ArticleMedical physics2019
Large field of view distortion assessment in a low-field MR-linac.
Article in Medical physics, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 16 papers.
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Who cites it
16 citing papers in PubMed, 26 citations in OpenAlex.
- Acceptance testing of a 0.35 T MR-Linac: procedures, QA baseline, and system limitations.Journal of applied clinical medical physics · 2026Article
- AAPM Task Group 334: A guidance document to using radiotherapy immobilization devices and accessories in an MR environment.Medical physics · 2024Article
- Characterization of spatial integrity with active and passive implants in a low-field magnetic resonance linear accelerator scanner.Physics and imaging in radiation oncology · 2024Article
- Distortion-corrected image reconstruction with deep learning on an MRI-Linac.Magnetic resonance in medicine · 2023Article
- Development of a vendor neutral MRI distortion quality assurance workflow.Journal of applied clinical medical physics · 2022Article
- First clinical experience of correcting phantom-based image distortion related to gantry position on a 0.35T MR-Linac.Journal of applied clinical medical physics · 2021Article
- Clinical assessment of geometric distortion for a 0.35T MR-guided radiotherapy system.Journal of applied clinical medical physics · 2021Article
- Effects of BMedical physics · 2021Article
- Article
- MRI-Guided Radiation Therapy.Advances in oncology · 2021Article
- [Magnetic-resonance-guided radiotherapy : The beginning of a new era in radiation oncology?]Der Radiologe · 2021Review
- Rapid multicontrast brain imaging on a 0.35T MR-linac.Medical physics · 2020Article
- BMedical physics · 2020Article
- Tumor-site specific geometric distortions in high field integrated magnetic resonance linear accelerator radiotherapy.Physics and imaging in radiation oncology · 2020Article
- MRI quality control for low-field MR-IGRT systems: Lessons learned.Journal of applied clinical medical physics · 2019Article
- Technical design and concept of a 0.35 T MR-Linac.Clinical and translational radiation oncology · 2019Review
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Authors and funding
4 authors at 1 institution in 1 country.
Funding
Abstract
purposeMR-guided radiation therapy (RT) offers unparalleled soft tissue contrast for localization and target tracking. However, MRI distortions may be detrimental to high precision RT. This work characterizes the gradient nonlinearity (GNL) and total distortions over the first year of clinical operation of a 0.35T MR-linac.
methodsFor GNL characterization, an in-house large field of view (FOV) phantom (60 × 42.5 × 55 cm
resultsThe scanner's spatial integrity within the first ~10 months was stable (maximum total distortion variation = 10/6/8%, maximum distortion = 1.41/0.99/1.56 mm in Axial/Coronal/Sagittal planes, respectively). GNL distortions measured during this time period <10 cm from isocenter were (-0.74, 0.45), (-0.67, 0.53), and (-0.86, 0.70) mm in AP/LR/SI directions. In the 10-20 cm range, <1.5% of the distortions exceeded 2 mm in the AP and LR axes while <4% of the distortions exceeded 2 mm for SI. After major repairs and magnet re-shim, detectable changes were observed in total and GNL distortions (20% reduction in AP and 36% increase in SI direction in the 20-25 cm range). Across all timepoints and axes, 38-53% of landmarks in the 20-25 cm range were displaced by >1 mm.
conclusionsGNL distortions were negligible within a 10 cm radius from isocenter. However, in the periphery, non-negligible distortions of up to ~7 mm were observed, which may necessitate GNL corrections for MR-IGRT for treatment sites distant from magnet isocenter.
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