Hyperpolarized 3He MRI previously revealed spatially persistent ventilation defects in
healthy, older compared with healthy, younger never-smokers. To understand better the
physiological consequences and potential relevance of 3He MRI ventilation defects, we
evaluated 3He-MRI ventilation-defect percent (VDP) and the effect of deep inspiration (DI)
and salbutamol on VDP in older never-smokers. To identify the potential determinants of
ventilation defects in these subjects, we evaluated dyspnea, pulmonary function, and …

MATERIALS AND METHODS Study subjects and logistics. All subjects provided written,
informed consent to a study protocol approved by a Local Research Ethics Board and
Health Canada. Subjects were enrolled between the ages of 60 and 90 yr with a smoking
history of 0.5 pack-years and no history of chronic respiratory or cardiovascular disease.
After providing consent, all subjects made a single, 2-to 3-h visit and underwent the
following evaluations in the same order: 1) BOLD occupational questionnaire (5), 2) …