4996481 Magnetic resonance RF probe with electromagnetically isolated transmitter and receiver coils

Abstract

An RF probe for use in magnetic resonance application includes a transmitter coil for transmitting RF energy to excite a specimen and receiver coil for sensing the RF energy absorbed or emitted by the specimen wherein, in a first embodiment, the receiver coil has a primary coil loop for placement immediately adjacent a specimen and a secondary coil loop, said receiver coil loops being anti-phase and connected in series and wherein the secondary receiver coil loop may be angularly rotated with respect to the transmit coil in order to balance the current induced in both receiver coil elements to achieve a zero net induced current from the transmit coil while the primary receiver coil element is in position for taking measurements. In a second embodiment, the receiver coil element has a pair of parallel connected anti-phase coil elements, and the primary coil element for placement immediately adjacent the specimen has a reduced inductance and, hence, impedance such that it exhibits an increased sensitivity and greater signal-to-noise ratio.