MAGNETIC RESONANCE IMAGING APPARATUS AND RF COIL DEVICE

• US 20140218035A1
• Filed: 04/07/2014
• Published: 08/07/2014
• Est. Priority Date: 01/23/2013
• Status: Active Grant

• Current Assignee: Toshiba Medical Systems Corporation (Canon Inc.)
• Original Assignee: Toshiba Medical Systems Corporation (Canon Inc.), Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: OKAMOTO, Kazuya
• Granted Patent: US 10,175,313 B2
• Time in Patent Office: Days
• US Class Current: 324/322
• CPC Class Codes: G01R 33/3635 Multi-frequency operation
• CPC Class Codes: G01R 33/3678 involving quadrature drive or detection, e.g. a circularly polarized RF magnetic field
• 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

According to one embodiment, an MRI apparatus (10) includes a power transmitting unit (49, WB1, PT1 and PT2), a signal receiving unit (104, C3, EC1 to EC4, DP1 to DP4, 140 and 160) and an image reconstruction unit (62). The power transmitting unit wirelessly transmits electric power to an RF coil device (100 or 100′) by magnetically coupled resonant type wireless power transfer. The signal receiving unit wirelessly receives a digitized nuclear magnetic resonance signal wirelessly transmitted from the RF coil device (100 or 100′). The image reconstruction unit (62) obtains a nuclear magnetic resonance signal received by the signal receiving unit, and reconstruct image data of an object (P) on the basis of the nuclear magnetic resonance signal.

Claims

1. A magnetic resonance imaging apparatus obtaining a nuclear magnetic resonance signal from an RF coil device that detects the nuclear magnetic resonance signal emitted from an object, the magnetic resonance imaging apparatus comprising:

a power transmitting unit configured to wirelessly transmit electric power to a power receiving unit of the RF coil device by magnetically coupled resonant type wireless power transfer;

a signal receiving unit configured to wirelessly receive a digitized nuclear magnetic resonance signal wirelessly transmitted from the RF coil device; and

an image reconstruction unit configured to obtain the digitized nuclear magnetic resonance signal received by the signal receiving unit and to reconstruct image data of the object based on the digitized nuclear magnetic resonance signal.

2. The magnetic resonance imaging apparatus according to claim 1,

wherein the RF coil device is a part of the magnetic resonance imaging apparatus;

and

the power receiving unit of the RF coil device is configured to receive electric power by the magnetically coupled resonant type wireless power transfer.

3. The magnetic resonance imaging apparatus according to claim 1,

wherein the power transmitting unit includes a double resonance type whole body coil configured to respectively resonate at a magnetic resonance frequency and at a frequency of alternating-current power different from the magnetic resonance frequency;

and

the double resonance type whole body coil is configured to induce the nuclear magnetic resonance signal from the object by resonating at the magnetic resonance frequency, and to wirelessly transmit the alternating-current power by resonating at the frequency of the alternating-current power.

4. The magnetic resonance imaging apparatus according to claim 1, further comprising a whole body coil configured to perform transmission of an RF pulse to an imaging region,

wherein the power transmitting unit includes a power transmitting coil configured to wirelessly transmit electric power as another component aside from the whole body coil.

5. The magnetic resonance imaging apparatus according to claim 1,

wherein the RF coil device is a part of the magnetic resonance imaging apparatus,

the RF coil device includes a coil element configured to respectively resonate at a magnetic resonance frequency and at a frequency of alternating-current power different from the magnetic resonance frequency;

and

the coil element is configured to detect the nuclear magnetic resonance signal from the object by resonating at the magnetic resonance frequency and to function as the power receiving unit by resonating at the frequency of the alternating-current power so as to receive the alternating-current power.

6. The magnetic resonance imaging apparatus according to claim 1,

wherein the RF coil device is a part of the magnetic resonance imaging apparatus;

and

the RF coil device includes (A) a power receiving coil configured to receive wirelessly transmitted electric power as the power receiving unit and (B) a coil element configured to detect the nuclear magnetic resonance signal from the object, the power receiving coil and the coil element being mutually separate components.

7. The magnetic resonance imaging apparatus according to claim 1,

wherein the power transmitting unit is configured to wirelessly transmit electric power to the RF coil device continuously, including a period during which an RF pulse is transmitted from the magnetic resonance imaging apparatus to an imaging region and a period during which the nuclear magnetic resonance signal is detected by the RF coil device.

8. The magnetic resonance imaging apparatus according to claim 1,

wherein the power transmitting unit is configured to wirelessly transmit electric power to the RF coil device, avoiding a period during which an RF pulse is transmitted from the magnetic resonance imaging apparatus to an imaging region.

9. The magnetic resonance imaging apparatus according to claim 1,

wherein the power transmitting unit is configured to wirelessly transmit electric power to the RF coil device, avoiding a period during which the nuclear magnetic resonance signal is detected by the RF coil device.

10. The magnetic resonance imaging apparatus according to claim 1,

wherein the power transmitting unit is configured to wirelessly transmit electric power to the RF coil device, avoiding (A) a period during which an RF pulse is transmitted from the magnetic resonance imaging apparatus to an imaging region and (B) a period during which the nuclear magnetic resonance signal is detected by the RF coil device.

11. An RF coil device including a coil element that detects a nuclear magnetic resonance signal emitted from an object, the RF coil device comprising:

a power receiving unit configured to receive electric power wirelessly transmitted by magnetically coupled resonant type wireless power transfer; and

a signal transmitting unit configured to digitize the nuclear magnetic resonance signal detected by the coil element and wirelessly transmit a digitized nuclear magnetic resonance signal to an magnetic resonance imaging apparatus, by consuming the electric power received by the power receiving unit.

12. The RF coil device according to claim 11,

wherein the power receiving unit includes a power receiving coil configured to function as an antenna that receives alternating-current power wirelessly transmitted from the magnetic resonance imaging apparatus by the magnetically coupled resonant type wireless power transfer.

13. The RF coil device according to claim. 12, further comprising a charge/discharge element and a rectifier,

wherein the power receiving unit is configured to input the alternating-current power to the rectifier;

and

the rectifier is configured to generate direct-current electricity from the alternating-current power and output the direct-current electricity as a charging current to the charge/discharge element.