Systems and methods for multi-frequency coil for magnetic resonance imaging

A method for designing a RF coil system for performing magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS) or magnetic resonance spectroscopy imaging (MRSI) operated at multiple resonant frequencies, the method comprising:

• selecting at least one conductive loop and at least one capacitor to form a radio frequency (RF) resonant antenna;
• configuring a tuning-matching circuit electrically coupled to the RF resonant antenna to generate multiple resonant frequencies across a desired operational range;
• electrically connecting at least two legs between the tuning-matching circuit and the at least one RF resonant antenna;
• and
• selecting components of the tuning-matching circuit and parameters of the conductive loop and the at least two legs to have a quantitative relationship between all capacitances and inductances under unloaded conditions, where the induced reactance is zero, using:
• 1
• 1
• 1
• 1
• ω
• 0
• ⁢
• L
• 2
• -
• ω
• 0
• ⁢
• C
• 4
• +
• ω
• 0
• ⁢
• L
• 1
• -
• ω
• 0
• ⁢
• C
• L
• -
• 1
• ω
• 0
• ⁢
• C
• 5
• -
• 1
• ω
• 0
• ⁢
• C
• S
• =
• 0
• ;
• wherein ω0 represents each of the multiple resonant frequencies of the coil, CS is a capacitance of a matching capacitor, CL is a capacitance of a tuning capacitor, L1 is inductance of the two legs, L2 is inductance of the conductive loop, and C4 is a capacitance connected to the two legs and the RF resonant antenna.