Evidence map›Paper›PMID 40903915›Full record

ArticleMedical physics2025

4D-MRI at 0.55T for internal target volume delineation in liver radiation therapy planning.

Xin Miao, Pan Su, Michael A Ohliger, Yang Yang, Jianing Pang, Alexandra E Hotca, Thomas A Hope, Cheng William Hong, Emily K Bergsland, Mary Feng and 1 more

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In one paragraph

Article in Medical physics, 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

11 authors.

Xin MiaoDepartment of Radiology, Children's Hospital Los Angeles, Los Angeles, California, USA.
Pan SuSiemens Medical Solutions USA Inc., Malvern, Pennsylvania, USA.
Michael A OhligerDepartment of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA.
Yang YangDepartment of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA.
Jianing PangSiemens Medical Solutions USA Inc., Malvern, Pennsylvania, USA.
Alexandra E HotcaDepartment of Radiation Oncology, University of California San Francisco, San Francisco, California, USA.
Thomas A HopeDepartment of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA.
Cheng William HongDepartment of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA.
Emily K BergslandDepartment of Medicine, University of California San Francisco, San Francisco, California, USA.
Mary FengDepartment of Radiation Oncology, University of California San Francisco, San Francisco, California, USA.
Jessica E ScholeyDepartment of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundLow-field MRI provides superior soft-tissue contrast compared to CT while costing significantly less than high-field MRI, which makes it a more accessible option for MRI-guided radiation therapy planning. Four-dimensional MRI (4D-MRI) is a technique that has been increasingly adopted clinically for internal target volume (ITV) delineation in free-breathing liver radiotherapy planning, and it requires high spatial resolution and accurate respiratory phase differentiation to enable precise dose planning. The feasibility of 4D-MRI at low-field strength, specifically at 0.55T, has not been evaluated. PURPOSE: This study aims to investigate the feasibility of 4D-MRI for ITV delineation in liver radiation therapy planning using a commercial 0.55T MRI scanner.

methodsA 3D stack-of-stars T1-weighted sequence was implemented with two respiratory self-navigation methods: (1) k-space center point tracking ("k-center") and (2) superior-inferior one-dimensional projection-based tracking ("SI-projection"). These methods were evaluated using ten phantom scans simulating diverse respiratory motion patterns and five liver tumor patient scans.

resultsBoth self-navigation approaches demonstrated strong correlation between the extracted self-gating signals (SGS) and ground-truth motion traces across four breathing patterns: sinusoidal waveform, typical respiration, drifting motion, and irregular breathing. For sinusoidal motion, measured ITV deviations were within 1.1% of the true ITV for both methods. In non-sinusoidal cases, ITV deviations remained within 2% except for two drifting motion cases where k-center SGS based reconstructions showed deviations of 6.0% and 2.4%. In liver tumor patient scans, both self-navigation techniques produced images with sufficient tumor delineation for treatment planning, with SI-projection SGS-based reconstructions yielding sharper images than k-center SGS-based reconstructions. ITV volumes contoured by two radiation oncologists showed strong and comparable inter-observer agreement across both techniques.

conclusionsThis study demonstrates that 4D-MRI at 0.55T is feasible and provides adequate image quality for ITV delineation. Self-navigation techniques play an important role in improving the sharpness of tumor boundaries, with SI-projection based self-navigation offering superior performance in cases of irregular respiratory motion.

Indexed as

Imaging, Three-DimensionalLiverLiver NeoplasmsMagnetic Resonance ImagingRadiotherapy Planning, Computer-AssistedFeasibility StudiesHumansPhantoms, ImagingRadiotherapy, Image-GuidedRespiration

Identifiers

PMID40903915
PMCPMC12409090

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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.