{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,7]],"date-time":"2026-08-07T17:05:44Z","timestamp":1786122344493,"version":"build-2736575974"},"reference-count":23,"publisher":"IOP Publishing","issue":"15","license":[{"start":{"date-parts":[[2026,8,7]],"date-time":"2026-08-07T00:00:00Z","timestamp":1786060800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/publishingsupport.iopscience.iop.org\/iop-standard\/v1"},{"start":{"date-parts":[[2026,8,7]],"date-time":"2026-08-07T00:00:00Z","timestamp":1786060800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/iopscience.iop.org\/info\/page\/text-and-data-mining"}],"funder":[{"DOI":"10.13039\/501100012226","name":"Fundamental Research Funds for the Central Universities","doi-asserted-by":"crossref","award":["KY2030000197"],"award-info":[{"award-number":["KY2030000197"]}],"id":[{"id":"10.13039\/501100012226","id-type":"DOI","asserted-by":"crossref"}]},{"name":"Ministry of Science and Technology of China Key Research and Development Projects","award":["2023YFC3504200"],"award-info":[{"award-number":["2023YFC3504200"]}]},{"name":"Hefei Comprehensive National Science Center"}],"content-domain":{"domain":["iopscience.iop.org"],"crossmark-restriction":false},"short-container-title":["Phys. Med. Biol."],"published-print":{"date-parts":[[2026,8,14]]},"abstract":"Abstract<\/jats:title>\n \n Objective.<\/jats:italic>\n Magnetic Resonance guided Radiation Therapy (MRgRT) integrates magnetic resonance imaging with radiation delivery, providing superior soft-tissue contrast and real-time treatment guidance. For preclinical MRgRT irradiators, a critical concern is whether the ambient magnetic fields compromise the radiation dose distribution. This study aims to investigate the influence of magnetic fields on X-ray tube electron trajectories and dosimetric outcomes.\n Approach.<\/jats:italic>\n The system integrates a 0.5 T MRI scanner and a 225 kVp X-ray tube. The local magnetic field distribution was characterized via finite element analysis. Electron trajectories were simulated across various magnetic field strengths and alignment angles to quantify the X-ray focal-spot displacement. Monte Carlo simulation was then performed to evaluate the dose distribution within homogeneous and heterogeneous tissue-equivalent phantoms.\n Main results.<\/jats:italic>\n In the proposed system, the fringe magnetic field across the X-ray tube electrodes measures 40.4 G and aligns nearly parallel to the electric field. This configuration restricts the X-ray focal-spot displacement to 0.15 mm, resulting in negligible dosimetric deviations. There is good agreement between the dose distributions in the phantoms with and without magnetic fields, maintaining\n \n \n \n <\/jats:tex-math>\n \n \n \u2a7e<\/mml:mtext>\n \n 99.9<\/mml:mn>\n \n \n %<\/mml:mi>\n <\/mml:mrow>\n <\/mml:mrow>\n <\/mml:mrow>\n <\/mml:math>\n <\/jats:inline-formula>\n gamma passing rates at 0.5 mm \/ 1% criteria even under a main magnetic field of up to 10 T.\n Significance.<\/jats:italic>\n This study confirms that, for the small animal MRgRT system, main magnetic field as low as 0.5 T exerts no significant dosimetric impact, provided the magnet and the X-ray tube are well separated, and it may be unnecessary to perform dosimetric corrections.\n <\/jats:p>","DOI":"10.1088\/1361-6560\/ae8fb2","type":"journal-article","created":{"date-parts":[[2026,7,23]],"date-time":"2026-07-23T22:55:28Z","timestamp":1784847328000},"page":"155025","update-policy":"https:\/\/doi.org\/10.1088\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Dosimetry evaluation of an MRI guided small animal irradiator"],"prefix":"10.1088","volume":"71","author":[{"ORCID":"https:\/\/orcid.org\/0009-0009-4095-5905","authenticated-orcid":true,"given":"Cheng","family":"Zheng","sequence":"first","affiliation":[{"name":"University of Science and Technology of China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0006-6669-2312","authenticated-orcid":true,"given":"Xiaogang","family":"Yuan","sequence":"additional","affiliation":[{"name":"University of Science and Technology of China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-3601-0540","authenticated-orcid":true,"given":"Yaowen","family":"Cao","sequence":"additional","affiliation":[{"name":"University of Science and Technology of China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ning","family":"Zhao","sequence":"additional","affiliation":[{"name":"Raycision Medical Technology Co. Ltd"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-6572-6898","authenticated-orcid":true,"given":"Yidong","family":"Yang","sequence":"additional","affiliation":[{"name":"University of Science and Technology of China"},{"name":"University of Science and Technology of China"},{"name":"Ion Medical Research Institute, University of Science and Technology of China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"266","published-online":{"date-parts":[[2026,8,7]]},"reference":[{"key":"pmbae8fb2bib1","doi-asserted-by":"publisher","first-page":"250","DOI":"10.1016\/S0168-9002(03)01368-8","type":"journal-article","article-title":"Geant4\u2014a simulation toolkit nuclear instruments and methods in physics research section a: accelerators, spectrometers","volume":"506","author":"Agostinelli","year":"2003","journal-title":"Detectors Assoc. 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All rights, including for text and data mining, AI training, and similar technologies, are reserved.","name":"copyright_information","label":"Copyright Information"},{"value":"2026-03-23","name":"date_received","label":"Date Received","group":{"name":"publication_dates","label":"Publication dates"}},{"value":"2026-07-23","name":"date_accepted","label":"Date Accepted","group":{"name":"publication_dates","label":"Publication dates"}},{"value":"2026-08-07","name":"date_epub","label":"Online publication date","group":{"name":"publication_dates","label":"Publication dates"}}]}}