title: In vivo lung morphometry with accelerated hyperpolarized (3) He diffusion MRI: a preliminary study.
abstract: OBJECTIVE
  Parallel imaging can be used to reduce imaging time and to increase the spatial coverage in hyperpolarized gas magnetic resonance imaging of the lung. In this proof-of-concept study, we investigate the effects of parallel imaging on the morphometric measurement of lung microstructure using diffusion magnetic resonance imaging with hyperpolarized (3) He.
  
  
  METHODS
  Fully sampled and under-sampled multi-b diffusion data were acquired from human subjects using an 8-channel (3) He receive coil. A parallel imaging reconstruction technique (generalized autocalibrating partially parallel acquisitions [GRAPPA]) was used to reconstruct under-sampled k-space data. The morphometric results of the generalized autocalibrating partially parallel acquisitions-reconstructed data were compared with the results of fully sampled data for three types of subjects: healthy volunteers, mild, and moderate chronic obstructive pulmonary disease patients.
  
  
  RESULTS
  Morphometric measurements varied only slightly at mild acceleration factors. The results were largely well preserved compared to fully sampled data for different lung conditions.
  
  
  CONCLUSIONS
  Parallel imaging, given sufficient signal-to-noise ratio, provides a reliable means to accelerate hyperpolarized-gas magnetic resonance imaging with no significant difference in the measurement of lung morphometry from the fully sampled images. GRAPPA is a promising technique to significantly reduce imaging time and/or to improve the spatial coverage for the morphometric measurement with hyperpolarized gases.
authors.affiliation: Biomedical Magnetic Resonance Laboratory, Mallinckrodt Institute of Radiology, Washington University, St. Louis, Missouri, USA.
authors.forename: Yulin V
authors.initials: YV
authors.lastname: Chang
authors.forename: James D
authors.initials: JD
authors.lastname: Quirk
authors.forename: Dmitriy A
authors.initials: DA
authors.lastname: Yablonskiy
mesh_terms: D000280:Administration, Inhalation; D000328:Adult; D000368:Aged; D000465:Algorithms; D005260:Female; D006371:Helium / Q000008:administration & dosage*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007554:Isotopes / Q000008:administration & dosage; D008168:Lung / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D019275:Radiopharmaceuticals / Q000008:administration & dosage; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D007554:Isotopes; D019275:Radiopharmaceuticals; D006371:Helium
keywords: g-factor; generalized autocalibrating partially parallel acquisitions; hyperpolarized gas MRI; lung morphometry; parallel imaging