Autonomous detector module as a building block for scalable PET and SPECT systems

Patent metadata

Field	Value
Publication number	US-9995829-B2
Application number	US-200913132934-A
Country	US
Kind code	B2
Filing date	Nov 16, 2009
Priority date	Dec 10, 2008
Publication date	Jun 12, 2018
Grant date	Jun 12, 2018

Abstract

When detecting scintillation events in a nuclear imaging system, time-stamping and energy-gating processing is incorporated into autonomous detection modules (ADM) ( 14 ) to reduce downstream processing. Each ADM ( 14 ) is removably coupled to a detector fixture ( 13 ), and comprises a scintillation crystal array ( 66 ) and associated light detect or (s) ( 64 ), such as a silicon photomultiplier or the like. The light detector(s) ( 64 ) is coupled to a processing module ( 62 ) in or on the ADM ( 14 ), which performs the energy gating and time-stamping.

First claim

The invention claimed is:

1. A nuclear scanning detector system, including:
a nuclear scanner comprising a plurality of nuclear detector fixtures;
one or more autonomous detector modules (ADM) removably coupled to each detector fixture, each ADM including:
a scintillation crystal array comprising one or more scintillation crystals;
one or more removable light detectors for detecting scintillation events in respective sectors of the scintillation crystal array;
a processing module that timestamps each detected scintillation event, executes an energy-gating protocol to identify Compton scattered events, and outputs time-stamped, energy-gated scintillation event information; and
a configuration connector via which the ADM is configured during setup.

2. The system according to claim 1 , further including:
a coincidence detection component that receives the time-stamped, energy-gated scintillation event information from the plurality of ADMs and identifies pairs of detected scintillation events that correspond to a single annihilation event in a subject.

3. The system according to claim 2 , further including:
a reconstruction processor that reconstructs an image volume of a subject from the identified pairs of scintillation events;
an image memory that stores the reconstructed image volume; and
a display on which the image volume is displayed to a viewer.

4. The system according to claim 1 , wherein each ADM includes:
a power connector via which the ADM receives power;
a clock connector via which the ADM receives timing information from a master clock for time-stamping detected scintillation events; and
an output connection via which the ADM transmits the time-stamped, energy-gated scintillation event information;
wherein the connections and corresponding connectors on a gantry have a plug-socket relationship.

5. The system according to claim 1 , wherein the scintillation crystal array has dimensions in the range approximately 3×3 cm2 to approximately 16×16 cm2.

6. The system according to claim 5 , wherein the scintillation crystals are formed of one of:
Bismuth Germanate (BGO) with the scintillation crystal array having dimensions in the range of approximately 3×3 cm2 to approximately 6×6 cm2; or
at least one of Lutetium Yttrium Orthosilicate (LYSO) or Lutetium Orthosilicate (LSO) with the scintillation crystal array having dimensions in the range of approximately 3×3 cm2 to approximately 8×8 cm2; or
Lanthium Bromide (LaBr) with the scintillation crystal array having dimensions in the range of approximately 6×6 cm2 to approximately 12×12 cm2.

7. The system according to claim 1 , wherein the light detectors each include a plurality of light sensitive elements arranged on a tile, each tile having light sensitive elements corresponding to a plurality of detector pixels with the light sensitive elements substantially covering the tile with minimal edge regions such that the tiles can be mounted abutting each other and maintain consistent detector pixel periodicity.

8. The system according to claim 7 , wherein the tiles are rectangular and each module includes at least four tiles in a close-packed relationship.

9. The system according to claim 1 , wherein the processing module includes flash memory that stores a lookup table including correction information used by the processing module to compensate for Compton-type scatter.

10. The system according to claim 1 , wherein the processing module includes at least one of field-programmable gate arrays (FPGAs) and application-specific integrated circuits (ASICs) for time-stamping and energy-gating detected scintillation events.

11. The system according to claim 1 , wherein the processing module includes at least one field-programmable gate array (FPGA) that receives timestamp information from a time-stamping unit integrated into the light detector.

12. A method of reducing downstream data processing demand in a nuclear imaging system, including:
detecting scintillation events in one or more autonomous detector modules (ADM) each comprising a plurality of removable light detectors;
time-stamping the scintillation events at the module-level on each ADM;
aggregating multiple scintillation events from a single gamma photon;
performing an energy-gating technique on the scintillation events at the module-level;
outputting time-stamped, energy-gated scintillation event information; and
processing and reconstructing the event information into a 3-D image volume; and
determining that one or more ADMs is faulty;
transmitting a fault signal that alerts a technician of the one or more faulty ADMs; and
replacing the one or more faulty ADM with a new pre-calibrated ADM.

13. The method according to claim 12 , further including:
executing a coincidence detection algorithm on the output scintillation event information to identify corresponding pairs of scintillation events.

14. A non-transitory computer-readable medium having stored thereon computer-executable instructions for performing the method according to claim 12 .

15. An autonomous detector module (ADM), including:
a scintillation crystal array;
at least one light detector that detects a scintillation event in all or a portion of the scintillation crystal array;
a processing module that time-stamps detected scintillation events or receives timestamp and energy information from a circuit integrated with the light detector, executes an energy-gating technique on the detected scintillation events and outputs time-stamped, energy-gated scintillation event information; and
a connector that removably couples the at least one light detector to a printed circuit board (PCB) that is coupled to the processing module; and
a configuration connector via which the ADM is configured during at least one of setup or during a scan.

16. The ADM according to claim 15 :
wherein the at least one light detector is coupled to all or a portion of the scintillation crystal array at a first side, and to the connector at a second side.

17. The ADM according claim 15 :
wherein the at least one light detector is coupled to all or a portion of the scintillation crystal array at a first side, and to a printed circuit board (PCB) at a second side, the printed circuit board being further coupled to the processing module.

18. The ADM according to claim 15 , further including:
a power connector via which the ADM receives power;
a clock connector via which the ADM receives timing information from a master clock for time-stamping detected scintillation events; and
an output connection via which the ADM transmits the time-stamped, energy-gated scintillation event information.

19. A positron emission tomography (PET) imaging system including a plurality of the ADMs according to claim 15 .

20. An autonomous detector module (ADM) comprising:
a plurality of tiles arranged in a close-packed array, each tile including:
a plurality of light sensitive elements corresponding to a plurality of detector pixels with the light sensitive elements substantially covering the tile with minimal edge regions, and
at least one scintillator optically coupled to the light sensitive elements;

wherein the tiles are removably mounted abutting each other with the light sensitive elements of one tile being sufficiently adjacent to the light sensitive elements of an adjacent tile that a consistent detector pixel periodicity is maintained across the plurality of tiles; and
a configuration connector via which the ADM is configured during setu

Assignees

• Degenhardt Carsten
• Frach Thomas
• Prescher Gordian
• Koninklijke Philips Nv

Inventors

• Degenhardt Carsten
• Frach Thomas
• Prescher Gordian

Classifications

• G01T1/00

  Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation (G01T3/00, G01T5/00 take precedence) · CPC title

• A61B6/037

  Emission tomography · CPC title

• G01T1/1644 Primary

  using an array of optically separate scintillation elements permitting direct location of scintillations (G01T1/1645 takes precedence) · CPC title

• G01T1/1645 Primary

  using electron optical imaging means, e.g. image intensifier tubes, coordinate photomultiplier tubes, image converter · CPC title