title: Direct comparison of129Xe diffusion measurements with quantitative histology in human lungs.
abstract: Chronic obstructive pulmonary disease (COPD) is an irreversible lung disease characterized by small-airway obstruction and alveolar-airspace destruction. Hyperpolarized129Xe diffusion MRI of lung is a promising biomarker for assessing airspace enlargement, but has yet to be validated by direct comparison to lung histology. Here we have compared diffusion measurements of hyperpolarized (HP)129Xe in explanted lungs to regionally matched morphological measures of airspace size.
  
  
  
  Explanted lungs from five COPD patients and two idiopathic pulmonary fibrosis (IPF) patients were imaged using MRI with hyperpolarized129Xe using a two-b-value gradient-echo diffusion sequence, and 34 histological samples were taken from these lungs for quantitative histology. Mean-linear-intercept (Lm) was compared with spatially matched measures of apparent diffusion coefficient (ADC) from129Xe MRI.
  
  
  
  The mean ADC from COPD lung samples was 0.071 ± 0.011 cm2/s, and for IPF lungs was 0.033 ± 0.001 cm2/s (P < 10-15between groups). The mean Lmin COPD samples was 0.076 ± 0.027 cm and 0.041 ± 0.004 cm in IPF (P = 2.7 × 10-7between groups). The Pearson-correlation between ADC and Lmmeasurements was r = 0.59.
  
  
  
  Diffusion MRI of HP129Xe quantifies regional airspace enlargement in COPD.129Xe ADC showed much less overlap between groups than quantitative histology, consistent with our past experience with3He diffusion MRI in COPD. Magn Reson Med 77:265-272, 2017. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Center for Pulmonary Imaging Research, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.|Department of Physics, Washington University in St. Louis, St. Louis, MO, USA.
authors.forename: Robert P
authors.initials: RP
authors.lastname: Thomen
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: James D
authors.initials: JD
authors.lastname: Quirk
authors.affiliation: Center for Pulmonary Imaging Research, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
authors.forename: David
authors.initials: D
authors.lastname: Roach
authors.affiliation: Center for Pulmonary Imaging Research, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
authors.forename: Tiffany
authors.initials: T
authors.lastname: Egan-Rojas
authors.affiliation: Center for Pulmonary Imaging Research, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
authors.forename: Kai
authors.initials: K
authors.lastname: Ruppert
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: Roger D
authors.initials: RD
authors.lastname: Yusen
authors.affiliation: Department of Radiology, University of Missouri, Columbia, MO, USA.
authors.forename: Talissa A
authors.initials: TA
authors.lastname: Altes
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: Dmitriy A
authors.initials: DA
authors.lastname: Yablonskiy
authors.affiliation: Center for Pulmonary Imaging Research, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.|Department of Physics, Washington University in St. Louis, St. Louis, MO, USA.
authors.forename: Jason C
authors.initials: JC
authors.lastname: Woods
mesh_terms: D000328:Adult; D000368:Aged; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006651:Histocytochemistry / Q000379:methods*; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000000981:diagnostic imaging; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008168:Lung / Q000737:chemistry / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D029424:Pulmonary Disease, Chronic Obstructive / Q000000981:diagnostic imaging; D014979:Xenon Isotopes / Q000737:chemistry*
chemical_list: D014979:Xenon Isotopes
keywords: 129Xe; ADC; COPD; IPF; MRI; apparent; chronic; coefficient; diffusion; disease; fibrosis; histology; hyperpolarized; idiopathic; obstructive; pulmonary; xenon