TY - JOUR T1 - Prospective Evaluation of Physiologic Uptake Detected with True Whole-Body <sup>18</sup>F-FDG PET/CT in Healthy Subjects JF - Journal of Nuclear Medicine Technology JO - J. Nucl. Med. Technol. SP - 31 LP - 37 DO - 10.2967/jnmt.108.055004 VL - 37 IS - 1 AU - Mark F. Reinking AU - Medhat M. Osman Y1 - 2009/03/01 UR - http://tech.snmjournals.org/content/37/1/31.abstract N2 - PET is a molecular imaging modality used to assess metabolic activity. Little is known about the physiologic uptake of radiopharmaceuticals such as 18F-FDG in healthy subjects. This study was designed to identify and describe normal patterns of physiologic uptake of 18F-FDG in healthy adult subjects and to examine the influence of low-level muscle activity during the 18F-FDG uptake phase. Methods: Twenty healthy adults received an intravenous injection of 18F-FDG and were subsequently scanned with a combined PET/CT scanner. The CT scan was used to accurately identify the location of 18F-FDG uptake. Of the 20 subjects, 10 were randomly selected to perform a low-level muscle activity during the 1-h 18F-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 18F-FDG uptake phase affected the pattern of 18F-FDG distribution on PET scans. In addition, the tissue uptake of 18F-FDG, although variable, showed some consistency among tissue types. Conclusion: 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 18F-FDG across subjects. Finally, the results suggested that 18F-FDG uptake may be used for the evaluation of muscle activity. ER -