Prospective evaluation of physiologic uptake detected with true whole-body 18F-FDG PET/CT in healthy subjects.
PET is a molecular imaging modality used to assess metabolic activity. Little is known about the physiologic uptake of radiopharmaceuticals such as (18)F-FDG in healthy subjects. This study was designed to identify and describe normal patterns of physiologic uptake of (18)F-FDG in healthy adult subjects and to examine the influence of low-level muscle activity during the (18)F-FDG uptake phase.


METHODS
Twenty healthy adults received an intravenous injection of (18)F-FDG and were subsequently scanned with a combined PET/CT scanner. The CT scan was used to accurately identify the location of (18)F-FDG uptake. Of the 20 subjects, 10 were randomly selected to perform a low-level muscle activity during the 1-h (18)F-FDG uptake phase. The PET/CT images were fused, and the location and intensity of metabolic activity were described for all subjects.


RESULTS
Muscle activity during the (18)F-FDG uptake phase affected the pattern of (18)F-FDG distribution on PET scans. In addition, the tissue uptake of (18)F-FDG, although variable, showed some consistency among tissue types.


CONCLUSIONS
The data suggested that technologists should be aware of low-level muscle activity before and during uptake to avoid potential false-positive interpretations. The data also showed that there is some variability in the normal physiologic uptake of (18)F-FDG across subjects. Finally, the results suggested that (18)F-FDG uptake may be used for the evaluation of muscle activity.
Reinking
Mark F
MF
Department of Physical Therapy and Athletic Training, Edward and Margaret Doisy College of Health Sciences, Saint Louis University, St. Louis, MO 63104, USA. reinking@slu.edu
Osman
Medhat M
MM
D000328:Adult; D000368:Aged; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging / Q000378:metabolism / Q000502:physiology; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics*; D014057:Tomography, X-Ray Computed; D051598:Whole Body Imaging
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18