Adverse events have limited the use of bronchial thermoplasty (BT) in severe asthma. Hall et al sought to evaluate the effectiveness and safety of using 129Xe magnetic resonance imaging (129Xe MRI) to prioritize the most involved airways for guided BT. Thirty subjects with severe asthma were imaged with volumetric computed tomography and 129Xe MRI to quantitate segmental ventilation defects. Subjects were randomized to treatment of the six most involved airways in the first session (guided group) or a standard three-session BT (unguided). The primary outcome was the change in Asthma Quality of Life Questionnaire score from baseline to 12 weeks after the first BT for the guided group compared with after three treatments for the unguided group. Results of this pilot study suggest that similar short-term improvements can be achieved with one BT treatment guided by 129Xe MRI when compared with standard three-treatment-session BT with fewer periprocedure adverse events.