PAXT: Pulmonary Imaging of Mild Asthma Using 129Xe MRI and Tc-99-Labeled-Carbon-Imaging (Tc99CImaging)

The goal of this observational study is to better understand how asthma affects the lungs in young adults (ages 17-35) with mild asthma. The main questions it aims to answer are: * Can advanced imaging detect abnormal airway function in people with mild asthma? * Do changes in ventilation imaging correlate with asthma symptoms or quality of life? Researchers will compare hyperpolarized xenon-129 MRI and Technegas (Tc-99m) imaging to see if these techniques reveal more detailed lung abnormalities than standard lung function tests. Participants will: * Complete a single 2-hour visit * Undergo two types of lung imaging: Hyperpolarized xenon-129 MRI (to visualize how air moves in the lungs), Technegas (Tc-99m) imaging (to assess airflow using nuclear medicine) * Perform spirometry and other breathing tests * Answer questionnaires about asthma symptoms and quality of life This study is designed to improve our understanding of subtle changes in lung function that may not be detected by standard tests in people with mild asthma. The findings may lead to better diagnostic tools and more personalized treatment strategies in the future.