Multiply-tuned probe for magnetic resonance imaging or spectroscopy
First Claim
1. A multi-frequency tuned probe, comprising:
- a first substantially planar inductor L1 disposed in a first plane;
first means for tuning said first planar inductor L1 to a first resonant frequency;
a second substantially planar inductor L2 disposed in a second plane, parallel to said first plane;
second means for tuning said second planar inductor L2 to a second resonant frequency; and
a substantially planar driving and receiving primary inductor Lp disposed in a third plane which is parallel to said first and second planes, said primary inductor Lp being adapted to transmit and receive RF pulses and signals and being disposed with respect to said first and second inductors L1 and L2 such that mutual inductance between L1 and Lp and between L2 and Lp occurs when a current is applied to L1, L2 and Lp, said mutual inductance being adjustable in accordance with the respective distances between each of said inductors L1, L2 and Lp in a direction perpendicular to said first, second and third planes and in accordance with the amount of overlap among said inductors L1, L2 and Lp in coordinate directions parallel to said first, second and third planes.
1 Assignment
0 Petitions
Accused Products
Abstract
A multiply-tuned probe for magnetic resonance imaging or spectroscopy in which a driving inductor is separately coupled to two or more trap inductors. The impedance match at each frequency is adjusted independently of the impedance match at the other frequencies and independent of the tuning by using a novel coil geometry with no overcoupling. In a preferred embodiment, a triple-tuned probe has a first inductor L1 disposed in a first plane and tuned to a first resonant frequency and a second inductor L2 disposed in a second plane parallel to the first plane and tuned to a second resonant frequency. A driving and receiving primary inductor Lp is disposed in a third plane parallel to the first and second planes and placed with respect to the first and second inductors L1 and L2 such that mutual inductance between L1 and Lp in between L2 and Lp is adjustable in accordance with the positions of the inductors L1, L2 and Lp. A sample surface inductor Ls tuned to a third resonant frequency provides the third frequency. Mutual inductance between L1 and Lp in between L2 and Lp is changed by repositioning the inductors L1, L2 and Lp to vary the amount of overlap between the cross-sections of the primary inductor Lp and the circular coils L1, L2 and the distances between inductors L1 and Lp and between inductors L2 and Lp. Since each inductive coupling adds another variable to the probe circuit, more and easier ways are provided for adjusting the tuning and impedance matching.
-
Citations
10 Claims
-
1. A multi-frequency tuned probe, comprising:
-
a first substantially planar inductor L1 disposed in a first plane; first means for tuning said first planar inductor L1 to a first resonant frequency; a second substantially planar inductor L2 disposed in a second plane, parallel to said first plane; second means for tuning said second planar inductor L2 to a second resonant frequency; and a substantially planar driving and receiving primary inductor Lp disposed in a third plane which is parallel to said first and second planes, said primary inductor Lp being adapted to transmit and receive RF pulses and signals and being disposed with respect to said first and second inductors L1 and L2 such that mutual inductance between L1 and Lp and between L2 and Lp occurs when a current is applied to L1, L2 and Lp, said mutual inductance being adjustable in accordance with the respective distances between each of said inductors L1, L2 and Lp in a direction perpendicular to said first, second and third planes and in accordance with the amount of overlap among said inductors L1, L2 and Lp in coordinate directions parallel to said first, second and third planes. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A multi-frequency tuned probe, comprising:
-
at least two trap circuits disposed concentrically about a common axis; means for tuning each trap circuit to a desired resonant frequency; and a driving and receiving primary inductor Lp substantially concentrically disposed with respect to said at least two trap circuits about said common axis such that mutual inductance between Lp and each of said trap circuits occurs when a current is applied to said trap circuits and Lp, said mutual inductance being adjustable in accordance with the respective distances between Lp and each of said trip circuits along said common axis.
-
Specification