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As a step towards addressing these while providing new degrees of freedom for spatial encoding and system design in Magnetic Resonance Imaging (MRI), a radio frequency (RF) gradient encoding system and pulse sequence for phase encoding using the Bloch\u2013Siegert (BS) shift were developed. Optimized BS spatial encoding coils with bucking windings (counter\u2010wound loops) were designed and constructed, along with compatible homogeneous imaging coils for excitation and signal reception. Two coil systems were developed: one for phantom imaging and a second for human wrist imaging. BS phase\u2010encoded imaging and BS RF pulse simulations were performed. Pulse sequences were designed for linear stepping in k\u2010space and implemented on a 47.5\u2010mT scanner to image resolution phantoms in both coil setups. Reconstructions were performed using both the full \n\u2010based encoding fields for each BS pulse amplitude and using inverse discrete Fourier transforms. A \n gradient was used for frequency encoding during signal readout, and the third axis was projected. Specific absorption ratio (SAR) calculations were performed for the wrist coil to determine the safety of BS\u2010based RF encoding for \n fields in the low field MRI regime. The optimized RF spatial encoding coils resulted in higher linearity (\n and 0.9921 in the phantom and wrist coils, respectively) than coils used in previous work. The phantom and wrist imaging coils were validated in simulations and experimentally to produce a peak \n G and 0.8 G with 12\u2010W input power, respectively, in the field\u2010of\u2010view (length = 11 cm) used for imaging. Nominal imaging resolutions of 5.22 and 7.21 mm were, respectively, achieved by the two\u2010coil systems in the RF phase\u2010encoded dimension. Coil systems, pulse sequences, and image reconstructions were developed for linear RF phase encoding using the BS shift and validated using a 47.5\u2010mT open low field scanner, establishing a key component required for \n\u00a0gradient\u2010free imaging at low \n\u00a0field strengths.<\/jats:p>","DOI":"10.1002\/nbm.5245","type":"journal-article","created":{"date-parts":[[2024,8,26]],"date-time":"2024-08-26T23:56:15Z","timestamp":1724716575000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Linear Bloch\u2013Siegert phase\u2010encoded low\u2010field MRI: RF coils, pulse sequence, and image reconstruction"],"prefix":"10.1002","volume":"37","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3595-1757","authenticated-orcid":false,"given":"Sai Abitha","family":"Srinivas","sequence":"first","affiliation":[{"name":"Department of Biomedical Engineering Case Western Reserve University  Cleveland Ohio USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jonathan B.","family":"Martin","sequence":"additional","affiliation":[{"name":"Vanderbilt University Institute of Imaging Science  Nashville Tennessee USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christopher E.","family":"Vaughn","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering Case Western Reserve University  Cleveland Ohio USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"William A.","family":"Grissom","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering Case Western Reserve University  Cleveland Ohio USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2024,8,26]]},"reference":[{"key":"e_1_2_10_2_1","doi-asserted-by":"publisher","DOI":"10.1002\/cmr.a.20163"},{"key":"e_1_2_10_3_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.1910390406"},{"key":"e_1_2_10_4_1","unstructured":"McDanielPC.Computational design and fabrication of portable MRI systems.Ph.D. Thesis. Massachusetts Institute of Technology;2020."},{"key":"e_1_2_10_5_1","volume-title":"Handbook of MRI Pulse Sequences","author":"Bernstein MA","year":"2004"},{"key":"e_1_2_10_6_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jmr.2005.03.015"},{"issue":"1","key":"e_1_2_10_7_1","first-page":"183","article-title":"Rotating frame zeugmatography","volume":"33","author":"Hoult DI","year":"1979","journal-title":"J Magn Reson"},{"key":"e_1_2_10_8_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.22188"},{"key":"e_1_2_10_9_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.29002"},{"key":"e_1_2_10_10_1","doi-asserted-by":"publisher","DOI":"10.1002\/mrm.29592"},{"key":"e_1_2_10_11_1","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRev.57.522"},{"key":"e_1_2_10_12_1","doi-asserted-by":"publisher","DOI":"10.1007\/s10334-013-0417-0"},{"key":"e_1_2_10_13_1","unstructured":"HasselwanderCJ GrissomWA.Bloch\u2013Siegert phase\u2010encoded MRI with a single RF coil and frequency\u2010swept pulses. 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