Evidence map›Paper›PMID 41024510›Full record

ArticleMagnetic resonance in medicine2026

A unipolar head gradient for high-field MRI without encoding ambiguity.

Markus Weiger, Johan Overweg, Franciszek Hennel, Emily Louise Baadsvik, Samuel Bianchi, Oskar Björkqvist, Roger Luechinger, Jens Metzger, Eric Seth Michael, Thomas Schmid and 9 more

Abstract read
In one paragraph

Article in Magnetic resonance in medicine, 2026. 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

19 authors.

Markus WeigerInstitute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland.ORCID 0000-0003-4758-3103
Johan OverwegUelzen, Germany.
Franciszek HennelInstitute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland.ORCID 0000-0003-0043-9921
Emily Louise BaadsvikInstitute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland.ORCID 0000-0001-5941-5532
Samuel BianchiInstitute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland.
Oskar BjörkqvistInstitute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland.ORCID 0009-0001-1918-8176
Roger LuechingerInstitute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland.ORCID 0000-0002-7365-0421
Jens MetzgerInstitute for Energy and Process Engineering, ETH Zurich, Zurich, Switzerland.
Eric Seth MichaelInstitute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland.ORCID 0000-0002-2513-4254
Thomas SchmidInstitute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland.
Lauro SingenbergerInstitute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland.
Urs SturzeneggerPhilips AG, Zurich, Switzerland.
Erik OskamPhilips AG, Zurich, Switzerland.
Gerrit VissersPhilips Healthcare, Best, The Netherlands.
Jos KoonenPhilips Healthcare, Best, The Netherlands.
Wout SchuthFutura Composites BV, Heerhugowaard, The Netherlands.
Jeroen KoelemanFutura Composites BV, Heerhugowaard, The Netherlands.
Martino BorgoFutura Composites BV, Heerhugowaard, The Netherlands.
Klaas Paul PruessmannInstitute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland.ORCID 0000-0003-0009-8362

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposeMRI gradients with a conventional, bipolar design generally face a trade-off among performance, encoding ambiguity, and radiofrequency selectivity used to circumvent said ambiguity. This problem is particularly limiting in cutting-edge brain imaging performed at field strengths ≥ 7 T and using high-performance head gradients.

methodsTo address this issue, the present work proposes to fundamentally eliminate the encoding ambiguity in head gradients by using a unipolar z-gradient design that takes advantage of the signal-free range on one side of the imaging volume. This concept is demonstrated by implementation of a unipolar head gradient for operation at 7 T.

resultsImaging in phantoms and in vivo demonstrates elimination of backfolding due to encoding ambiguity. At the same time, the unipolar design achieves efficiency on par with conventional bipolar design, resulting in high amplitude and slew-rate performance.

conclusionThe prospect of gradient systems based on a unipolar design holds promise for all advanced neuroimaging that demands high gradient performance. It will make the greatest difference at 7 T and beyond, where the absence of ambiguity removes a key concern and constraint in terms of radiofrequency behavior and instrumentation.

Indexed as

BrainHeadMagnetic Resonance ImagingAlgorithmsEquipment DesignHumansImage Processing, Computer-AssistedPhantoms, Imaging7 Taliasingbackfoldingbipolarbrain MRInerve stimulation

Identifiers

PMID41024510
PMCPMC12681299

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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.