Inclusion Criteria:  Diagnosed with Stage IV metastatic melanoma, or inoperable Stage III equivalent Baseline fluorodeoxyglucose (FDG)-PET scan available from within 30 days prior to date of enrollment Blood counts and metabolic results within protocol limits within 14 days prior to enrollment Ability to lie flat and still for a minimum of two hours for imaging Male and female participants with reproductive potential must agree to use highly effective contraception in preparation of the study, during the study, and for 4 weeks following the last dose of an investigative imaging agent Documented life expectancy of at least 3 months  Exclusion Criteria:  Active secondary malignancy Prior treatment (for any reason) with radioactive nuclides; imaging tracers are acceptable Pregnancy or breast feeding a child Uncontrolled infection Treatment with another investigational drug within 30 days prior to enrollment date Any treatment with BRAF inhibitors since the baseline FDG-PET scan or plans for such treatment during the study Kidney function not within protocol limits BMI>40 kg/m2 History of a condition resulting in anaphylaxis or angioedema