Genentech Xenon MRI Idiopathic Pulmonary Fibrosis

Inclusion Criteria: * Outpatients of either gender, age \> 18. * Willing and able to give informed consent and adhere to visit/protocol schedules. (Consent must be given before any study procedures are performed) * Clinical diagnosis of IPF by confirmed by multidisciplinary diagnosis and naïve to treatment with an approved IPF therapy (either nintedanib or pirfenidone) Exclusion Criteria: * Subject is less than 18 years old * Subjects who have been previously on either pirfenidone or nintedanib * MRI is contraindicated based on responses to MRI screening questionnaire * Subject is pregnant or lactating * Resting oxygen saturation on room air \<90% on supplemental oxygen * Respiratory illness of a bacterial or viral etiology within 30 days of MRI * Subject with ventricular cardiac arrhythmia in the past 30 days. * Subject has history of cardiac arrest within the last year * Subject does not fit into 129 Xenon vest coil used for MRI * Subject deemed unlikely to be able to comply with instructions during imaging * Recent exacerbation (within 30 days) defined by the need for antibiotics and/or systemic steroids * Medical or psychological conditions which, in the opinion of the investigator, might create undue risk to the subject or interfere with the subject's ability to comply with the protocol requirements