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Cardiorenal sodium MRI at 7.0 Tesla using a 4/4 channel 1 H/ 23 Na radiofrequency antenna array
Author(s) -
Boehmert Laura,
Kuehne Andre,
Waiczies Helmar,
Wenz Daniel,
Eigentler Thomas Wilhelm,
Funk Stephanie,
KnobelsdorffBrenkenhoff Florian,
SchulzMenger Jeanette,
Nagel Armin M.,
Seeliger Erdmann,
Niendorf Thoralf
Publication year - 2019
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.27880
Subject(s) - magnetic resonance imaging , sodium , specific absorption rate , cardiorenal syndrome , kidney , nuclear magnetic resonance , biomedical engineering , materials science , nuclear medicine , physics , medicine , computer science , antenna (radio) , radiology , telecommunications , metallurgy
Purpose Cardiorenal syndrome describes disorders of the heart and the kidneys in which a dysfunction of 1 organ induces a dysfunction in the other. This work describes the design, evaluation, and application of a 4/4‐channel hydrogen‐1/sodium ( 1 H/ 23 Na) RF array tailored for cardiorenal MRI at 7.0 Tesla (T) for a better physiometabolic understanding of cardiorenal syndrome. Methods The dual‐frequency RF array is composed of a planar posterior section and a modestly curved anterior section, each section consisting of 2 loop elements tailored for 23 Na MR and 2 loopole‐type elements customized for 1 H MR. Numerical electromagnetic field and specific absorption rate simulations were carried out. Transmission field ( B 1 + ) uniformity was optimized and benchmarked against electromagnetic field simulations. An in vivo feasibility study was performed. Results The proposed array exhibits sufficient RF characteristics, B 1 + homogeneity, and penetration depth to perform 23 Na MRI of the heart and kidney at 7.0 T. The mean B 1 + field for sodium in the heart is 7.7 ± 0.8 µT/√kW and in the kidney is 6.9 ± 2.3 µT/√kW. The suitability of the RF array for 23 Na MRI was demonstrated in healthy subjects (acquisition time for 23 Na MRI: 18 min; nominal isotropic spatial resolution: 5 mm [kidney] and 6 mm [heart]). Conclusion This work provides encouragement for further explorations into densely packed multichannel transceiver arrays tailored for 23 Na MRI of the heart and kidney. Equipped with this technology, the ability to probe sodium concentration in the heart and kidney in vivo using 23 Na MRI stands to make a critical contribution to deciphering the complex interactions between both organs.