- © 2007 by the American Society of Radiologic Technologists
18FDG Uptake in Brown Fat: Potential for False Positives
- KEVIN D. EVANS, PH.D., R.T.(R)(M)(BD), RDMS, RVS, FSDMS,
- TIMOTHY A. TULLOSS, B.S., R.T.(R) and
- NATHAN HALL, M.D., PH.D.
Abstract
Context 18FDG 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 18FDG uptake in brown fat.
Method A review of the literature was conducted on factors that contribute to false-positive diagnoses caused by 18FDG 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 18FDG uptake. Studies also have indicated that cold climate affects the uptake of 18FDG, 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.
