 nodules were identified in 3 cases. All nodules in all cases were less than 10 mm in diameter. Areas of air-space consolidation were identified in 2 (40%) patients. All patients were available for follow-up; lesions improved in 4 patients.
  
  
  CONCLUSIONS
  The thin-section CT manifestations of HMPV pneumonia usually consist of a mixture of patterns, including, most commonly, ground-glass attenuation and nodular opacities.
authors.affiliation: Department of Radiology, Hospital de Sant Pau, Universitat Autonoma de Barcelona, Barcelona, Spain. 19429tfc@comb.es
authors.forename: Tomás
authors.initials: T
authors.lastname: Franquet
authors.forename: Sonia
authors.initials: S
authors.lastname: Rodríguez
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Martino
authors.forename: Teresa
authors.initials: T
authors.lastname: Salinas
authors.forename: Ana
authors.initials: A
authors.lastname: Giménez
authors.forename: Alberto
authors.initials: A
authors.lastname: Hidalgo
mesh_terms: D000328:Adult; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008168:Lung / Q000000981:diagnostic imaging; D008297:Male; D029121:Metapneumovirus; D008828:Microbiological Techniques; D008875:Middle Aged; D009894:Opportunistic Infections / Q000000981:diagnostic imaging*; D018184:Paramyxoviridae Infections / Q000000981:diagnostic imaging*; D011024:Pneumonia, Viral / Q000000981:diagnostic imaging*; D011237:Predictive Value of Tests; D011658:Pulmonary Fibrosis / Q000000981:diagnostic imaging; D012680:Sensitivity and Specificity; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging; D036542:Tomography, Spiral Computed