Apparatus and method for synchronizing clocks between devices of magnetic resonance imaging (MRI) system

• US 9,091,740 B2
• Filed: 07/03/2012
• Issued: 07/28/2015
• Est. Priority Date: 11/17/2011
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Cho, Hyug-rae, Kwon, Young-cheol
• Primary Examiner(s): Vargas, Dixomara
• Application Number:
  US13/540,966
• Publication Number:
  US 20130127465A1
• Time in Patent Office: 1,120 Days
• Field of Search: 324300-322, 600407-465
• US Class Current: 1/1
• 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 33/3692 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
• CPC Class Codes: H04L 7/0091 Transmitter details
• CPC Class Codes: H04W 56/00 Synchronisation arrangements

Abstract

A method of synchronizing clocks between a central controlling unit and a radio frequency (RF) coil which are wirelessly connected to each other in a magnetic resonance imaging (MRI) system, which includes receiving a first clock from the central controlling unit, synchronizing a second clock of the RF coil with a received first clock, and discontinuing the receiving of the first clock from the central controlling unit when the second clock is synchronized with the first clock.

Claims

1. A method of synchronizing clocks between a central controlling unit and a radio frequency (RF) coil which are wirelessly connected to each other in a magnetic resonance imaging (MRI) system, the method comprising:

receiving a first clock from the central controlling unit;

synchronizing a second clock of the RF coil with the received first clock based on a phase difference between the first clock and the second clock; and

discontinuing the receiving of the first clock from the central controlling unit when the second clock is synchronized with the first clock,

wherein the synchronizing comprises obtaining the phase difference between the first clock and the second clock.

2. The method of claim 1, further comprising requesting the central controlling unit to discontinue transmission of the first clock.

3. The method of claim 2, wherein the requesting to discontinue the transmission of the first clock is performed before an RF excitation signal is generated in the MRI system.

4. The method of claim 3, further comprising requesting the central controlling unit to delay generation of the RF excitation signal if the second clock is not synchronized with the first clock.

5. The method of claim 1, further comprising storing the second clock that is synchronized with the first clock.

6. The method of claim 1, wherein the receiving of the first clock from the central controlling unit comprises receiving the first clock via a body coil connected by wire to the central controlling unit.

7. The method of claim 6, wherein the receiving of the first clock from the central controlling unit comprises decoupling the RF coil from the first clock before the first clock is received.

8. The method of claim 1, further comprising providing the RF coil with the second clock synchronized with the first clock.

9. The method of claim 1, wherein the synchronizing of the second clock of the RF coil with the received first clock comprises matching a frequency of the second clock with a frequency of the first clock.

10. The method of claim 1, wherein the synchronizing of the second clock of the RF coil with the received first clock comprises:

obtaining the phase difference between the first clock and second clock;

outputting a control voltage to control an oscillation frequency of a clock based on the obtained phase difference; and

varying the second clock according to the control voltage,

wherein the second clock comprises a varied second clock that is fed back.

11. A non-transitory computer-readable recording medium having recorded thereon a program for executing the method of claim 1.

12. An apparatus for synchronizing clocks between a central controlling unit and a radio frequency (RF) coil which are wirelessly connected to each other in a magnetic resonance imaging (MRI) system, the apparatus comprising:

a receiving unit which receives a first clock from the central controlling unit; and

a synchronization unit which synchronizes a second clock of the RF coil with the received first clock based on a phase difference between the first clock and the second clock,

wherein the receiving unit discontinues the receiving of the first clock from the central controlling unit when the second clock is synchronized with the first clock, and

wherein the synchronization unit includes a phase comparator which obtains the phase difference between the first clock and the second clock.

13. The apparatus of claim 12, further comprising a request unit which requests the central controlling unit to discontinue transmission of the first clock.

14. The apparatus of claim 13, wherein the request unit requests the central controlling unit to discontinue transmission of the first clock before an RF excitation signal is generated in the MRI system.

15. The apparatus of claim 14, wherein the request unit requests the central controlling unit to delay generation of the RF excitation signal if the second clock is not synchronized with the first clock.

16. The apparatus of claim 12, further comprising a storage unit which stores the second clock that is synchronized with the first clock.

17. The apparatus of claim 12, wherein the receiving unit receives the first clock via a body coil connected by wire to the central controlling unit.

18. The apparatus of claim 17, wherein the synchronization unit further comprises a decoupling unit which decouples the RF coil from the first clock before the first clock is received.

19. The apparatus of claim 12, wherein the synchronization unit further comprises a transmission unit which provides the RF coil with the second clock that has been synchronized with the first clock.

20. The apparatus of claim 12, wherein the synchronization unit matches a frequency of the second clock to a frequency of the first clock.

21. The apparatus of claim 12, wherein the synchronization unit comprises:

a phase comparison unit which obtains a phase difference between the first clock and the second clock;

a control voltage output unit which outputs a control voltage to control an oscillation frequency of a clock based on the obtained phase difference; and

a numerical control oscillator which varies the second clock according to the control voltage,

wherein the varied second clock is fed back to the phase comparison unit.

22. A method of synchronizing clocks between a central controlling unit and a radio frequency (RF) coil which are wirelessly connected to each other in a magnetic resonance imaging (MRI) system, the method comprising:

transmitting a first clock to the RF coil, using the central controlling unit;

synchronizing a second clock of the RF coil with a received first clock based on a phase difference between the first clock and the second clock, using the RF coil; and

discontinuing transmitting of the first clock, using the central controlling unit, when the second clock is synchronized with the first clock,

wherein the synchronizing comprises obtaining the phase difference between the first clock and the second clock.

23. The method of claim 22, further comprising transmitting, by the RF coil, a frame indicating completion of synchronization, the frame being transmitted to the central controlling unit.

24. A radio frequency (RF) coil comprising an apparatus for synchronizing clocks between a central controlling unit and the radio frequency (RF) coil which are wirelessly connected to each other in a magnetic resonance imaging (MRI) system, said apparatus comprising:

a receiving unit which receives a first clock from the central controlling unit; and

a synchronization unit which synchronizes a second clock of the RF coil with the received first clock based on a phase difference between the first clock and the second clock,

wherein the receiving unit discontinues the receiving of the first clock from the central controlling unit when the second clock is synchronized with the first clock, and

wherein the synchronization unit includes a phase comparator which obtains the phase difference between the first clock and the second clock.