Abstract #0906

Evaluating Bronchodilator Effects in Chronic Obstructive Pulmonary Disease using Hyperpolarized Helium-3 Magnetic Resonance Imaging

Miranda Kirby^1,2, Roya Etemad-Rezai³, David G. McCormack⁴, Grace Parraga^1,5

¹Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada; ²Medical Biophysics, the University of Western Ontario, London, Ontario, Canada; ³Department of Medical Imaging, the University of Western Ontario, London, Ontario, Canada; ⁴Division of Respirology, Department of Medicine, the University of Western Ontario, London, Ontario, Canada; ⁵Graduate Program in Biomedical Engineering, the University of Western Ontario, London , Ontario, Canada

The objective of this study was to evaluate short-acting bronchodilator effects in fourteen subjects with chronic obstructive pulmonary disease (COPD) using hyperpolarized helium-3 (³He) magnetic resonance imaging (MRI), spirometry, and plethysmography before and after administration of salbutamol. ³He MRI ventilation segmentation was performed using a semi-automated k-means clustering algorithm and ³He ADC was calculated using diffusion-weighted imaging. ³He MRI detected significant reductions in ³He clusters that contained no or diminished MR signal (p<.0001) and significant improvements in ³He ventilation clusters (p<.05), but no changes in ³He ADC post-salbutamol (p=.56), indicating that regional distribution of ventilation improves in COPD patients post-bronchodilator.