title: Chronic pulmonary microaspiration: high-resolution computed tomographic findings in 13 patients.
abstract: OBJECTIVE
  The aim of the study was to describe the high-resolution computed tomography (CT) manifestations of chronic pulmonary microaspiration, a condition characterized by recurrent subclinical aspiration of small droplets of gastric contents or foreign particles into the lungs.
  
  
  METHODS
  We reviewed the CT findings in 13 consecutive patients with clinical (n=13) and histologic (n=1) diagnosis of chronic pulmonary microaspiration. Twelve patients presented with persistent cough, but none had a clinical history of acute aspiration. One patient was asymptomatic. All patients had volumetric CT of the chest reconstructed using thin sections (1 to 1.3 mm) at the time of diagnosis. The CT scans were interpreted by 3 chest radiologists who reached a final decision by consensus.
  
  
  RESULTS
  All 13 patients had centrilobular nodules and ground-glass opacities that involved mainly the dependent lung regions in 11 patients and had a random distribution in 2. Other common findings included branching opacities (n=10), small foci of consolidation (n=7), septal lines (n=5), and bronchiectasis (n=7). The 13 patients had at least 1 risk factor for aspiration including gastroesophageal reflux (n=9), hiatus hernia (n=6), esophageal dysfunction (n=3), oropharyngeal dysphagia (n=1), esophageal carcinoma (n=1), and use of sedatives (n=2).
  
  
  CONCLUSIONS
  The high-resolution CT manifestations of chronic pulmonary microaspiration consist mainly of centrilobular nodules and ground-glass opacities that tend to involve predominately the dependent regions. Branching opacities and small foci of consolidation are seen in the majority of cases.
authors.affiliation: *Faculty of Medicine, Department of Pulmonary Medicine, Federal University of Bahia †Department of Radiology, Delfin Clinic and Portuguese Hospital ‡Image Memorial §Clínica AMO (Assistência Multidisciplinar em Oncologia), Bahia, Brazil ∥Department of Radiology, University of British Columbia, BC, Canada.
authors.forename: Jorge L
authors.initials: JL
authors.lastname: Pereira-Silva
authors.forename: Cleonice Isabela S
authors.initials: CI
authors.lastname: Silva
authors.forename: Cesar A
authors.initials: CA
authors.lastname: Araújo Neto
authors.forename: Thamine L
authors.initials: TL
authors.lastname: Andrade
authors.forename: Nestor L
authors.initials: NL
authors.lastname: Müller
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011015:Pneumonia, Aspiration / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*