Role of Positron Emission Tomography-Computed Tomography Scan in Reaching Definite Diagnosis in Patients With Fever of Unknown Origin and Inflammation of Unknown Origin in Rheumatology Outpatient Clinic

PET/CT reliably helps 50% FUO/IUO patients in receiving definite diagnosis. PET/CT's high sensitivity implies that negative results can reliably exclude malignancies in most cases. However, due to its low specificity, positive test may not always imply a serious underlying condition. Majority of the definite diagnoses were rheumatic diseases with a very low proportion of infections and malignancies. This is mainly due to the detailed initial evaluations that are performed in internal medicine clinics. Future studies with more patients will better define the role of PET/CT in FUO/IUO patients in rheumatology clinics.