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. 2020 Sep;41(9):1703-1706.
doi: 10.3174/ajnr.A6675. Epub 2020 Jun 25.

Anosmia in COVID-19 Associated with Injury to the Olfactory Bulbs Evident on MRI

M F V V Aragão  1   2 , M C Leal  3   4 , O Q Cartaxo Filho  4 , T M Fonseca  4 , M M Valença  3
Affiliations

Anosmia in COVID-19 Associated with Injury to the Olfactory Bulbs Evident on MRI

M F V V Aragão et al. AJNR Am J Neuroradiol. 2020 Sep.

Abstract

Patients with coronavirus disease 2019 (COVID-19) may have symptoms of anosmia or partial loss of the sense of smell, often accompanied by changes in taste. We report 5 cases (3 with anosmia) of adult patients with COVID-19 in whom injury to the olfactory bulbs was interpreted as microbleeding or abnormal enhancement on MR imaging. The patients had persistent headache (n = 4) or motor deficits (n = 1). This olfactory bulb injury may be the mechanism by which the Severe Acute Respiratory Syndrome coronavirus 2 causes olfactory dysfunction.

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Figures

FIG 1.
FIG 1.
MR imaging shows probably microbleeding (methemoglobin) in the left olfactory bulb of a patient (case 1) with COVID-19 and anosmia. The left olfactory bulb (long arrows) has partial hyperintensity on precontrast fat-suppressed T1WI (A) and also on postcontrast fat-suppressed T1WI (B) and STIR (C).
FIG 2.
FIG 2.
The coronal postcontrast fat-suppressed T1WI shows hyperintensity suggestive of enhancement or methemoglobin in the olfactory bulbs of 4 patients with COVID-19 (A–D; cases 2–5) compared with a healthy patient with normal olfactory bulbs (E and F). The coronal postcontrast fat-suppressed T1WI in 3 patients with COVID-19 (A–C; cases 2–4) shows that both olfactory bulbs (long arrows) are small oval images that are hyperintense with contrast, having signal intensity higher than the intensity of the cortex. D, A patient (case 5) with COVID-19 shows hyperintensity only on the left bulb (long arrow), the right olfactory bulb being normal (short arrow). In a healthy 60-year-old man, the coronal T2WI (E) and the postcontrast fat-suppressed T1WI (F) demonstrate normal olfactory bulbs (long arrows), which are isointense to the cortex and normally hypointense on postgadolinium sequence (F).
See this image and copyright information in PMC

Comment in

  • Reply.
    Aragão MFVV, Leal MC, Fonseca TM, Cartaxo Filho OQ, Valença MM. Aragão MFVV, et al. AJNR Am J Neuroradiol. 2021 Jan;42(2):E2-E3. doi: 10.3174/ajnr.A6943. Epub 2020 Dec 3. AJNR Am J Neuroradiol. 2021. PMID: 33272952 Free PMC article. No abstract available.
  • Seeing What We Expect to See in COVID-19.
    Mamourian A. Mamourian A. AJNR Am J Neuroradiol. 2021 Jan;42(2):E1. doi: 10.3174/ajnr.A6912. Epub 2020 Dec 3. AJNR Am J Neuroradiol. 2021. PMID: 33272953 Free PMC article. No abstract available.
  • Reply.
    Aragao MFVV, deAndrade PHP, da Nobrega Segundo VS, Marques MM, de Azevedo HJG, de Mello RJV, de Carvalho Leal M, Soares ML, Valenca MM. Aragao MFVV, et al. AJNR Am J Neuroradiol. 2021 Sep;42(9):E66-E68. doi: 10.3174/ajnr.A7234. Epub 2021 Aug 5. AJNR Am J Neuroradiol. 2021. PMID: 34353782 Free PMC article. No abstract available.
  • Susceptibility Artifacts in the Anterior Cranial Fossa Mimicking Hemorrhage in Patients with Anosmia.
    Manov JJ, Alfonso M, Saigal G. Manov JJ, et al. AJNR Am J Neuroradiol. 2021 Sep;42(9):E64-E65. doi: 10.3174/ajnr.A7184. Epub 2021 Aug 5. AJNR Am J Neuroradiol. 2021. PMID: 34353783 Free PMC article. No abstract available.

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