PET-MRI COMBINATION APPARATUS

• US 20100217112A1
• Filed: 09/24/2009
• Published: 08/26/2010
• Est. Priority Date: 02/24/2009
• Status: Active Grant

• Current Assignee: Sogang University Research Foundation
• Original Assignee: Sungkyunkwan University Foundation For Corporate Collaboration (SungKyunKwan University)
• Inventors: Hu, Wei, Kang, Ji Hoon, Jung, Jin-Ho, Min, Byung Jun, Choi, Yong, Hong, Key Jo
• Granted Patent: US 8,401,613 B2
• Time in Patent Office: Days
• US Class Current: 600/411
• CPC Class Codes: G01R 33/481 MR combined with positron emission tomography [PET] or single photon emission computed tomography [SPECT]
• CPC Class Codes: G01T 1/16 Measuring radiation intensity G01T1/29 takes precedence ; self-powered detectors G01T3/006; using an ionisation chamber filled with a liquid or solid, e.g. frozen liquid, dielectric G01T3/008
• CPC Class Codes: G01T 1/1603 with a combination of at least two different types of detector see provisionally also G01T1/16

Abstract

Disclosed herein is a PET-MRI combination apparatus which can extend transaxial and axial fields of view (FOV) by transmitting an output signal from a photo sensor to the outside of an MRI bore using cable. The PET-MRI combination apparatus includes an MRI bore for capturing an MR image of an object. A PET detector is installed inside imaging space of the MRI bore, and is configured such that a plurality of scintillation crystal arrays, each having scintillation crystals arranged in a ring shape, is arranged in a longitudinal direction so as to extend a axial field of view (FOV). A PET circuit unit is installed outside the MRI bore to prevent the PET circuit unit from being influenced by a magnetic field in the MRI bore, and is configured to include a signal amplification circuit and a signal processing circuit. A cable is configured to connect the PET detector to the PET circuit unit.

Claims

1. A Positron Emission Tomography (PET)-Magnetic Resonance Imaging (MRI) combination apparatus, comprising:

an MRI bore configured to capture an MR image of an object placed in an imaging space;

a PET detector installed inside the imaging space of the MRI bore, and comprising a plurality of scintillation crystal arrays, each having a plurality of scintillation crystals arranged in a ring shape, wherein the plurality of scintillation crystal arrays is arranged in a longitudinal direction so as to extend a axial field of view (FOV);

a PET circuit configured to amplify and process PET signals, wherein the PET circuit is installed outside the MRI bore to avoid or minimize influence of a magnetic field produced in the MRI bore; and

a cable connecting the PET detector to the PET circuit.

2. The PET-MRI combination apparatus according to claim 1, wherein:

the PET detector comprises a photo sensor for converting scintillation detected by the scintillation crystals into charge signals; and

the cable is connected to the photo sensor and is configured to transmit the charge signals to the PET circuit.

3. The PET-MRI combination apparatus according to claim 2, wherein the photo sensor is a semiconductor photo sensor.

4. The PET-MRI combination apparatus according to claim 1, further comprising an object table equipped with a movable bed for allowing the object to move into the imaging space,

wherein the PET circuit is installed within the object table.

5. The PET-MRI combination apparatus according to claim 4, wherein the scintillation crystals are each implemented as one of Bismuth Germanate (BGO), Lutetium Oxyorthosilicate (LSO), Lutetium Yttrium Oxyorthosilicate (LYSO), Lutetium Aluminum Perovskite (LuAP), Lutetium Yttrium Aluminum Perovskite (LuYAP), Lanthanum Bromide (LaBr₃) and Lutetium Iodide (LuI₃), which are free from gadolinium, or as a multi-layer structure thereof.

6. The PET-MRI combination apparatus according to claim 1, wherein the cable is a low-capacitance cable which does not influence performance of PET imaging even if a cable having such a length as to extend outwards from the MRI bore is used.

7. The PET-MRI combination apparatus according to claim 1, wherein the cable is a low conductive resistance cable which does not influence performance of PET imaging even if a cable having such a length as to extend outwards from the MRI bore is used.

8. The PET-MRI combination apparatus according to claim 1, wherein the cable is a high-characteristic impedance cable which does not influence performance of PET imaging even if a cable having such a length as to extend outwards from the MRI bore is used.

9. The PET-MRI combination apparatus according to claim 1, wherein the cable has a length from 5 cm to 900 cm so as to prevent performance of PET and MRI imaging from being deteriorated.

10. The PET-MRI combination apparatus according to claim 7, wherein the scintillation crystals are each implemented as one of Bismuth Germanate (BGO), Lutetium Oxyorthosilicate (LSO), Lutetium Yttrium Oxyorthosilicate (LYSO), Lutetium Aluminum Perovskite (LuAP), Lutetium Yttrium Aluminum Perovskite (LuYAP), Lanthanum Bromide (LaBr₃) and Lutetium Iodide (LuI₃), which are free from gadolinium, or as a multi-layer structure thereof.

11. The PET-MRI combination apparatus according to claim 2, wherein the cable is a multi-channel cable which comprises a number of channels corresponding to a number of charge signals output from the photo sensor and transmits respective charge signals to the PET circuit through corresponding channels.

12. The PET-MRI combination apparatus according to claim 2, wherein:

the cable is a multi-channel cable comprising a number of channels exceeding a number of charge signals output from the photo sensor; and

the channels corresponding to the charge signals in number transmit respective charge signals to the PET circuit, and remaining channels not participating in the transmission of the charge signals are grounded, thus minimizing interference of the charge signals.

13. The PET-MRI combination apparatus according to claim 2, wherein the cable is a multi-channel fine coaxial cable having an excellent shielding ability.

14. The PET-MRI combination apparatus according to claim 2, wherein the cable is a multi-channel twisted-pair cable having minimized interference.

15. The PET-MRI combination apparatus according to claim 1, wherein the scintillation crystals are each implemented as one of Bismuth Germanate (BGO), Lutetium Oxyorthosilicate (LSO), Lutetium Yttrium Oxyorthosilicate (LYSO), Lutetium Aluminum Perovskite (LuAP), Lutetium Yttrium Aluminum Perovskite (LuYAP), Lanthanum Bromide (LaBr₃) and Lutetium Iodide (LuI₃), which are free from gadolinium, or as a multi-layer structure thereof.