Free-breathing Functional Pulmonary MRI Response to Bronchodilator and Bronchoprovocation in Severe Asthma

RATIONALE AND OBJECTIVES: Ventilation heterogeneity is a hallmark feature of asthma. Our objective was to evaluate ventilation heterogeneity in patients with severe asthma, both pre- and post-salbutamol, as well as post-methacholine (MCh) challenge using the lung clearance index, free-breathing pulmonary ¹H magnetic resonance imaging (FDMRI), and inhaled-gas MRI ventilation defect percent (VDP). MATERIALS AND METHODS: Sixteen severe asthmatics …