Figure 28a. Attenuation correction artifact. (a) Attenuation-corrected coronal fused FDG PET-CT image shows a focus of intense hypermetabolism in the right supraclavicular region (arrow). (b) Attenuation-uncorrected fused FDG PET-CT image obtained at the same level shows that the apparent focus of hypermetabolism is an attenuation correction artifact from a pacemaker (arrow).