title: Peri-diaphragmatic lung volume assessed by computed tomography correlates with quality of life in patients with chronic obstructive pulmonary disease.
abstract: OBJECTIVE
  Health-related quality of life (HRQoL) is important in the management of chronic obstructive pulmonary disease (COPD). In patients with emphysema, lung hyperinflation identified radiologically as shortening and flattening of the diaphragm is associated with impaired HRQoL. It remains unclear whether shortening of the diaphragm and/or alteration in chest wall shape are associated with reduced pulmonary function and HRQoL.
  
  
  METHODS
  Pulmonary function testing and chest computed tomography (CT) were performed, and the St. George's Respiratory Questionnaire (SGRQ) was administered to 123 patients with COPD. Using CT images, the ratio of volume of lung region adjacent to the diaphragm dome to total lung volume (DLV%) was evaluated as a novel CT index, and conventional indices, including percent low attenuation volume (LAV%), wall area percent (WA%), total lung volume and diaphragm length (Ldi) were calculated.
  
  
  RESULTS
  DLV% was significantly correlated with Ldi. DLV% and Ldi were inversely correlated with lung hyperinflation, assessed as the ratio of residual volume to total lung capacity, independent of LAV% and WA%. Unlike Ldi, DLV% was inversely associated with all components and total scores for the SGRQ, independent of the severity of emphysema and airflow limitation.
  
  
  CONCLUSIONS
  Reduced lung volume around the diaphragm correlated with lung hyperinflation and HRQoL, independent of emphysema severity. This needs to be verified in additional studies.
authors: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto, Japan.
authors: Naoya
authors: N
authors: Tanabe
authors: Shigeo
authors: S
authors: Muro
authors: Yoshinori
authors: Y
authors: Fuseya
authors: Susumu
authors: S
authors: Sato
authors: Tsuyoshi
authors: T
authors: Oguma
authors: Hirofumi
authors: H
authors: Kiyokawa
authors: Tamaki
authors: T
authors: Takahashi
authors: Daisuke
authors: D
authors: Kinose
authors: Yuma
authors: Y
authors: Hoshino
authors: Takeshi
authors: T
authors: Kubo
authors: Toyohiro
authors: T
authors: Hirai
authors: Michiaki
authors: M
authors: Mishima
mesh_terms: D000368:Aged; D003964:Diaphragm / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008176:Lung Volume Measurements / Q000379:methods*; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011656:Pulmonary Emphysema / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011788:Quality of Life; D011795:Surveys and Questionnaires; D014057:Tomography, X-Ray Computed / Q000379:methods*