Eigenmode Transmit Array Coil for Magnetic Resonance Imaging

A method of fabricating a coil array for use in a magnetic resonance imaging (MRI) system, comprising:

• a) determining a first set of parameters for a first coil array, wherein said first set of parameters are determined so as to minimize a normalized reflected power generated by coils in said first coil array in response to excitation thereof via at least one excitation signal;
• b) fabricating said first coil array based on said first set of parameters;
• c) measuring impedance values and constructing a first impedance matrix associated with said first coil array for one or more frequencies;
• d) obtaining a first scattering matrix (S) associated with said first coil array;
• and
• e) minimizing a first cost function for said first coil array by adjusting capacitor values of said coils and obtaining a second set of parameters for a second coil array.

A transmit coil array for use in a magnetic resonance imaging (MRI) system, comprising:

• one or more coils;
• one or more capacitors disposed between adjacent coils of said one or more coils;
• and
• a power supply configured to supply electrical power to said one or more coils,
• wherein said one or more capacitors are configured to reduce inductive coupling between said coils.

A computer-implemented method of designing a coil array for use in a magnetic resonance imaging (MRI) system, comprising:

• calculating a normalized reflected power generated by coils in said coil array in response to excitation thereof via at least one excitation signal;
• adjusting one or more parameters of at least one of said coils so as to minimize said normalized reflected power, thereby arriving at design values for said parameters, wherein said at least one excitation signal comprises an excitation vector comprising one or more excitation signals each of which is associated with excitation of one coil of said coil array;
• expanding said excitation vector as a linear combination of excitation eigenmodes of said coil array;
• representing said normalized reflected power as a function of said at least one excitation signal and a scattering matrix (S) associated with said coil array;
• determining, for each of said excitation eigenmodes, a modal reflected power value, wherein said step of determining said normalized reflected power comprises computing a weighted sum of the modal reflected power values;
• and
• adjusting said one or more parameters so as to increase a number of excitation eigenmodes that produces said modal reflected power value equal to or less than about 50%.