{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,15]],"date-time":"2026-08-15T11:52:53Z","timestamp":1786794773969,"version":"build-2736575974"},"reference-count":48,"publisher":"Wiley","license":[{"start":{"date-parts":[[2024,8,12]],"date-time":"2024-08-12T00:00:00Z","timestamp":1723420800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001659","name":"Deutsche Forschungsgemeinschaft","doi-asserted-by":"publisher","award":["SCHM 2677\/4\u20101"],"award-info":[{"award-number":["SCHM 2677\/4\u20101"]}],"id":[{"id":"10.13039\/501100001659","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001659","name":"Deutsche Forschungsgemeinschaft","doi-asserted-by":"publisher","award":["GRK2260"],"award-info":[{"award-number":["GRK2260"]}],"id":[{"id":"10.13039\/501100001659","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Magnetic Resonance in Med"],"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>Purpose<\/jats:title><jats:p>This study aims to map the transmit magnetic field () in the human body at 7T using MR fingerprinting (MRF), with a focus on achieving high accuracy and precision across a large dynamic range, particularly at low flip angles (FAs).<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>A FLASH\u2010based MRF sequence (B1\u2010MRF) with high  sensitivity was developed. Phantom and in vivo abdominal imaging were performed at 7T, and the results were compared with established reference methods, including a slow but precise preparation\u2010based method (PEX), saturated TurboFLASH (satTFL), actual flip angle imaging (AFI) and Bloch\u2010Siegert shift (BSS).<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>The MRF signal curve was highly sensitive to , while T<jats:sub>1<\/jats:sub> sensitivity was comparatively low. The phantom experiment showed good agreement of  to PEX for a T<jats:sub>1<\/jats:sub> range of 204\u20131691\u2009ms evaluated at FAs from 0\u00b0 to 70\u00b0. Compared to the references, a dynamic range increase larger than a factor of two was determined experimentally. In vivo liver scans showed a strong correlation between B1\u2010MRF, satTFL, and RPE\u2010AFI in a low body mass index (BMI) subject (18.1\u2009kg\/m<jats:sup>2<\/jats:sup>). However, in larger BMI subjects (\u226525.5\u2009kg\/m<jats:sup>2<\/jats:sup>), inconsistencies were observed in low  regions for satTFL and RPE\u2010AFI, while B1\u2010MRF still provided consistent results in these regions.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>B1\u2010MRF provides accurate and precise  maps over a wide range of FAs, surpassing the capabilities of existing methods in the FA range\u2009&lt;\u200960\u00b0. Its enhanced sensitivity at low FAs is advantageous for various applications requiring precise  estimates, potentially advancing the frontiers of ultra\u2010high field (UHF) body imaging at 7T and beyond.<\/jats:p><\/jats:sec>","DOI":"10.1002\/mrm.30242","type":"journal-article","created":{"date-parts":[[2024,8,12]],"date-time":"2024-08-12T16:55:46Z","timestamp":1723481746000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["B1\u2010MRF: Large dynamic range MRF\u2010based absolute B1+ mapping in the human body at <scp>7T<\/scp>"],"prefix":"10.1002","author":[{"ORCID":"https:\/\/orcid.org\/0009-0001-1956-3757","authenticated-orcid":false,"given":"Max","family":"Lutz","sequence":"first","affiliation":[{"name":"Physikalisch\u2010Technische Bundesanstalt  Braunschweig and Berlin Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3618-9610","authenticated-orcid":false,"given":"Christoph Stefan","family":"Aigner","sequence":"additional","affiliation":[{"name":"Physikalisch\u2010Technische Bundesanstalt  Braunschweig and Berlin Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0865-9021","authenticated-orcid":false,"given":"Sebastian","family":"Flassbeck","sequence":"additional","affiliation":[{"name":"Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology New York University Grossman School of Medicine  New York New York USA"},{"name":"Center for Advanced Imaging Innovation and Research (CAI<sup>2<\/sup>R), Department of Radiology New York University Grossman School of Medicine  New York New York USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9453-8992","authenticated-orcid":false,"given":"Felix","family":"Krueger","sequence":"additional","affiliation":[{"name":"Physikalisch\u2010Technische Bundesanstalt  Braunschweig and Berlin Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Constance G. F.","family":"Gatefait","sequence":"additional","affiliation":[{"name":"Physikalisch\u2010Technische Bundesanstalt  Braunschweig and Berlin Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4355-8368","authenticated-orcid":false,"given":"Christoph","family":"Kolbitsch","sequence":"additional","affiliation":[{"name":"Physikalisch\u2010Technische Bundesanstalt  Braunschweig and Berlin Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8227-3632","authenticated-orcid":false,"given":"Berk","family":"Silemek","sequence":"additional","affiliation":[{"name":"Physikalisch\u2010Technische Bundesanstalt  Braunschweig and Berlin Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7065-2528","authenticated-orcid":false,"given":"Frank","family":"Seifert","sequence":"additional","affiliation":[{"name":"Physikalisch\u2010Technische Bundesanstalt  Braunschweig and Berlin Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tobias","family":"Schaeffter","sequence":"additional","affiliation":[{"name":"Physikalisch\u2010Technische Bundesanstalt  Braunschweig and Berlin Germany"},{"name":"Einstein Center Digital Future  Berlin Germany"},{"name":"Department of Biomedical Engineering Technical University of Berlin  Berlin Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4410-6790","authenticated-orcid":false,"given":"Sebastian","family":"Schmitter","sequence":"additional","affiliation":[{"name":"Physikalisch\u2010Technische Bundesanstalt  Braunschweig and Berlin Germany"},{"name":"Center for Magnetic Resonance Research University of Minnesota  Minneapolis Minnesota USA"},{"name":"Medical Physics in Radiology German Cancer Research Center (DKFZ)  Heidelberg Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2024,8,12]]},"reference":[{"key":"e_1_2_7_2_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.28178"},{"key":"e_1_2_7_3_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.23150"},{"key":"e_1_2_7_4_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.neuroimage.2017.03.035"},{"key":"e_1_2_7_5_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.10353"},{"key":"e_1_2_7_6_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.20011"},{"key":"e_1_2_7_7_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.1156"},{"key":"e_1_2_7_8_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.10137"},{"key":"e_1_2_7_9_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.20708"},{"key":"e_1_2_7_10_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.21120"},{"key":"e_1_2_7_11_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.22423"},{"key":"e_1_2_7_12_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.24158"},{"key":"e_1_2_7_13_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.22357"},{"key":"e_1_2_7_14_1","doi-asserted-by":"publisher","DOI":"10.1002\/nbm.2844"},{"key":"e_1_2_7_15_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.26925"},{"key":"e_1_2_7_16_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.28602"},{"key":"e_1_2_7_17_1","doi-asserted-by":"publisher","DOI":"10.1038\/nature11971"},{"key":"e_1_2_7_18_1","doi-asserted-by":"publisher","DOI":"10.1148\/radiol.2016152037"},{"key":"e_1_2_7_19_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.26580"},{"key":"e_1_2_7_20_1","doi-asserted-by":"publisher","DOI":"10.1038\/ncomms12445"},{"key":"e_1_2_7_21_1","article-title":"Analysis of the precision of variable Flip angle T1 mapping with emphasis on the noise Propagated from RF transmit field maps","volume":"11","author":"Lee Y","year":"2017","journal-title":"Front Neurosci"},{"key":"e_1_2_7_22_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.26009"},{"key":"e_1_2_7_23_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.mri.2017.04.003"},{"key":"e_1_2_7_24_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.27558"},{"key":"e_1_2_7_25_1","unstructured":"CloosMA Pa\u0161kaJ YuZ et al.Abdominal imaging with heterogeneous radiofrequency fields at 7 tesla.In\u00a0Proceedings of the 25th Annual Meeting of ISMRM Honolulu HI; 2017:1125."},{"key":"e_1_2_7_26_1","doi-asserted-by":"publisher","DOI":"10.1002\/nbm.4531"},{"key":"e_1_2_7_27_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.20896"},{"key":"e_1_2_7_28_1","doi-asserted-by":"publisher","DOI":"10.1016\/0730-725X(93)90078-R"},{"key":"e_1_2_7_29_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.27588"},{"key":"e_1_2_7_30_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.22089"},{"key":"e_1_2_7_31_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.25559"},{"key":"e_1_2_7_32_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.1910350216"},{"key":"e_1_2_7_33_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.27726"},{"key":"e_1_2_7_34_1","doi-asserted-by":"publisher","DOI":"10.1137\/18M120885X"},{"key":"e_1_2_7_35_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.acha.2020.10.002"},{"key":"e_1_2_7_36_1","doi-asserted-by":"publisher","DOI":"10.1016\/0730-725X(88)90451-1"},{"key":"e_1_2_7_37_1","doi-asserted-by":"publisher","DOI":"10.1002\/jmri.21149"},{"key":"e_1_2_7_38_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.29402"},{"key":"e_1_2_7_39_1","doi-asserted-by":"publisher","DOI":"10.1002\/jmri.24489"},{"key":"e_1_2_7_40_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.22948"},{"key":"e_1_2_7_41_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.27675"},{"key":"e_1_2_7_42_1","unstructured":"LutzM AignerCS FlassbeckS et al.MRF\u2010based channel\u2010wise absoluteB1+$$ {B}_1^{+} $$mapping at low RF power in the human abdomen at 7T. Proceedings of the 31st Annual Meeting of ISMRM Toronto Canada; 2023:1420."},{"key":"e_1_2_7_43_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.29845"},{"key":"e_1_2_7_44_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.29144"},{"key":"e_1_2_7_45_1","doi-asserted-by":"publisher","DOI":"10.13104\/jksmrm.2014.18.2.87"},{"key":"e_1_2_7_46_1","doi-asserted-by":"publisher","DOI":"10.1109\/TMI.2018.2873704"},{"key":"e_1_2_7_47_1","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.2020516118"},{"key":"e_1_2_7_48_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.mri.2017.02.010"},{"key":"e_1_2_7_49_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.24263"}],"container-title":["Magnetic Resonance in Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/mrm.30242","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,8,12]],"date-time":"2024-08-12T16:55:51Z","timestamp":1723481751000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1002\/mrm.30242"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,8,12]]},"references-count":48,"alternative-id":["10.1002\/mrm.30242"],"URL":"https:\/\/doi.org\/10.1002\/mrm.30242","archive":["Portico"],"relation":{},"ISSN":["0740-3194","1522-2594"],"issn-type":[{"value":"0740-3194","type":"print"},{"value":"1522-2594","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,8,12]]},"assertion":[{"value":"2024-02-02","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2024-07-21","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2024-08-12","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"mrm.30242"}}