Fibrosis in Chronic and Delayed Myocardial Infarction

In this study the investigators aim to examine the role that fibrosis plays in heart conditions such as aortic stenosis , chemotherapy-induced cardiotoxicity and carcinoid syndrome . Fibrosis is a common final result following any injury to the heart muscle and the investigators aim to identify this process early and in its active state. This will be examined by using a radiotracer 68Ga-FAPI or 18F-AlF-FAPI and PET-MRI or PET-CT.

Inclusion Criteria: Cohort 1(Aortic stenosis): * Male or female above the age of 50 years old * Provision of informed consent prior to any study specific procedures * 25 patients with symptomatic severe aortic stenosis (peak velocity \>4.0 m/s) * 25 patients with moderate aortic stenosis (peak velocity 3.0-4.0 m/s) * 10 patients with mild aortic stenosis (peak velocity 2.6-2.9 m/s) * 10 patients with aortic sclerosis (tri-leaflet thickened aortic valve with no obstruction of ventricular outflow) * 10 healthy volunteers (no other significant co-morbidities, as assessed by the study PI) Cohort 2 (Chemotherapy-induced cardiotoxicity): * Male or female over the age of 35 years with evidence of cardiotoxicity on cardiac MRI (performed as part of the Cardiac care study), at least 1 year after anthracycline treatment. * 10 patients over the age of 35 years (male or females) without evidence of fibrosis on their 1-year scan after anthracycline treatment. * 10 healthy volunteers (\>35 years of age) with no significant co-morbidities, as assessed by the study PI. * Provision of informed consent prior to any study specific procedures Cohort 3 (Carcinoid syndrome): * 30 patients with carcinoid syndrome (with or without cardiac involvement), over the age of 35 years, diagnosed as per consensus guidelines * Provision of informed consent prior to any study specific procedures Exclusion Criteria: * Inability or unwilling to give informed consent. * History of claustrophobia or feeling of inability to tolerate supine position for the MRI scans. * Impaired renal function with eGFR of \