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CN-122017927-A - PET detector and system

CN122017927ACN 122017927 ACN122017927 ACN 122017927ACN-122017927-A

Abstract

The invention discloses a PET detector and a system. The PET detector comprises a crystal array and a photoelectric sensing layer, wherein the crystal array comprises a first crystal layer and a second crystal layer which are stacked, the first crystal layer comprises a plurality of first scintillation crystals which are arrayed, the second crystal layer comprises a plurality of second scintillation crystals which are arrayed, the first scintillation crystals and the second scintillation crystals extend along a first direction, the first direction is parallel to the stacking direction, the first crystal layer and the second crystal layer are coupled and bonded in the first direction, the photoelectric sensing layer is arranged on a first end face of one side, far away from the first crystal layer, of the second crystal layer, and the quantity ratio between the first scintillation crystals and the second scintillation crystals is different at different positions of the first end face. The embodiment of the invention can improve the DOI spatial resolution of the PET detector and the definition of the image.

Inventors

  • ZHU ZHILIANG
  • YANG JING
  • LIU HAO
  • XIE SIWEI

Assignees

  • 湾影科技(深圳)有限公司

Dates

Publication Date
20260512
Application Date
20260317

Claims (10)

  1. 1. A PET detector is characterized by comprising a crystal array and a photoelectric sensing layer; The crystal array comprises a first crystal layer and a second crystal layer which are stacked, wherein the first crystal layer comprises a plurality of first scintillation crystals which are arrayed, the second crystal layer comprises a plurality of second scintillation crystals which are arrayed, and the first scintillation crystals and the second scintillation crystals extend along a first direction, and the first direction is parallel to the stacking direction; The photoelectric sensing layer is arranged on a first end face of one side of the second crystal layer, which is far away from the first crystal layer; the number ratio between the first scintillation crystal and the second scintillation crystal is different at different positions of the first end face.
  2. 2. The PET detector of claim 1, wherein the number of first scintillation crystals is less than the number of second scintillation crystals.
  3. 3. The PET detector of claim 2, wherein the first end face comprises a central region; In the central region, a number ratio between the first scintillation crystal and the second scintillation crystal is 1:4.
  4. 4. The PET detector of claim 2, wherein the first end face comprises an edge region; at the edge region, a quantity ratio between the first scintillation crystal and the second scintillation crystal is 1:2.
  5. 5. The PET detector of claim 2, wherein the first end face comprises a vertex angle region; in the vertex angle region, a quantity ratio between the first scintillation crystal and the second scintillation crystal is 1:1.
  6. 6. The PET detector of claim 1, wherein the photo-sensing layer comprises a plurality of photo-sensors; The photoelectric sensors are arranged in an array, and the quantity ratio between the photoelectric sensors and the second scintillation crystals is 1:4.
  7. 7. The PET detector of claim 6, wherein each of the photosensors is in the first direction The four second scintillation crystals arranged in an array are correspondingly arranged; Wherein the four second scintillation crystals are respectively in the form of The four first scintillation crystals arranged in the array are arranged in a one-to-one correspondence.
  8. 8. The PET detector of claim 1, wherein the material of the first scintillation crystal and the second scintillation crystal each include thallium sodium iodide crystals, bismuth germanate crystals, lutetium silicate crystals, and lutetium-yttrium silicate crystals.
  9. 9. The PET detector of claim 1, wherein reflective material is disposed between adjacent ones of the first scintillation crystals and between adjacent ones of the second scintillation crystals.
  10. 10. A PET system comprising a PET detector as claimed in any one of claims 1 to 9.

Description

PET detector and system Technical Field The invention relates to the technical field of radiation detectors, in particular to a PET detector and a PET detector system. Background Positron emission tomography (Positron Emission Tomography, PET) is a new medical instrument invented in the 70 s of the last century and applied in a large number in this century. As the core of PET systems, currently gamma-ray detectors generally employ a configuration of crystal array coupled position sensitive optoelectronic devices, and positioning inside the detector is achieved in combination with Anger logic algorithm. With the improvement of the performance of modern equipment, the requirement on the spatial resolution of the system is increased, and the depth-of-interaction (DOI) capability of the current front-end detector is insufficient, so that the reconstruction of annihilation positions is offset, parallax errors are generated, and the spatial resolution of the PET system is poor. Disclosure of Invention The invention provides a PET detector and a system thereof, which are used for improving the DOI spatial resolution of the PET detector and improving the definition of images. According to an aspect of the present invention, there is provided a PET detector comprising a crystal array and a photo-sensing layer; The crystal array comprises a first crystal layer and a second crystal layer which are stacked, wherein the first crystal layer comprises a plurality of first scintillation crystals which are arrayed, the second crystal layer comprises a plurality of second scintillation crystals which are arrayed, and the first scintillation crystals and the second scintillation crystals extend along a first direction, and the first direction is parallel to the stacking direction; The photoelectric sensing layer is arranged on a first end face of one side of the second crystal layer, which is far away from the first crystal layer; the number ratio between the first scintillation crystal and the second scintillation crystal is different at different positions of the first end face. Optionally, the number of first scintillation crystals is smaller than the number of second scintillation crystals. Optionally, the first end face includes a central region; In the central region, a number ratio between the first scintillation crystal and the second scintillation crystal is 1:4. Optionally, the first end face includes an edge region; at the edge region, a quantity ratio between the first scintillation crystal and the second scintillation crystal is 1:2. Optionally, the first end face includes a vertex angle region; in the vertex angle region, a quantity ratio between the first scintillation crystal and the second scintillation crystal is 1:1. Optionally, the photo-sensing layer comprises a plurality of photo-sensors; The photoelectric sensors are arranged in an array, and the quantity ratio between the photoelectric sensors and the second scintillation crystals is 1:4. Optionally, in the first direction, each of the photosensors is arranged to be in a rowThe four second scintillation crystals arranged in an array are correspondingly arranged; Wherein the four second scintillation crystals are respectively in the form of The four first scintillation crystals arranged in the array are arranged in a one-to-one correspondence. Optionally, the material of the first scintillation crystal and the second scintillation crystal each include thallium sodium iodide crystals, bismuth germanate crystals, lutetium silicate crystals, and lutetium-yttrium silicate crystals. Optionally, reflective material is disposed between adjacent ones of the first scintillation crystals and between adjacent ones of the second scintillation crystals. According to another aspect of the present invention there is provided a PET system comprising a PET detector as described in any of the embodiments of the first aspect. The PET detector provided by the embodiment of the invention comprises a first crystal layer and a second crystal layer which are stacked, wherein the first crystal layer comprises a plurality of first scintillation crystals which are densely arranged in an array manner, and the second crystal layer comprises a plurality of second scintillation crystals which are densely arranged in an array manner. The first scintillation crystal and the second scintillation crystal are both regular quadrangular prisms extending in the first direction. The first end face of one side, far away from the first crystal layer, of the second crystal layer is provided with a photoelectric sensing layer, the photoelectric sensing layer comprises a plurality of array type closely arranged photosensitive devices, the photosensitive devices corresponding to the adjacent second scintillation crystals can be the same or different, and the corresponding first scintillation crystals can be the same or different. The corresponding quantity ratio between the first scintillation crys