title: Hyperpolarized 3He magnetic resonance imaging of chronic obstructive pulmonary disease: reproducibility at 3.0 tesla.
abstract: OBJECTIVE
  We assessed subjects with stage II and stage III chronic obstructive pulmonary disease (COPD) and age-matched healthy volunteers at a single center using (3)He magnetic resonance imaging (MRI) at 3.0 T. Measurements of the (3)He apparent diffusion coefficient (ADC) and center coronal slice (3)He ventilation defect volume (VDV) were examined for same-day and 7-day reproducibility as well as subgroup comparisons.
  
  
  METHODS
  Twenty-four subjects who provided written informed consent (15 males; mean age 67 +/-7 years) with stage II (n = 9), stage III COPD (n = 7), and age-matched healthy volunteers (n = 8) were enrolled based on their age and pulmonary function test results. All subjects underwent plethysmography, spirometry, and MRI at 3.0 T. The time frame between scans was 7 +/- 2 minutes (same-day rescan) and again 7 +/- 2 days later (7-day rescan). (3)He ADC and VDV reproducibility was evaluated using linear regression, intraclass correlation coefficients (ICC) and Lin's concordance correlation coefficients (CCC).
  
  
  RESULTS
  ADC reproducibility was high for same-day rescan (r(2) = 0.934) and 7-day rescan (r(2) = 0.960, ICC and CCC of 0.96 and 0.98, respectively). Same-day rescan VDV reproducibility evaluated using the ICC and CCC (0.97 and 0.98, respectively) as well as linear regression (r(2) = 0.941) was also high, but VDV 7-day rescan reproducibility was lower and significantly different (r(2) = 0.576, P < .001, ICC 0.74, CCC 0.75, P < .01).
  
  
  CONCLUSIONS
  Hyperpolarized (3)He MRI was well-tolerated in subjects with stage II and stage III COPD. Seven-day repeated scanning was highly reproducible for ADC and moderately reproducible for VDV.
authors.affiliation: Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, ON, Canada N6A 5K8.
authors.forename: Lindsay
authors.initials: L
authors.lastname: Mathew
authors.forename: Andrea
authors.initials: A
authors.lastname: Evans
authors.forename: Alexei
authors.initials: A
authors.lastname: Ouriadov
authors.forename: Roya
authors.initials: R
authors.lastname: Etemad-Rezai
authors.forename: Robert
authors.initials: R
authors.lastname: Fogel
authors.forename: Giles
authors.initials: G
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; D003287:Contrast Media; D005260:Female; D006371:Helium; D006801:Humans; D007554:Isotopes; D008168:Lung / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D007554:Isotopes; D019275:Radiopharmaceuticals; D006371:Helium