History: 64 yo male with history of adenocarcinoma of unknown primary. Had barium enema, CT C/A/P, and PET imaging as part of the workup. You are presented with the PET imaging findings.
Solution: Attenuation correction can be responsible for producing artifactual findings on PET imaging. In this case, residual barium in the rectum results in a hot spot on the attenuation correction images, but if you review the non-attenuation corrected images, you see that this is artifactual. Remember that there are many artifacts associated with PET imaging and you must review all of the images (CT correlation if available) before assuming that a hot spot represents a focus of hypermetabolism. The non-attenuation corrected images and a CT performed earlier confirm the artifactual nature of this finding.
Nuclear Medicine Images
