Miranda Kirby1,2, Roya Etemad-Rezai3,
David G. McCormack4, Grace Parraga1,5
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.