Arrangement to transmit magnetic resonance signals via multiplexed multiplexer reception branches

• US 7,834,628 B2
• Filed: 10/01/2008
• Issued: 11/16/2010
• Est. Priority Date: 10/01/2007
• Status: Active Grant

• Current Assignee: Siemens Healthineers AG (Siemens AG)
• Original Assignee: Siemens AG
• Inventors: Vester, Markus, Biber, Stephan, Bollenbeck, Jan, Oppelt, Ralph
• Primary Examiner(s): Shrivastav; Brij B
• Assistant Examiner(s): Vargas; Dixomara
• Application Number:
  US12/243,038
• Publication Number:
  US 20090096455A1
• Time in Patent Office: 776 Days
• Field of Search: 324300-322
• US Class Current: 324/318
• CPC Class Codes: G01R 33/3415 comprising arrays of sub-coils , i.e. phased-array coils with flexible receiver channels
• CPC Class Codes: G01R 33/3621 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 Class Codes: G01R 33/3664 Switching for purposes other than coil coupling or decoupling, e.g. switching between a phased array mode and a quadrature mode, switching between surface coil modes of different geometrical shapes, switching from a whole body reception coil to a local reception coil or switching for automatic coil selection in moving table MR or for changing the field-of-view G01R33/3671 takes precedence
• CPC Class Codes: G01R 33/3692 involving signal transmission without using electrically conductive connections, e.g. wireless communication or optical communication of the MR signal or an auxiliary signal other than the MR signal

Abstract

An arrangement to transmit magnetic resonance signals has at least two reception branches. Each reception branch contains a single antenna of a local coil as well as an amplifier connected with the single antenna, such that an amplified magnetic resonance signal is formed from a magnetic resonance signal that is acquired via the single antenna. In a multiplexer, each input is connected with a respective reception branch, such that the amplified magnetic resonance signals of the reception branch are combined by the multiplexer into a resulting signal using a time multiplexing method. A transmission path is connected on one side with an output of the multiplexer and on the other side with a receiver, such that the resulting signal is transmitted from the multiplexer to the receiver via the transmission path.

Claims

1. An arrangement for transmitting magnetic resonance signals respectively generated by individual antennas of a magnetic resonance local coil, said arrangement comprising:

a plurality of reception branches, each reception branch comprising one individual antenna of the local coil and an amplifier connected thereto that produces an amplified magnetic resonance signal as an output signal of that reception branch on a magnetic resonance signal acquired by the individual antenna;

a multiplexer having a plurality of multiplexer inputs respectively connected to said plurality of reception branches to receive the respective amplified magnetic resonance signals therefrom, said multiplexer emitting a resulting signal at a multiplexer output by time-multiplexing the respective amplified magnetic resonance signals from the reception branches;

a transmission path having a first end connected to said multiplexer output;

a receiver connected to a second end of said transmission path that receives said resulting signal from said multiplexer output via said transmission path and

said local coil having a local coil housing, and said plurality of reception branches and said multiplexer being contained in said local coil housing.

2. An arrangement as claimed in claim 1 wherein said transmission path is selected from the group consisting of optical transmission paths, hard-wired transmission paths, and radio transmission paths.

3. An arrangement as claimed in claim 1 wherein each transmission branch additionally comprises a filter that filters the amplified magnetic resonance signal in that transmission branch before the respective multiplexer input to which that transmission branch is connected.

4. An arrangement for transmitting magnetic resonance signals respectively generated by individual antennas of a magnetic resonance local coil, said arrangement comprising:

a plurality of reception branches, each reception branch comprising one individual antenna of the local coil and an amplifier connected thereto that produces an amplified magnetic resonance signal as an output signal of that reception branch on a magnetic resonance signal acquired by the individual antenna;

a multiplexer having a plurality of multiplexer inputs respectively connected to said plurality of reception branches to receive the respective amplified magnetic resonance signals therefrom, said multiplexer emitting a resulting signal at a multiplexer output by time-multiplexing the respective amplified magnetic resonance signals from the reception branches;

a transmission path having a first end connected to said multiplexer output;

a counter that is clocked by a clock signal, said counter being connected to said multiplexer and controlling the time multiplexing in said multiplexer;

said receiver comprising a clock signal generator that generates said clock signal and supplies said clock signal to said counter; and

a first coupling device connected between said multiplexer output and said first end of said transmission path and a second coupling device connected between said second end of said transmission path and said receiver, said first and second coupling devices operating in combination to couple said resulting signal from said multiplexer output into said transmission path and to couple said clock signal from said clock signal generator in said receiver into said transmission path.

5. An arrangement for transmitting magnetic resonance signals respectively generated by individual antennas of a magnetic resonance local coil, said arrangement comprising:

a plurality of reception branches, each reception branch comprising one individual antenna of the local coil and an amplifier connected thereto that produces an amplified magnetic resonance signal as an output signal of that reception branch on a magnetic resonance signal acquired by the individual antenna;

a multiplexer having a plurality of multiplexer inputs respectively connected to said plurality of reception branches to receive the respective amplified magnetic resonance signals therefrom, said multiplexer emitting a resulting signal at a multiplexer output by time-multiplexing the respective amplified magnetic resonance signals from the reception branches;

a transmission path having a first end connected to said multiplexer output;

a receiver connected to a second end of said transmission path that receives said resulting signal from said multiplexer output via said transmission path; and

a sample and hold circuit connected at a location selected from the group consisting of between said multiplexer output and said first end of said transmission path and between said second end of said transmission end and said receiver, and wherein said receiver comprises an analog-to-digital converter, with said resulting signal passing through said sample and hold circuit before reaching said analog-to-digital convert.

6. An arrangement as claimed in claim 5 wherein said multiplexer is configured to implement said time multiplexing to cause respective multiplexer inputs to be connected to said multiplexer output only for a duration that is a portion of a sample interval of said sample and hold circuit.

7. An arrangement for transmitting magnetic resonance signals respectively generated by individual antennas of a magnetic resonance local coil, said arrangement comprising:

a plurality of reception branches, each reception branch comprising one individual antenna of the local coil and an amplifier connected thereto that produces an amplified magnetic resonance signal as an output signal of that reception branch on a magnetic resonance signal acquired by the individual antenna;

a multiplexer having a plurality of multiplexer inputs respectively connected to said plurality of reception branches to receive the respective amplified magnetic resonance signals therefrom, said multiplexer emitting a resulting signal at a multiplexer output by time-multiplexing the respective amplified magnetic resonance signals from the reception branches;

a transmission path having a first end connected to said multiplexer output;

a receiver connected to a second end of said transmission path that receives said resulting signal from said multiplexer output via said transmission path;

said receiver comprising;

an analog-to-digital converter; and

an equalizer connected downstream of said second end of said transmission path, preceding said analog-to-digital converter.

8. An arrangement for transmitting magnetic resonance signals respectively generated by individual antennas of a magnetic resonance local coil, said arrangement comprising:

a plurality of reception branches, each reception branch comprising one individual antenna of the local coil and an amplifier connected thereto that produces an amplified magnetic resonance signal as an output signal of that reception branch on a magnetic resonance signal acquired by the individual antenna;

a multiplexer having a plurality of multiplexer inputs respectively connected to said plurality of reception branches to receive the respective amplified magnetic resonance signals therefrom, said multiplexer emitting a resulting signal at a multiplexer output by time-multiplexing the respective amplified magnetic resonance signals from the reception branches;

a transmission path having a first end connected to said multiplexer output;

a receiver connected to a second end of said transmission path that receives said resulting signal from said multiplexer output via said transmission path; and

each reception branch additionally comprising a converter that converts the amplified magnetic resonance signal in that reception branch into an intermediate frequency and that supplies the amplified magnetic resonance signal at said intermediate frequency to the multiplexer input connected to that reception branch.

9. An arrangement as claimed in claim 8 wherein said converter is a single sideband mixer.

10. An arrangement for transmitting magnetic resonance signals respectively generated by individual antennas of a magnetic resonance local coil, said arrangement comprising:

a plurality of reception branches, each reception branch comprising one individual antenna of the local coil and an amplifier connected thereto that produces an amplified magnetic resonance signal as an output signal of that reception branch on a magnetic resonance signal acquired by the individual antenna;

a multiplexer having a plurality of multiplexer inputs respectively connected to said plurality of reception branches to receive the respective amplified magnetic resonance signals therefrom, said multiplexer emitting a resulting signal at a multiplexer output by time-multiplexing the respective amplified magnetic resonance signals from the reception branches;

a transmission path having a first end connected to said multiplexer output;

a receiver connected to a second end of said transmission path that receives said resulting signal from said multiplexer output via said transmission path; and

each amplifier in each reception branch generating an amplified positive magnetic resonance signal and an amplified negative magnetic resonance signal.

11. An arrangement as claimed in claim 10 wherein each reception branch comprises a switch connected downstream of the amplifier in that reception branch, said switch supplying either the amplified positive magnetic resonance signal or the amplified negative magnetic resonance signal to the multiplexer input connected to that reception branch.

12. An arrangement as claimed in claim 10 wherein the respective multiplexer inputs connected to the reception branches are first multiplexer inputs, and wherein said multiplexer comprises, for each of said reception branches, a second multiplexer input, and wherein, for each reception branch, the amplified positive magnetic resonance signal is supplied to the first multiplexer input and the amplified negative magnetic resonance signal is simultaneously supplied to said second multiplexer input.

13. An arrangement as claimed in claim 10 wherein the respective multiplexer inputs connected to said plurality of reception branches are first multiplexer inputs, and wherein said multiplexer comprises, for each of said reception branches, a second multiplexer input, and wherein the amplifier in each reception branch is connected to both of the first and second multiplexer inputs for that reception branch and simultaneously supplies the amplified positive magnetic resonance signal and the amplified negative resonance signal respectively to said first and second multiplexer inputs for that reception branch.

14. An arrangement as claimed in claim 13 comprising, in each reception branch, a phase shifter for 0°

phase shifting connected between the amplifier and the first multiplexer input, and a phase shifter for 90°

phase shifting connected between the amplifier and the second multiplexer input.

15. An arrangement for transmitting magnetic resonance signals respectively generated by individual antennas of a magnetic resonance local coil, said arrangement comprising:

a plurality of reception branches, each reception branch comprising one individual antenna of the local coil and an amplifier connected thereto that produces an amplified magnetic resonance signal as an output signal of that reception branch on a magnetic resonance signal acquired by the individual antenna;

a multiplexer having a plurality of multiplexer inputs respectively connected to said plurality of reception branches to receive the respective amplified magnetic resonance signals therefrom, said multiplexer emitting a resulting signal at a multiplexer output by time-multiplexing the respective amplified magnetic resonance signals from the reception branches;

a transmission path having a first end connected to said multiplexer output;

a receiver connected to a second end of said transmission path that receives said resulting signal from said multiplexer output via said transmission path; and

an analog-to-digital converter in said receiver, said analog-to-digital converter being connected downstream of said transmission path.