title: A generalized strategy for designing (19)F/(1)H dual-frequency MRI coil for small animal imaging at 4.7 Tesla.
abstract: OBJECTIVE
  To propose and test a universal strategy for building (19) F/(1) H dual-frequency RF coil that permits multiple coil geometries.
  
  
  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.
  
  
  CONCLUSIONS
  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.affiliation: Department of Physics, Washington University in St. Louis, Missouri, USA.
authors.forename: Lingzhi
authors.initials: L
authors.lastname: Hu
authors.forename: Frank D
authors.initials: FD
authors.lastname: Hockett
authors.forename: Junjie
authors.initials: J
authors.lastname: Chen
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.forename: Shelton D
authors.initials: SD
authors.lastname: Caruthers
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Lanza
authors.forename: Samuel A
authors.initials: SA
authors.lastname: Wickline
mesh_terms: D000818:Animals; D004560:Electricity; D004867:Equipment Design; D005462:Fluorine Radioisotopes / Q000494:pharmacology*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods*; D008422:Materials Testing; D015233:Models, Statistical; D019047:Phantoms, Imaging; D011522:Protons; D011827:Radiation; D011846:Radio Waves; D015203:Reproducibility of Results
chemical_list: D005462:Fluorine Radioisotopes; D011522:Protons