title: Difference in diaphragmatic motion during tidal breathing in a standing position between COPD patients and normal subjects: Time-resolved quantitative evaluation using dynamic chest radiography with flat panel detector system ("dynamic X-ray phrenicography").
abstract: OBJECTIVE
  To quantitatively compare diaphragmatic motion during tidal breathing in a standing position between chronic obstructive pulmonary disease (COPD) patients and normal subjects using dynamic chest radiography.
  
  
  METHODS
  Thirty-nine COPD patients (35 males; age, 71.3±8.4years) and 47 normal subjects (non-smoker healthy volunteers) (20 males; age, 54.8±9.8years) underwent sequential chest radiographs during tidal breathing using dynamic chest radiography with a flat panel detector system. We evaluated the excursions and peak motion speeds of the diaphragms. The results were analyzed using an unpaired t-test and a multiple linear regression model.
  
  
  RESULTS
  The excursions of the diaphragms in COPD patients were significantly larger than those in normal subjects (right, 14.7±5.5mm vs. 10.2±3.7mm, respectively, P<0.001; left, 17.2±4.9mm vs. 14.9±4.2mm, respectively, P=0.022). Peak motion speeds in inspiratory phase were significantly faster in COPD patients compared to normal subjects (right, 16.3±5.0mm/s vs. 11.8±4.2mm/s, respectively, P<0.001; left, 18.9±4.9mm/s vs. 16.7±4.0mm/s, respectively, P=0.022). The multivariate analysis demonstrated that having COPD and higher body mass index were independently associated with increased excursions of the bilateral diaphragm (all P<0.05), after adjusting for other clinical variables.
  
  
  CONCLUSIONS
  Time-resolved quantitative evaluation of the diaphragm using dynamic chest radiography demonstrated that the diaphragmatic motion during tidal breathing in a standing position is larger and faster in COPD patients than in normal subjects.
authors.affiliation: Department of Radiology, Center for Pulmonary Functional Imaging, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St., Boston, MA 02215, USA; Department of Diagnostic Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan. Electronic address: yamada@rad.med.keio.ac.jp.
authors.forename: Yoshitake
authors.initials: Y
authors.lastname: Yamada
authors.affiliation: Department of Health Care, Fukujuji Hospital, Japan Anti-Tuberculosis Association, 3-1-24 Matsuyama, Kiyose, Tokyo 204-8522, Japan. Electronic address: ueyamam@fukujuji.org.
authors.forename: Masako
authors.initials: M
authors.lastname: Ueyama
authors.affiliation: Department of Radiology, Fukujuji Hospital, Japan Anti-Tuberculosis Association, 3-1-24 Matsuyama, Kiyose, Tokyo 204-8522, Japan. Electronic address: takehikoabe@hotmail.com.
authors.forename: Takehiko
authors.initials: T
authors.lastname: Abe
authors.affiliation: Department of Radiology, Center for Pulmonary Functional Imaging, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St., Boston, MA 02215, USA. Electronic address: TARAKI@partners.org.
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Araki
authors.affiliation: Department of Preventive Medicine and Public Health, Biostatistics Unit at Clinical and Translational Research Center, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan. Electronic address: abe.t@keio.jp.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Abe
authors.affiliation: Department of Radiology, Center for Pulmonary Functional Imaging, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St., Boston, MA 02215, USA. Electronic address: Mizuki_Nishino11@dfci.harvard.edu.
authors.forename: Mizuki
authors.initials: M
authors.lastname: Nishino
authors.affiliation: Department of Diagnostic Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan. Electronic address: jinzaki@rad.med.keio.ac.jp.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Jinzaki
authors.affiliation: Department of Radiology, Center for Pulmonary Functional Imaging, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St., Boston, MA 02215, USA. Electronic address: hhatabu@partners.org.
authors.forename: Hiroto
authors.initials: H
authors.lastname: Hatabu
authors.affiliation: Department of Respiratory Medicine, Fukujuji Hospital, Japan Anti-Tuberculosis Association, 3-1-24 Matsuyama, Kiyose, Tokyo 204-8522, Japan. Electronic address: skudoh@jatahq.org.
authors.forename: Shoji
authors.initials: S
authors.lastname: Kudoh
mesh_terms: D000328:Adult; D000368:Aged; D003964:Diaphragm / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009038:Motion; D011187:Posture; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D013902:Radiography, Thoracic / Q000379:methods*; D012119:Respiration; D014965:X-Rays
keywords: Chronic obstructive pulmonary disease; Diaphragm; Radiography; Respiration; X-ray