阅读说明：本技术 正电子发射计算机断层成像装置及方法 (Positron emission computed tomography device and method ) 是由 李炳轩 王侃 于 2021-07-22 设计创作，主要内容包括：本发明公开了正电子发射计算机断层成像装置及方法,装置的探测部包括若干个探测模组,探测模组的探测面沿着第一圆周分布,其中至少两组探测模组的探测面相对布置且位于第一圆周的直径方向上,第一圆周上形成有至少一个开口；探测部的探测面在检测时通过运动变化为沿着第二圆周分布,第一圆周和第二圆周的直径不同；方法包括：采用PET装置进行成像,PET装置包括沿着第一圆周分布的若干个探测模组和至少一个开口；改变PET装置的形状,使探测模组的探测面和开口沿着第二圆周分布；采用采用形状变化的PET装置再次进行成像。本发明不仅提供了良好的系统开放性,而且可以改变开口部分的大小和角度,适配性好,同时能够保证系统灵敏度和响应均一性。(The invention discloses a positron emission computed tomography device and a method, wherein a detection part of the device comprises a plurality of detection modules, detection surfaces of the detection modules are distributed along a first circumference, the detection surfaces of at least two groups of detection modules are oppositely arranged and positioned in the diameter direction of the first circumference, and at least one opening is formed on the first circumference; the detection surface of the detection part is changed into distribution along a second circumference through movement during detection, and the diameters of the first circumference and the second circumference are different; the method comprises the following steps: imaging by using a PET device, wherein the PET device comprises a plurality of detection modules and at least one opening which are distributed along a first circumference; changing the shape of the PET device to ensure that the detection surfaces and the openings of the detection modules are distributed along a second circumference; imaging was again performed using a PET apparatus employing a shape change. The invention not only provides good system openness, but also can change the size and the angle of the opening part, has good adaptability, and can ensure the sensitivity and the response uniformity of the system.)

1. A positron emission computed tomography imaging apparatus, comprising:

the detection part comprises a plurality of detection modules, detection surfaces of the detection modules are distributed along a first circumference, the detection surfaces of at least two groups of detection modules are oppositely arranged and are positioned in the diameter direction of the first circumference, and at least one opening is formed on the first circumference; the detection surface of the detection part moves and changes to be distributed along a second circumference when being detected, and the diameters of the first circumference and the second circumference are different.

2. The positron emission computed tomography apparatus as claimed in claim 1, wherein there are two of said detector portions and said openings, respectively, said openings and said detector portions being spaced apart and together forming said circumference.

3. The positron emission computed tomography apparatus as claimed in claim 1, wherein the detecting portion and the opening are one each, the opening and the detecting portion being spaced apart and together forming the circumference.

4. The positron emission computed tomography apparatus as claimed in claim 2 or 3, wherein all of the detection modules in the detection portion are in one-to-one correspondence in the circumferential diameter direction, respectively.

5. The positron emission computed tomography apparatus as claimed in claim 2 or 3, wherein a part of the detection modules in the detection portion correspond to each other in a diameter direction of the circumference.

6. The positron emission computed tomography apparatus as claimed in claim 2 or 3, wherein a diameter of the first circumference is smaller than a diameter of the second circumference after the movement of the detecting portion.

7. The positron emission computed tomography apparatus as claimed in claim 2 or 3, wherein a diameter of the first circumference is larger than a diameter of the second circumference after the movement of the detecting portion.

8. The positron emission computed tomography apparatus as claimed in claim 1, wherein an angle of a central angle corresponding to the opening is unchanged after the detecting portion moves, and the number of the detecting modules in the detecting portion is reduced.

9. The positron emission computed tomography apparatus as claimed in claim 1, wherein an angle of a central angle corresponding to the opening is unchanged after the detecting portion moves, and the number of the detecting modules in the detecting portion increases.

10. The positron emission computed tomography apparatus as claimed in claim 1, wherein the number of the openings and the detecting portion is changed to one after the movement of the detecting portion.

11. The positron emission computed tomography apparatus as claimed in claim 1, wherein the openings are two before the movement, and the openings disappear after the movement of the detecting portion.

12. The positron emission computed tomography apparatus as claimed in claim 1, wherein the number of the openings is one, and the number of the detecting portions and the number of the openings are changed to two after the movement of the detecting portions.

13. The positron emission computed tomography apparatus as claimed in claim 1, wherein the at least one detecting portion rotates along the second circumference after moving, and the detecting surfaces of at least two groups of the detecting modules are still oppositely arranged and located on the same straight line after rotating.

14. The positron emission computed tomography apparatus of claim 13, wherein both of the detector portions are rotated simultaneously by the same angle.

15. A positron emission computed tomography imaging apparatus, comprising:

the detection part comprises a plurality of detection modules, detection surfaces of the detection modules are distributed along the same circumference, at least one opening is formed in the circumference, at least one detection part generates angular displacement along the circumference when in detection, and at least two groups of detection surfaces of the detection modules are oppositely arranged and are positioned in the diameter direction of the circumference before and after movement.

16. The positron emission computed tomography apparatus as claimed in claim 15, wherein there are two of said detecting portions, and the same angular displacement occurs simultaneously at both of said detecting portions during detection.

17. The positron emission computed tomography apparatus as claimed in claim 15, wherein there are two of said detecting portions, and the angular displacements of the two detecting portions occurring simultaneously at the time of detection are different.

18. The positron emission computed tomography imaging apparatus as claimed in claim 15, wherein there are two of said detecting portions, one of said detecting portions being angularly displaced during detection.

19. The positron emission computed tomography imaging apparatus of claim 15, wherein the number of detection modules in one of the detection sections decreases after the detection sections are moved.

20. The positron emission computed tomography imaging apparatus of claim 15, wherein the number of detection modules in one of the detection sections increases after the detection sections are moved.

21. A positron emission computed tomography imaging apparatus, comprising:

the detection part comprises a plurality of detection modules, the detection surfaces of the detection modules are distributed along a first circumference, and the detection surfaces of the detection modules are arranged oppositely and are positioned in the diameter direction of the first circumference; the detection surface of the detection part moves and changes to be distributed along a second circumference and forms at least one opening when being detected.

22. The positron emission computed tomography apparatus as claimed in claim 21, wherein the detector portion splits into at least two portions opposing each other after the movement, the openings being distributed along the second circumference in common with the detector portion.

23. The positron emission computed tomography apparatus as claimed in claim 21, wherein a portion of the detector portions are still disposed opposite each other after movement, the openings being distributed along the second circumference in common with the detector portions.

24. A positron emission computed tomography method, characterized by at least the steps of:

step S1: the method comprises the following steps of imaging by adopting a PET device, wherein the PET device comprises a plurality of detection modules and at least one opening, detection surfaces of the detection modules and the opening are distributed along a first circumference, and detection surfaces of at least two groups of detection modules are oppositely arranged and are positioned in the diameter direction of the first circumference;

step S2: changing the shape of the PET apparatus in the step S1 such that the detection surfaces of the detection modules are oppositely arranged along a second circumference;

step S3: imaging is performed using the PET apparatus subjected to the step S2.

25. The positron emission tomography method of claim 24, wherein in step S2, the changing of the shape of the PET apparatus includes rotating a portion of the detection modules along the first circumference or the second circumference.

26. The positron emission computed tomography method of claim 24, wherein the detection module calibration is performed prior to the step S1 or the step S3.

27. The positron emission tomography method of claim 24, wherein in said step S2, said PET devices distributed along a second circumference have no openings or at least one of said openings.

28. The positron emission tomography method according to claim 24, wherein in step S2, the shape of the PET apparatus is changed by a driving apparatus and/or the number of the detection modules is increased or decreased.

29. A positron emission computed tomography method, characterized by at least the steps of:

step S1: the method comprises the following steps of imaging by adopting a PET device, wherein the PET device comprises a plurality of detection modules, detection surfaces of the detection modules are distributed along a first circumference, and the detection surfaces of the detection modules are oppositely arranged and are positioned in the diameter direction of the first circumference;

step S2: changing the shape of the PET apparatus in the step S1 such that the detection surfaces of the detection modules have an opening therebetween, the opening and the detection surfaces being oppositely arranged along a second circumference;

step S3: imaging is performed using the PET apparatus subjected to the step S2.

30. The positron emission tomography method of claim 29, wherein in step S2, the changing of the shape of the PET apparatus includes rotating a portion of the detection modules in the first circumferential direction or the second circumferential direction.

31. The positron emission computed tomography method of claim 29, wherein the detection module calibration is performed prior to the step S1 or the step S3.

32. The positron emission tomography method of claim 29, wherein in said step S2, said PET devices distributed along a second circumference have no openings or at least one of said openings.

33. The positron emission tomography method according to claim 29, wherein in step S2, the shape of the PET apparatus is changed by a driving apparatus and/or the number of the detection modules is increased or decreased.

Technical Field

The invention relates to the field of medical instruments, in particular to a positron emission computed tomography device and a positron emission computed tomography method.

Background

Positron Emission Tomography (PET) is a large-scale and sophisticated nuclear medicine imaging technique, and PET can non-invasively, quantitatively and dynamically evaluate the metabolic level, biochemical reaction and functional activity of each organ in vivo at the cellular level, thereby detecting relevant biochemical changes before structural changes or symptom deterioration are caused by many diseases. PET has great and unique application value for diagnosing and treating serious diseases, especially for clinically diagnosing and treating tumors, cardiovascular diseases and nervous system diseases.

PET detectors, when detecting gamma photons, are typically arranged around the object under test. The prior art can be divided into the following types according to the arrangement mode of PET detectors: a fixed ring PET device (shown in figure 1) and an application adaptive PET, wherein the fixed ring is the most traditional PET arrangement form, but the size and the position of the detection ring 1 in the arrangement form are not adjustable, and the application range is narrow; although the detection modules of the PET (e.g., CN101856236A and CN102178542A) of the adaptive type can move radially, move circularly and change directions through module rails, the PET apparatus of the adaptive type has a complicated mechanical structure, is inconvenient to move, and essentially has a ring-shaped arrangement of detectors, which are formed into a closed ring shape after being changed positions.

In clinical practice, in order to examine and treat a patient with serious diseases or inconvenience in movement, the PET apparatus needs to be moved to the side of a patient bed for scanning. Because bedside PET needs to be combined with other equipment such as a hospital bed, radiotherapy equipment and the like at any time, the bedside PET needs to have an open structure, and the traditional fixed annular PET structure cannot meet the requirement. In the prior art, to solve the problem, a flat plate PET (as shown in fig. 2), a C-type PET (as shown in fig. 3) and a double-arc PET (as shown in fig. 4) are generally adopted, however, the arrangement structure of the flat plate PET may cause the uniformity of the system response to be inferior to that of a ring structure, and the solid angle β of a flat plate PET system formed by adopting the same number of detectors is smaller than that of a ring PET, so that the sensitivity of the system is reduced, and the image quality corresponding to the edge detector is reduced; when the inner diameters and the detector quantity of the C-shaped PET and the double-arc PET are the same as those of the flat-plate PET, a larger solid angle alpha can be covered, and the sensitivity is higher. The bedside PET equipment can also be used for proton treatment monitoring, biopsy puncture guiding, intraoperative navigation and the like, and has wide application prospect.

Therefore, there is a need to develop a PET device with high adjustability, high sensitivity and low cost.

Disclosure of Invention

It is an object of the present invention to provide a positron emission computed tomography apparatus and method that solves at least one of the problems of the prior art.

The invention provides a positron emission computed tomography device.A detection part of the positron emission computed tomography device comprises a plurality of detection modules, detection surfaces of the detection modules are distributed along a first circumference, wherein the detection surfaces of at least two groups of detection modules are oppositely arranged and positioned in the diameter direction of the first circumference, and at least one opening is formed on the first circumference; the detection surface of the detection part is changed into distribution along a second circumference through movement during detection, and the diameters of the first circumference and the second circumference are different.

According to one embodiment of the invention, the number of the detecting parts and the number of the openings are two, and the openings and the detecting parts are arranged at intervals and form a complete circle together.

According to one embodiment of the invention, the detecting part and the opening are respectively one, and the opening and the detecting part are arranged at intervals and jointly form a complete circle.

According to one embodiment of the present invention, all the detection modules in the detection portion respectively correspond one-to-one in the circumferential diameter direction.

According to one embodiment of the present invention, some of the detection modules in the detection section correspond to each other in a diameter direction of the circumference.

According to one embodiment of the invention, the diameter of the first circumference is smaller than the diameter of the second circumference after the probe is moved.

According to one embodiment of the invention, the diameter of the first circumference is larger than the diameter of the second circumference after the probe portion is moved.

According to one embodiment of the invention, after the detection part moves, the angle of the central angle corresponding to the opening is unchanged, and the number of detection modules in the detection part is reduced.

According to one embodiment of the invention, after the detection part moves, the angle of the central angle corresponding to the opening is unchanged, and the number of detection modules in the detection part is increased.

According to one embodiment of the present invention, the number of the openings and the number of the sensing portions are at least two, and the number of the openings is changed to one after the sensing portions are moved.

According to one embodiment of the invention, the openings are two before the movement, and the openings disappear after the movement of the detecting part.

According to one embodiment of the present invention, the number of the openings is only one, and the number of the openings and the number of the sensing parts are changed to two after the movement of the sensing part.

According to one embodiment of the invention, the at least one detection part rotates along the second circumference after moving, and the detection surfaces of the at least two groups of detection modules are still oppositely arranged and positioned on the same straight line after rotating.

According to one embodiment of the invention, both detection portions are rotated simultaneously by the same angle.

According to one embodiment of the invention, the detection part of the positron emission computed tomography device comprises a plurality of detection modules, detection surfaces of the detection modules are distributed along the same circumference, at least one opening is formed on the circumference, at least one detection part generates angular displacement along the circumference during detection, and the detection surfaces of at least two groups of detection modules are oppositely arranged before and after movement and are positioned in the diameter direction of the circumference.

According to one embodiment of the invention, the number of the detecting parts is two, and the two detecting parts generate the same angular displacement during detection.

According to one embodiment of the invention, the number of the detection parts is two, and the angular displacement of the two detection parts is different during detection.

According to one embodiment of the invention, there are two detecting portions, and one of the detecting portions is angularly displaced during detection.

According to one embodiment of the invention, after the detection parts move, the number of detection modules in one of the detection parts is reduced.

According to one embodiment of the present invention, after the probe portions are moved, the number of probe modules in one of the probe portions is increased.

According to one embodiment of the invention, the detection part of the positron emission computed tomography device comprises a plurality of detection modules, detection surfaces of the detection modules are distributed along a first circumference, and the detection surfaces of the detection modules are arranged oppositely and are positioned in the diameter direction of the first circumference; the detection surface of the detection part is changed into distribution along the second circumference by movement when detecting and forms at least one opening.

According to one embodiment of the invention, the probe part is split after the movement into at least two parts facing each other and a plurality of openings, which are distributed along the second circumference together with the probe part.

According to one embodiment of the invention, some of the probe portions are arranged opposite each other after the movement, and the openings are distributed along the second circumference together with the probe portions.

The invention also provides a positron emission computed tomography method, which at least comprises the following steps:

step S1: the PET device is used for imaging and comprises a plurality of detection modules and at least one opening, detection surfaces and the openings of the detection modules are distributed along a first circumference, and detection surfaces of at least two groups of detection modules are oppositely arranged and are positioned in the diameter direction of the first circumference;

step S2: changing the shape of the PET device in the step S1 to make the detection surface and the opening of the detection module oppositely arranged along the second circumference;

step S3: imaging is performed using the PET apparatus passing through step S2.

According to an embodiment of the present invention, in step S2, a part of the detection modules may also be rotated.

According to an embodiment of the present invention, before step S1 or step S3, the detection module calibration may also be performed.

The invention also provides a positron emission computed tomography method, which at least comprises the following steps:

step S1: the PET device is used for imaging and comprises a plurality of detection modules, detection surfaces of the detection modules are distributed along a first circumference, and the detection surfaces of the detection modules are oppositely arranged and are positioned in the diameter direction of the first circumference;

step S2: changing the shape of the PET device in the step S1 to make the detection surfaces of the detection modules have openings therebetween, wherein the openings and the detection surfaces are oppositely arranged along a second circumference;

step S3: imaging is performed using the PET apparatus passing through step S2.

According to an embodiment of the present invention, in step S2, the shape change of the PET apparatus may further include rotating a part of the detection modules.

According to an embodiment of the present invention, before step S1 or step S3, the detection module calibration may also be performed.

According to one embodiment of the invention, in step S2, the PET devices distributed along the second circumference have no openings or at least one opening.

According to an embodiment of the present invention, in step S2, the shape of the PET apparatus can be changed by the driving device and/or increasing or decreasing the number of the detection modules.

The positron emission computed tomography device and the method not only provide good system openness, so that the device can be combined with equipment such as a hospital bed, radiotherapy equipment and the like only through the shape change of the detection part, but also can change the size and the angle of the opening part to adapt to different operations, different detection parts and different human body detection requirements, simultaneously, the optimal system sensitivity can be realized through the size adjustment of the inner diameter of the detection part, all detection modules are always positioned in a circular imaging view, the response uniformity of the system is also ensured, the adjustability, the sensitivity and the response uniformity of the system are considered, and the application value is huge.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic view of the arrangement of a stationary ring PET according to the prior art;

FIG. 2 is a schematic diagram of a flat PET arrangement according to the prior art;

FIG. 3 is a schematic view of a type C PET arrangement according to the prior art;

FIG. 4 is a schematic view of a double arc PET arrangement according to the prior art;

FIG. 5 is a schematic diagram of a change in shape of a PET according to one embodiment of the invention;

FIG. 6 is a schematic diagram of a change in shape of a PET according to another embodiment of the invention;

FIG. 7 is a schematic diagram of a change in shape of a PET according to yet another embodiment of the invention;

FIG. 8 is a schematic diagram of a change in shape of a PET according to one embodiment of the invention;

FIG. 9 is a schematic diagram of a change in shape of a PET according to another embodiment of the invention;

FIG. 10 is a schematic view of a change in shape of a PET according to yet another embodiment of the invention;

FIG. 11 is a schematic diagram of a change in shape of a PET according to another embodiment of the invention;

FIG. 12 is a schematic diagram of a change in shape of a PET according to one embodiment of the invention;

FIG. 13 is a detector drive schematic of a PET according to one embodiment of the invention;

FIG. 14 is a detector drive schematic of a PET according to another embodiment of the invention;

FIG. 15 is a detector drive schematic of a PET according to yet another embodiment of the invention;

FIG. 16 is a schematic diagram of a change in shape of a PET according to one embodiment of the invention;

FIG. 17 is a schematic illustration of detector position calibration according to one embodiment of the present invention;

FIG. 18 is a graphical comparison of imaging results for different shaped PET's in accordance with one embodiment of the present invention;

figure 19 is a graphical illustration of a contrast in imaging parameters for different shaped PET's in which the abscissa represents the diameter of the region of interest and the ordinate represents the contrast recovery coefficient and background variation rate, in accordance with one embodiment of the present invention.

Detailed Description

The present invention will be further described with reference to the following specific examples. It should be understood that the following examples are illustrative only and are not intended to limit the scope of the present invention.

It will be understood that when an element/feature is referred to as being "disposed on" another element/feature, it can be directly on the other element/feature or intervening elements/features may also be present. When a component/part is referred to as being "connected/coupled" to another component/part, it can be directly connected/coupled to the other component/part or intervening components/parts may also be present. The term "connected/coupled" as used herein may include electrical and/or mechanical physical connections/couplings. The term "comprises/comprising" as used herein refers to the presence of features, steps or components/features, but does not preclude the presence or addition of one or more other features, steps or components/features. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

In addition, in the description of the present invention, the terms "first", "second", and the like are used for descriptive purposes only and to distinguish similar objects, and there is no precedence between them, and no indication or suggestion of relative importance is understood. In addition, in the description of the present invention, "a plurality" means two or more unless otherwise specified.

Fig. 5 is a schematic diagram illustrating a shape change of a PET according to an embodiment of the present invention, and as can be seen from fig. 5, the PET apparatus according to the present invention includes a first detecting part 10 and a second detecting part 20, in the embodiment of fig. 5, the first detecting part 10 and the second detecting part 20 are circular arcs arranged opposite to each other and located on the same circumference, symmetry axes AA and BB respectively pass through centers of circles and are perpendicular to each other, the first detecting part 10 and the second detecting part 20 are respectively symmetrical with respect to the symmetry axis AA, and the first detecting part 10 and the second detecting part 20 are arranged symmetrically with respect to the symmetry axis BB. Each of the detecting parts includes a plurality of individual detecting modules 11/21, and the centers of the detecting surfaces of the detecting modules 11/21 are located on the circumference of the detecting part.

In general, each detection module may be a single PET detector or a unit formed by a plurality of PET detectors, each PET detector includes a scintillation crystal, a photoelectric conversion device and an electronic device, which are coupled to each other, wherein the scintillation crystal is configured to convert high-energy rays into visible light, the photoelectric conversion device is configured to convert visible light into electrical signals, the electronic device outputs the electrical signals, and the electrical signals may be digitized by corresponding sampling devices. The detection surface of the detection module can be a surface of a single detector for receiving high-energy rays, and can also be a combination of surfaces of a plurality of detectors for receiving high-energy rays. The PET detectors, signal sampling and subsequent image reconstruction are all technical means commonly used in the art, which are not the core of the present invention and will not be described in detail herein.

Each of the detecting portions 10/20 further includes a driving unit (not shown), the driving unit can drive the detecting portion 10/20 to change the shape, for example, in the embodiment of fig. 5, the shape of the first detecting portion 10 and the second detecting portion 20 in the initial state is shown by the dotted line in the figure, and under the driving of the driving unit, the first detecting portion 10 and the second detecting portion 20 move away from each other on one hand, and on the other hand, the first detecting portion 10 and the second detecting portion 20 respectively move in the extending direction of the arrow at both ends, so that the diameter of the circumference where the detecting surface of each detecting module is located is enlarged. The separation movement specifically means that the two detecting parts are away from each other along the arrow direction on the AA axis, and the extension movement means that the two detecting parts expand in diameter along the arrow directions at the two ends. More specifically, the phase-away motion and the stretching motion cause the shape change of the PET apparatus to appear as two types: the first change is that the radian of the detecting part 10/20 changes, and changes from the dotted line part in fig. 5 to the corresponding solid line part, the changed first detecting part 10 and second detecting part 20 are still arc-shaped, and the detecting surface is still located on one circle, but the diameter of the circle where the arc-shaped is located is increased; the second variation is the position variation between the adjacent detection modules, and in order to meet the requirement of the overall shape variation of the detection part, the relative angle between the adjacent detection modules is changed, so that the detection surface is still located on the circumference of the detection part after the variation, and the detection modules 12/13 at both ends of the first detection part 10 and the detection modules 22/23 at both ends of the second detection part 20 are compressed toward the direction of the symmetry axis AA after the shape variation, and the detection modules are compacted.

It will be understood by those skilled in the art that since the detection surfaces are generally planar, the term "detection surface lies on a circle" means that each side of a polygon formed by the connection of the detection surfaces is tangent to the same circle, or the midpoint of each detection surface lies on the same circle. If the manufacturing cost of the detection surface is not considered, the detection surface can be made into an arc-shaped plane, which is easily thought by those skilled in the art and is not described herein again.

The shape change of the detector in fig. 5 can increase the openness of the structure, the operable space on the left and right sides is enlarged, so that the PET equipment can be better combined with a sickbed, radiotherapy equipment and other equipment, or more operation space is provided for an operator, and meanwhile, the increase of the inner diameter of the detector also enables the PET equipment to more conveniently detect different body parts of the same patient in real time, such as changing from a head part to a trunk part, or more conveniently switching patients with different volumes. In addition, the detection part is always positioned on the circumference before and after the structural change, the imaging visual field can be ensured to be positioned in the circle, the uniformity of the response of the PET equipment system is ensured, and the system sensitivity is not obviously reduced.

Fig. 6 is a schematic diagram illustrating a shape change of a PET according to another embodiment of the present invention, and as can be seen from fig. 6, the PET apparatus provided in the present invention can further implement a relative movement and a bending movement, the relative movement specifically means that two detecting portions approach each other along the arrow direction on the AA axis, and the bending movement means that the two detecting portions respectively perform a bending movement along the arrow directions on both ends, so that the diameter of the circumference where the detecting surface of each detecting module is located is reduced. More specifically, the opposing motion and the bending motion cause the shape change of the PET apparatus to appear as two types: the first change is a change in the shape of the detecting portion 10/20 itself, the radian of the detecting portion changes from the dotted line portion in fig. 6 to the corresponding solid line portion, the changed first detecting portion 10 and second detecting portion 20 are still in the shape of an arc, and the detecting surface is still on one circle, but the diameter of the arc becomes smaller; the second variation is a position variation between adjacent detection modules, and in order to meet the requirement of the overall shape variation of the detection part, the relative angle between adjacent detection modules is changed, so that the center of the detection surface is still located on the circumference where the detection part is located after the change, which is represented by that the detection modules 12/13 at both ends of the first detection part 10 and the detection modules 22/23 at both ends of the second detection part 20 both move towards the center of the circle after the shape variation, and the first detection part 10 and the second detection part 20 look elongated on the surface along the arc direction and the detection modules become sparse.

Although the shape change of the detector in fig. 6 may reduce the openness of the structure, i.e. the operable space on the left and right sides becomes smaller, in some special applications, when a particularly large operation space is not required, or when the combination of the PET apparatus with a hospital bed, a radiotherapy apparatus, or other equipment is not affected or the operation of an operator is not affected, the structural change can significantly improve the uniformity of the response of the PET apparatus system and improve the sensitivity of the system, which is beneficial to obtain more accurate scanning results.

Fig. 7 is a schematic view showing a change in shape of PET according to still another embodiment of the present invention, and the embodiment of fig. 7 can perform a rotational motion in addition to the separation and facing motion and the stretching and bending motion, compared to the embodiments of fig. 5 and 6. The moving away from and towards each other and the extending and bending movements are the same as those described in the embodiment of fig. 5 and 6 and will not be described again here. The rotation motion means that after the two detection parts complete the separation and opposite motion and the extension and bending motion, at least one of the detection parts can also rotate around a corresponding circle along the direction indicated by the arrow C in fig. 7 to generate a certain angular displacement. When only one detection part rotates or two detection parts rotate at different angles, because the gamma photons flying in the same straight line in opposite directions need to be found out in the PET imaging process, a part of the detection modules in one detection part cannot correspond to the detection modules in the other detection part, so the coverage angle τ of the PET device can be changed, for example, after the PET imaging process moves in opposite directions in fig. 7, the detection module 12 should correspond to the detection module 23, the detection module 13 should correspond to the detection module 22, after the rotation motion, the detection module 12 and the detection module 22 lose the corresponding detection modules, the detection module 13 corresponds to the detection module 24, the detection module 23 corresponds to the detection module 14, and the coverage angle τ is reduced. When the two detecting portions rotate along the circumference by the same angle, the corresponding relationship between the detecting modules does not change, for example, the detecting module 12 still corresponds to the detecting module 23 and the detecting module 22 still corresponds to the detecting module 13 after the rotation.

In fig. 7, when one detecting part or two detecting parts rotate at different angles, although the sensitivity of a part of the system is sacrificed and the image quality is reduced, the reduction is still within an acceptable range, in this case, the rotation motion will greatly improve the openness of one side of the structure, i.e. the operable space of one side is enlarged, which is convenient for the operation in some special applications (such as surgery). When the two detection parts rotate simultaneously, the sensitivity and the image quality of the system are not reduced, and the relative positions of the openings at the two sides and the object to be detected can be changed by the rotation motion on the premise that the object to be detected is not moved, so that different parts can be operated conveniently, or the result obtained by initial scanning can be verified/supplemented.

Fig. 8 is a schematic diagram illustrating a shape change of PET according to an embodiment of the present invention, in the embodiment of fig. 8, the double-arc arrangement of the PET apparatus provided by the present invention may form a circular ring arrangement after moving, that is, the detecting parts 10 and 15 enclose a circular ring shape without a gap after being moved in a similar manner and being bent. It will be appreciated by those skilled in the art that the PET device may also be reversed from a circular arrangement to a double arc arrangement and will not be described in detail herein. The advantage that this kind of structural change brought is can be according to actual need select required detection precision or whether the selection needs further operation, for example, after the operation is accomplished, when needing to examine postoperative achievement thereupon, can arrange the form with the double arc and change into the ring shape immediately and arrange the form to obtain the imaging result of high accuracy, conveniently carry out real-time achievement and judge.

Fig. 9 is a schematic diagram illustrating a shape change of a PET according to another embodiment of the present invention, in order to keep an angle of an opening angle δ before and after the shape change unchanged in the embodiment of fig. 9, after the PET apparatus provided by the present invention undergoes a proximity motion and a bending motion, a plurality of detection modules at two ends of each detection portion need to be removed, for example, two detection modules 12 and 13 at two ends of a first detection portion 10 and two detection modules adjacent to the detection modules 12 and 13 are removed after the motion, and two detection modules 22 and 23 at two ends of a second detection portion 20 and two detection modules adjacent to the detection modules 22 and 23 are removed at the same time. It should be noted by those skilled in the art that after the PET apparatus is subjected to the reverse phase-separation motion and the stretching motion, the opening angle δ at both sides will become larger, and in order to keep the angle relatively stable, a corresponding number of detection modules may be added at both ends of each detection portion after the motion, which is not described herein again. The advantage that this structural change brought makes things convenient for operating personnel or the required space of operating instrument for can selecting fixed opening angle according to actual need, can guarantee the cover angle front-back unanimity that detects simultaneously to compromise the quality of simple operation and formation of image result.

Fig. 10 is a schematic view showing a change in shape of PET according to still another embodiment of the present invention, and in the embodiment of fig. 10, the PET apparatus provided by the present invention may also be C-shaped with only one opening. In the initial state, the position of the detection module is shown by the dotted line in the figure, and the opening angle is delta₁. In order to make the opening angle larger, the C-type PET needs to make stretching movement, which makes the shape change of the PET device appear as two types: the first variation is that the diameter of the circumference in which the probe 20 is located changes, from that of FIG. 10The dotted line part is changed into a corresponding solid line part, the changed detection surface is still positioned on a circle, but the diameter of the circle is increased; the second variation is the position variation between the adjacent detection modules, and in order to meet the requirement of the overall shape variation of the detection part, the relative angle between the adjacent detection modules is changed, so that the detection surface is still located on the circumference of the detection part after the change, which means that the detection modules 21/22 are compressed in the direction of the arrow shown in the figure after the shape variation and the detection modules become relatively compact, and at this time, the opening angle δ₂Becomes larger. The advantage that this structural change brought makes things convenient for operating personnel or the required space of operating instrument for can selecting the fixed opening angle in one side according to actual need, can guarantee the cover angle unanimous all around that detects simultaneously to compromise the quality of simple operation and formation of image result, this is because C type PET for double arc PET and flat PET, when surveying the module quantity the same, can cover bigger solid angle, sensitivity is also higher.

FIG. 11 is a schematic view showing a change in shape of PET according to another embodiment of the present invention, and the embodiment of FIG. 11 is compared with the embodiment of FIG. 10, and the PET apparatus can also perform a bending motion against an extension motion, as indicated by an arrow, and an opening angle is shown by δ shown by an initial broken line₁Is reduced to delta shown by a solid line₂. It should be noted by those skilled in the art that, in order to keep the opening angle relatively stable, the detection modules 21/22 with corresponding numbers at two ends may be removed after the movement, and will not be described herein again. The advantage that this structural change brought makes things convenient for operating personnel or the required space of operating instrument for can selecting the fixed opening angle in one side according to actual need, can guarantee the cover angle unanimous all around that detects simultaneously to compromise the quality of simple operation and formation of image result, this is because C type PET for double arc PET and flat PET, when surveying the module quantity the same, can cover bigger solid angle, sensitivity is also higher.

Fig. 12 is a schematic diagram showing the shape change of PET according to an embodiment of the present invention, in the embodiment of fig. 12, the PET apparatus provided by the present invention is initially in a C-shaped arrangement form, and after moving, a double-arc arrangement form can be formed, that is, the detecting portion can be moved away from each other and extended to form the double-arc arrangement form shown in fig. 5 and 6, and the opening is changed from one to two sides. It should be understood by those skilled in the art that the PET device can be reversely changed from a double-arc arrangement to a C-shaped arrangement, and the circular, double-arc and C-shaped arrangements can be changed from one to another, and the embodiment shown in fig. 12 is only an example and not a limitation, and will not be described again. The advantage that this kind of structural change brought is under the prerequisite of guaranteeing required detection precision or sensitivity, very big improvement the openness of structure, can the rapid change shape moreover, be applicable to multiple application scenario.

The above-mentioned separation motion, proximity motion, and rotation motion can be realized by any driving unit capable of realizing linear motion or rotation motion, for example, by driving each detection module to move by a hydraulic driving unit or driving the whole detection part to move. The hydraulic drive unit may also be connected to a computer to facilitate accurate control of the distance of the phase or near phase movements. Technical means such as how to arrange the driving unit and how to connect the driving unit and the detecting part are easy to be realized by those skilled in the art according to the technical content disclosed by the present invention, and are not described herein again.

The stretching movement and the bending movement can be achieved by arranging a driving unit between adjacent detection modules, for example, in the embodiment of fig. 13, a hinge 2 can be arranged between adjacent detection modules 11/21, the hinge 2 can allow the adjacent two detection modules 11/21 to rotate, so that the radian of the whole detection part can be changed by a plurality of hinges or by a plurality of hinges cooperating with other driving units, and the detection parts with changed shapes can still be located on the same circle; in the embodiment of fig. 14, a motor 3 may be disposed between adjacent detection modules 11/21, and the motor 3 can directly drive two adjacent detection modules 11/21 to rotate, so that the radian of the entire detection part is changed by driving a plurality of motors, and the detection part with the changed shape can still be located on the same circumference; in the embodiment of fig. 15, a plurality of mutually hinged connecting rods 5/6 may be disposed between the plurality of detecting modules 11/21 of the same detecting part, and the connecting rods 5/6 are hinged to the hinge points 4/7/8, so as to allow the adjacent detecting modules 11/21 to rotate, thereby changing the radian of the whole detecting part, and allowing the detecting part with the changed shape to still be located on the same circumference. Specifically, how to drive the detection module to rotate around the hinge through the driving unit/motor and how to connect the driving unit with the detection part/detection module/hinge/connecting rod are easy to be realized by those skilled in the art according to the technical content disclosed in the present invention, and are not described herein again.

In addition to the above embodiments, the shape change of the detecting part in the present invention can be realized by the method shown in fig. 16. In the embodiment of fig. 16, in the initial state, the PET apparatus includes the first detecting unit 30 and the second detecting unit 40, the shapes and relative positions of the first detecting unit 30 and the second detecting unit 40 may be the same as those of the above-mentioned embodiments, except that the number of the detecting modules 31/41 included in the first detecting unit 30 and the second detecting unit 40 may be different, meanwhile, each/a plurality of the detecting modules in each detecting unit is/are connected to the supporting rod 32, the supporting rod 32 is movably disposed on one/a plurality of the ring-shaped supports 33, the extending direction of the supporting rod 32 passes through the center of the circle formed by the detecting units and can perform linear motion and rotational motion on the ring-shaped supports 33, the linear motion specifically means that the supporting rod 32 can drive the corresponding detecting module 31/41 to move along the extending direction of the supporting rod 32, and the rotational motion specifically means that the supporting rod 32 and the corresponding detecting module 31/41 can move along the ring-shaped supports 33 Is moved in the circumferential direction. When it is necessary to change the state, a plurality of detection modules 31/41 can be selected from the first detection part 30 and the second detection part 40 respectively, and the selected detection module 31/41 can make a linear motion and/or a rotational motion, for example, the detection module shown by the dotted line in fig. 16 can be moved to the corresponding solid line position, so as to form the third detection part 50 and the fourth detection part 60, and the third detection part 50 and the fourth detection part 60 are still formed in a double arc structure opposite to each other and still located on the same circle.

The embodiment of fig. 16 is particularly suitable for applications requiring fast switching of imaging positions, and when only one of the detection modules is selected, although the sensitivity of a part of the system is sacrificed and the image quality is reduced, the reduction is still within an acceptable range, in this case, since the distance from the detection module to the object to be measured is greatly reduced, the accuracy of the measured signal is improved, so as to counteract some of the aforementioned adverse effects, and facilitate the operation in some special applications. When the detection part rotates, the sensitivity and the image quality of the system are not reduced, and the relative position between the openings at two sides and the object to be detected can be changed by the rotation motion on the premise that the object to be detected is not moved, so that different parts can be conveniently operated, or the result obtained by initial scanning can be verified/supplemented.

In all the above embodiments, since the shape of the detecting portion changes, it is also possible to calibrate whether the detecting modules correspond to each other, and fig. 17 shows one of the calibration methods provided by the present invention. The method comprises the following steps:

step 1: randomly selecting two groups of detection modules positioned on the diameter of the circumference where the detection part is positioned, and marking the intersection point O of perpendicular lines in the detection surfaces of the two groups of detection modules;

step 2: optionally selecting another group of detection modules and marking the perpendicular bisector of the detection surface of the detection module;

and step 3: if the perpendicular bisector in the step 2 passes through the intersection point O in the step 1, it can be determined that the detection modules on the detection part are located on the same circumference; if the perpendicular bisector in the step 2 does not pass through the intersection point O in the step 1, it can be determined that the detection modules on the detection part are not located on the same circumference, and at this time, the shape of the detection part needs to be further adjusted;

and 4, step 4: and after the shape of the detection part is changed, repeating the steps 1-3 until the detection modules are judged to be positioned on the same circumference.

The invention also provides a positron emission computed tomography imaging method, which comprises the following steps:

step S1: imaging by using a PET device;

step S2: changing the shape of the PET device in the step S1 to make the PET device at least have a notch and/or change the diameter of the circle where the detection part of the PET device is located;

step S3: imaging is performed using the PET apparatus passing through step S2.

In the above step S1, the initial shape of the probe portion of the PET apparatus may be a circle, a double arc, or a C shape, where the circle, the double arc, or the C shape indicates that each side of a polygon formed by connecting the probe surfaces of the probe portion is tangent to the same circumference, or the midpoint of each probe surface is located on the same circumference.

In the above step S2, the shape of the PET apparatus is changed by:

the first method comprises the following steps: if the PET device is circular in step S1, the shape of the PET device in step S2 may be changed to a double arc shape or a C shape, and a diameter of a circle where the double arc shape or the C shape is located may be changed or rotated along with the change.

And the second method comprises the following steps: if the PET device is double-arc shaped in step S1, the shape of the PET device in step S2 may be changed to circular, double-arc or C-shaped, and the diameter of the circle where the double-arc or C-shaped is located may be changed or rotated along with the change.

And the third is that: if the PET device is C-shaped in step S1, the shape of the PET device in step S2 may be changed to a circular shape, a double arc shape, or a C-shape, and the change may be accompanied by a change in diameter or rotation of the circle in which the double arc shape or the C-shape is located.

The above-described variations in the shape of the PET device are included in the embodiments shown in fig. 5 to 16, and will not be described again.

In the above step S2, changing the shape of the PET apparatus in the step S1 may be performed by the embodiment shown in fig. 14 to 16, and a description thereof will not be repeated.

Before the above step S1 or step S3, the PET apparatus may be calibrated, and the specific calibration step is the same as the calibration step described in fig. 17.

FIG. 18 is a schematic diagram showing the comparison of the imaging results of PET of different shapes according to an embodiment of the present invention, wherein the parameters of the object and the detection module in each embodiment are consistent, and the imaging result of the round PET device is shown in the upper left corner, and the imaging result is quite clear; the imaging result obtained after the detection module at the upper left corner is removed 1/4 and the arrangement form of the PET devices is changed into a double-arc structure is the upper right corner, and the quality of the imaging result is not obviously reduced compared with the imaging result at the upper left corner; the lower left corner is the imaging result obtained by removing 1/2 the detection module in the upper left corner and changing the arrangement form of the PET apparatus into a double-arc structure, the imaging result has a quality which is still within an acceptable range though the quality is reduced compared with the imaging result in the upper left corner, and the resolution of the simulated lesion is still clear and recognizable, which proves that the PET apparatus has a good effect in terms of considering the imaging quality, the system sensitivity and the operability.

FIG. 19 is a schematic diagram of contrast of imaging parameters for different shaped PET's, where the abscissa represents the diameter of the region of interest, the ordinate represents the contrast recovery coefficient and the background variation rate, CRC represents the contrast recovery coefficient, BV represents the background variation rate, the circular black blocks correspond to the parameters associated with the circular PET apparatus, the triangular black blocks correspond to the parameters associated with the number of detectors 3/4 for circular PET, and the quadrangular black blocks correspond to the parameters associated with the number of detectors 1/2 for circular PET, it can be seen from FIG. 19 that as the number of detectors decreases, i.e., the PET apparatus changes from circular to double-arc, both CRC and BV decrease, but the background variation rate decreases by only 4.5% to 6.1%, while the contrast of the hot zone (black part in the figure, whose activity is higher than that of the background region) decreases by only 3.9% to 11.8%, and the sacrifice of small amount of performance is fully controllable with respect to the obtained openness and high sensitivity, and the diagnosis of the focus is not influenced, and the openness, adjustability, sensitivity and response uniformity of the system can be well considered.

For example, according to the above-described embodiments, a person skilled in the art can design the shape of the detecting portion to be a plurality of circular arcs located on the same circumference, wherein at least two groups of circular arcs are in one-to-one correspondence. All simple and equivalent changes and modifications made according to the claims and the content of the specification of the present application fall within the scope of the claims of the present patent application. The invention has not been described in detail in order to avoid obscuring the invention.