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A human cerebral and cerebellar 8‐channel transceive RF dipole coil array at 7T
Author(s) -
Clément Jérémie D.,
Gruetter Rolf,
Ipek Özlem
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.27476
Subject(s) - dipole , electromagnetic coil , specific absorption rate , nuclear magnetic resonance , physics , human brain , frontal lobe , optics , computer science , neuroscience , telecommunications , biology , quantum mechanics , antenna (radio)
Purpose Dipole antennas that provide high transmit field penetration with large coverage, and their use in a parallel transmit setup, may be advantageous in minimizing B1 + ‐field inhomogeneities at ultra‐high field, i.e 7T. We have developed and evaluated an 8‐channel RF dipole coil array for imaging the entire cerebral and cerebellar regions in man. Methods A coil array was modeled with seven dipoles: six placed covering the occipital and temporal lobes; one covering the parietal lobe; and two loops covering the frontal lobe. Center‐shortened and fractionated dipoles were simulated for the array configuration and assessed with respect to B1 + ‐field at maximum specific absorption rate averaged over 10 g tissue regions in human brain. The whole‐brain center‐shortened dipoles with frontal loops coil array was constructed and its transmit properties were assessed with respect to MR images, B1 + ‐field, and homogeneity. Results In simulations, the dipole arrays showed comparable performances to cover the whole‐brain. However, for ease of construction, the center‐shortened dipole was favored. High spatial resolution anatomical images of the human brain with the coil array demonstrated a full coverage of the cerebral cortex and cerebellum. Conclusions The 8‐channel center‐shortened dipoles and frontal loops coil array promises remarkable efficiency in highly challenging regions as the cerebellum, and phase‐only RF shimming of whole‐brain could greatly benefit ultra‐high field magnetic resonance imaging of the human brain at 7T.