Inclusion Criteria:  Males and females age ≥18 years Able to understand, sign and date written informed consent Written informed consent must be obtained before any assessment is performed Subjects being considered for a possible diagnosis of cardiac amyloidosis  Any of the following conditions:  Established systemic amyloidosis without proven cardiac involvement, OR Known plasma cell dyscrasia (MGUS, multiple myeloma), OR Pathological free light chain levels in urine or serum, OR Presence of heart failure with preserved ejection fraction  In combination with at least one of the following parameters, indicative of cardiac manifestation:  Mean (left ventricular (LV) wall + septum) thickness >12mm as measured by echocardiography in absence of other known cause of left ventricular hypertrophy (LVH), OR NT-proBNP >335 ng/L Planned diagnostic procedure to establish diagnosis and cardiac involvement (e.g., endomyocardial biopsy or extracardiac biopsy in conjunction with cardiac magnetic resonance imaging or echocardiography) Female subjects must be documented by medical records or physician's note to be either surgically sterile (by means of hysterectomy, bilateral salpingectomy, or bilateral oophorectomy) or post-menopausal for at least 1 year (no menses for 12 months without an alternative medical cause). If they are of child-bearing potential, must commit to use of a highly effective contraceptive measure for at least one week following the PET scan Male subjects and their partners of childbearing potential must commit to the use of a highly effective method of contraception for a minimum of 90 days following the PET scan Male subjects must commit to not donate sperm for a minimum of 90 days after the PET scan  Exclusion Criteria:  Any concurrent medical condition or disease that would likely interfere with study procedures or results Inability to lay flat for up to 60 min Pregnant, lactating or breastfeeding Unwilling and/or unable to cooperate with study procedures Having been administered a radiopharmaceutical within 10 radioactive half-lives prior to study drug administration in this study