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Ventilation–perfusion heterogeneity measured by the multiple inert gas elimination technique is minimally affected by intermittent breathing of 100% O(2)

Proton magnetic resonance (MR) imaging to quantify regional ventilation–perfusion ( [Formula: see text]) ratios combines specific ventilation imaging (SVI) and separate proton density and perfusion measures into a composite map. Specific ventilation imaging exploits the paramagnetic properties of O(...

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Autores principales: Elliott, Ann R., Kizhakke Puliyakote, Abhilash S., Tedjasaputra, Vincent, Pazár, Beni, Wagner, Harrieth, Sá, Rui C., Orr, Jeremy E., Prisk, G. Kim, Wagner, Peter D., Hopkins, Susan R.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7340847/
https://www.ncbi.nlm.nih.gov/pubmed/32638530
http://dx.doi.org/10.14814/phy2.14488
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author Elliott, Ann R.
Kizhakke Puliyakote, Abhilash S.
Tedjasaputra, Vincent
Pazár, Beni
Wagner, Harrieth
Sá, Rui C.
Orr, Jeremy E.
Prisk, G. Kim
Wagner, Peter D.
Hopkins, Susan R.
author_facet Elliott, Ann R.
Kizhakke Puliyakote, Abhilash S.
Tedjasaputra, Vincent
Pazár, Beni
Wagner, Harrieth
Sá, Rui C.
Orr, Jeremy E.
Prisk, G. Kim
Wagner, Peter D.
Hopkins, Susan R.
author_sort Elliott, Ann R.
collection PubMed
description Proton magnetic resonance (MR) imaging to quantify regional ventilation–perfusion ( [Formula: see text]) ratios combines specific ventilation imaging (SVI) and separate proton density and perfusion measures into a composite map. Specific ventilation imaging exploits the paramagnetic properties of O(2), which alters the local MR signal intensity, in an F(I)O(2)‐dependent manner. Specific ventilation imaging data are acquired during five wash‐in/wash‐out cycles of breathing 21% O(2) alternating with 100% O(2) over ~20 min. This technique assumes that alternating F(I)O(2) does not affect [Formula: see text] heterogeneity, but this is unproven. We tested the hypothesis that alternating F(I)O(2) exposure increases [Formula: see text] mismatch in nine patients with abnormal pulmonary gas exchange and increased [Formula: see text] mismatch using the multiple inert gas elimination technique (MIGET).The following data were acquired (a) breathing air (baseline), (b) breathing alternating air/100% O(2) during an emulated‐SVI protocol (eSVI), and (c) 20 min after ambient air breathing (recovery). MIGET heterogeneity indices of shunt, deadspace, ventilation versus [Formula: see text] ratio, LogSD [Formula: see text] , and perfusion versus [Formula: see text] ratio, LogSD [Formula: see text] were calculated. LogSD [Formula: see text] was not different between eSVI and baseline (1.04 ± 0.39 baseline, 1.05 ± 0.38 eSVI, p = .84); but was reduced compared to baseline during recovery (0.97 ± 0.39, p = .04). There was no significant difference in LogSD [Formula: see text] across conditions (0.81 ± 0.30 baseline, 0.79 ± 0.15 eSVI, 0.79 ± 0.20 recovery; p = .54); Deadspace was not significantly different (p = .54) but shunt showed a borderline increase during eSVI (1.0% ± 1.0 baseline, 2.6% ± 2.9 eSVI; p = .052) likely from altered hypoxic pulmonary vasoconstriction and/or absorption atelectasis. Intermittent breathing of 100% O(2) does not substantially alter [Formula: see text] matching and if SVI measurements are made after perfusion measurements, any potential effects will be minimized.
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spelling pubmed-73408472020-07-14 Ventilation–perfusion heterogeneity measured by the multiple inert gas elimination technique is minimally affected by intermittent breathing of 100% O(2) Elliott, Ann R. Kizhakke Puliyakote, Abhilash S. Tedjasaputra, Vincent Pazár, Beni Wagner, Harrieth Sá, Rui C. Orr, Jeremy E. Prisk, G. Kim Wagner, Peter D. Hopkins, Susan R. Physiol Rep Original Research Proton magnetic resonance (MR) imaging to quantify regional ventilation–perfusion ( [Formula: see text]) ratios combines specific ventilation imaging (SVI) and separate proton density and perfusion measures into a composite map. Specific ventilation imaging exploits the paramagnetic properties of O(2), which alters the local MR signal intensity, in an F(I)O(2)‐dependent manner. Specific ventilation imaging data are acquired during five wash‐in/wash‐out cycles of breathing 21% O(2) alternating with 100% O(2) over ~20 min. This technique assumes that alternating F(I)O(2) does not affect [Formula: see text] heterogeneity, but this is unproven. We tested the hypothesis that alternating F(I)O(2) exposure increases [Formula: see text] mismatch in nine patients with abnormal pulmonary gas exchange and increased [Formula: see text] mismatch using the multiple inert gas elimination technique (MIGET).The following data were acquired (a) breathing air (baseline), (b) breathing alternating air/100% O(2) during an emulated‐SVI protocol (eSVI), and (c) 20 min after ambient air breathing (recovery). MIGET heterogeneity indices of shunt, deadspace, ventilation versus [Formula: see text] ratio, LogSD [Formula: see text] , and perfusion versus [Formula: see text] ratio, LogSD [Formula: see text] were calculated. LogSD [Formula: see text] was not different between eSVI and baseline (1.04 ± 0.39 baseline, 1.05 ± 0.38 eSVI, p = .84); but was reduced compared to baseline during recovery (0.97 ± 0.39, p = .04). There was no significant difference in LogSD [Formula: see text] across conditions (0.81 ± 0.30 baseline, 0.79 ± 0.15 eSVI, 0.79 ± 0.20 recovery; p = .54); Deadspace was not significantly different (p = .54) but shunt showed a borderline increase during eSVI (1.0% ± 1.0 baseline, 2.6% ± 2.9 eSVI; p = .052) likely from altered hypoxic pulmonary vasoconstriction and/or absorption atelectasis. Intermittent breathing of 100% O(2) does not substantially alter [Formula: see text] matching and if SVI measurements are made after perfusion measurements, any potential effects will be minimized. John Wiley and Sons Inc. 2020-07-07 /pmc/articles/PMC7340847/ /pubmed/32638530 http://dx.doi.org/10.14814/phy2.14488 Text en © 2020 The Authors. Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society. This is an open access article under the terms of the http://creativecommons.org/licenses/by/4.0/ License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
spellingShingle Original Research
Elliott, Ann R.
Kizhakke Puliyakote, Abhilash S.
Tedjasaputra, Vincent
Pazár, Beni
Wagner, Harrieth
Sá, Rui C.
Orr, Jeremy E.
Prisk, G. Kim
Wagner, Peter D.
Hopkins, Susan R.
Ventilation–perfusion heterogeneity measured by the multiple inert gas elimination technique is minimally affected by intermittent breathing of 100% O(2)
title Ventilation–perfusion heterogeneity measured by the multiple inert gas elimination technique is minimally affected by intermittent breathing of 100% O(2)
title_full Ventilation–perfusion heterogeneity measured by the multiple inert gas elimination technique is minimally affected by intermittent breathing of 100% O(2)
title_fullStr Ventilation–perfusion heterogeneity measured by the multiple inert gas elimination technique is minimally affected by intermittent breathing of 100% O(2)
title_full_unstemmed Ventilation–perfusion heterogeneity measured by the multiple inert gas elimination technique is minimally affected by intermittent breathing of 100% O(2)
title_short Ventilation–perfusion heterogeneity measured by the multiple inert gas elimination technique is minimally affected by intermittent breathing of 100% O(2)
title_sort ventilation–perfusion heterogeneity measured by the multiple inert gas elimination technique is minimally affected by intermittent breathing of 100% o(2)
topic Original Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7340847/
https://www.ncbi.nlm.nih.gov/pubmed/32638530
http://dx.doi.org/10.14814/phy2.14488
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