Understanding Airway Structure's Impact on Asthma Treatment

Inclusion Criteria: * Able and willing to provide written informed consent. * Able and willing to comply with the study protocol. * Males and females ≥ 18 years of age. * Asthma diagnosed by a respiratory physician. * Airway hyperresponsiveness (defined as methacholine PC20 ≤8mg/mL) and/or bronchodilator reversibility (defined as post-bronchodilator FEV1 improvement ≥200mL and 12%) in the last 6 months * ACQ ≥1.5 during the screening period. * Sputum eosinophils ≥3% and/or FeNO ≥35ppb during the screening period. Exclusion Criteria: * Current smoker, defined as someone having smoked ≥1 cigarette/day (or vape/pipe/cigar/marijuana) for ≥30 days within 12 months prior to screening. * Pregnant or breastfeeding * Non-English speaking * Oral corticosteroids in past 1-month * Biologic therapy in past 6-months * Unable to perform proper MDI technique during the screening period * Other pulmonary diseases (e.g., chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, cystic fibrosis, pulmonary arterial hypertension, tuberculosis) requiring treatment within 12 months prior to screening. * Unable to undergo MRI. Patient has an implanted mechanically, electrically, or magnetically activated device or any metal in their body which cannot be removed, including but not limited to pacemakers, neurostimulators, biostimulators, implanted insulin pumps, aneurysm clips, bioprosthesis, artificial limb, metallic fragment or foreign body, shunt, surgical staples (including clips or metallic sutures and/or ear implants) (at the discretion of the MRI Technologist). Suffers from any physical, psychological, or other condition(s) that might prevent performance of the MRI, such as severe claustrophobia.