Fibrotic Disease Activity in Cardiopulmonary Disorders Using 18F-Fibroblast Activation Protein Inhibitor (18F-FAPI-74) PET/CT Imaging

Background: Injury or diseases of the heart and lung can sometimes cause scar tissue (fibrosis) to build up in those organs. Current imaging scans can see this scar tissue once it has formed, but researchers want to find a way to detect the fibrosis in its earliest stages, while there might still be time to prevent serious damage. A new tracer (a radioactive substance injected during imaging scans) may be able to help. Objective: To test a new tracer (18F-FAPI-74) during imaging scans in people with heart or lung disease. Eligibility: People aged 18 years and older with lung or heart disease that may cause scarring in those organs. Design: Participants will have 6 clinic visits over 2 years. Participants will be screened: They will have blood tests and tests of their heart and lung function. Those with heart disease will have a magnetic resonance imaging (MRI) scan of the heart. The study tracer will be used with positron emission tomography (PET)/computed tomography (CT) scans. The study tracer will be injected into a vein in the arm. Participants will lie on a padded bed that slides through a donut-shaped machine. Participants will have scans with the study tracer 2 times, 8 to 12 months apart. They will also have standard CT scans and blood tests during these visits. They will also have blood tests at 3 and 6 months between these visits. Participants will have a follow-up visit after 18 to 24 months. The study scans, MRI and standard CT scans, and lung function tests may be repeated....

* INCLUSION CRITERIA In order to be eligible to participate in this study, an individual must meet all of the following criteria: 1. Provision of signed and dated informed consent form 2. Stated willingness to comply with all study procedures and availability for the duration of the study 3. Participant \>=18 years old 4. Has a specific diagnosis of a cardiopulmonary and/or vascular disease that puts them at risk of developing or having developed tissue fibrosis. 5. Has undergone prior imaging of lungs, heart, and/or vasculature with chest CT 6. Able to lie on the PET/CT scanner for imaging up to 45 minutes. 7. For females of reproductive potential: use of highly effective contraception for at least 1 month prior to screening and agreement to use such a method during study participation and for an additional 4 weeks after the end of FAPI-PET/CT or the FDG PET/CT scan. 8. For males of reproductive potential: use of condoms or other methods to ensure effective contraception with partner during study participation and for an additional 4 weeks after the end of FAPI-PET/CT or the FDG PET/CT scan. 9. Ability of subject to understand and the willingness to sign a written informed consent document. EXCLUSION CRITERIA An individual who meets any of the following criteria will be excluded from participation in this study: 1. History of allergic reactions attributed to compounds of similar chemical or biologic composition to 18F-FAPI-74 or other agents used in the study. 2. Uncontrolled intercurrent illness, factors, or social situations that would limit compliance with study requirements 3. Pregnancy or lactation 4. Women able to become pregnant or men actively trying to father a child and are unwilling to use an effective form of birth control during the study and 4 weeks after the last 18F-FAPI-74 PET/CT scan or the FDG PET/CT scan. 5. Subjects with severe claustrophobia unresponsive to oral anxiolytics. 6. Subjects weighing \> 350 lbs (weight limit for PET scanner table), or unable to fit within the imaging gantry