Development of FAPI PET as a Non-invasive Biomarker of Pulmonary Fibrogenesis

Inclusion Criteria:

• Age 18 years or older

• Able and willing to provide informed consent

• Group A: Clinically evaluated for need for initiation of new treatment (in patientsnot on current treatment), initiation of change in current treatment, or addition ofnew treatment (to any current treatment) in the setting of fibrotic hypersensitivitypneumonitis (HSP) or idiopathic pulmonary fibrosis (IPF), per standard of clinicalcare at UW Health.

• Group B: Clinically evaluated and stable without need for initiation of newtreatment (in patients not on current treatment), initiation of change in currenttreatment, nor addition of new treatment (to any current treatment) in the settingof fibrotic hypersensitivity pneu-monitis (HSP) or idiopathic pulmonary fibrosis (IPF), per standard of clinical care at UW Health.

• Crossover (Group B to A): Enrolled in Group B and found at next SOC clinical followup to have need for initiation of new treatment (in patients not on currenttreatment), initiation of change in current treatment, or addition of new treatment (to any current treatment) in the setting of fibrotic hypersensitivity pneumonitis (HSP) or idiopathic pulmonary fibrosis (IPF), per standard of clinical care at UWHealth.

• Willing and able to undergo PET/MRI.

• Participants requiring intravenous (IV) conscious sedation for imaging are noteligible; participants requiring mild, oral anxiolytics for the clinical MRI will beallowed to participate as long as the following criteria are met:

• The subject has their own prescription for the medication

• Informed consent is obtained prior to the self-administration of thismedication

• They come to the research visit with a driver

Exclusion Criteria:

• Participant is unable or unwilling to provide informed consent

• Participant is pregnant

• Participant with contraindication(s) to or inability to undergo PET/MRI

• Participants with contraindications to GBCA will be asked to undergo researchimaging without the use of contrast. Contraindications may be severe kidney diseaseor previously documented GFR < 30 ml/min/1.73 m2