title: Positron emission tomography-based evidence of low-amplitude respiratory motion in patients with chronic obstructive pulmonary disease.
abstract: OBJECTIVE
  Chronic obstructive pulmonary disease (COPD) is characterized by low vital capacity and tidal volume, which translate into smaller respiratory motions. We sought to demonstrate the limited respiratory motion in COPD by comparing respiratory-gated and free-breathing positron emission tomography (PET) images of lung nodules ("CT-based" and "Ungated" images) in patients with and without COPD.
  
  
  METHODS
  We studied 74 lung lesions (37 malignant) in 60 patients (23 patients with COPD; 37 without). An Ungated PET examination was followed by a CT-based acquisition. Maximum standard uptake value (SUVmax) for each lesion on PET images was measured. On CT images, we checked for the presence of emphysema and pleural adhesions or indentations associated with the nodules. Lastly, we used univariate and then multivariate analyses to determine the lung function parameters possibly affecting respiratory motion in patients with and without COPD.
  
  
  RESULTS
  The mean "CT-based" vs. "Ungated" difference in SUVmax was 0.3 and 0.6 for patients with and without COPD, respectively. Statistical analysis revealed that lesion site, hyperinflation and pleural indentation were independently associated with a difference in SUVmax.
  
  
  CONCLUSIONS
  PET lung lesion images in patients with COPD are barely influenced by respiratory motion. Thoracic hyperinflation in patients with COPD was found to be independently associated with an effect of respiratory motion on PET images. Moreover, pleural indentation limits the respiratory motion of lung nodules, regardless of the presence or absence of COPD.
authors.affiliation: Jules Verne University of Picardie, Amiens, France.
authors.forename: Joël
authors.initials: J
authors.lastname: Daouk
authors.forename: Pascal
authors.initials: P
authors.lastname: Bailly
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Kamimura
authors.forename: David
authors.initials: D
authors.lastname: Sacksick
authors.forename: Vincent
authors.initials: V
authors.lastname: Jounieaux
authors.forename: Marc-Etienne
authors.initials: ME
authors.lastname: Meyer
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D004646:Emphysema / Q000150:complications / Q000000981:diagnostic imaging; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D008175:Lung Neoplasms / Q000150:complications / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D009038:Motion; D064847:Multimodal Imaging; D015999:Multivariate Analysis; D049268:Positron-Emission Tomography / Q000379:methods; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000000981:diagnostic imaging*; D019275:Radiopharmaceuticals; D012119:Respiration; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18