18F-2-deoxy?d?glucose positron emission tomography (FDG-PET) is used to identify recurrence and metastatic colorectal cancer. Abdominal lymph node metastases from colorectal carcinoma tend to be as small as 1 cm, which can be detected by FDG-PET but due to lack of anatomical reference exact localization and evaluation of the extent of local pathology on PET alone is hampered. To overcome this the combination of PET and CT is currently used.