Evidence map›Paper›PMID 41039908›Full record

ArticleMagnetic resonance in medicine2026

Cartesian MaxGIRF: Model-based EPI reconstruction incorporating gradient nonlinearity and concomitant field effects.

Nam G Lee, Sophia X Cui, Krishna S Nayak

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

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2 · The registry

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3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

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4 · The record

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5 · Who and what money

Authors and funding

3 authors.

Nam G LeeAlfred E. Mann Department of Biomedical Engineering, University of Southern California, Los Angeles, California, USA.ORCID https://orcid.org/0000-0001-5462-1492
Sophia X CuiSiemens Medical Solutions USA, Los Angeles, California, USA.ORCID https://orcid.org/0000-0002-5133-4903
Krishna S NayakAlfred E. Mann Department of Biomedical Engineering, University of Southern California, Los Angeles, California, USA.ORCID https://orcid.org/0000-0001-5735-3550

Funding

Improved Diagnostic MRI around Metallic ImplantsR01AR078912 · NIAMS · UNIVERSITY OF SOUTHERN CALIFORNIA · PI Brian Andrew Hargreaves, Krishna Shrinivas Nayak · 2022 to 2026
$2.4M
Volumetric Real-Time MRI at 0.55 TeslaU01HL167613 · NHLBI · UNIVERSITY OF SOUTHERN CALIFORNIA · PI Adrienne Campbell, Krishna Shrinivas Nayak · 2023 to 2026
$2.0M
Division of Computing and Communication Foundations 1828736National Heart and Lung Institute U01-HL167613NHLBI NIH HHS U01 HL167613NIAMS NIH HHS R01 AR078912NIAMS NIH HHS R01AR078912
6 · The paper itself

Abstract

purposeLower field strength scanners with large bore size or complex geometries, and scanners with stronger gradient systems experience increased gradient nonlinearity and concomitant fields, each of which causes distortions in EPI. Current correction approaches based on image-domain interpolation introduce undesirable spatial blurring. To avoid spatial blurring, we introduce a model-based EPI reconstruction framework, denoted Cartesian MaxGIRF ("Max"well field correction using "GIRF"-predicted gradients), that simultaneously compensates the effects of concomitant fields, gradient nonlinearity, and off-resonance during image reconstruction. THEORY AND

methodsPerformance of the proposed framework was compared against standard correction methods using phantom datasets at 0.55T: (1) 2D spin-echo EPI (SE-EPI) with reversed phase-encoding directions and (2) accelerated 2D SE-EPI with partial Fourier. Two unique EPI image artifacts induced by concomitant fields ("parabolic shift" and "slice-dependent Nyquist ghost") were demonstrated and mitigated by the proposed framework using long-ETL 3D GRE-EPI and high-resolution 3D GRE-EPI, respectively. Resolution improvements and artifact mitigations by the proposed framework were demonstrated using in-vivo human brain datasets: (1) accelerated 2D diffusion-weighted SE-EPI and (2) high-resolution 3D GRE-EPI at 0.55T.

resultsThe amount of the parabolic shift for each imaging case was theoretically analyzed. The proposed framework demonstrated the mitigation of both parabolic shifts and slice-dependent Nyquist ghosts and retained better image details than standard correction methods when mitigating geometric distortions for all scenarios.

conclusionThe Cartesian MaxGIRF framework simultaneously mitigates the effects of concomitant fields, gradient nonlinearity, and static off-resonance. This approach is particularly useful to mitigate artifacts induced by second-order concomitant fields present in both symmetric and asymmetric gradient systems.

Indexed as

BrainEcho-Planar ImagingImage Processing, Computer-AssistedAlgorithmsArtifactsFourier AnalysisHumansImaging, Three-DimensionalPhantoms, Imagingconcomitant fieldsecho planar imaginggradient nonlinearityhigher‐order image reconstructionmodel‐based reconstructionoff‐resonance correction

Identifiers

PMID41039908
PMCPMC12681320

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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.