Hyperpolarized 129Xe MRI of Survivors of COVID-19

Inclusion Criteria: * Oxygenation saturation of ≥88% at rest by study staff within 48 hours prior to study entry. * The participant has a previous diagnosis of COVID-19 confirmed by COVID-19 PCR or antibody testing and is being seen for outpatient follow-up. * Subject is at least 10 days post-symptom-onset and do not have a fever (\<99.5°). * Ability to read and understand English or Spanish Exclusion Criteria: * Subject is less than 18 years old * MRI is contraindicated based on responses to MRI screening questionnaire * Subject is pregnant or lactating * Subject does not fit into 129Xe vest coil used for MRI * Subject cannot hold his/her breath for 15-16 seconds * Subject deemed unlikely to be able to comply with instructions during imaging * Oxygen saturation \<88% on room air or with supplemental oxygen * Cognitive deficits that preclude ability to provide consent * Institutionalization