We have observed a pattern of symmetrically increased uptake of [18F]fluorodeoxyglucose (FDG) in the neck and thoracic paravertebral regions of several patients referred for whole-body PET. The distribution is suggestive of uptake in contracting skeletal muscle in tense patients.
Methods: To test this hypothesis, six successive patients who exhibited this pattern of uptake underwent rescanning using an identical imaging protocol but with oral diazepam before injection of FDG.
Results: The increased neck and paravertebral uptake was significantly reduced or abolished with diazepam, confirming the supposition that this increased neck and paravertebral uptake represents a normal variant of muscle uptake.
Conclusion: Oral diazepam, given before the uptake period can be helpful in such patients to exclude the masking of potential abnormalities by this characteristic pattern of FDG uptake.