Effect of wearing a face mask on fMRI BOLD contrast
International spread of the coronavirus SARS-CoV-2 has prompted many MRI scanning facilities to require scan subjects to wear a facial covering (“mask”) during scanning as a precaution against transmission of the virus. Because wearing a mask mixes expired air with the subject's inspired air st...
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doaj-05aef272edfb4ebda99cb6b8dc94d46f2021-03-17T04:13:42ZengElsevierNeuroImage1095-95722021-04-01229117752Effect of wearing a face mask on fMRI BOLD contrastChristine S.W. Law0Patricia S. Lan1Gary H. Glover2Systems Neuroscience and Pain Lab, Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Palo Alto, CA, 94304, USA; Corresponding author.Department of Bioengineering, Stanford University, 443 Via Ortega, Stanford, CA, 94305, USA; Department of Radiology, Stanford University, 1201 Welch Road, Stanford, CA, 94305, USADepartment of Bioengineering, Stanford University, 443 Via Ortega, Stanford, CA, 94305, USA; Department of Radiology, Stanford University, 1201 Welch Road, Stanford, CA, 94305, USAInternational spread of the coronavirus SARS-CoV-2 has prompted many MRI scanning facilities to require scan subjects to wear a facial covering (“mask”) during scanning as a precaution against transmission of the virus. Because wearing a mask mixes expired air with the subject's inspired air stream, the concentration of inspired carbon dioxide [CO2] is elevated, resulting in mild hypercapnia. Changes in the inspired gas mixture have been demonstrated to alter R2*-weighted Blood Oxygen Dependent (BOLD) contrast. In this study, we investigate a potential for face masking to alter BOLD contrast during a sensory-motor task designed to activate visual, auditory, and sensorimotor cortices in 8 subjects. We utilize a nasal cannula to supply air to the subject wearing a surgical mask in on-off blocks of 90s to displace expired CO2, while the subject performs the sensory-motor task. While only a small fraction (2.5%) of the sensory-motor task activation is related to nasal air modulation, a 30.0% change in gray matter BOLD signal baseline is found due to air modulation. Repeating the scan with mask removed produces a small subject-specific bias in BOLD baseline signal from nasal air supply, which may be due to cognitive influence of airflow or cannula-induced hypoxia. Measurements with capnography demonstrate wearing a mask induces an average increase in ETCO2 of 7.4%. Altogether, these results demonstrate that wearing a face mask during gradient-echo fMRI can alter BOLD baseline signal but minimally affects task activation.http://www.sciencedirect.com/science/article/pii/S105381192100029XfMRIBOLD contrastMaskFacial coveringCOVID-19SARS-CoV2 |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Christine S.W. Law Patricia S. Lan Gary H. Glover |
spellingShingle |
Christine S.W. Law Patricia S. Lan Gary H. Glover Effect of wearing a face mask on fMRI BOLD contrast NeuroImage fMRI BOLD contrast Mask Facial covering COVID-19 SARS-CoV2 |
author_facet |
Christine S.W. Law Patricia S. Lan Gary H. Glover |
author_sort |
Christine S.W. Law |
title |
Effect of wearing a face mask on fMRI BOLD contrast |
title_short |
Effect of wearing a face mask on fMRI BOLD contrast |
title_full |
Effect of wearing a face mask on fMRI BOLD contrast |
title_fullStr |
Effect of wearing a face mask on fMRI BOLD contrast |
title_full_unstemmed |
Effect of wearing a face mask on fMRI BOLD contrast |
title_sort |
effect of wearing a face mask on fmri bold contrast |
publisher |
Elsevier |
series |
NeuroImage |
issn |
1095-9572 |
publishDate |
2021-04-01 |
description |
International spread of the coronavirus SARS-CoV-2 has prompted many MRI scanning facilities to require scan subjects to wear a facial covering (“mask”) during scanning as a precaution against transmission of the virus. Because wearing a mask mixes expired air with the subject's inspired air stream, the concentration of inspired carbon dioxide [CO2] is elevated, resulting in mild hypercapnia. Changes in the inspired gas mixture have been demonstrated to alter R2*-weighted Blood Oxygen Dependent (BOLD) contrast. In this study, we investigate a potential for face masking to alter BOLD contrast during a sensory-motor task designed to activate visual, auditory, and sensorimotor cortices in 8 subjects. We utilize a nasal cannula to supply air to the subject wearing a surgical mask in on-off blocks of 90s to displace expired CO2, while the subject performs the sensory-motor task. While only a small fraction (2.5%) of the sensory-motor task activation is related to nasal air modulation, a 30.0% change in gray matter BOLD signal baseline is found due to air modulation. Repeating the scan with mask removed produces a small subject-specific bias in BOLD baseline signal from nasal air supply, which may be due to cognitive influence of airflow or cannula-induced hypoxia. Measurements with capnography demonstrate wearing a mask induces an average increase in ETCO2 of 7.4%. Altogether, these results demonstrate that wearing a face mask during gradient-echo fMRI can alter BOLD baseline signal but minimally affects task activation. |
topic |
fMRI BOLD contrast Mask Facial covering COVID-19 SARS-CoV2 |
url |
http://www.sciencedirect.com/science/article/pii/S105381192100029X |
work_keys_str_mv |
AT christineswlaw effectofwearingafacemaskonfmriboldcontrast AT patriciaslan effectofwearingafacemaskonfmriboldcontrast AT garyhglover effectofwearingafacemaskonfmriboldcontrast |
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