BIG BORE PET/MR SYSTEM

• US 20110288401A1
• Filed: 01/12/2010
• Published: 11/24/2011
• Est. Priority Date: 02/17/2009
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Solf, Torsten, Schulz, Volkmar
• Granted Patent: US 8,467,848 B2
• Time in Patent Office: Days
• US Class Current: 600/411
• CPC Class Codes: A61B 6/037 Emission tomography
• CPC Class Codes: A61B 6/4417 related to combined acquisition of different diagnostic modalities
• CPC Class Codes: A61B 6/5247 combining images from an ionising-radiation diagnostic technique and a non-ionising radiation diagnostic technique, e.g. X-ray and ultrasound
• CPC Class Codes: G01R 33/345 of waveguide type G01R33/343 takes precedence
• CPC Class Codes: G01R 33/3453 Transverse electromagnetic [TEM] coils
• CPC Class Codes: G01R 33/3685 Means for reducing sheath currents, e.g. RF traps, baluns
• CPC Class Codes: G01R 33/385 using gradient magnetic field coils
• CPC Class Codes: G01R 33/422 of the radio frequency field
• CPC Class Codes: G01R 33/481 MR combined with positron emission tomography [PET] or single photon emission computed tomography [SPECT]

Abstract

A nuclear detector module (24) is housed within an electrically conductive hollow resonator element (18) that is to be used in a combined MR and nuclear imaging unit. The resonator element has an inner face (26) which is radiation transparent facing an examination region (14) and a plurality of other faces (28) disposed facing and spaced from an RF screen (22).

Claims

1. A combined MR and nuclear imaging unit comprising of:

an electrically conductive hollow resonator element;

a nuclear detector module mounted within the resonator element; and

an RF screen adjacent to the resonator element.

2. A combined MR and nuclear imaging system comprising:

a main magnet;

a gradient coil coil which defines an annular recess therein; and

a plurality of the combined MR and nuclear imaging units according to claim 1 disposed in the annular recess between the gradient coils.

3. The combined MR and nuclear imaging system according to claim 2, wherein:

each of the resonator elements has an inner face which is radiation translucent facing an examination region; and

a plurality of other faces disposed facing and spaced from the RF screen.

4. The combined MR and nuclear imaging system element according to claim 2, wherein each resonator element is electronically coupled to the RF screen by capacitors configured to tune an operating frequency of the resonator element.

5. The combined MR and nuclear imaging system according to claim 3, wherein:

faces of the resonator element are configured to shield the nuclear detector module from RF interference.

6. The combined MR and nuclear imaging system according to claim 5, the nuclear detector module includes:

an array of scintillator crystals;

a plurality of silicon photomultiplier sensor tiles optically coupled to the array of scintillator crystals;

a plurality of ASICs electronically coupled to silicon photomultiplier sensor tiles.

7. The combined MR and nuclear imaging system according to claim 3, wherein the resonator element is configured such that current flows primarily of the inner face.

8. The combined MR and nuclear imaging system according to claim 3, a radiofrequency trap electronically connected to one of the other faces.

9. The combined MR and nuclear imaging system according to claim 2, wherein

the resonator element is electronically connected to at least one of a radiofrequency transmitter and a radiofrequency receiver;

the nuclear detector module is a PET detector module which includes timestamp circuitry and a coincidence detection unit.

10. The combined MR and nuclear imaging system according to claim 9, further including:

an MR resonance processor which processes data from the resonator elements to produce magnetic resonance image representations; and

a PET reconstruction processor which processes data from the PET detector module to produce PET imaging representations.

11. The combined MR and nuclear imaging system according to claim 10, further including:

a fusion processor which combines the MR and PET image representations; and

a user interface including a display which displays the MR, PET, or combined MR/PET image representations.

12. A method of making a combined MR and nuclear imaging unit comprising:

manufacturing a nuclear detector module;

disposing a hollow resonator element around the nuclear detector module, the resonator element having faces which shield the nuclear detector module from RF radiation, one of the faces being translucent to γ

radiation.

13. The method according to claim 12, further including:

mounting an RF shield in an annular recess defined in a gradient coil of a magnetic resonance system;

mounting a plurality of the combined MR and Nuclear imaging units in the annular recess spaced from the RF screen; and

capacitively coupling the resonator element to the RF screen.

14. The method according to claim 13, further included:

connecting an RF trap with one of the faces to cause RF current to flow preferentially on the radio translucent face.

15. The method according to claim 13, further including:

concurrently receiving γ

radiation through the radio translucent face with the nuclear detector unit and at least one of the transmitting MR excitation signals to and receiving resonance signals from the resonator elements; and

reconstructing nuclear imaging representations from the received γ

radiation and MR image representations from the received resonances signals.

16. A method of combined MR and nuclear imaging comprising:

concurrently (a) receiving γ

radiation through a γ

radiation translucent face of a resonator element with a nuclear detector unit which is disposed inside the resonator element and (b) at least one of transmitting MR excitation signals and receiving resonance signals with the resonator element; and

reconstructing nuclear image representations from the received γ

radiation and MR image representations from the received resonance signals.

17. The method according to claim 16, further including:

electronically coupling the resonator element to an adjacent RF screen by capacitors configured to tune an operating frequency of the resonator element.

18. The method according to claim 16, further including:

configuring the resonator element such that current flows primarily on the radiation translucent face.

19. The method according to claim 18, further including:

electronically connecting a radiofrequency trap to at least one of other faces of the resonator element.

20. The method according to claim 16, wherein the nuclear detector module is a PET detector module.