Magnetic resonance imaging (MRI) coil with constant capacitance coupling

Patent metadata

Field	Value
Publication number	US-10048333-B2
Application number	US-201514728627-A
Country	US
Kind code	B2
Filing date	Jun 2, 2015
Priority date	Jun 2, 2015
Publication date	Aug 14, 2018
Grant date	Aug 14, 2018

Abstract

Example minimalist magnetic resonance imaging (MRI) radio frequency (RF) coils that are connected to off coil circuitry by capacitive coupling plates are described. A minimalist MRI RF coil may have some elements that form a traditional coil located off the coil in off coil circuitry. An MR procedure may involve a number of minimalist MRI RF coils that are moved through an excitation zone as a patient is moved through the excitation zone. Example minimalist MRI RF coils may be selectively connected to off coil circuitry while the coils are in the excitation zone. The coupling may be made by capacitive coupling plates. Unlike conventional systems, example systems have capacitive coupling plates with properties that facilitate maintaining a constant capacitance between a coupling plate associated with the coil and coupling plates associated with the off coil circuitry as the coupling plates move relative to each other.

First claim

What is claimed is:

1. A system, comprising:
one or more coil couplers electrically connected to a corresponding number of minimalist magnetic resonance radio frequency (MMRRF) coils in a one-to-one manner, wherein each coil coupler is a capacitive plate;
a plurality of off coil circuitry couplers (OCCCs) electrically connected to a corresponding plurality of off coil MR circuits (OCMRCs) in a one-to-one manner, wherein each OCCC is a capacitive plate;
wherein the one or more coil couplers is moveable relative to the plurality of OCCCs by a magnetic resonance (MR) apparatus during an MR procedure,
wherein the one or more coil couplers and the plurality of OCCCs are arranged such that, at a given instance of time during the MR procedure, one OCCC can be in capacitive contact with at most one member of the one or more coil couplers, and one member of the one or more coil couplers can be in capacitive contact with one or more OCCCs, wherein when a member of the one or more coil couplers is in capacitive contact with one or more selected OCCCs, a MR signal detected by a MMRRF coil associated with the member of the one or more coil couplers is allowed to flow from the MMRRF coil to the one or more selected OCCCs via the member of the one or more coil couplers and wherein the MR signal further flows from the one or more selected OCCCs to one or more OCMRCs associated with the one or more selected OCCCs,
wherein when the member of the one or more coil couplers is in capacitive contact with the one or more selected OCCCs and while the member of the one or more coil couplers is moving relative to the plurality of OCCCs, there is a constant capacitance between the member of the one or more coil couplers and the one or more selected OCCCs to which the member of the one or more coil couplers is in capacitive contact with, and wherein the constant capacitance remains within a desired capacitance range for the MMRRF coil causing the MMRRF coil to remain tuned within a desired frequency range, and
wherein the capacitance for the MMRRF coil is described by:

C
1

⁢

C
d

C
1

+

2
⁢

C
d

+

C
2

⁢

C
d

C
2

+

2
⁢

C
d

=

C
0

⁢

C
d

C
0

+

2
⁢

C
d

wherein:
C d is the equivalent total break point capacitance produced by a decoupling capacitor on a member of the plurality of OCMRCs,
C 0 is the capacitance produced during a capacitive coupling between the member of the one or more coil couplers and a single OCCC when the member of the one or more coil couplers is in capacitive connection with the single OCCC,
C 1 is the capacitance produced by a first capacitive coupling between the member of the one or more coil couplers and a first OCCC when the member of the one or more coil couplers is in capacitive connection with the first OCCC and a second OCCC, where C 1 is a function of the shape of the first OCCC, and
C 2 is the capacitance produced by a second capacitive coupling between the member of the one or more coil couplers and the second OCCC when the member of the one or more coil couplers is in capacitive connection with the first OCCC and the second OCCC, where C 2 is a function of the shape of the second OCCC.

2. The system of claim 1 , wherein when the value for C 1 is known, C 2 is defined by:

C
2

=

2
⁢

C
d

·

(

1

1
+

2
⁢

C
d

C
0

+

2
⁢

C
d

-

2
⁢

C
d

C
1

+

2
⁢

C
d

-
1

)

.

3. The system of claim 2 , wherein the sha

Assignees

• Quality Electrodynamics Llc
• Quality Electrodynamis Llc

Inventors

• Fujita Hiroyuki
• Heid Oliver
• Yang Xiaoyu

Classifications

• G01R33/3621

  NMR receivers or demodulators, e.g. preamplifiers, means for frequency modulation of the MR signal using a digital down converter, means for analog to digital conversion [ADC] or for filtering or processing of the MR signal such as bandpass filtering, resampling, decimation or interpolation · CPC title

• G01R33/3642 Primary

  Mutual coupling or decoupling of multiple coils, e.g. decoupling of a receive coil from a transmission coil, or intentional coupling of RF coils, e.g. for RF magnetic field amplification · CPC title

• H01F5/04

  Arrangements of electric connections to coils, e.g. leads · CPC title