title: Direct measurement of lung motion using hyperpolarized helium-3 MR tagging.
abstract: OBJECTIVE
  To measure lung motion between end-inhalation and end-exhalation using a hyperpolarized helium-3 (HP (3)He) magnetic resonance (MR) tagging technique.
  
  
  METHODS
  Three healthy volunteers underwent MR tagging studies after inhalation of 1 L HP (3)He gas diluted with nitrogen. Multiple-slice two-dimensional and volumetric three-dimensional MR tagged images of the lungs were obtained at end-inhalation and end-exhalation, and displacement vector maps were computed.
  
  
  RESULTS
  The grids of tag lines in the HP (3)He MR images were well defined at end-inhalation and remained evident at end-exhalation. Displacement vector maps clearly demonstrated the regional lung motion and deformation that occurred during exhalation. Discontinuity and differences in motion pattern between two adjacent lung lobes were readily resolved.
  
  
  CONCLUSIONS
  Hyperpolarized helium-3 MR tagging technique can be used for direct in vivo measurement of respiratory lung motion on a regional basis. This technique may lend new insights into the regional pulmonary biomechanics and thus provide valuable information for the deformable registration of lung.
authors: Department of Radiation Oncology, University of Virginia, Charlottesville, VA 22908, USA.
authors: Jing
authors: J
authors: Cai
authors: G Wilson
authors: GW
authors: Miller
authors: Talissa A
authors: TA
authors: Altes
authors: Paul W
authors: PW
authors: Read
authors: Stanley H
authors: SH
authors: Benedict
authors: Eduard E
authors: EE
authors: de Lange
authors: Gordon D
authors: GD
authors: Cates
authors: James R
authors: JR
authors: Brookeman
authors: John P
authors: JP
authors: Mugler
authors: Ke
authors: K
authors: Sheng
mesh_terms: D000280:Administration, Inhalation; D000328:Adult; D003287:Contrast Media / Q000008:administration & dosage*; 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 / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009068:Movement / Q000502:physiology*; D019275:Radiopharmaceuticals / Q000008:administration & dosage; D015656:Respiratory Mechanics / Q000502:physiology*; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D007554:Isotopes; D019275:Radiopharmaceuticals; D006371:Helium