Setup of SIPM based PET detector using LSO background radiation

Patent metadata

Field	Value
Publication number	US-10527741-B2
Application number	US-201615075334-A
Country	US
Kind code	B2
Filing date	Mar 21, 2016
Priority date	Apr 7, 2015
Publication date	Jan 7, 2020
Grant date	Jan 7, 2020

Abstract

Systems and methods for configuring a radiation detector are provided. A first event is detected at a first scintillator crystal of a first detector unit. A second coincident event is detected at a second scintillator crystal of a second detector unit adjacent to the first detector unit. Operating parameters are calculated for the first detector unit based on the coincident events.

First claim

The invention claimed is:

1. A method for configuring a radiation detector including a plurality of detector units, each detector unit comprising a plurality of scintillator crystals, the method comprising:
acquiring self-activity event data at multiple operating voltages, and at each operative voltage of the multiple operating voltages at multiple leading-edge threshold values including time-mark, energy, and location information for the self-activity event data;
generating crystal region maps for the detector units and the plurality of scintillator crystals from the self-activity event data;
identifying, in the self-activity event data, a first radiation event at a first scintillator crystal of a first detector unit of the radiation detector, the first radiation event being assigned a first time mark and a first position within the first detector unit using the crystal region maps, wherein the first radiation event is caused by a decay of a material in the first detector unit;
identifying, in the self-activity event data, a second radiation event at a second scintillator crystal of a second detector unit of the radiation detector, the second radiation event related to and coincident to the first radiation event and being assigned a second time mark and a second position within the second detector unit using the crystal region maps, wherein the first and second detector units are adjacent within the radiation detector; and
calculating operating parameters for the first detector unit based on the timing differences of the coincident events and a distance between the first position and second position of the coincident events.

2. The method of claim 1 , wherein the first radiation event and second radiation event are caused by decay of Lu-176 in the first scintillator crystal.

3. The method of claim 1 , wherein the first radiation event is related to a beta particle of the decay of the material and the second radiation event is related to a gamma particle of the decay of the material.

4. The method of claim 1 , wherein detecting the first and second radiation events comprises detecting energy deposition information and position information for the first and second radiation events.

5. The method of claim 4 , further comprising:
determining a time-walk correction calibration factor for the first and second detector units based on the energy deposition information, position information and time marks of one or more coincident events.

6. The method of claim 4 , further comprising:
determining an energy calibration factor for the first and second detector units based on the energy deposition information, position information and time marks of one or more coincident events.

7. The method of claim 4 , further comprising:
determining a photo-sensor bias voltage for the first and second detector units based on the energy deposition information, position information and time marks of one or more coincident events.

8. The method of claim 4 , further comprising:
determining a discriminator trigger threshold for the first and second detector units based on the energy deposition information, position information and time marks of one or more coincident events.

9. A method comprising:
selecting initial operating parameters for a plurality of detector units in a positron emission tomography detector, wherein the plurality of detector units each include a plurality of scintillator crystals that are multiplexed to generate a single arrival time measurement;
generating crystal region maps for each of the plurality of detector units;
acquiring self-activity data from the plurality of detector units at multiple operating voltages, and at each operative voltage of the multiple operating voltages at multiple leading-edge threshold values including time-mark, energy, and location information for the self-activity event data;
identifying one or more coincident events in adjacent detector units from the self-activity data and the crystal region maps, wherein each coincident event of the one or more coincident events includes a first time mark and a first position within a first detector unit of the plurality of detector units and a second time mark and a second position within a second detector unit adjacent to the first detector unit; and
calculating a timing offset for one or more of the plurality of scintillator crystals based on a time difference between the first time mark and the second time mark and a distance between the first position and the second position for each of the coincident events of the one or more coincident events.

10. The method of claim 9 , further comprising:
selecting new operating parameters based on the one or more coincident events for each of the plurality of detector units, wherein the new operating parameters generate less jitter in the plurality of detector units than the initial operating parameters.

11. The method of claim 9 , further comprising:
calculating average time differences between the plurality of detector units.

12. The method of claim 9 , further comprising:
calculating a photo sensor bias voltage and a discriminator trigger threshold for each of the plurality of detector units.

13. The method of claim 9 , wherein the self-activity data is generated from intrinsic radiation of the composite detector.

Assignees

• Siemens Medical Solutions Usa Inc

Inventors

• Cho Sanghee
• Mintzer Robert
• Breuer Johannes

Classifications

• G01T7/005

  calibration techniques (stabilization of spectrometer G01T1/40) · CPC title

• G01T1/2985 Primary

  In depth localisation, e.g. using positron emitters; Tomographic imaging (longitudinal and transverse section imaging; apparatus for radiation diagnosis sequentially in different planes, steroscopic radiation diagnosis); (using external radiation sources A61B6/02) · CPC title