Patent ID: 7714578

Claim:
A magnetic resonance imaging system including: a main magnet which establishes a main magnet field in an imaging region; at least one RF coil assembly including: a coil segment having at least one circuit including a light sensitive capacitor, an RF characteristic being adjusted by adjusting a capacitance of the light-sensitive capacitor, an optical fiber optically coupled to the light-sensitive capacitor, and at least one light source for supplying light of adjustable intensity to the optical fiber, such that the RF characteristic of the RF coil assembly is selectable; an RF transmitter connected to the RF coil assembly for generating resonance exciting and manipulating RF pulses to excite and manipulate resonance of dipoles in the imaging region; gradient coils which generate magnetic field gradients across the imaging region; a sequence controller for controlling the gradient coils and the RF transmitter; at least one RF receive coil disposed adjacent the imaging region; a receiver that receives resonance signals from the RF receive coil assembly; an RF field optimizing processor that optimizes the RF characteristics, the RF field optimizing processor programmed to perform the steps of: causing the RF transmitter to generate RF characteristic sensitive pulse sequences; analyzing the received resonance signals received by the receiver to determine the RF characteristics; and adjusting the at least one variable light source to adjust the RF characteristics.