Evidence map›Paper›PMID 39937834›Full record

ArticleThe Journal of physiology2025

Feasibility of multimodal magnetic resonance imaging to assess maternal hyperoxygenation in sheep pregnancy.

Dimitra Flouri, Jack R T Darby, Stacey L Holman, Georgia Williams, Vasileios Vavourakis, Anna L David, Janna L Morrison, Andrew Melbourne

Abstract read
In one paragraph

Article in The Journal of physiology, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

8 authors.

Dimitra FlouriIn Silico Modelling Group, Department of Mechanical & Manufacturing Engineering, University of Cyprus, Nicosia, Cyprus.ORCID 0000-0002-8846-3573
Jack R T DarbyEarly Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, Adelaide, SA, Australia.
Stacey L HolmanEarly Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, Adelaide, SA, Australia.ORCID 0000-0002-6326-4797
Georgia WilliamsPreclinical Imaging and Research Laboratories, South Australian Health and Medical Research Institute, Adelaide, SA, Australia.ORCID 0000-0002-5529-1322
Vasileios VavourakisIn Silico Modelling Group, Department of Mechanical & Manufacturing Engineering, University of Cyprus, Nicosia, Cyprus.ORCID 0000-0002-4102-2084
Anna L DavidElizabeth Garrett Anderson Institute for Women's Health, University College London, London, UK.ORCID 0000-0002-0199-6140
Janna L MorrisonPreclinical Imaging and Research Laboratories, South Australian Health and Medical Research Institute, Adelaide, SA, Australia.ORCID 0000-0002-8602-8519
Andrew MelbourneSchool of Biomedical Engineering & Imaging Sciences, King's College London, London, UK.ORCID 0000-0001-7667-3947

Funding

Development and validation of MR imaging methods for in vivo assessment of placental perfusion and oxygen transportR01HD108833 · NICHD · OREGON HEALTH & SCIENCE UNIVERSITY · PI Victoria HJ Roberts · 2023 to 2026
$1.9M
NICHD NIH HHS R01 HD108833
6 · The paper itself

Abstract

An adequate supply of oxygen is crucial for optimal fetal growth and development. Estimation of quantitative indices that reflect tissue diffusivity and oxygenation have been enabled by advances in magnetic resonance imaging (MRI) technology. However, the current diagnostic tools in clinical obstetrics, such as Doppler ultrasound measurements of umbilical blood flow and cardiotocography, do not offer direct information about the oxygen supply to the fetus, nor placental function in vivo. Although MRI provides an opportunity to identify critical changes in fetal oxygenation, exact tissue oxygen content cannot be established in humans. Preclinical models such as pregnant sheep allow the use of invasive methods to validate MRI measurements. The present study investigates the relationship between changes in MRI signal and conventional blood gas analyser measurements during normoxic and hyperoxic conditions in pregnant sheep. Several studies have reported an increase in human fetal oxygenation during 100% maternal oxygen inhalation. We investigated the physiological impact of maternal hyperoxygenation on the placenta in normal pregnant sheep using multimodal functional MRI. Using a multicompartment MRI signal model, we observed the expected increase in feto-placental oxygen saturation with maternal hyperoxygenation. In addition, maternal hyperoxygenation resulted in a significant increase in blood-oxygenation-level-dependent (BOLD) signal intensities, suggesting that BOLD MRI allows non-invasive assessment of the feto-placental response to maternal hyperoxygenation in sheep. Our data suggest that diffusion and relaxation-based MRI is sensitive to acute changes in maternal and feto-placental oxygenation and demonstrate a link between MRI-parameter estimated and reference oxygen saturation. KEY POINTS: Quantification of feto-placental oxygenation and function are important for correct differential diagnosis of placental insufficiency. The only current method for obtaining information about fetal oxygen delivery is cordocentesis. However, there is a risk of inducing preterm birth and/or fetal loss associated with the procedure. Magnetic resonance imaging (MRI) can estimate changes in oxygenation in specific areas of placental and fetal tissue. Using the DECIDE (i.e. diffusion-relaxation combined imaging for detailed placental evaluation) multicompartment model that is sensitive to changes in maternal and feto-placental oxygenation and the blood-oxygenation-level-dependent (BOLD) MRI technique in the sheep fetus, we have demonstrated that maternal hyperoxygenation increases oxygenation of fetal tissue in the placenta. There was a differential effect according to placentome morphological type. This study shows a link between MRI estimated parameters and reference maternal and fetal

Indexed as

HyperoxiaMagnetic Resonance ImagingOxygenPlacentaAnimalsFeasibility StudiesFemaleOxygen SaturationPregnancySheepOxygenDECIDEmagnetic resonance imagingmaternal hyperoxiaoxygenplacentasheep

Identifiers

PMID39937834
PMCPMC11870080

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LicenceCC BY
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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.