title: Diaphragmatic motion in the sitting and supine positions: Healthy subject study using a vertically open magnetic resonance system.
abstract: OBJECTIVE
  To determine the postural difference of diaphragmatic motion between the sitting and supine positions.
  
  
  METHODS
  A total of 10 healthy men were examined using a vertically open 0.5-T magnetic resonance (MR) system. A total of 40 sequential MR images were obtained in both the sitting and supine positions during two to five respiratory cycles. The diaphragmatic excursions (DEs) were measured on three diaphragmatic points of six sagittal planes for both positions. The differences in DEs between the anterior and posterior parts of the diaphragm were also determined.
  
  
  RESULTS
  DEs in the supine position were significantly greater than those in the sitting position at 15 of the 18 points. In five of the six sagittal planes, the difference of DE between posterior and anterior points was significantly larger in the supine position than in the sitting position.
  
  
  CONCLUSIONS
  Diaphragmatic movement in the supine position is greater than that in the sitting position, especially in the posterior part of the diaphragm.
authors.affiliation: Department of Radiology, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga, Japan. rtryu@belle.shiga-med.ac.jp
authors.forename: Ryutaro
authors.initials: R
authors.lastname: Takazakura
authors.forename: Masashi
authors.initials: M
authors.lastname: Takahashi
authors.forename: Norihisa
authors.initials: N
authors.lastname: Nitta
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Murata
mesh_terms: D000328:Adult; D003964:Diaphragm / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation; D008297:Male; D009068:Movement / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D012119:Respiration; D016683:Supine Position / Q000502:physiology