Medical detectors and medical imaging devices

1. A medical detector comprising:

a photoelectric conversion device;

a first crystal array layer comprising a plurality of first scintillation crystals arranged in a first crystal array, the first crystal array layer being disposed over the photoelectric conversion device along a length direction of the first scintillation crystals, a first coupling medium being filled between every adjacent two of the first scintillation crystals; and

a second crystal array layer disposed over the first crystal array layer along the length direction, the second crystal array layer comprising a plurality of second scintillation crystals arranged in a second crystal array, a second coupling medium being filled between every adjacent two of the second scintillation crystals,

wherein the first crystal array layer comprises a bottom surface and a top surface along the length direction, and the bottom surface of the first crystal array layer is bonded to the photoelectric conversion device, and the top surface of the first crystal array layer is bonded to a bottom surface of the second crystal array layer,

wherein a first light transmittance of the first coupling medium is different from a second light transmittance of the second coupling medium,

wherein a crystal material of the first scintillation crystal is different from a crystal material of the second scintillation crystal, and

wherein, along the length direction, a length of the first coupling medium corresponds to a length of each of the plurality of first scintillation crystals over the photoelectric conversion device, and a length of the second coupling medium corresponds to a length of each of the plurality of second scintillation crystals over the plurality of first scintillation crystals.

2. The medical detector of claim 1 , wherein:

a higher one of the first and second light transmittances is no lower than 70%, and

a lower one of the first and second light transmittances is no higher than 10%.

3. The medical detector of claim 1 , further comprising:

adhesive material disposed between the plurality of first scintillation crystals of the first crystal array layer and the plurality of second scintillation crystals of the second crystal array layer.

4. The medical detector of claim 1 , further comprising:

adhesive material disposed between the plurality of first scintillation crystals of the first crystal array layer and the photoelectric conversion device.

5. The medical detector of claim 1 , further comprising:

a light guide adhesively arranged between the first crystal array layer and the photoelectric conversion device.

6. The medical detector of claim 1 , wherein the first crystal array layer comprises:

side surfaces, together with side surfaces of the second crystal array and a top surface of the second crystal array layer, covered with a reflective layer.

7. The medical detector of claim 6 , wherein a light transmittance of the reflective layer is no greater than 10%.

8. The medical detector of claim 1 , wherein each of the first scintillation crystals comprises a same first crystal selected from a group of crystals comprising: a lutetium silicate crystal, an yttrium lutetium silicate crystal, a lutetium fine silicate crystal, a gadolinium silicate crystal, a lanthanum bromide crystal, a gadolinium aluminum gallium garnet crystal, and a cerium-doped yttrium aluminate crystal, and

wherein each of the second scintillation crystals comprises a same second crystal selected from the group of crystals.

9. The medical detector of claim 1 , wherein an array arrangement of the second crystal array is same as that of the first crystal array, and

wherein a center distance of adjacent two of the second scintillation crystals is same as that of adjacent two of the first scintillation crystals.

10. A medical imaging device comprising:

a detection ring assembled by assembling a plurality of medical detectors;

a centralized data managing board;

a reconstruction processor;

a display; and

a scanning bed,

wherein each of the plurality of medical detectors comprises:

a photoelectric conversion device;

a first crystal array layer comprising a plurality of first scintillation crystals arranged in a first crystal array, the first crystal array layer being disposed over the photoelectric conversion device along a length direction of the first scintillation crystals, a first coupling medium being filled between every adjacent two of the first scintillation crystals; and

a second crystal array layer disposed over the first crystal array layer along the length direction, the second crystal array layer comprising a plurality of second scintillation crystals arranged in a second crystal array, a second coupling medium being filled between every adjacent two of the second scintillation crystals,

wherein the first crystal array layer comprises a bottom surface and a top surface along the length direction, and the bottom surface of the first crystal array layer is bonded to the photoelectric conversion device, and the top surface of the first crystal array layer is bonded to a bottom surface of the second crystal array layer,

wherein a first light transmittance of the first coupling medium is different from a second light transmittance of the second coupling medium,

wherein a crystal material of the first scintillation crystal is different from a crystal material of the second scintillation crystal, and

wherein, along the length direction, a length of the first coupling medium corresponds to a length of each of the plurality of first scintillation crystals over the photoelectric conversion device, and a length of the second coupling medium corresponds to a length of each of the plurality of second scintillation crystals over the plurality of first scintillation crystals.

11. A medical detector comprising:

a photoelectric conversion device; and

a crystal array comprising a plurality of scintillation crystals arranged in an array, the crystal array being disposed over the photoelectric conversion device along a length direction of the scintillation crystals, the crystal array being divided into a first crystal region and a second crystal region along the length direction of the scintillation crystals, the first crystal region comprising first parts of the scintillation crystals and the second crystal region comprising second parts of the scintillation crystals, a first coupling medium being filled between the first parts of every adjacent two of the scintillation crystals in the first crystal region, and a second coupling medium being filled between the second parts of every adjacent two of the scintillation crystals in the second crystal region,

wherein the crystal array comprises a bottom surface and a top surface along the length direction, and the bottom surface of the crystal array is bonded to the photoelectric conversion device along the length direction,

wherein a first light transmittance of the second coupling medium is different from that of the first coupling medium,

and

wherein, along the length direction, a length of the first coupling medium corresponds to a length of the first crystal region over the photoelectric conversion device, and a length of the second coupling medium corresponds to a length of the second crystal region over the first crystal region.

12. The medical detector of claim 11 , wherein:

a higher one of the first and second light transmittances is no lower than 70%, and

a lower one of the first and second light transmittances is no higher than 10%.

13. The medical detector of claim 11 , further comprising:

adhesive material disposed between the plurality of scintillation crystals of the crystal array and the photoelectric conversion device.

14. The medical detector of claim 11 , further comprising:

a light guide adhesively arranged between the crystal array and the photoelectric conversion device.

15. The medical detector of claim 11 ,

wherein side surfaces of the crystal array and the top surface of the crystal array are covered with a reflective layer.

16. The medical detector of claim 11 , wherein each of the plurality of scintillation crystals is selected from a group comprising: a lutetium silicate crystal, an yttrium lutetium silicate crystal, a lutetium fine silicate crystal, a gadolinium silicate crystal, a lanthanum bromide crystal, a gadolinium aluminum gallium garnet crystal, and a cerium-doped yttrium aluminate crystal.