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.
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.
Authors: Myriam N Bouchlaka; Kai D Ludwig; Jeremy W Gordon; Matthew P Kutz; Bryan P Bednarz; Sean B Fain; Christian M Capitini Journal: Oncoimmunology Date: 2016-02-18 Impact factor: 8.110
Authors: Jeff W M Bulte; Anne H Schmieder; Jochen Keupp; Shelton D Caruthers; Samuel A Wickline; Gregory M Lanza Journal: Nanomedicine Date: 2014-05-14 Impact factor: 5.307
Authors: Anne H Schmieder; Shelton D Caruthers; Jochen Keupp; Samuel A Wickline; Gregory M Lanza Journal: Engineering (Beijing) Date: 2016-03-16 Impact factor: 7.553