FDG PET/CT: Artifacts and Pitfalls

Fluorodeoxyglucose positron emission tomography (FDG PET)/CT is commonly performed for evaluation of malignancy, and combines the most sensitive imaging modality (PET)with the highest resolution cross sectional imaging modality (CT). Artifacts present on PET/CT include those from both the PET and CT portions of the examination and also artifacts related to the examination’s dual acquisition technique and associated process of PET attenuation correction. They are categorized into three main categories: radiotracer related, patient related, and instrument related artifacts. Radiotracer-related artifacts usually occur due to an error during the radiotracer injection process. It has three main subtypes: hot clot artifact (due to pulmonary micro emboli of coagulated blood containing FDG), dose extravasation (at injection site), and scatter artifact (intense accumulation of radiotracer in bladder)
Main Patient-related artifacts are misregistration (secondary to motion), large size patient and beam hardening artifacts.
Attenuation correction and truncation artifacts are the most common types of Instrument related artifacts.
In this session we will briefly review these artifacts and ways to prevent or reduce them