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A generalized strategy for designing 19 F/ 1 H dual‐frequency MRI coil for small animal imaging at 4.7 Tesla
Author(s) -
Hu Lingzhi,
Hockett Frank D.,
Chen Junjie,
Zhang Lei,
Caruthers Shelton D.,
Lanza Gregory M.,
Wickline Samuel A.
Publication year - 2011
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.22516
Subject(s) - electromagnetic coil , resonator , homogeneity (statistics) , imaging phantom , physics , radio frequency , nuclear magnetic resonance , electrical impedance , radiofrequency coil , impedance matching , materials science , acoustics , optics , computer science , telecommunications , quantum mechanics , machine learning
Purpose: To propose and test a universal strategy for building 19 F/ 1 H dual‐frequency RF coil that permits multiple coil geometries. Materials and Methods: The feasibility to design 19 F/ 1 H dual‐frequency RF coil based on coupled resonator model was investigated. A series capacitive matching network enables robust impedance matching for both harmonic oscillating modes of the coupled resonator. Two typical designs of 19 F/ 1 H volume coils (birdcage and saddle) at 4.7T were implemented and evaluated with electrical bench test and in vivo 19 F/ 1 H dual‐nuclei imaging. Results: For various combinations of internal resistances of the sample coil and secondary resonator, numerical solutions for the tunable capacitors to optimize impedance matching were obtained using a root‐seeking program. Identical and homogeneous B1 field distribution at 19 F and 1 H frequencies were observed in bench test and phantom image. Finally, in vivo mouse imaging confirmed the sensitivity and homogeneity of the 19 F/ 1 H dual‐frequency coil design. Conclusion: A generalized strategy for designing 19 F/ 1 H dual‐frequency coils based on the coupled resonator approach was developed and validated. A unique feature of this design is that it preserves the B1 field homogeneity of the RF coil at both resonant frequencies. Thus it minimizes the susceptibility effect on image co‐registration. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.