Optimization of Resonance Mode Stability in RF Coil Design for Very High Field MRI
Li Y, Saylor C
Invivo Diagnostic Imaging
At very high field MRI, substantial B1 field inhomogeneity exists in RF excitation. The causes of this field inhomogeneity can be categorized into three groups: 1) dielectric resonances within the sample; 2) cylindrical waveguide modes because of the size of the RF resonator, and 3) resonance modes generated by the RF coil. In this study, we took into account these factors and used the resonance mode stability to evaluate the B1 field in a volume coil. Based on this method, a 7T volume coil was optimized and both B1 field homogeneity and power efficiency were improved.