AJR Am J Roentgenol 2002 Aug;179(2):477-81
Application of oral contrast media in coregistered positron emission
tomography-CT.
Dizendorf EV, Treyer V, Von Schulthess GK, Hany TF.
OBJECTIVE: Coregistration of positron emission tomography (PET) and CT images
results in significantly improved localization of abnormal FDG uptake compared
with PET images alone. For delineation of intestinal structures, application of
oral contrast media is a standard procedure in CT. The influence of oral
contrast agents in PET imaging using CT data for attenuation correction was
evaluated in a comparative study on an in-line PET-CT system. SUBJECTS AND
METHODS: Sixty patients referred for PET-CT were evaluated in two groups. One
group of 30 patients received oral Gastrografin 45 min before data acquisition.
The second group received no contrast medium. PET images were reconstructed,
using CT data for attenuation correction. Image analysis was performed by two
reviewers in consensus, using a 4-point scale comparing FDG-uptake in the
gastrointestinal tract in PET images of both groups. Furthermore, correlation of
FDG uptake and localization of contrast media in the intestinal tract in CT
images were determined. RESULTS: No significant difference in FDG uptake in PET
images in all regions of the gastrointestinal tract except the ascending colon
was seen in both groups. No correlation was found in the location of increased
FDG uptake and contrast media in the CT images. CONCLUSION: An oral contrast
agent can be used for coregistered PET-CT without the introduction of artifacts
in PET.
