The goal of this clinical trial is to gain more information about how FAPI (fibroblast activation protein inhibitor) binds to certain type of cells in the tumor tissue. The main question it aims to answer is how this information can be used to better diagnose and track prostate cancer.

Participants will undergo two PET/MRI scans during two research visits, each of which may last up to 2.5 hours.

Inclusion Criteria:

• Age 18 years or older
• Able and willing to provide informed consent
• Known diagnosis of prostate cancer
• Scheduled for or recently performed (within 4 weeks) standard-of-care PSMA PET
• Optional: Scheduled for SOC biopsy of an established or suspected non-osseous, non-nodal metastases.
• Willing and able to undergo PET/MRI as part of this research

Exclusion Criteria:

• Unable or unwilling to provide informed consent
• Contraindication(s) to or inability to undergo PET/MRI
• Participants for whom PET/MRI will delay timely delivery of treatment
• Participants requiring intravenous (IV) conscious sedation for imaging care; those requiring mild, oral anxiolytics for the clinical MRI will be allowed to participate as long as the following criteria are met:
• Have their own prescription for the medication
• The informed consent process is conducted prior to the self-administration of this medication
• Come to the research visit with a driver

De-identified data with GE Healthcare: images, diagnosis, image quality scores, quantitative PET/MR measurements, BMI, weight, height, age and gender. The Department of Radiology Medical Imaging Research Support (MIRS) Radius team will serve as an honest broker for the sharing of de-identified data.