title: Usefulness of the double-wall sign in detecting pneumothorax in patients with giant bullous emphysema.
abstract: OBJECTIVE
  We describe a new sign improving detection of pneumothorax in patients with giant bullous emphysema: air surrounding both sides of the bulla wall (the intrathoracic equivalent of the double-wall sign of pneumoperitoneum). We report the radiographic and CT appearances of the double-wall sign in seven patients with giant bullous emphysema, four of whom had pneumothorax.
  
  
  CONCLUSIONS
  Recognizing the double-wall sign of pneumothorax should aid in the triage of patients with giant bullous emphysema.
authors.affiliation: Department of Radiology, Harborview Medical Center, University of Washington, Seattle 98104, USA.
authors.forename: G M
authors.initials: GM
authors.lastname: Waitches
authors.forename: E J
authors.initials: EJ
authors.lastname: Stern
authors.forename: T J
authors.initials: TJ
authors.lastname: Dubinsky
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011030:Pneumothorax / Q000150:complications / Q000000981:diagnostic imaging*; D011656:Pulmonary Emphysema / Q000150:complications* / Q000000981:diagnostic imaging; D013902:Radiography, Thoracic; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed