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ORIGINAL RESEARCH article

Front. Radiol.
Sec. Neuroradiology
Volume 4 - 2024 | doi: 10.3389/fradi.2024.1322851
This article is part of the Research Topic Insights in Neuroradiology View all 7 articles

7 Tesla Magnetic Resonance Imaging of the Nervus Terminalis, Olfactory Tracts and Bulbs in COVID-19 Anosmia and Hypogeusia

Provisionally accepted
Claudia F. Kirsch Claudia F. Kirsch 1,2,3*Ali Khurram Ali Khurram 3Daniel Lambert Daniel Lambert 3Puneet Belani Puneet Belani 4Akbar Alipour Akbar Alipour 4Shams Rashid Shams Rashid 4Mackenzie Langan Mackenzie Langan 4Sera Saju Sera Saju 4Bradley Delman Bradley Delman 5Hung-Mo Lin Hung-Mo Lin 6Priti Balchandani Priti Balchandani 4
  • 1 Department of Radiology and Biomedical Imaging, School of Medicine, Yale University, New Haven, United States
  • 2 Mount Sinai Hospital, New York, New York, United States
  • 3 The School of Clinical Dentistry, The University of Sheffield, Sheffield, England, United Kingdom
  • 4 Icahn School of Medicine at Mount Sinai, New York, New York, United States
  • 5 Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, United States
  • 6 Department of Biostatistics, School of Public Health, Yale University, New Haven, Connecticut, United States

The final, formatted version of the article will be published soon.

    Linking the olfactory epithelium to the central nervous system are cranial nerve one, the olfactory nerve and cranial nerve "0" the nervus terminalis (NT). Since there is minimal expression of the virus entry protein, angiotensin-converting enzyme 2 (ACE2), in cranial nerve one, olfactory bulbs (OB), and olfactory tracts (OT), it is unclear how SARS-CoV-2 causes anosmia (loss of smell) and hypogeusia (reduction of taste). The NT are often overlooked nerve fibers found in all vertebrates, including humans adjacent to the OB and OT. In animal models, NT express ACE-2 receptors, suggestive of a possible SARS-CoV-2 viral entry site in humans. The purpose of this study was to determine whether ultra-high field 7 Tesla (7T) magnetic resonance imaging (MRI) could visualize the NT, OB, and OT in healthy controls and COVID patients with and without anosmia or hypogeusia and qualitatively assess for OB, OT volume loss and T2 alterations in the NT, OB and OT. In this study, 7T MRI visualized the NT in all imaged subjects. In addition, the increased occurrence of T2 hyperintensity in the NT, OB, and OT in COVID patients with anosmia or hypogeusia was statistically significant when compared to healthy controls and when compared to COVID patients without anosmia or hypogeusia. We propose that viral infection of the NT may reduce blood supply to olfactory pathways and thereby may cause anosmia.

    Keywords: Nervus Terminalis (NT), olfactory tract, magnetic resonance imaging (MRI), Hypothalamus, Angiotensin Converting Enzyme (ACE)-2 receptor, immune response

    Received: 16 Oct 2023; Accepted: 02 Sep 2024.

    Copyright: © 2024 Kirsch, Khurram, Lambert, Belani, Alipour, Rashid, Langan, Saju, Delman, Lin and Balchandani. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Claudia F. Kirsch, Department of Radiology and Biomedical Imaging, School of Medicine, Yale University, New Haven, United States

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