{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,12]],"date-time":"2026-06-12T16:13:44Z","timestamp":1781280824616,"version":"3.54.1"},"reference-count":10,"publisher":"Wiley","issue":"2","license":[{"start":{"date-parts":[[2023,10,17]],"date-time":"2023-10-17T00:00:00Z","timestamp":1697500800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"funder":[{"DOI":"10.13039\/100019599","name":"European Partnership on Metrology","doi-asserted-by":"publisher","award":["21NRM05 STASIS"],"award-info":[{"award-number":["21NRM05 STASIS"]}],"id":[{"id":"10.13039\/100019599","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100007352","name":"Staatssekretariat f\u00fcr Bildung, Forschung und Innovation","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100007352","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Magnetic Resonance in Med"],"published-print":{"date-parts":[[2024,2]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>Purpose<\/jats:title><jats:p>Radiofrequency (RF) exposure during MR examination is limited by IEC 60601\u20102\u201033 to prevent thermal hazards to patients. These limits are also the basis to derive the maximum induced field for the demonstration of MR safety of implants per ISO\/TS 10974 (2018). One limit is the head\u2010averaged specific absorption rate (SAR), for which the head extent is defined differently by MR and implant vendors. The purpose of this technical note is to inform MR safety stakeholders on the sensitivity of safety evaluations due to different head extent definitions.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>RF distributions from the validated MRIxViP exposure libraries of 12 high\u2010resolution human anatomical models were scaled to the normative SAR limits for different definitions of the head extent to compare the corresponding induced SAR and electric (E\u2010)field levels.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>The definitions of the head extent used by major implant vendors and defined in ISO\/TS 10974 (2018) are larger than those introduced in IEC 60601\u20102\u201033 (2022), resulting in lower RF head exposure by up to 2.4\u2009dB (factor 1.7). Other proposed definitions of the head result in intermediate values.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>The different head extents result in different maximum RF exposures affecting the risk assessment by up to a factor of 1.7. The results of this study can be used to estimate the additional uncertainty in safety assessments. Future revisions of MR standards should eliminate this inconsistency.<\/jats:p><\/jats:sec>","DOI":"10.1002\/mrm.29894","type":"journal-article","created":{"date-parts":[[2023,10,18]],"date-time":"2023-10-18T02:38:23Z","timestamp":1697596703000},"page":"735-740","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Influence of patient head definition on induced E\u2010fields during MR examination"],"prefix":"10.1002","volume":"91","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4377-0676","authenticated-orcid":false,"given":"Tolga","family":"Goren","sequence":"first","affiliation":[{"name":"IT'IS Foundation  Zurich Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sylvain","family":"Reboux","sequence":"additional","affiliation":[{"name":"ZMT Zurich MedTech AG  Zurich Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0756-192X","authenticated-orcid":false,"given":"Silvia","family":"Farcito","sequence":"additional","affiliation":[{"name":"IT'IS Foundation  Zurich Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0935-9530","authenticated-orcid":false,"given":"Bryn","family":"Lloyd","sequence":"additional","affiliation":[{"name":"IT'IS Foundation  Zurich Switzerland"},{"name":"ZMT Zurich MedTech AG  Zurich Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5827-3728","authenticated-orcid":false,"given":"Niels","family":"Kuster","sequence":"additional","affiliation":[{"name":"IT'IS Foundation  Zurich Switzerland"},{"name":"Department of Information Technology and Electrical Engineering Swiss Federal Institute of Technology (ETH)  Zurich Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2023,10,17]]},"reference":[{"key":"e_1_2_8_2_1","unstructured":"IEC 60601\u20102\u201033 ED4.0: Particular requirements for the basic safety and essential performance of magnetic resonance equipment for medical diagnosis.2022."},{"key":"e_1_2_8_3_1","unstructured":"ASTM F2182 \u2010 19e2. Standard test method for measurement of radio frequency induced heating on or near passive implants during magnetic resonance imaging.2019."},{"key":"e_1_2_8_4_1","unstructured":"ISO\/TS 10974. Assessment of the safety of magnetic resonance imaging for patients with an active implantable medical device.2018."},{"key":"e_1_2_8_5_1","unstructured":"Team ISO\/IEC Joint Directives Management.ISO\/IEC Directives Part 2: principles and rules for the structure and drafting of ISO and IEC documents.2021."},{"key":"e_1_2_8_6_1","doi-asserted-by":"publisher","DOI":"10.1088\/0031-9155\/59\/18\/5287"},{"key":"e_1_2_8_7_1","unstructured":"MDDT Summary of evidence and basis of qualification decision for IMAnalytics with MRIxViP 1.5T\/3.0T and BCLib. MDDT Q181884\/S004: IT'IS Foundation Zurich Switzerland.2020."},{"key":"e_1_2_8_8_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.pbiomolbio.2011.09.017"},{"key":"e_1_2_8_9_1","volume-title":"Guidance for the Submission of Premarket Notifications for Magnetic Resonance Diagnostic Devices","author":"FDA Center for Devices and Radiological","year":"1998"},{"key":"e_1_2_8_10_1","doi-asserted-by":"publisher","DOI":"10.1002\/jmri.20041"},{"key":"e_1_2_8_11_1","article-title":"Induced radiofrequency fields in patients undergoing MR examinations: insights for risk assessment","volume":"66","author":"Aiping Y","year":"2021","journal-title":"Phys Med Biol"}],"container-title":["Magnetic Resonance in Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/mrm.29894","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,12,14]],"date-time":"2023-12-14T21:56:56Z","timestamp":1702591016000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1002\/mrm.29894"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,10,17]]},"references-count":10,"journal-issue":{"issue":"2","published-print":{"date-parts":[[2024,2]]}},"alternative-id":["10.1002\/mrm.29894"],"URL":"https:\/\/doi.org\/10.1002\/mrm.29894","archive":["Portico"],"relation":{},"ISSN":["0740-3194","1522-2594"],"issn-type":[{"value":"0740-3194","type":"print"},{"value":"1522-2594","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,10,17]]},"assertion":[{"value":"2023-07-19","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2023-10-03","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2023-10-17","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}