title: Emphysema: hyperpolarized helium 3 diffusion MR imaging of the lungs compared with spirometric indexes--initial experience.
abstract: OBJECTIVE
  To quantitatively evaluate hyperpolarized helium 3 ((3)He) diffusion magnetic resonance (MR) images of the lung in patients with emphysema and to determine whether apparent diffusion coefficients (ADCs) measured with MR imaging correlate with spirometric indexes.
  
  
  METHODS
  Hyperpolarized (3)He diffusion MR imaging was performed in 16 healthy volunteers and 11 patients. Coronal diffusion-sensitized MR images were obtained during suspended respiration after inhalation of laser-polarized (3)He gas, and images of the ADC were calculated. Spirometry was performed immediately before imaging. The mean and SD of the ADCs were compared between subject groups and were correlated with spirometric indexes.
  
  
  RESULTS
  ADC images were homogeneous in volunteers, but demonstrated regional variations in patients. The mean and SD of the ADCs for patients were significantly larger (P <.002) than those for volunteers. The mean ADCs for all subjects correlated with the percentage of predicted forced expiratory volume in 1 second, or FEV(1), (r = -0.797, P <.001) and the ratio of FEV(1) to forced vital capacity, or FVC, (r = -0.930, P <.001). ADC images in patients demonstrated a significant increase (P <.001) in the ADCs in the upper regions compared with the lower regions of the lung.
  
  
  CONCLUSIONS
  Hyperpolarized (3)He diffusion MR imaging demonstrated potential for use in evaluating the global and regional severity of emphysema.
authors.affiliation: Center for In-vivo Hyperpolarized Gas MR Imaging, Department of Radiology, University of Virginia School of Medicine, 1000 Lee St, Box 800170, Charlottesville, VA 22908, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Salerno
authors.forename: Eduard E
authors.initials: EE
authors.lastname: de Lange
authors.forename: Talissa A
authors.initials: TA
authors.lastname: Altes
authors.forename: Jonathon D
authors.initials: JD
authors.lastname: Truwit
authors.forename: James R
authors.initials: JR
authors.lastname: Brookeman
authors.forename: John P
authors.initials: JP
authors.lastname: Mugler
mesh_terms: D000328:Adult; D000368:Aged; D004058:Diffusion; D005260:Female; D006371:Helium; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011656:Pulmonary Emphysema / Q000473:pathology* / Q000503:physiopathology; D012044:Regression Analysis; D013147:Spirometry
chemical_list: D006371:Helium