Unilateral forearm muscle 18F-FDG uptake after using a smartphone.

F-FDG PET is a tool widely used in many indications, mainly for staging malignant neoplasm. A correct interpretation of images requires knowledge of physiological uptake. The most frequently encountered can be found in head and neck area (language, masticator muscles, and ocular muscles). Many of them can be limited through preventive care before the completion of the exam (e.g., no practicing physical activity, no chewing, no reading). Growth of telecommunication technology has spread the use of smartphones, leading to new uptake artifacts during the acquisition of PET images: a unilateral hyper metabolism of forearm muscles.