Fig. 2.

62-year-old man with a history of squamous cell cancer. The upper row is the PET/CT from 2019, which was obtained for cancer staging. The fused PET/CT axial image at the axilla level is unremarkable. MIP image on the right shows hypermetabolic tongue cancer and metastatic left cervical lymphadenopathy (pink circle). The lower row is the PET/CT obtained in early September in 2021, 1 day after the third dose of COVID-19 vaccine targeted to the left arm. Yellow arrows show hypermetabolic lung nodules, consistent with metastasis, and new hypermetabolic left axillary lymph nodes (blue arrows). Bilateral symmetric uptake in the deltoid muscles in the lower right MIP image was considered physiologic muscle uptake.