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US 12,625,285 B2Granted
3D semiconductor detector system
AssigneeSiSnap AB
InventorsMats Danielsson, Elias Rieger
Life of this patent
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Abstract
A detector system for molecular imaging of a radionuclide comprises a 3D semiconductor detector comprising a plurality of sensor stacks of sensors made of a semiconductor material having an average atomic number Z below 40. A read-out circuitry connected to the pixels is configured to output, for each interaction induced by an incident gamma ray in the detector, a signal representative of a time, a position and an energy of the interaction in the detector. The interactions in the detector belonging to a same event induced by the incident gamma ray are predicted based on the output signals and used to estimate a direction of the incident gamma ray and reconstruct an image based on the estimated directions of incident gamma rays.
Claims27
A detector system for molecular imaging of a radionuclide, comprising:
- a three-dimensional (3D) semiconductor detector comprising a plurality of sensor stacks, wherein each sensor stack of the plurality of sensor stacks comprises a plurality of semiconductor sensors each comprising a plurality of pixels, wherein the plurality of semiconductor sensors is made of a semiconductor material having an average atomic number Z below 40;
- a read-out circuitry connected to the pixels in the 3D semiconductor detector and configured to output, for each pixel along an electron track in the 3D semiconductor detector, a pixel value representative of an energy deposited at the pixel by a Compton recoil electron along the electron track in the 3D semiconductor detector, wherein the Compton recoil electron is created by a Compton scatter interaction induced by an incident gamma ray in the 3D semiconductor detector;
- at least one processor;
- and
- at least one memory comprising instructions, which when executed by the at least one processor, cause the at least one processor to, if an estimated energy of the Compton recoil electron is below a first threshold value, predict a position of a start of the electron track based on a center of a charge cloud in the 3D semiconductor detector by a Gaussian fit to the pixel values output by the read-out circuitry by:
- summing pixel values over a first dimension in the 3D semiconductor detector to obtain a first one-dimensional projection,
- summing pixel values over a second dimension in the 3D semiconductor detector to obtain a second one-dimensional projection,
- fitting a first Gaussian function to the first one-dimensional projection,
- fitting a second Gaussian function to the second one-dimensional projection,
- determining a first coordinate in the first dimension in the 3D semiconductor detector based on a mean of the first Gaussian function,
- determining a second coordinate in the second dimension in the 3D semiconductor detector based on a mean of the second Gaussian function, and
- predicting the position of a start of the electron track based on the first coordinate and the second coordinate.
9 more elements
A detector system for molecular imaging of a radionuclide, comprising:
- a three-dimensional (3D) semiconductor detector comprising a plurality of sensor stacks, wherein each sensor stack of the plurality of sensor stacks comprises a plurality of semiconductor sensors each comprising a plurality of pixels, wherein the plurality of semiconductor sensors is made of a semiconductor material having an average atomic number Z below 40;
- a read-out circuitry connected to the pixels in the 3D semiconductor detector and configured to output, for each pixel along an electron track in the 3D semiconductor detector, a pixel value representative of an energy deposited at the pixel by a Compton recoil electron along the electron track in the 3D semiconductor detector, wherein the Compton recoil electron is created by a Compton scatter interaction induced by an incident gamma ray in the 3D semiconductor detector;
- at least one processor;
- and
- at least one memory comprising instructions, which when executed by the at least one processor, cause the at least one processor to predict a position of a start of the electron track based on a center of a charge cloud in the 3D semiconductor detector if an estimated energy of the Compton recoil electron is below a first threshold value, wherein the first threshold value is 100 keV.
2 more elements
A detector system for molecular imaging of a radionuclide, comprising:
- a three-dimensional (3D) semiconductor detector comprising a plurality of sensor stacks, wherein each sensor stack of the plurality of sensor stacks comprises a plurality of semiconductor sensors each comprising a plurality of pixels, wherein the plurality of semiconductor sensors is made of a semiconductor material having an average atomic number Z below 40;
- a read-out circuitry connected to the pixels in the 3D semiconductor detector and configured to output, for each pixel along an electron track in the 3D semiconductor detector, a pixel value representative of an energy deposited at the pixel by a Compton recoil electron along the electron track in the 3D semiconductor detector, wherein the Compton recoil electron is created by a Compton scatter interaction induced by an incident gamma ray in the 3D semiconductor detector;
- at least one processor;
- and
- at least one memory comprising instructions, which when executed by the at least one processor, cause the at least one processor to, if an estimated energy of the Compton recoil electron is above a threshold value:
- perform linear regression to fit a line to the pixel values;
- compare a pixel value at a start of the line with a pixel value at an end of the line;
- and
- predict a position of a start of the electron track as the one of the start of the line and the end of the line having a pixel value representing a lowest amount of energy deposited at the pixel.
6 more elements
A detector system for molecular imaging of a radionuclide, comprising:
- a three-dimensional (3D) semiconductor detector comprising a plurality of sensor stacks, wherein each sensor stack of the plurality of sensor stacks comprises a plurality of semiconductor sensors each comprising a plurality of pixels, wherein the plurality of semiconductor sensors is made of a semiconductor material having an average atomic number Z below 40;
- a read-out circuitry connected to the pixels in the 3D semiconductor detector and configured to output, for each pixel along an electron track in the 3D semiconductor detector, a pixel value representative of an energy deposited at the pixel by a Compton recoil electron along the electron track in the 3D semiconductor detector, wherein the Compton recoil electron is created by a Compton scatter interaction induced by an incident gamma ray in the 3D semiconductor detector;
- at least one processor;
- and
- at least one memory comprising instructions, which when executed by the at least one processor, cause the at least one processor to predict a position of a start of the electron track based on a distribution of the energies deposited at each pixel along the electron track in the 3D semiconductor detector, wherein each semiconductor sensor of the plurality of semiconductor sensors comprises:
- a plurality of electrodes;
- at least one counter electrode;
- and
- an electric field circuitry connected to the plurality of electrodes and the least one counter electrode and configured to apply a bias voltage between each electrode of the plurality of electrodes and a counter electrode of the at least one counter electrode.
6 more elements
A detector system for molecular imaging of a radionuclide, comprising:
- a three-dimensional (3D) semiconductor detector comprising a plurality of sensor stacks, wherein each sensor stack of the plurality of sensor stacks comprises a plurality of semiconductor sensors each comprising a plurality of pixels, wherein the plurality of semiconductor sensors is made of a semiconductor material having an average atomic number Z below 40;
- a read-out circuitry connected to the pixels in the 3D semiconductor detector and configured to output, for each pixel along an electron track in the 3D semiconductor detector, a pixel value representative of an energy deposited at the pixel by a Compton recoil electron along the electron track in the 3D semiconductor detector, wherein the Compton recoil electron is created by a Compton scatter interaction induced by an incident gamma ray in the 3D semiconductor detector;
- at least one processor;
- and
- at least one memory comprising instructions, which when executed by the at least one processor, cause the at least one processor to:
- predict a position of a start of the electron track based on a distribution of the energies deposited at each pixel along the electron track in the 3D semiconductor detector;
- estimate a momentum of a Compton recoil electron by a linear fit to a first part of the electron track in the 3D semiconductor detector;
- and
- calculate a kinematic constraint for the Compton scatter interaction based on the estimated momentum of the Compton recoil electron.
6 more elements
Dependencies are inferred from the claim text.