Positron emission computed tomography device and method

Abstract

The present invention discloses a positron emission tomography device and method, wherein the detection part of the device includes a plurality of detection modules, the 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 arranged relatively and located 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 changes to be distributed along a second circumference through movement during detection, and the diameters of the first circumference and the second circumference are different; the method includes: using a PET device for imaging, the PET device includes a plurality of detection modules and at least one opening distributed along the first circumference; changing the shape of the PET device so that the detection surface and the opening of the detection module are distributed along the second circumference; and using the PET device with a changed shape for imaging again. The present invention not only provides good system openness, but also can change the size and angle of the opening part, has good adaptability, and can ensure system sensitivity and response uniformity at the same time.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and more specifically to a positron emission tomography device and method. Background Art

[0002] Positron Emission Tomography (PET) is a large-scale, cutting-edge nuclear medicine imaging technology that can non-invasively, quantitatively, and dynamically evaluate the metabolic levels, biochemical reactions, and functional activities of various organs in the body at the cellular level. Therefore, it can detect related biochemical changes before many diseases cause structural changes or worsening symptoms. PET has great and unique application value in the diagnosis and treatment of major diseases, especially in the diagnosis and treatment of tumors, cardiovascular diseases, and nervous system diseases.

[0003] When detecting gamma photons, PET detectors are usually arranged around the target. In the prior art, the arrangement of PET detectors can be divided into the following types: fixed annular PET devices (such as Figure 1 As shown) and application-adaptive PET, among which the fixed ring is the most traditional PET arrangement, but the size and position of the detection ring 1 in this arrangement are not adjustable, and the application scope is narrow; although the detection module of the application-adaptive PET (for example, CN101856236A and CN102178542A) can perform radial movement, circular motion and direction change through the module track, this application-adaptive PET device has a complex mechanical structure and is inconvenient to move, and its detectors are essentially still arranged in a ring structure, and the detectors still form a closed ring after changing their positions.

[0004] In clinical practice, in order to facilitate the examination and treatment of seriously ill or immobile patients, the PET device needs to be moved to the bedside for scanning. Since bedside PET needs to be combined with other equipment such as the bed and radiotherapy equipment at any time, it needs to have an open structure. At this time, the traditional fixed annular PET structure can no longer meet the needs. In order to solve this problem, the prior art usually adopts a flat PET (such as Figure 2 As shown), C-PET (as Figure 3 ) and double-curved PET (as shown Figure 4As shown), however, the arrangement structure of flat-panel PET will result in a less uniform system response than the annular structure. The solid angle β of a flat-panel PET system composed of the same number of detectors is smaller than that of annular PET, which reduces the sensitivity of the system and leads to a decrease in the image quality corresponding to the edge detectors. When the inner diameter and number of detectors of C-type PET and double-arc PET are the same as those of flat-panel PET, they will cover a larger solid angle α and have a higher sensitivity. However, the structures of C-type PET and double-arc PET are also relatively fixed, and the sensitivity cannot be further improved, nor can they be applied to objects of different sizes and different precision requirements. Bedside PET equipment can also be used for proton therapy monitoring, biopsy puncture guidance, intraoperative navigation, etc., and has broad application prospects.

[0005] Therefore, it is necessary to develop a PET device with strong adjustability, high sensitivity and low cost. Summary of the invention

[0006] The object of the present invention is to provide a positron emission tomography device and method, thereby solving at least one problem in the prior art.

[0007] The present invention provides a positron emission tomography device, a positron emission tomography device, wherein the detection part includes a plurality of detection modules, the 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 arranged opposite to each other and are located in the diameter direction of the first circumference, and at least one opening is formed on the first circumference; during detection, the detection surface of the detection part changes through movement to be distributed along a second circumference, and the diameters of the first circumference and the second circumference are different.

[0008] According to an embodiment of the present invention, there are two detection parts and two openings respectively, and the openings and the detection parts are arranged at intervals and together form a complete circumference.

[0009] According to an embodiment of the present invention, the detection portion and the opening are each one, and the opening and the detection portion are arranged at intervals and together form a complete circumference.

[0010] According to an embodiment of the present invention, all detection modules in the detection part correspond to each other one by one in the circumferential diameter direction.

[0011] According to one embodiment of the present invention, a part of the detection modules in the detection portion correspond to each other in the diameter direction of the circumference.

[0012] According to an embodiment of the present invention, after the detection part moves, the diameter of the first circle is smaller than the diameter of the second circle.

[0013] According to an embodiment of the present invention, after the detection part moves, the diameter of the first circle is greater than the diameter of the second circle.

[0014] According to an embodiment of the present invention, after the detection part moves, the central angle of the circle corresponding to the opening remains unchanged, and the number of detection modules in the detection part is reduced.

[0015] According to an embodiment of the present invention, after the detection part moves, the central angle of the circle corresponding to the opening remains unchanged, and the number of detection modules in the detection part increases.

[0016] According to an embodiment of the present invention, there are at least two openings and at least two detection parts, and after the detection part moves, the number of the openings changes to one.

[0017] According to an embodiment of the present invention, there are two openings before the movement, and after the detection part moves, the openings disappear.

[0018] According to an embodiment of the present invention, there is only one opening, and after the detection part moves, the number of the openings and the number of the detection parts both change to two.

[0019] According to an embodiment of the present invention, at least one detection part rotates along the second circle after the movement, and after the rotation, the detection surfaces of at least two groups of detection modules are still arranged relatively to each other and located on the same straight line.

[0020] According to an embodiment of the present invention, the two detection parts rotate at the same angle simultaneously.

[0021] According to one embodiment of the present invention, the detection portion of the positron emission tomography device includes a plurality of detection modules, the 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 portion undergoes angular displacement along the circumference during detection, and before and after the movement, the detection surfaces of at least two groups of detection modules are arranged relatively to each other and are located in the diameter direction of the circumference.

[0022] According to an embodiment of the present invention, there are two detection parts, and the two detection parts undergo the same angular displacement during detection.

[0023] According to an embodiment of the present invention, there are two detection parts, and the angular displacements of the two detection parts are different during detection.

[0024] According to an embodiment of the present invention, there are two detection parts, and one of the detection parts undergoes angular displacement during detection.

[0025] According to an embodiment of the present invention, after the detection part moves, the number of detection modules in one of the detection parts is reduced.

[0026] According to one embodiment of the present invention, after the detection part moves, the number of detection modules in one of the detection parts increases.

[0027] According to one embodiment of the present invention, the detection part of the positron emission tomography device includes a plurality of detection modules, the detection surfaces of the detection modules are distributed along a first circumference, the detection surfaces of the detection modules are relatively arranged and located in the diameter direction of the first circle; the detection surface of the detection part changes through movement during detection to be distributed along a second circumference and form at least one opening.

[0028] According to an embodiment of the present invention, the detection portion is split into at least two parts opposite to each other and a plurality of openings after the movement, and the openings and the detection portion are distributed along the second circumference.

[0029] According to an embodiment of the present invention, a portion of the detection parts are still arranged opposite to each other after the movement, and the openings and the detection parts are distributed along the second circumference.

[0030] The present invention also provides a positron emission tomography method, which comprises at least the following steps:

[0031] Step S1: using a PET device for imaging, the PET device comprising a plurality of detection modules and at least one opening, the detection surfaces of the detection modules and the openings being distributed along a first circumference, wherein the detection surfaces of at least two groups of detection modules are arranged opposite to each other and are located in the diameter direction of the first circumference;

[0032] Step S2: changing the shape of the PET device in step S1 so that the detection surface and the opening of the detection module are arranged relatively along the second circumference;

[0033] Step S3: Perform imaging using the PET device obtained in step S2.

[0034] According to an embodiment of the present invention, in step S2, a part of the detection modules may be rotated.

[0035] According to an embodiment of the present invention, before step S1 or step S3, the detection module calibration may be performed.

[0036] The present invention also provides a positron emission tomography method, which comprises at least the following steps:

[0037] Step S1: using a PET device for imaging, the PET device includes 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 relatively and located in the diameter direction of the first circumference;

[0038] Step S2: changing the shape of the PET device in step S1 so that there are openings between the detection surfaces of the detection module, and the openings and the detection surfaces are arranged relatively along the second circumference;

[0039] Step S3: Perform imaging using the PET device obtained in step S2.

[0040] According to an embodiment of the present invention, in step S2, the shape change of the PET device may further include rotating a portion of the detection module.

[0041] According to an embodiment of the present invention, before step S1 or step S3, the detection module calibration may be performed.

[0042] According to an embodiment of the present invention, in step S2, the PET devices distributed along the second circumference have no opening or have at least one opening.

[0043] According to one embodiment of the present invention, in step S2, the shape change of the PET device can be achieved by a driving device and / or increasing or decreasing the number of detection modules.

[0044] The positron emission tomography device and method provided by the present invention not only provide good system openness, so that the device can not only be combined with equipment such as a hospital bed and radiotherapy equipment by changing the shape of the detection part, but also can change the size and angle of the opening part to adapt to different operations, different detection parts and different human body detection needs. At the same time, the optimal system sensitivity can be achieved by adjusting the size of the inner diameter of the detection part. All detection modules are always in the circular imaging field of view, which also ensures the uniformity of system response, and realizes the system's adjustability, sensitivity and response uniformity. The application value is huge. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0046] Figure 1 is a schematic diagram of the arrangement of a fixed annular PET according to the prior art;

[0047] Figure 2 It is a schematic diagram of the arrangement of a flat PET according to the prior art;

[0048] Figure 3 It is a schematic diagram of the arrangement of a C-type PET according to the prior art;

[0049] Figure 4 It is a schematic diagram of the arrangement of a double-arc PET according to the prior art;

[0050] Figure 5is a schematic diagram of the shape change of PET according to one embodiment of the present invention;

[0051] Figure 6 is a schematic diagram of shape change of PET according to another embodiment of the present invention;

[0052] Figure 7 is a schematic diagram of the shape change of PET according to another embodiment of the present invention;

[0053] Figure 8 is a schematic diagram of the shape change of PET according to one embodiment of the present invention;

[0054] Fig. 9 is a schematic diagram of shape change of PET according to another embodiment of the present invention;

[0055] Fig.10 is a schematic diagram of the shape change of PET according to another embodiment of the present invention;

[0056] Fig.11 is a schematic diagram of shape change of PET according to another embodiment of the present invention;

[0057] Fig.12 is a schematic diagram of the shape change of PET according to one embodiment of the present invention;

[0058] Fig.13 is a schematic diagram of a PET detector drive according to an embodiment of the present invention;

[0059] Fig.14 is a schematic diagram of driving a PET detector according to another embodiment of the present invention;

[0060] Fig.15 is a schematic diagram of driving a PET detector according to yet another embodiment of the present invention;

[0061] Fig.16 is a schematic diagram of the shape change of PET according to one embodiment of the present invention;

[0062] Fig.17 is a schematic diagram of detector position calibration according to an embodiment of the present invention;

[0063] Fig.18 is a schematic diagram comparing imaging results of PET with different shapes according to an embodiment of the present invention;

[0064] Fig.19 3 is a schematic diagram for comparing imaging parameters of PETs of different shapes according to an embodiment of the present invention, wherein the abscissa represents the diameter of the region of interest, and the ordinate represents the contrast recovery coefficient and the background variation rate. DETAILED DESCRIPTION

[0065] The present invention is further described below in conjunction with specific examples. It should be understood that the following examples are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0066] It should be noted that when a component / part is referred to as being "set on" another component / part, it may be directly set on the other component / part or there may also be an intermediate component / part. When a component / part is referred to as being "connected / coupled" to another component / part, it may be directly connected / coupled to the other component / part or there may be an intermediate component / part at the same time. The term "connection / coupling" as used herein may include electrical and / or mechanical physical connections / couplings. The term "includes / comprising" as used herein refers to the presence of a feature, step or component / part, but does not exclude the presence or addition of one or more other features, steps or components / parts. The term "and / or" as used herein includes any and all combinations of one or more relevant listed items.

[0067] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0068] In addition, in the description of the present invention, the terms "first", "second", etc. are only used for descriptive purposes and to distinguish similar objects. There is no order of precedence between the two, and they cannot be understood as indicating or implying relative importance. In addition, in the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

[0069] Figure 5 is a schematic diagram of the shape change of PET according to an embodiment of the present invention, Figure 5 It can be seen that the PET device provided by the present invention includes a first detection unit 10 and a second detection unit 20. Figure 5 In the embodiment, the first detection part 10 and the second detection part 20 are arranged in an arc shape opposite to each other and are located on the same circumference, the symmetry axes AA and BB respectively pass through the center of the circle and are perpendicular to each other, the first detection part 10 and the second detection part 20 are symmetrical about the symmetry axis AA, and the first detection part 10 and the second detection part 20 are arranged symmetrically about the symmetry axis BB. Each detection part includes a plurality of separate detection modules 11 / 21, and the centers of the detection surfaces of these detection modules 11 / 21 are located on the circumference where the detection part is located.

[0070] Typically, each detection module can be a separate PET detector or a unit formed by multiple PET detectors. The PET detector includes mutually coupled scintillation crystals, photoelectric conversion devices, and electronic devices, wherein the scintillation crystals are used to convert high-energy rays into visible light, the photoelectric conversion devices are used to convert visible light into electrical signals, and the electronic devices output these electrical signals, which can be digitized through corresponding sampling devices. The detection surface of the detection module can refer to a surface of a single detector for receiving high-energy rays, or it can refer to a combination of surfaces of multiple detectors for receiving high-energy rays. PET detectors, signal sampling, and subsequent image reconstruction can all be commonly used technical means in the field, which are not the core of the present invention and will not be described in detail here.

[0071] Each detector 10 / 20 also includes a driving unit (not shown in the figure), which can drive the detector 10 / 20 to change its shape. Figure 5 In the embodiment, the shapes of the first detection part 10 and the second detection part 20 in the initial state are shown as the dotted lines in the figure. Driven by the driving unit, the first detection part 10 and the second detection part 20, on the one hand, move away from each other, and on the other hand, the first detection part 10 and the second detection part 20 each make stretching motion along the directions of the arrows at both ends, so that the circumferential diameter of the detection surface of each detection module is expanded. The move away specifically refers to the two detection parts moving away from each other in the directions of the arrows on the AA axis, and the stretching motion refers to the two detection parts expanding in diameter in the directions of the arrows at both ends. More specifically, the move away and the stretching motion cause the shape changes of the PET device to manifest in two ways: the first change is that the curvature of the detection part 10 / 20 itself changes, from Figure 5 The dotted part in the figure is changed to the corresponding solid part. After the change, the first detection part 10 and the second detection part 20 are still arc-shaped, and the detection surface is still located on a circle, but the diameter of the circle where the arc is located becomes larger; the second change is the position change between adjacent detection modules. In order to meet the overall shape change requirements of the detection part, the relative angles between adjacent detection modules will change accordingly, so that the detection surface is still located on the circumference of the detection part after the change, which is manifested as 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 in the direction of the symmetry axis AA after the shape change and the detection modules become compact.

[0072] Those skilled in the art should understand that, since the detection surface is usually a plane, "the detection surface is located on the circumference" means that each side of the polygon formed by connecting the detection surfaces is tangent to the same circumference, or the midpoint of each detection surface is located on the same circumference. If the production cost of the detection surface is not considered, the detection surface can also be made into an arc-shaped plane, which is easy for those skilled in the art to think of and will not be repeated here.

[0073] Figure 5 The shape change of the central detector can increase the openness of the structure. The larger operable space on the left and right sides allows the PET device to be better combined with equipment such as hospital beds and radiotherapy equipment, or to give operators more operating space. At the same time, the increase in the inner diameter of the detector also allows the PET device to more conveniently detect different body parts of the same patient in real time, such as changing from the head to the torso, or more conveniently switch patients of different sizes. In addition, the detector is always on the circumference before and after the structural change, which can ensure that the imaging field of view is within the circle, ensure the uniformity of the PET device system response and do not significantly reduce the system sensitivity.

[0074] Figure 6 is a schematic diagram of the shape change of PET according to another embodiment of the present invention, Figure 6 It can be seen that the PET device provided by the present invention can also realize opposite movement and bending movement. The opposite movement specifically refers to the two detection parts approaching each other along the arrow direction on the AA axis, and the bending movement refers to the two detection parts bending along the arrow directions at both ends, so that the diameter of the circle where the detection surface of each detection module is located is reduced. More specifically, the opposite movement and bending movement cause the shape change of the PET device to manifest in two ways: the first change is the change in the shape of the detection part 10 / 20 itself, and its own curvature changes, from Figure 6 The dotted part in the figure is changed to the corresponding solid part. The changed first detection part 10 and the second detection part 20 are still arc-shaped, and the detection surface is still located on a circle, but the diameter of the arc is smaller; the second change is the position change between adjacent detection modules. In order to meet the overall shape change requirements of the detection part, the relative angles between adjacent detection modules will change accordingly, so that the center of the detection surface is still located on the circumference of the detection part after the change, which is manifested as 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 move toward the center of the circle after the shape change, and the first detection part 10 and the second detection part 20 appear to be elongated along the arc direction and the detection modules become sparse.

[0075] Figure 6 Although the shape change of the middle detection part will lead to a decrease in the openness of the structure, that is, the operable space on the left and right sides becomes smaller, but in some special applications when a particularly large operating space is not required, or when it does not affect the combination of the PET device with equipment such as a bed, radiotherapy equipment, or does not affect the operation of the operator, this structural change can significantly improve the uniformity of the PET device system response and increase the sensitivity of the system, which is conducive to obtaining more accurate scanning results.

[0076] Figure 7 is a schematic diagram of the shape change of PET according to another embodiment of the present invention, Figure 7 Examples and Figure 5 , Figure 6 Compared with the embodiment of the present invention, in addition to being able to complete the separation, movement towards each other and stretching and bending movements, it is also possible to achieve rotational movement. Figure 5 , Figure 6 The same as described in the embodiment, no further description is given here. Rotational motion means that after the two detection parts complete the movement of separation, movement of movement towards each other, extension and bending, at least one of the detection parts can also move along Figure 7 The direction indicated by the arrow C in the middle rotates around the corresponding circle, resulting in a certain angular displacement. When only one detector rotates or the two detectors rotate at different angles, since the PET imaging process needs to find gamma photons flying in opposite directions on the same straight line, part of the detection modules in one of the detection modules cannot correspond to the detection modules in the other detection module, thus changing the coverage angle τ of the PET device. For example, Figure 7 After the movement towards each other, the detection module 12 should correspond to the detection module 23, and the detection module 13 should correspond to the detection module 22. After the rotation, the detection module 12 and the detection module 22 lose the corresponding detection module, the detection module 13 corresponds to the detection module 24, and the detection module 23 corresponds to the detection module 14, and the coverage angle τ becomes smaller. When the two detection parts rotate along the circumference by the same angle, the corresponding relationship between the detection modules does not change. For example, after the rotation, the detection module 12 still corresponds to the detection module 23, and the detection module 22 still corresponds to the detection module 13.

[0077] Figure 7 When one detector rotates or the two detectors rotate at different angles, although the sensitivity of a part of the system will be sacrificed and the image quality will be reduced, this reduction is still within an acceptable range. In this case, the rotational movement will greatly increase the openness of one side of the structure, that is, the operable space on one side becomes larger, which is convenient for operations in certain special applications (such as surgery). When the two detectors rotate at the same time, the sensitivity and image quality of the system will not be reduced. The rotational movement can change the relative position between the openings on both sides and the object under test without moving the object under test, which is convenient for operating different parts or verifying / supplementing the results obtained from the initial scan.

[0078] Figure 8 is a schematic diagram of the shape change of PET according to an embodiment of the present invention, Figure 8In the embodiment of the present invention, the double arc arrangement of the PET device can form a circular ring arrangement after movement, that is, the detection parts 10 and 15 are surrounded by a circular ring shape without a gap after similar movement and bending movement. It should be understood by those skilled in the art that the PET device can also be reversely changed from a circular ring arrangement to a double arc arrangement, which will not be described in detail here. The advantage brought by this structural change is that the required detection accuracy can be selected according to actual needs or whether further operation is required. For example, when the surgical operation is completed and the postoperative results need to be checked, the double arc arrangement can be immediately changed to a circular ring arrangement, thereby obtaining high-precision imaging results and facilitating real-time effectiveness judgment.

[0079] Fig. 9 is a schematic diagram of the shape change of PET according to another embodiment of the present invention, Fig. 9 In the embodiment, in order to keep the angle size of the opening angle δ on both sides unchanged before and after the shape change, the PET device provided by the present invention needs to remove several detection modules at both ends of each detection part after the approximate movement and the bending movement. For example, after the movement, the two detection modules 12 and 13 at both ends of the first detection part 10 and the two detection modules adjacent to the detection modules 12 and 13 are removed, and the two detection modules 22 and 23 at both ends of the second detection part 20 and the two detection modules adjacent to the detection modules 22 and 23 are removed. It should be noted by those skilled in the art that when the PET device undergoes reverse separation movement and stretching movement, the opening angle δ on both sides will become larger. In order to maintain the relative stability of the angle, a corresponding number of detection modules can be added at both ends of each detection part after the movement, which will not be repeated here. The advantage brought by this structural change is that a fixed opening angle can be selected according to actual needs, which is convenient for operators or the space required for operating equipment, and at the same time, it can ensure that the coverage angle of the detection is consistent before and after, thereby taking into account both the convenience of operation and the quality of the imaging results.

[0080] Fig.10 is a schematic diagram of the shape change of PET according to another embodiment of the present invention, Fig.10 In the embodiment of the present invention, the PET device provided by the present invention can 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 δ 1 In order to increase the opening angle, the C-type PET needs to stretch. The stretching movement causes the shape of the PET device to change in two ways: the first change is that the diameter of the circle where the detection part 20 is located changes from Fig.10The dotted part in the figure is changed to the corresponding solid part. The changed detection surface is still located on a circle, but the diameter of the circle becomes larger. The second change is the position change between adjacent detection modules. In order to meet the overall shape change requirements of the detection part, the relative angles between adjacent detection modules will change accordingly, so that the detection surface is still located on the circumference of the detection part after the change. It is manifested that the detection modules 21 / 22 are compressed in the direction of the arrow in the figure after the shape change and the detection modules become relatively compact. At this time, the opening angle δ 2 The advantage of this structural change is that the fixed opening angle on one side can be selected according to actual needs, which is convenient for operators or the space required for operating equipment, and at the same time, it can ensure that the coverage angle of the detection is consistent, thus taking into account both the convenience of operation and the quality of the imaging results. This is because C-type PET, compared with double-arc PET and flat-plate PET, will cover a larger solid angle and have a higher sensitivity when the number of detection modules is the same.

[0081] Fig.11 is a schematic diagram of the shape change of PET according to another embodiment of the present invention, Fig.11 Examples and Fig.10 Compared with the embodiment shown in the figure, the PET device can also perform a bending movement opposite to the stretching movement, as shown by the arrow in the figure, and the opening angle is changed from δ indicated by the initial dotted line to 1 It decreases to the solid line δ 2 . Those skilled in the art should note that, in order to maintain the relative stability of the opening angle, the corresponding number of detection modules 21 / 22 at both ends can also be removed after the movement, which will not be repeated here. The advantage of this structural change is that a fixed opening angle on one side can be selected according to actual needs, which is convenient for operators or the space required for operating equipment, while ensuring that the coverage angle of the detection is consistent, thereby taking into account both convenient operation and the quality of the imaging results. This is because C-type PET, compared with double-arc PET and flat-plate PET, will cover a larger solid angle and have a higher sensitivity when the number of detection modules is the same.

[0082] Fig.12 is a schematic diagram of the shape change of PET according to an embodiment of the present invention, Fig.12 In the embodiment of the present invention, the PET device provided by the present invention is initially arranged in a C-shaped form, and can form a double arc arrangement after movement, that is, the detection part can form a double arc arrangement after separation movement and extension movement. Figure 5 , Figure 6 The double arc arrangement shown in the figure has openings on both sides instead of one. It should be understood by those skilled in the art that the PET device can also be reversely changed from the double arc arrangement to the C-shaped arrangement, and the circular, double arc and C-shaped arrangements can also be changed to each other. Fig.12The embodiment shown is only an example and not a limitation, and will not be described in detail here. The advantage of this structural change is that it greatly improves the openness of the structure while ensuring the required detection accuracy or sensitivity, and can quickly change the shape, which is suitable for a variety of application scenarios.

[0083] The above-mentioned separation motion, approach motion, and rotational motion can be realized by any driving unit that can realize linear motion or rotational motion, such as driving each detection module to move or driving the detection unit as a whole to move by a hydraulic driving unit. The hydraulic driving unit can also be connected to a computer to facilitate accurate control of the distance of separation motion or approach motion. The specific technical means such as how to set the driving unit and how to connect the driving unit to the detection unit are easy to realize by those skilled in the art based on the technical content disclosed in the present invention, and will not be repeated here.

[0084] The above-mentioned stretching movement and bending movement can be realized by arranging a driving unit between adjacent detection modules, for example, Fig.13 In the embodiment, a hinge 2 can be provided between adjacent detection modules 11 / 21, and the hinge 2 can allow rotation between two adjacent detection modules 11 / 21, so that the curvature change of the entire detection part can be changed through multiple hinges or through multiple hinges in cooperation with other driving units, so that the detection part after the shape change can still be located on the same circumference; Fig.14 In the embodiment, a motor 3 can be arranged between adjacent detection modules 11 / 21, and the motor 3 can directly drive the two adjacent detection modules 11 / 21 to rotate, thereby changing the curvature of the entire detection part through multiple motor drives, so that the detection part after the shape change can still be located on the same circumference; Fig.15 In the embodiment, a plurality of mutually hinged connecting rods 5 / 6 may be provided between the plurality of detection modules 11 / 21 of the same detection part, and these connecting rods 5 / 6 are hinged at the hinge points 4 / 7 / 8, so as to allow rotation between two adjacent detection modules 11 / 21, thereby changing the curvature of the entire detection part, so that the detection part after the shape change can still be located on the same circumference. The specific technical means of how to drive the detection module to rotate around the hinge through the drive unit / motor and how to connect the drive unit with the detection part / detection module / hinge / connecting rod are easy to implement by those skilled in the art based on the technical contents disclosed in the present invention, and will not be repeated here.

[0085] In addition to the above-mentioned embodiments, the shape change of the detection part in the present invention can also be achieved by Fig.16 The method shown is implemented. Fig.16In the embodiment, in the initial state, the PET device includes a first detection part 30 and a second detection part 40. The shapes and relative positions of the first detection part 30 and the second detection part 40 can be the same as those in the above-mentioned embodiment. The difference is that the number of detection modules 31 / 41 included in the first detection part 30 and the second detection part 40 can be different. At the same time, each / multiple detection modules in each detection part are connected to the support rod 32, and these support rods 32 can be movably arranged on one / multiple annular brackets 33. The extension direction of these support rods 32 passes through the center of the circle formed by the detection part and can perform linear motion and rotational motion on the annular bracket 33. The linear motion specifically refers to that the support rod 32 can drive the corresponding detection module 31 / 41 to move along the extension direction of the support rod 32, and the rotational motion specifically refers to that the support rod 32 and the corresponding detection module 31 / 41 can move along the circumferential direction of the annular bracket 33. When the state needs to be changed, several detection modules 31 / 41 can be selected from the first detection unit 30 and the second detection unit 40, respectively, to make the selected detection modules 31 / 41 perform linear motion and / or rotational motion, for example, Fig.16 The detection module shown by the dotted line can be moved to the corresponding solid line position to form the third detection part 50 and the fourth detection part 60. The third detection part 50 and the fourth detection part 60 are still formed into a double arc structure opposite to each other and are still on the same circle.

[0086] Fig.16 The embodiment is particularly suitable for applications that require rapid switching of imaging positions. When only a part of the detection modules is selected, although part of the system sensitivity will be sacrificed and the image quality will be reduced, this reduction is still within an acceptable range. In this case, since the distance between the detection module and the object to be measured is greatly reduced, the accuracy of the measured signal will be improved, thereby offsetting part of the aforementioned adverse effects and facilitating operations in certain special applications. When the detection part rotates, the sensitivity and image quality of the system will not decrease. The rotational motion can change the relative position between the openings on both sides and the object to be measured without moving the object to be measured, which is convenient for operating different parts or verifying / supplementing the results obtained from the initial scan.

[0087] In all the above embodiments, since the shape of the detection part changes, it is also possible to calibrate whether the detection modules correspond to each other. Fig.17 One of the calibration methods provided by the present invention is shown. The method comprises the following steps:

[0088] Step 1: arbitrarily select two groups of detection modules located on the circumference diameter of the detection part, and mark the intersection point O of the perpendicular lines of the detection surfaces of the two groups of detection modules;

[0089] Step 2: randomly select another set of detection modules and mark the perpendicular midline of the detection surface of the detection module;

[0090] Step 3: If the perpendicular bisector in step 2 passes through the intersection point O in step 1, it can be determined that the detection modules on the detection part are on the same circumference; if the perpendicular bisector in step 2 does not pass through the intersection point O in step 1, it can be determined that the detection modules on the detection part are not on the same circumference, and the shape of the detection part needs to be further adjusted.

[0091] Step 4: When the shape of the detection part changes, repeat the above steps 1 to 3 until it is determined that the detection modules are located on the same circumference.

[0092] The present invention also provides a method for positron emission tomography, which comprises the following steps:

[0093] Step S1: using a PET device for imaging;

[0094] Step S2: changing the shape of the PET device in step S1 so that it has at least one notch and / or the diameter of the circle where the detection part of the PET device is located is changed;

[0095] Step S3: Perform imaging using the PET device obtained in step S2.

[0096] In the above step S1, the initial shape of the detection part of the PET device can be circular, double-arc or C-shaped, wherein circular, double-arc or C-shaped means that each side of the polygon formed by connecting the detection surfaces of the detection part is tangent to the same circle, or the midpoint of each detection surface is located on the same circle.

[0097] In the above step S2, the shape of the PET device is changed in the following ways:

[0098] The first one: if the PET device in step S1 is circular, the shape of the PET device in step S2 can be changed to a double arc or a C shape, and the diameter of the circle where the double arc or the C shape is located can also be changed or rotated during the change process.

[0099] Second: if the PET device in step S1 is double-arc shaped, then the shape of the PET device in step S2 can be changed to circular, double-arc shaped or C-shaped, and the diameter of the circle where the double-arc or C-shaped is located can also change or rotate during the change process.

[0100] The third type: if the PET device in step S1 is C-shaped, then the shape of the PET device in step S2 can be changed to circular, double-arc or C-shaped, and the diameter of the circle where the double-arc or C-shaped is located can also change or rotate during the change process.

[0101] The shape changes of the above PET devices are all included in Figure 5-Figure 16In the illustrated embodiment, the description is not repeated here.

[0102] In the above step S2, the shape of the PET device in step S1 can be changed by Figure 14-16 The embodiments shown in the drawings are described in detail and will not be described again here.

[0103] Before the above step S1 or step S3, the PET device may be calibrated. The specific calibration steps are as follows: Fig.17 The calibration steps are the same as described.

[0104] Fig.18 : is a schematic diagram comparing imaging results of PETs of different shapes according to an embodiment of the present invention, wherein the parameters of the object to be measured and the detection module in each embodiment are kept consistent, the upper left corner is the imaging result of the circular PET device, and the image of the imaging result is very clear; the upper right corner is the imaging result after removing 1 / 4 of the detection module in the upper left corner and changing the arrangement of the PET device to a double-arc structure, and the quality of this imaging result is not significantly reduced compared with the imaging result in the upper left corner; the lower left corner is the imaging result after removing 1 / 2 of the detection module in the upper left corner and changing the arrangement of the PET device to a double-arc structure, although the quality of this imaging result is reduced compared with the imaging result in the upper left corner, it is still within an acceptable range, and the resolution of the simulated lesion is still clearly discernible, proving that the PET device is quite effective in balancing imaging quality, system sensitivity and operability.

[0105] Fig.19 is a schematic diagram for comparing imaging parameters of PETs of different shapes according to an embodiment of the present invention, wherein 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 block corresponds to the relevant parameters of the circular PET device, the triangular black block corresponds to the relevant parameters when the number of detectors is 3 / 4 of the circular PET, the quadrilateral black block corresponds to the relevant parameters when the number of detectors is 1 / 2 of the circular PET, and Fig.19 It can be seen that when the number of detectors is reduced, that is, when the PET device changes from a circular ring shape to a double arc shape, both CRC and BV will decrease. However, the background variation rate is only reduced by 4.5% to 6.1%, and the contrast of the hot zone (the black part in the figure, whose activity is higher than the background area) is only reduced by 3.9% to 11.8%. The sacrifice of a small amount of performance is completely controllable relative to the obtained openness and high sensitivity, and does not affect the diagnosis of lesions. It can well take into account the openness, adjustability, sensitivity and response uniformity of the system.

[0106] The above is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. The above embodiments of the present invention can also be changed in various ways. For example, according to the specific embodiments described above, those skilled in the art can also design the shape of the detection part to be multiple arc shapes located on the same circumference, wherein at least two groups of arcs are one-to-one corresponding. That is, all simple, equivalent changes and modifications made according to the claims and the contents of the specification of the present invention application fall within the scope of protection of the claims of the present invention patent. The contents not described in detail in the present invention are all conventional technical contents.

Claims

1. A positron emission tomography device, characterized in that: include: The detection part comprises a plurality of detection modules, wherein the detection surfaces of the detection modules are distributed along a first circumference, wherein the detection surfaces of at least two groups of the detection modules are arranged relatively to each other and are located 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 during detection, and before and after the movement change, the relative angle between adjacent detection modules changes, and the diameters of the first circumference and the second circumference are different.

2. The positron emission tomography imaging device according to claim 1, characterized in that: There are two detection parts and two openings respectively, and the openings and the detection parts are arranged at intervals and form the circumference together.

3. The positron emission tomography imaging device according to claim 1, characterized in that: The detection portion and the opening are each one, and the opening and the detection portion are arranged at intervals and together form the circumference.

4. The positron emission tomography device according to claim 2 or 3, characterized in that: All the detection modules in the detection part correspond to each other in the circumferential diameter direction.

5. The positron emission tomography device according to claim 2 or 3, characterized in that: A portion of the detection modules in the detection portion correspond to each other in the diameter direction of the circumference.

6. The positron emission tomography imaging device according to claim 2 or 3, characterized in that: After the detection part moves, the diameter of the first circle is smaller than the diameter of the second circle.

7. The positron emission tomography imaging device according to claim 2 or 3, characterized in that: After the detection part moves, the diameter of the first circle is greater than the diameter of the second circle.

8. The positron emission tomography imaging device according to claim 1, characterized in that: After the detection part moves, the central angle of the circle corresponding to the opening remains unchanged, and the number of the detection modules in the detection part is reduced.

9. The positron emission tomography imaging device according to claim 1, characterized in that: After the detection part moves, the central angle of the circle corresponding to the opening remains unchanged, and the number of the detection modules in the detection part increases.

10. The positron emission tomography imaging device according to claim 1, characterized in that: There are at least two of the openings and the detection parts, and after the detection part moves, the number of the openings changes to one.

11. The positron emission tomography imaging device according to claim 1, characterized in that: There are two openings before the movement, and the openings disappear after the detection part moves.

12. The positron emission tomography imaging device according to claim 1, characterized in that: The number of the opening is one, and after the detection part moves, the number of the openings and the number of the detection parts both change to two.

13. The positron emission tomography imaging device according to claim 1, characterized in that: The at least one detection part rotates along the second circle after the movement, and after the rotation, the detection surfaces of at least two groups of the detection modules are still arranged relatively to each other and located on the same straight line.

14. The positron emission tomography imaging device according to claim 13, characterized in that: The two detection parts rotate at the same angle simultaneously.

15. The positron emission tomography imaging device according to claim 1, characterized in that: There are two detection parts in total, and during detection, the two detection parts undergo the same angular displacement simultaneously.

16. The positron emission tomography imaging device according to claim 1, characterized in that: There are two detection parts in total, and the angular displacements of the two detection parts occurring simultaneously during detection are different.

17. The positron emission tomography imaging device according to claim 1, characterized in that: There are two detection parts in total, and one of the detection parts undergoes angular displacement during detection.

18. The positron emission tomography imaging device according to claim 1, characterized in that: There are two detection parts in total. After movement, the number of detection modules in one of the detection parts is reduced.

19. The positron emission tomography imaging device according to claim 15, characterized in that: There are two detection parts in total. After the movement, the number of the detection modules in one of the detection parts increases.

20. A positron emission tomography device, characterized in that: include: The detection part comprises a plurality of detection modules, the detection surfaces of the detection modules are distributed along a first circumference, the detection surfaces of the detection modules are arranged relatively to each other and are located in the diameter direction of the first circumference; the detection surface of the detection part moves and changes during detection to be distributed along a second circumference and form at least one opening, before and after the movement change, the relative angle between adjacent detection modules changes, and the diameters of the first circumference and the second circumference are different.

21. The positron emission tomography imaging device according to claim 20, characterized in that: After the movement, the detection part is split into at least two parts opposite to each other, and the opening and the detection part are distributed along the second circumference.

22. The positron emission tomography imaging device according to claim 20, characterized in that: A portion of the detection parts are still arranged opposite to each other after the movement, and the openings and the detection parts are distributed together along the second circumference.

23. A positron emission tomography method, characterized in that: At least the following steps are included: Step S1: using a PET device for imaging, the PET device comprising a plurality of detection modules and at least one opening, the detection surfaces of the detection modules and the opening being distributed along a first circumference, wherein the detection surfaces of at least two groups of detection modules are arranged opposite to each other and are located in the diameter direction of the first circumference; Step S2: changing the shape of the PET device in step S1 so that the detection surfaces of the detection modules are relatively arranged along a second circumference, and before and after the movement change, the relative angle between adjacent detection modules changes, and the diameters of the first circumference and the second circumference are different; Step S3: Perform imaging using the PET device obtained through step S2.

24. The positron emission tomography method according to claim 23, characterized in that: In the step S2, the shape change of the PET device includes rotating a portion of the detection module along the first circumference or the second circumference.

25. The positron emission tomography method according to claim 23, characterized in that: Before step S1 or step S3, the detection module is calibrated.

26. The positron emission tomography method according to claim 23, characterized in that: In the step S2, the PET devices distributed along the second circumference have no openings or have at least one opening.

27. The positron emission tomography method according to claim 23, characterized in that: In step S2, the shape change of the PET device is achieved by a driving device and / or increasing or decreasing the number of detection modules.

28. A positron emission tomography method, characterized in that: At least the following steps are included: Step S1: using a PET device for imaging, the PET device comprising a plurality of detection modules, the detection surfaces of the detection modules being distributed along a first circumference, the detection surfaces of the detection modules being arranged relative to each other and located in a diameter direction of the first circumference; Step S2: changing the shape of the PET device in step S1 so that there is an opening between the detection surfaces of the detection modules, the opening and the detection surface are arranged relatively along a second circumference, and before and after the movement change, the relative angle between adjacent detection modules changes, and the diameters of the first circumference and the second circumference are different; Step S3: Perform imaging using the PET device obtained through step S2.

29. The positron emission tomography method according to claim 28, characterized in that: In the step S2, the shape change of the PET device includes rotating a portion of the detection module along the first circumferential direction or the second circumferential direction.

30. The positron emission tomography method according to claim 28, characterized in that: Before step S1 or step S3, the detection module is calibrated.

31. The positron emission tomography method according to claim 28, characterized in that: In the step S2, the PET devices distributed along the second circumference have no openings or have at least one opening.

32. The positron emission tomography method according to claim 28, characterized in that: In step S2, the shape change of the PET device is achieved by a driving device and / or increasing or decreasing the number of detection modules.

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