18FDG uptake in brown fat: potential for false positives.
BACKGROUND
(18)FDG is used widely to enhance PET and PET-CT images. However, this radiotracer tends to be taken up by brown fat, which can lead to false-positive diagnoses. Purpose To determine which patients, areas of the body and circumstances are more likely to be associated with false-positive diagnoses due to (18)FDG uptake in brown fat.


METHODS
A review of the literature was conducted on factors that contribute to false-positive diagnoses caused by (18)FDG uptake in brown fat.


RESULTS
Brown fat commonly is found in women and children and can be located in the supraclavicular, mediastinal, paravertebral and perirenal areas of the body. Research has shown that these areas can be sources of a false-positive diagnosis because of (18)FDG uptake. Studies also have indicated that cold climate affects the uptake of (18)FDG, contributing to false-positive results on PET-CT examinations.


CONCLUSIONS
This literature review should stimulate continued research into and awareness of the potential for false-positive PET findings in women and children during the winter months and in cold climates. This information is especially applicable to young female patients undergoing PET or PET-CT.
Evans
Kevin D
KD
Radiologic Sciences and Therapy, Division of the School of Allied Medical Professions and the Department of Radiology at the Ohio State University, Columbus, OH, USA.
Tulloss
Timothy A
TA
Hall
Nathan
N
D002001:Adipose Tissue, Brown / Q000000981:diagnostic imaging* / Q000378:metabolism*; D016477:Artifacts; D005189:False Positive Reactions; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D006801:Humans; D009369:Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18