Multi-current elements for magnetic resonance radio frequency coils
A current unit having two or more current paths allows control of magnitude, phase, time, frequency and position of each of element in a radio frequency coil. For each current element, the current can be adjusted as to a phase angle, frequency and magnitude. Multiple current paths of a current unit can be used for targeting multiple spatial domains or strategic combinations of the fields generated/detected by combination of elements for targeting a single domain in magnitude, phase, time, space and frequency.
1 . A current unit for a radio frequency coil comprising:
a first radio frequency current path proximate a dielectric; and
a second radio frequency current path independent of the first current path and proximate the dielectric; and
wherein the first radio frequency current path and the second radio frequency current path are configured for magnetic resonance imaging.
2 . The current unit of claim 1 further including a third radio frequency current path proximate the dielectric and wherein the third radio frequency current path is independent of the first current path and second current path and the third radio frequency current path is configured for magnetic resonance imaging.
3 . The current unit of claim 2 wherein the first radio frequency current path, the second radio frequency current path and the radio frequency current path are substantially planar and in parallel alignment.
4 . The current unit of claim 1 wherein at least one of the first current path and the second current path is embedded in a dielectric.
5 . The current unit of claim 1 wherein at least one of the first current path and the second current path includes a plurality of perforations, slots, holes or apertures.
6 . The current unit of claim 1 wherein at least one of the first current path and the second current path is configured to encode along a z-axis.
7 . The current unit of claim 1 wherein at least one of the first current path and the second current path is configured to encode along at least one of an x-axis and a y-axis.
8 . The current unit of claim 1 wherein at least one of the first current path and the second current path includes a conductive loop.
9 . The current unit of claim 1 wherein at least one of the first current path and the second current path is tapered along a surface.
10 . A magnetic resonance radio frequency coil comprising:
at least two current units arranged proximate each other and each current unit having at least two current paths wherein a first current path is configured for generating an excitation field and a second current path is configured for detecting a signal.
11 . The coil of claim 10 wherein the at least two current units are distributed about a volume.
12 . The coil of claim 10 wherein the at least two current units are distributed about a surface.
13 . The coil of claim 10 wherein the coil is configured for operating in a static magnetic field having a field strength of between 1 and 12 Tesla.
14 . A current unit for a magnetic resonance radio frequency coil comprising:
a first current element and a second current element, each current element having a first current path and a second current path in parallel relation with the first current path, wherein the first current element lies in a first plane and the second current element lies in a second plane and
wherein the first plane is different from the second plane and the first plane and second plane intersect on a line.
15 . The current unit of claim 14 wherein at least one of the first current element and the second current element include a loop conductor.
16 . The current unit of claim 15 further including a third current element disposed proximate the first current element and the second current element.
17 . The current unit of claim 15 further including a plurality of planar current elements, each planar current element in substantially parallel alignment and disposed proximate the first current element and the second current element.
18 . A method comprising:
generating a first field in a radio frequency magnetic resonance coil using a first current path of a current unit;
generating a second field using a second current path of the current unit; and
detecting a signal using the current unit.
19 . The method of claim 18 wherein detecting includes encoding along a z-axis of the coil.
20 . The method of claim 18 wherein generating includes modulating at least one of a current, a frequency, a phase angle, space and timing.
21 . The method of claim 18 wherein generating includes modulating power delivered to the current unit.
22 . The method of claim 18 further including tuning the first current path to a first particular resonant frequency.
23 . The method of claim 22 further including tuning the second current path to a second particular resonant frequency wherein the first particular resonant frequency differs from the second particular resonant frequency.
24 . The method of claim 18 further including reactively coupling the first current path and the second current path.
25 . The method of claim 18 further including reactively decoupling the first current path and the second current path.
26 . The method of claim 18 further including coupling the first current path to a first spatial domain and coupling the second current path to a second spatial domain.
27 . A magnetic resonance radio frequency coil comprising:
at least two current units arranged proximate each other and each current unit having at least two current paths wherein at least one current path is configured for at least one of generating a field or receiving a signal.
28 . The coil of claim 27 wherein the at least two current units are distributed about a volume.
29 . The coil of claim 27 wherein the at least two current units are distributed about a surface.
30 . The coil of claim 27 wherein the coil is configured for operating in a static magnetic field having a field strength of between 1 and 12 Tesla.