title: Helium3 polarization using spin exchange technique: application to simultaneous pulmonary ventilation/perfusion imaging in small animals.
abstract: OBJECTIVE
  To develop a simple and robust helium3 polarization system dedicated to small animal imaging. To demonstrate the potential of helium3 imaging for pulmonary ventilation and perfusion studies.
  
  
  METHODS
  A home-built polarization system based on spin-exchange technique was used. This system was applied for magnetic resonance imaging ventilation studies on rats using a 2-T magnet. Projection-reconstruction sequences combined with the sliding-window technique were used for acquisition of high temporal resolution ventilation images.
  
  
  RESULTS
  Helium3 polarization levels up to 25% were obtained. Simultaneous ventilation and lung perfusion images were acquired with intravenous injection of superparamagnetic contrast agents. Dose effects were investigated using several contrast agent concentration values.
  
  
  CONCLUSIONS
  A tabletop helium3 polarization system was realized. This equipment, which is easy to operate, allows the production of polarized gas appropriate to the requirements of small animal studies. This polarization system was used successfully on a ventilation/perfusion imaging study using intravascular contrast agent.
authors.affiliation: Laboratoire de RMN, UMR CNRS 5012, Université Lyon1-CPE, Villeurbanne, France.
authors.forename: Vasile
authors.initials: V
authors.lastname: Stupar
authors.forename: Yves
authors.initials: Y
authors.lastname: Berthezène
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Canet
authors.forename: Hervé
authors.initials: H
authors.lastname: Tournier
authors.forename: David
authors.initials: D
authors.lastname: Dupuich
authors.forename: Yannick
authors.initials: Y
authors.lastname: Crémillieux
mesh_terms: D000818:Animals; D006371:Helium; D007554:Isotopes; D008168:Lung / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D014692:Ventilation-Perfusion Ratio
chemical_list: D007554:Isotopes; D006371:Helium