Hyperpolarized helium-3 magnetic resonance imaging of chronic obstructive pulmonary disease exacerbation.

A chronic obstructive pulmonary disease (COPD) exsmoker underwent pulmonary function tests and hyperpolarized helium-3 ((3) He) magnetic resonance imaging (MRI) serially over 4 years, twice prior to and twice following an acute exacerbation (AE). About 2.5 years pre-AE, (3) He ventilation defect percent (VDP) was 16%, the apparent diffusion coefficient (ADC) was 0.34 cm(2) /s, and forced expiratory volume in 1 sec (FEV1 ) was 41%pred . Six months pre-AE, VDP and ADC were worse (29% and 0.38 cm(2) /s, respectively) without worsening FEV1 (47%pred ). After hospitalization and AE treatment, VDP was 20%, whereas FEV1 did not improve (45%pred ); 16 months post-AE, both VDP and ADC remained improved and similar to 4 years prior.