68Ga Citrate PET/MRI for Evaluation of Fever of Unknown Origin (FUO)

Inclusion Criteria: * Patient is \>/=18 years old at the time of the scan. * Patient with diagnosis of FUO. * Patient is capable of complying with study procedures. * Patient can remain still for duration of imaging procedure. * Able to provide written consent. Exclusion Criteria: * Patient is pregnant or nursing. * Metallic implants (contraindicated for MRI). * History of renal insufficiency (only for MRI contrast administration). * Inability to lie still for the entire imaging time. * Inability to complete the needed investigational and standard of care imaging examinations due to other reasons (severe claustrophobia, radiation phobia, etc.). * Any additional medical condition, serious intercurrent illness, or other extenuating circumstance that, in the opinion of the investigator, may significantly interfere with study compliance. * Known allergy, hypersensitivity, or intolerance to the investigational product or its excipients.