Incidental Findings Suggestive of COVID-19 in Asymptomatic Patients Undergoing Nuclear Medicine Procedures in a High-Prevalence Region

J Nucl Med. 2020 May;61(5):632-636. doi: 10.2967/jnumed.120.246256. Epub 2020 Apr 1.


Infection with the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may remain asymptomatic, leading to under-recognition of the related disease, coronavirus disease, 2019 (COVID-19), and to incidental findings in nuclear imaging procedures performed for standard clinical indications. Here, we report about our local experience in a region with high COVID-19 prevalence and dynamically increasing infection rates. Methods: Within the 8-d period of March 16-24, 2020, hybrid imaging studies of asymptomatic patients who underwent 18F-FDG PET/CT or 131I SPECT/CT for standard oncologic indications at our institution in Brescia, Italy, were analyzed for findings suggestive of COVID-19. The presence, radiologic features, and metabolic activity of interstitial pneumonia were identified, correlated with the subsequent short-term clinical course, and described in a case series. Results: Six of 65 patients (9%) who underwent PET/CT for various malignancies showed unexpected signs of interstitial pneumonia on CT and elevated regional 18F-FDG avidity. Additionally, 1 of 12 patients who received radioiodine for differentiated thyroid carcinoma also showed interstitial pneumonia on SPECT/CT. Five of 7 patients had subsequent proof of COVID-19 by reverse-transcriptase polymerase chain reaction. The remaining 2 patients were not tested immediately but underwent quarantine and careful monitoring. Conclusion: Incidental findings suggestive of COVID-19 may not be infrequent in hybrid imaging of asymptomatic patients in regions with an expansive spread of SARS-CoV-2. Nuclear medicine services should prepare accordingly.

Keywords: COVID-19; PET/CT; nuclear medicine; pneumonia.

Publication types

  • Case Reports

MeSH terms

  • Aged
  • Asymptomatic Diseases
  • Betacoronavirus
  • COVID-19
  • Coronavirus Infections / complications
  • Coronavirus Infections / diagnosis*
  • Female
  • Fluorodeoxyglucose F18
  • Humans
  • Incidental Findings*
  • Infection Control
  • Lung Diseases, Interstitial* / diagnostic imaging
  • Lung Diseases, Interstitial* / etiology
  • Male
  • Membrane Glycoproteins
  • Middle Aged
  • Neoplasms / diagnostic imaging
  • Nuclear Medicine / trends
  • Pandemics
  • Pneumonia, Viral / complications
  • Pneumonia, Viral / diagnosis*
  • Positron Emission Tomography Computed Tomography*
  • Prevalence
  • Reverse Transcriptase Polymerase Chain Reaction
  • SARS-CoV-2
  • Tomography, Emission-Computed, Single-Photon
  • Tomography, X-Ray Computed


  • A74 protein, Halocynthia roretzi
  • Membrane Glycoproteins
  • Fluorodeoxyglucose F18