Features of Systemic Immune Response From COVID-19 Vaccination on 18F-FDG PET/CT

Clin Nucl Med. 2022 Jan 1;47(1):e89-e90. doi: 10.1097/RLU.0000000000003859.


The rapid rollout of COVID-19 vaccination is accompanied by incidental findings on 18F-FDG PET/CT. Most cases describe reactive axillary lymphadenopathy. A 46-year-old woman with previous history of stage 3A breast cancer underwent follow-up 18F-FDG PET/CT, which demonstrated avid left axillary nodes and intense diffuse splenic uptake and moderate diffuse bone marrow uptake. She had been administered COVID-19 vaccination in the left deltoid 1 week earlier and required hospitalization for 24 hours due to fever. Symptoms settled with supportive treatment. One month after the PET/CT scan, she remained well. Sites of uptake were taken to relate to a systemic immune response.

Publication types

  • Case Reports

MeSH terms

  • COVID-19 Vaccines
  • COVID-19*
  • Female
  • Fluorodeoxyglucose F18
  • Humans
  • Immunity
  • Middle Aged
  • Positron Emission Tomography Computed Tomography*
  • SARS-CoV-2
  • Vaccination


  • COVID-19 Vaccines
  • Fluorodeoxyglucose F18