FIGURE 1. An 81-y-old man with cancer of sigmoid colon, after surgery, increasing carcinoembryonic antigen (CEA) serum levels, and a repeated negative CT study. (A) PET shows focal area of increased ¹⁸F-FDG uptake in right upper abdomen. (B) Hybrid PET/CT images precisely localized this uptake to colon, consistent with physiologic bowel excretion. Malignancy was excluded and study was reported as normal. Patient had no evidence of recurrence in colon during 15 mo of clinical follow-up.