Hyperpolarized (3) He and (129) Xe MRI: differences in asthma before bronchodilation

J Magn Reson Imaging. 2013 Dec;38(6):1521-30. doi: 10.1002/jmri.24111. Epub 2013 Apr 15.

Abstract

Purpose: To compare hyperpolarized helium-3 ((3) He) and xenon-129 ((129) Xe) MRI in asthmatics before and after salbutamol inhalation.

Materials and methods: Seven asthmatics provided written informed consent and underwent spirometry, plethysmography, and MRI before and after salbutamol inhalation. (3) He and (129) Xe ventilation defect percent (VDP) and ventilation coefficient of variation (COV) were measured. To characterize the airways spatially related to ventilation defects, wall area percent (WA%) and lumen area (LA) were evaluated for two subjects who had thoracic x-ray computed tomography (CT) acquired 1 year before MRI.

Results: Before salbutamol inhalation, (129) Xe VDP (8 ± 5%) was significantly greater than (3) He VDP (6 ± 5%, P = 0.003). Post-salbutamol, there was a significant improvement in both (129) Xe (5 ± 4%, P < 0.0001) and (3) He (4 ± 3%, P = 0.001) VDP, and the improvement in (129) Xe VDP was significantly greater (P = 0.008). (129) Xe MRI COV (Pre: 0.309 ± 0.028, Post: 0.296 ± 0.036) was significantly greater than (3) He MRI COV (Pre: 0.282 ± 0.018, Post: 0.269 ± 0.024), pre- (P < 0.0001) and post-salbutamol (P < 0.0001) and the decrease in COV post-salbutamol was significant ((129) Xe, P = 0.002; (3) He, P < 0.0001). For a single asthmatic, a sub-segmental (129) Xe MRI ventilation defect that was visible only before salbutamol inhalation but not visible using (3) He MRI was spatially related to a remodeled fourth generation sub-segmental airway (WA% = 78%, LA = 2.9 mm(2) ).

Conclusion: In asthma, hyperpolarized (129) Xe MRI may help reveal ventilation abnormalities before bronchodilation that are not observed using hyperpolarized (3) He MRI.

Keywords: airway obstruction; bronchodilator; functional imaging; gas distribution; ventilation defect.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Inhalation
  • Adolescent
  • Adult
  • Albuterol / administration & dosage*
  • Asthma / drug therapy*
  • Asthma / pathology*
  • Bronchodilator Agents / administration & dosage
  • Contrast Media
  • Female
  • Helium*
  • Humans
  • Isotopes
  • Lung / drug effects
  • Lung / pathology*
  • Magnetic Resonance Imaging / methods*
  • Male
  • Middle Aged
  • Radiopharmaceuticals
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Treatment Outcome
  • Xenon Isotopes*
  • Young Adult

Substances

  • Bronchodilator Agents
  • Contrast Media
  • Isotopes
  • Radiopharmaceuticals
  • Xenon Isotopes
  • Helium
  • Albuterol