title: Time-Resolved Quantitative Analysis of the Diaphragms During Tidal Breathing in a Standing Position Using Dynamic Chest Radiography with a Flat Panel Detector System ("Dynamic X-Ray Phrenicography"): Initial Experience in 172 Volunteers.
abstract: Diaphragmatic motion in a standing position during tidal breathing remains unclear. The purpose of this observational study was to evaluate diaphragmatic motion during tidal breathing in a standing position in a health screening center cohort using dynamic chest radiography in association with participants' demographic characteristics.
  
  
  
  One hundred seventy-two subjects (103 men; aged 56.3 ± 9.8 years) underwent sequential chest radiographs during tidal breathing using dynamic chest radiography with a flat panel detector system. We evaluated the excursions of and peak motion speeds of the diaphragms. Associations between the excursions and participants' demographics (gender, height, weight, body mass index [BMI], smoking history, tidal volume, vital capacity, and forced expiratory volume) were investigated.
  
  
  
  The average excursion of the left diaphragm (14.9 ± 4.6 mm, 95% CI 14.2-15.5 mm) was significantly larger than that of the right (11.0 ± 4.0 mm, 95% CI 10.4-11.6 mm) (P <0.001). The peak motion speed of the left diaphragm (inspiratory, 16.6 ± 4.2 mm/s; expiratory, 13.7 ± 4.2 mm/s) was significantly faster than that of the right (inspiratory, 12.4 ± 4.4 mm/s; expiratory, 9.4 ± 3.8 mm/s) (both P <0.001). Both simple and multiple regression models demonstrated that higher BMI and higher tidal volume were associated with increased excursions of the bilateral diaphragm (all P <0.05).
  
  
  
  The average excursions of the diaphragms are 11.0 mm (right) and 14.9 mm (left) during tidal breathing in a standing position. The diaphragmatic motion of the left is significantly larger and faster than that of the right. Higher BMI and tidal volume are associated with increased excursions of the bilateral diaphragm.
authors.affiliation: Department of Radiology, Center for Pulmonary Functional Imaging, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St., Boston, MA 02215; 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, Kiyose, Tokyo, Japan.
authors.forename: Masako
authors.initials: M
authors.lastname: Ueyama
authors.affiliation: Department of Radiology, Fukujuji Hospital, Japan Anti-Tuberculosis Association, Kiyose, Tokyo, Japan.
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.
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, Tokyo, Japan.
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.
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.
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. 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, Kiyose, Tokyo, Japan.
authors.forename: Shoji
authors.initials: S
authors.lastname: Kudoh
mesh_terms: D015331:Cohort Studies; D003964:Diaphragm / Q000000981:diagnostic imaging / Q000502:physiology; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology*; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000502:physiology*; D011187:Posture; D013902:Radiography, Thoracic / Q000379:methods*; D012119:Respiration; D013990:Tidal Volume / Q000502:physiology*; D014838:Volunteers
keywords: Radiography; X-ray; diaphragm; respiration; thorax