The accurate interpretation of 18-F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET/CT) images requires knowledge of the normal patterns, intensities, and frequencies of FDG distribution in the whole body.
In this study, we aimed to evaluate distribution patterns, frequencies, and intensities of visible physiological FDG cord uptake in patients with no known abnormality in this region on PET/CT.
A total of 113 patients (71 men, 42 women; mean age 57.2±14.2 y; range 24 to 88 y) who had been investigated by FDG PET/CT were studied retrospectively. For each scan, spinal cord was visually assessed for FDG uptake, and its intensity was semiquantitatively graded on a 3-point scale as grade 0 (no visible uptake), grade 1 (mild uptake), or grade 2 (moderate uptake).
Mild or moderate FDG cord uptake was observed in 82 patients (82/113; 72.6%). In most of the cases uptake was observed in all cervical (72/113; 63.7%), thoracic 11-12 (66/113; 58.4%), and lumbar 1 (24/113; 21.2%) vertebral levels of the cord.
Visible mild FDG uptake in the spinal cord is a common finding in PET/CT imaging. No significant association with age or sex was observed. Such physiological uptake can appear mostly at the cervical and T11-L1 vertebral levels. At these levels, moderate uptake is also frequently encountered. However, in the upper thoracic regions, only mild uptake is observed.