Radiology 2002 Sep;224(3):783-7
Incidental colonic fluorodeoxyglucose uptake: correlation with colonoscopic
and histopathologic findings.
Tatlidil R, Jadvar H, Bading JR, Conti PS.
PURPOSE: To evaluate the pattern and degree of incidental colonic
fluorodeoxyglucose (FDG) uptake in patients without colorectal carcinoma who
underwent whole-body FDG positron emission tomography (PET) for other purposes
and compare them with colonoscopic and/or histopathologic findings. MATERIALS
AND METHODS: Cases of 27 patients without known history of colorectal carcinoma
who were referred for evaluation with whole-body FDG PET and displayed
incidental colonic uptake were reviewed retrospectively. Colonoscopy was
performed in 10 patients; histopathologic analysis, in two; and both, in 15. The
colonic FDG uptake patterns were nodular-focal, nodular-multifocal, segmental,
and diffuse. The FDG uptake level was scored with a four-point scale in relation
to hepatic uptake. Binomial distribution was used to calculate 95% CIs for the
probability of finding an abnormality at histologic examination, as predicted by
findings at FDG PET. RESULTS: Colonoscopic findings in eight patients with a
diffuse uptake pattern were normal. Thirteen patients with nodular high FDG
uptake had pathologic findings. Six (22%) of the 27 patients were not suspected
of having a malignancy, and seven had benign neoplasms. With a 95% CI, nodular
high FDG uptake implies at least a 79% chance that histopathologic findings may
be abnormal. Colitis was seen in five of six patients with a segmental pattern
of high FDG uptake. CONCLUSION: Colonoscopy is a reasonable next step for
further diagnostic examination of patients who display nodular high FDG uptake
in the colon. Diffuse FDG uptake often is associated with normal findings at
colonoscopy, while segmental high uptake may imply inflammation. Copyright RSNA,
2002
