Secondary Logo

Journal Logo

Interesting Images

Laboratory-Proven Asymptomatic SARS-CoV-2 (COVID-19) Infection on 18F-FDG PET/CT

Krebs, Simone MD; Petkovska, Iva MD; Ho, Alan L. MD, PhD†,‡; Ulaner, Gary A. MD, PhD∗,§

Author Information
doi: 10.1097/RLU.0000000000003141
  • Free


A 87-year-old man with primary salivary duct carcinoma and hepatic metastases was referred for restaging with 18F-FDG PET/CT. A, 18F-FDG PET maximum intensity projection of the body demonstrates multiple FDG-avid foci overlying the thorax (arrows), as well as an 18F-FDG–avid hepatic metastasis (curved arrow). Prominent but physiologic 18F-FDG avidity was also seen in the colon (arrowheads). Axial CT and 18F-FDG PET images at the level of upper lungs (B), aortic arch (C), and mainstem bronchi (D) demonstrate that the FDG avidity corresponds to multiple areas of ground-glass and patchy opacities with intralobular septal thickening in both lungs (arrows). Despite being asymptomatic for pneumonia, these imaging findings suggested COVID-19 infection. The patient tested positive for COVID-19 using real-time reverse transcription–polymerase chain reaction. COVID-19 is a pneumonia caused by the SARS-CoV-2 virus, first identified in China and now pandemic.1 SARS-CoV-2 infection may present with a broad array of findings, ranging for asymptotic infection, through upper and lower respiratory symptoms of varying severity, to death.2 The current criterion-standard diagnostic test for SARS-CoV-2 infection is real-time reverse transcription polymerase chain reaction (RT-PCR) test of viral RNA collected from upper respiratory tract samples. It has recently been reported that these molecular tests may yield false-negative results, and supplementary role of clinical data, including laboratory examination results and CT features, can be considered.3 The most common CT findings of COVID-19 pneumonia are ground-glass opacities and intralobular septal thickening with a peripheral dominant distribution, as seen in our patient. Consolidative opacities have correlated with more severe clinical symptoms, which were lacking in our asymptomatic patient.4–8 This case demonstrated that outpatient 18F-FDG PET/CT studies can identify radiologic signs of COVID-19 pneumonia, even in asymptomatic patients. Outpatients undergoing oncologic 18F-FDG PET/CT should be evaluated for radiologic findings suggestive of COVID-19 during this pandemic. Imaging findings leading to a positive COVID-19 laboratory test could lead to quarantine of a patient.


1. Zhu N, Zhang D, Wang W, et al. A novel coronavirus from patients with pneumonia in China. N Engl J Med. 2020;382:727–733.
2. Wang D, Hu B, Hu C, et al. Clinical characteristics of 138 hospitalized patients with 2019 novel coronavirus-infected pneumonia in Wuhan, China [published online February 7, 2020]. JAMA doi: 10.1001/jama.2020.1585. 2020.
    3. Li D, Wang D, Dong J, et al. False-negative results of real-time reverse-transcriptase polymerase chain reaction for severe acute respiratory syndrome coronavirus 2: role of deep-learning-based CT diagnosis and insights from two cases. Korean J Radiol. 2020;21:505–508.
    4. Caruso D, Zerunian M, Polici M, et al. Chest CT features of COVID-19 in Rome, Italy [published online April 3, 2020]. Radiology. 2020;201237. doi:10.1148/radiol.2020201237.
      5. Wong HYF, Lam HYS, Fong AH, et al. Frequency and distribution of chest radiographic findings in COVID-19 positive patients [published online March 27, 2020]. Radiology. 2019;201160. doi:10.1148/radiol.2020201160.
        6. Wang Y, Dong C, Hu Y, et al. Temporal changes of CT findings in 90 patients with COVID-19 pneumonia: a longitudinal study [published online March 19, 2020]. Radiology. 2020;200843. doi:10.1148/radiol.2020200843.
          7. Xu X, Yu C, Qu J, et al. Imaging and clinical features of patients with 2019 novel coronavirus SARS-CoV-2. Eur J Nucl Med Mol Imaging. 2020;47:1275–1280.
          8. Shi H, Han X, Jiang N, et al. Radiological findings from 81 patients with COVID-19 pneumonia in Wuhan, China: a descriptive study. Lancet Infect Dis. 2020;20:425–434.

          COVID-19; FDG PET/CT; ground-glass opacities; intralobular septal thickening; SARS-CoV-2 infection

          Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.