title: CT examination of the pericardium and lungs in helicopter pilots exposed to vibration and noise.
abstract: BACKGROUND
  Helicopter pilots are exposed to whole body vibration and noise in their working environment. Some researchers have found that kinetic energy from both noise and vibration is believed to affect pericardial thickness and lead to pulmonary fibrosis, known as vibroacoustic disease. The aim of this project was to determine whether we could discover similar findings in a selection of helicopter pilots.
  
  
  METHODS
  A case control study where 27 helicopter pilots were compared to an age-matched control group of typical office workers was conducted. High resolution CT scanning of the thorax was used as the diagnostic method. Two medical radiologists interpreted the images independently, blinded to whether the subjects were pilots or from the control group.
  
  
  RESULTS
  There were no signs of pericardial thickening or significant lung fibrosis formations in either of the groups. The average pericardium thickness for the helicopter group was 1.38 mm, SD = 0.54 mm, and for the control group: 1.37 mm, SD = 0.33 mm. There was no significant correlation between pericardium thickness and flight hours or age.
  
  
  CONCLUSIONS
  The average pericardial thickness values for the helicopter and the age-matched control groups were almost identical. The results are within normal limits and comparable to an American study where 21 normal individuals were measured to 1.2 mm +/- 0.8 mm in an average of 26 different points by using trans-esophageal echocardiography.
  
  
  CONCLUSIONS
  On the basis of the CT scans, our findings do not support the existence of vibroacoustic disease, where pericardial thickening is the most prominent sign.
authors.affiliation: Norwegian Defense Medical Services, Institute of Aviation Medicine, Oslo, Norway. jik@flymed.no
authors.forename: Jan Ivar
authors.initials: JI
authors.lastname: Kåsin
authors.forename: Tor Ole
authors.initials: TO
authors.lastname: Kjellevand
authors.forename: John
authors.initials: J
authors.lastname: Kjekshus
authors.forename: Geir B
authors.initials: GB
authors.lastname: Nesheim
authors.forename: Anthony
authors.initials: A
authors.lastname: Wagstaff
mesh_terms: D000328:Adult; D000337:Aerospace Medicine; D016022:Case-Control Studies; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D009623:Noise, Occupational; D016273:Occupational Exposure; D010496:Pericardium / Q000000981:diagnostic imaging*; D011658:Pulmonary Fibrosis / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed; D014732:Vibration