title: Chronic obstructive pulmonary disease: longitudinal hyperpolarized (3)He MR imaging.
abstract: OBJECTIVE
  To quantitatively evaluate a small pilot group of ex-smokers with chronic obstructive pulmonary disease (COPD) and healthy volunteers during approximately 2 years by using hyperpolarized helium 3 ((3)He) magnetic resonance (MR) imaging.
  
  
  METHODS
  All subjects provided written informed consent to the study protocol, which was approved by the local research ethics board and Health Canada and was compliant with the Personal Information Protection and Electronic Documents Act and HIPAA. Hyperpolarized (3)He MR imaging, hydrogen 1 MR imaging, spirometry, and plethysmography were performed in 15 ex-smokers with COPD and five healthy volunteers (with the same mean age and age range) at baseline and 26 months +/- 2 (standard deviation) later. Apparent diffusion coefficients (ADCs) derived from (3)He MR imaging were calculated from diffusion-weighted (3)He MR images, and (3)He ventilation defect volume (VDV) and ventilation defect percentage (VDP) were generated after manual segmentation of (3)He MR spin-density images.
  
  
  RESULTS
  For subjects with COPD, significant increases in (3)He MR imaging-derived VDV (P = .03), VDP (P = .006), and ADC (P = .02) were detected, whereas there was no significant change in forced expiratory volume in 1 second (FEV(1)) (P = .97). For healthy never-smokers, there was no significant change in imaging or pulmonary function measurements at follow-up. There was a significant correlation between changes in FEV(1) and changes in VDV (r = -0.70, P = .02) and VDP (r = -0.70, P = .03).
  
  
  CONCLUSIONS
  For this small pilot group of ex-smokers with COPD, (3)He MR imaging-derived VDV, VDP, and ADC measurements worsened significantly, but there was no significant change in FEV(1), suggesting increased sensitivity of hyperpolarized (3)He MR imaging for depicting COPD changes during short time periods.
authors.affiliation: Imaging Research Laboratories, Robarts Research Institute, London, ON, Canada.
authors.forename: Miranda
authors.initials: M
authors.lastname: Kirby
authors.forename: Lindsay
authors.initials: L
authors.lastname: Mathew
authors.forename: Andrew
authors.initials: A
authors.lastname: Wheatley
authors.forename: Giles E
authors.initials: GE
authors.lastname: Santyr
authors.forename: David G
authors.initials: DG
authors.lastname: McCormack
authors.forename: Grace
authors.initials: G
authors.lastname: Parraga
mesh_terms: D000368:Aged; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005541:Forced Expiratory Volume; D006371:Helium; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D010991:Plethysmography; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000503:physiopathology*; D012907:Smoking / Q000009:adverse effects; D013147:Spirometry; D018709:Statistics, Nonparametric; D051598:Whole Body Imaging
chemical_list: D006371:Helium