Prevalence and patterns of metal artifacts in FDG PET/CT

2123 Objectives In PET/CT, the use of CT for attenuation correction (AC) and image fusion offers several advantages including shorter image acquisition, improved lesion localization and identification. However, metal artifacts in the CT portion of the study may propagate to the PET portion when CT is used for AC. Dental artifacts have been previously reported. The objective of the current study was to evaluate prevalence and patterns of extra cranial metal artifacts detected on FDG PET/CT. Methods PET/CT reports of 1,300 patients, age >18 were retrospectively reviewed to determine the presence of metals and their locations within the body. Mean age of the patients was 61 years (SD±13). A log was kept to record cases of metals causing CT artifacts. Location of the metal was grouped by anatomic area into: chest, abdomen, pelvis and musculoskeletal regions. Head and neck area was not included in the analysis. Results Of the 1300, 131 patients (10%) had metals below the head and neck area (Table 1). The musculoskeletal region was the most common site for metals and related artifacts. Conclusions We conclude that extra cranial metal artifacts are not uncommon (10%) in the CT portion of the PET/CT. When present, the extent and propagation of metal artifacts to the CTAC may depend on the type/composition of metal. It is important to be aware of metal artifacts resulting from using CT for AC in FDG PET/CT in order to avoid false interpretations