Abstract: An NMR radio-frequency (RF) coil is made up, in the preferred embodiment, of upper and lower coil assemblies. Each coil assembly includes a tuned circuit. In operation, only one of the tuned circuits is energized, while the other is mutually inductively coupled such that they resonate together as one circuit at substantially the same frequency. A first set of latches is provided to fasten the lower coil assembly to a patient cradle. A second set of latches is utilized to fasten the upper coil assembly to the lower while permitting relative longitudinal motion between the two assemblies.In another embodiment, which does not utilize mutual inductance, the tuned circuits on each assembly are electrically connected to form a complete coil by means of, for example, an electrical plug-and-jack arrangement.

Abstract: A matching device uses mutual inductance to couple an NMR radio frequency (RF) coil to an RF power amplifier and RF receiver preamplifier. The device includes a matching coil connected to the RF power amplifier and preamplifier and which is positioned between the NMR RF coil and a decoupling shield in a region where RF flux density, produced by the NMR RF coil, is maximum. This ensures effective coupling to the NMR RF coil and provides a way for adjusting the degree of coupling (hence, input impedance) by varying the area of the matching coil available for intercepting the RF flux.