WO2023000478A1 - Positron emission tomography apparatus and method - Google Patents

Abstract

Disclosed in the present invention are a positron emission tomography apparatus and method. A detection part of the apparatus comprises a plurality of detection modules, wherein detection surfaces of the detection modules are distributed along a first circumference, the detection surfaces of at least two groups of detection modules are arranged opposite each other and are located in a diameter direction of the first circumference, and at least one opening is formed on the first circumference; and a detection surface of the detection part is changed, by means of movement, to be distributed along a second circumference during detection, and the diameters of the first circumference and the second circumference are different. The method comprises: performing imaging by using a PET apparatus, wherein the PET apparatus comprises a plurality of detection modules, which are distributed along a first circumference, and at least one opening; changing the shape of the PET apparatus, such that detection surfaces of the detection modules and the opening are distributed along a second circumference; and performing imaging again by using the PET apparatus, the shape of which has been changed. By means of the present invention, a good system openness is provided; the size and the angle of an opening part can also be changed; and the apparatus and method have a good adaptability, and can also ensure system sensitivity and response uniformity.

Description

Positron emission computed tomography device and method

This disclosure claims the priority of Chinese patent application 202110828771.X filed on July 22, 2021, the entire contents of which are incorporated herein by reference.

technical field

The present invention relates to the field of medical devices, and more particularly relates to a positron emission computed tomography device and method.

Background technique

Positron Emission Tomography (PET for short, or Positron Emission Tomography) is a large-scale and cutting-edge nuclear medical imaging technology. PET can non-invasively, quantitatively and dynamically evaluate the in vivo Metabolic levels, biochemical reactions, and functional activities of various organs, so that many diseases can detect relevant biochemical changes before they cause structural changes or worsen symptoms. PET has great and unique application value in the diagnosis and treatment of major diseases, especially in the clinical diagnosis and treatment of tumors, cardiovascular diseases and nervous system diseases.

PET detectors are usually arranged around the target when detecting gamma photons. According to the arrangement of PET detectors in the prior art, it can be divided into the following types: fixed ring PET device (as shown in Figure 1) and application-adapted PET, etc. Among them, fixed ring is the most traditional PET arrangement form, but this The size and position of the detection ring 1 in this layout form are not adjustable, and the scope of application is narrow; the application of adaptive PET (for example, CN101856236A and CN102178542A) although the detection module can perform radial movement, circular movement and direction change through the module track However, this application-adaptive PET device has a complicated mechanical structure and is inconvenient to move, and its detectors are still arranged in a ring structure in essence, and the detectors still form a closed ring after changing positions.

In clinical practice, in order to facilitate the examination and treatment of seriously ill or immobile patients, it is necessary to move the PET device to the bedside for scanning. Since bedside PET needs to be combined with other equipment such as hospital beds and radiotherapy equipment at any time, it needs to have an open structure. At this time, the traditional fixed ring PET structure can no longer meet the needs. In order to solve this problem in the prior art, generally adopt flat PET (as shown in Figure 2), C-shaped PET (as shown in Figure 3) and double arc PET (as shown in Figure 4), however, the arrangement of flat PET The structure will cause the uniformity of the system response to be inferior to that of the ring structure. The solid angle β of the flat-panel PET system composed of the same number of detectors is smaller than that of the ring-shaped PET system, which reduces the sensitivity of the system and leads to the image quality corresponding to the edge detector. lower; C-type PET and double-arc PET have the same inner diameter and number of detectors as flat PET, and will cover a larger solid angle α, and the sensitivity is also higher. However, the structure of C-type PET and double-arc PET is also relatively Fixed, the sensitivity cannot be further improved, and it cannot be applied to measured 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.

Therefore, it is necessary to develop a PET device with strong tunability, high sensitivity and low cost.

Contents of the invention

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

The positron emission computed tomography device provided by the present invention is a positron emission computed tomography device. The detection surface of the module is arranged oppositely and is 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 is changed to be distributed along the second circumference through movement during detection, and the first circumference and The diameter of the second circumference is different.

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

According to an embodiment of the present invention, there are one detection portion and one opening respectively, and the openings and detection portions are arranged at intervals and together form a complete circle.

According to an embodiment of the present invention, all the detection modules in the detection part are in one-to-one correspondence in the circumferential diameter direction.

According to an embodiment of the present invention, some of the detection modules in the detection part correspond to each other in the diameter direction of the circumference.

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.

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

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

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

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

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

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

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 opposite and on the same straight line.

According to an embodiment of the present invention, the two detection parts rotate at the same angle at the same time.

According to an embodiment of the present invention, the detection part of the positron emission computed tomography device includes several detection modules, the detection surfaces of the detection modules are distributed along the same circumference, at least one opening is formed on the circumference, and at least one detection part Angular displacement occurs along the circumference during detection, and the detection surfaces of at least two groups of detection modules are arranged opposite to each other and located in the diameter direction of the circumference before and after the movement.

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.

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.

According to an embodiment of the present invention, there are two detection parts, and an angular displacement occurs in one of the detection parts during detection.

According to an embodiment of the present invention, after the detection part moves, the number of detection modules in one detection part decreases.

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

According to an embodiment of the present invention, the detection part of the positron emission computed tomography apparatus includes several detection modules, the detection surfaces of the detection modules are distributed along the first circumference, and the detection surfaces of the detection modules are arranged opposite and located at In the diameter direction of the first circle; the detection surface of the detection part changes to distribute along the second circle and form at least one opening through movement during detection.

According to an embodiment of the present invention, the detection part 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 part are distributed along the second circumference.

According to an embodiment of the present invention, some of the detection parts are still arranged opposite to each other after the movement, and the openings and the detection parts are jointly distributed along the second circumference.

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

Step S1: Using a PET device for imaging, the PET device includes several detection modules and at least one opening, the detection surfaces and openings of the detection modules are distributed along the first circumference, and the detection surfaces of at least two groups of detection modules are arranged opposite to each other and is 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 surface and the opening of the detection module are relatively arranged along the second circumference;

Step S3: Imaging is performed using the PET device that has passed 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, detection module calibration may also be performed.

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

Step S1: using a PET device for imaging, the PET device includes several detection modules, the detection surfaces of the detection modules are distributed along the first circle, and the detection surfaces of the detection modules are arranged relatively and located in the diameter direction of the first circle;

Step S2: change the shape of the PET device in step S1, so that there is an opening between the detection surfaces of the detection module, and the opening and the detection surface are relatively arranged along the second circumference;

Step S3: Imaging is performed using the PET device that has passed through step S2.

According to an embodiment of the present invention, in step S2, changing the shape of the PET device may also include rotating a part of the detection modules.

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

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.

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

The positron emission computed 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 hospital beds and radiotherapy equipment through the shape change of the detection part, but also can change the size of the opening part and angles to adapt to different operations, different detection parts and different human body detection requirements. At the same time, the best system sensitivity can be achieved by adjusting the inner diameter of the detection part. All detection modules are always in the circular imaging field of view. It also guarantees the response uniformity of the system, realizes the balance between the adjustability, sensitivity and response uniformity of the system, and has great application value.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments described in the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

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

Fig. 2 is a schematic diagram of the layout of flat PET according to the prior art;

Fig. 3 is a schematic diagram of the layout of C-type PET according to the prior art;

Fig. 4 is a schematic diagram of the arrangement of double-arc PET according to the prior art;

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

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

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

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

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

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

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

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

Fig. 13 is a schematic diagram of driving a PET detector according to an embodiment of the present invention;

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

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

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

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

Fig. 18 is a schematic diagram showing the comparison of imaging results of different shapes of PET according to an embodiment of the present invention;

Fig. 19 is a schematic diagram showing the comparison of imaging parameters of PET with 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 restoration coefficient and the background variation rate.

detailed description

The present invention will be further described below in conjunction with specific embodiments. It should be understood that the following examples are only used to illustrate the present invention but not to limit the scope of the present invention.

It should be noted that when a component/feature is referred to as being “disposed on” another component/part, it can be directly disposed on the other component/part or an intervening component/part 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 parts/parts may also be present. As used herein, the term "connected/coupled" may include electrical and/or mechanical physical connections/coupled. As used herein, the term "comprising/comprising" 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. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

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

In addition, in the description of the present invention, the terms "first", "second" and so on are only used to describe the purpose and distinguish similar objects, there is no sequence between the two, and it cannot be understood as indicating or implying relative importance sex. In addition, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

Fig. 5 is a schematic diagram of the shape change of PET according to an embodiment of the present invention. It can be seen from Fig. 5 that the PET device provided by the present invention includes a first detection part 10 and a second detection part 20. In the embodiment of Fig. 5, the first The detection part 10 and the second detection part 20 are circular arcs arranged oppositely and 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, and the first detection part 10 and the second detection part 20 themselves are respectively about The symmetry axis AA is symmetrical, and the first detection part 10 and the second detection part 20 are arranged symmetrically with respect to the symmetry axis BB. Each detection part includes a plurality of individual 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.

Usually, each detection module can be a single PET detector or a unit formed by multiple PET detectors, and the PET detector includes mutually coupled scintillation crystals, photoelectric conversion devices and electronic devices, wherein the scintillation crystals are used for Convert high-energy rays into visible light, photoelectric conversion devices are used to convert visible light into electrical signals, electronic devices output these electrical signals, and these electrical signals can be digitized through corresponding sampling devices. The detection surface of the detection module may refer to the surface of a single detector for receiving high-energy rays, or may 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.

Each detection part 10/20 also includes a driving unit (not shown in the figure), and the driving unit can drive the detection part 10/20 to change in shape. For example, in the embodiment of FIG. 5, the first detection part 10 in the initial state and the shape of the second detection part 20 is shown by the dotted line in the figure, driven by the driving unit, the first detection part 10 and the second detection part 20 move away from each other on the one hand, and the first detection part 10 on the other hand and the second detection part 20 each perform stretching motion along the direction of the arrow at both ends, so that the diameter of the circle where the detection surface of each detection module is located is enlarged. The separation movement specifically refers to the two detection parts moving away from each other along the direction of the arrow on the AA axis, and the extension movement refers to the expansion of the diameter of the two detection parts along the directions of the arrows at both ends. More specifically, the separation movement and extension movement make the shape change of the PET device appear in two ways: the first change is that the curvature of the detection part 10/20 itself changes, from the dotted line in Figure 5 to the corresponding solid line part, the changed first detection part 10 and 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 that the adjacent detection modes The position changes between groups, in order to meet the overall shape change requirements of the detection part, the relative angle 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, expressed 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 toward the axis of symmetry AA after shape change and the detection modules become compact.

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 circle, or that each detection surface The midpoints of the surfaces all lie on the same circumference. If the production cost of the detection surface is not considered, the detection surface can also be made as an arc-shaped plane, which is easily thought of by those skilled in the art, and will not be repeated here.

The shape change of the detection part in Figure 5 can increase the openness of the structure, and the operable space on the left and right sides becomes larger so that the PET equipment can be better combined with equipment such as hospital beds and radiotherapy equipment, or give operators more operating space. At the same time, the increase in the inner diameter of the detection part also makes it easier for the PET device to detect different body parts of the same patient in real time, such as changing from the head to the torso, or switching between patients of different volumes more conveniently. In addition, the detection part is always on the circumference before and after the structural change, which can ensure that the imaging field of view is in a circle, guarantee the uniformity of the system response of the PET equipment, and not significantly reduce the system sensitivity.

Fig. 6 is a schematic diagram of the shape change of PET according to another embodiment of the present invention. It can be seen from Fig. 6 that the PET device provided by the present invention can also realize relative movement and bending movement. The relative movement specifically refers to the two detection parts along the AA axis. The directions of the arrows are close to each other, and the bending motion refers to the bending motion of the two detection parts along the direction of the arrows 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 the bending movement make the shape change of the PET device appear in two ways: the first kind of change is the change of the shape of the detection part 10/20 itself, and its own radian changes, changing from the dotted line part in Fig. 6 is the corresponding part of the solid line, the changed first detection part 10 and second detection part 20 are still arc-shaped, and the detection surface is still located on a circle, but the diameter of the arc becomes smaller; the second change is the phase The position changes between adjacent detection modules, in order to meet the overall shape change requirements of the detection part, the relative angle between adjacent detection modules will change accordingly, so that the center of the detection surface after the change is still located at the location of the detection part. On the circle of the first detection part 10, 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 towards the center of the circle after the shape changes, and the first detection part 10 and The second detection part 20 appears to be elongated along the arc direction and the detection modules become sparse.

Although the shape change of the detection part in Figure 6 will lead to a reduction in the openness of the structure, that is, the operable space on the left and right sides will become smaller, but in some special applications that do not require a particularly large operating space, or without affecting the PET equipment When combined with equipment such as hospital beds and radiotherapy equipment or does not affect the operation of the operator, this structural change can significantly improve the uniformity of the PET equipment system response and improve the sensitivity of the system, which is conducive to obtaining more accurate scanning results.

Fig. 7 is a schematic diagram of the shape change of PET according to another embodiment of the present invention. Compared with the embodiments of Fig. 5 and Fig. 6, the embodiment of Fig. 7 can complete the separation, opposite movement, stretching and bending movement, Rotational motion is also possible. The separation, movement toward each other, stretching, and bending movement are the same as those described in the embodiments of Fig. 5 and Fig. 6 , and will not be repeated here. Rotational motion refers to that after the two detection parts complete the separation, relative movement, stretching and bending motion, at least one of the detection parts can also rotate around the corresponding circle along the direction shown by arrow C in Figure 7, and a certain amount of movement will occur. angular displacement. When only one detection part rotates or the rotation angles of the two detection parts are different, because the PET imaging process needs to find the gamma photons flying in the opposite direction on the same straight line, a part of one of the detection parts detects The module cannot correspond to the detection module in another detection section, so the coverage angle τ of the PET device will be changed. For example, after moving towards each other in Fig. 7, 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 movement, the detection module 12 and the detection module 22 lost the corresponding detection module, the detection module 13 corresponds to the detection module 24, the detection module 23 and the detection module 14 Correspondingly, the coverage angle τ becomes smaller. When the two detection parts rotate at the same angle along the circumference, the corresponding relationship between the various detection modules will not change. For example, after the rotation, the detection module 12 still corresponds to the detection module 23, and the detection module 22 is still Corresponding to the detection module 13.

In Figure 7, when one detection part rotates or two detection parts rotate at different angles, although part of the sensitivity of the system will be sacrificed and the quality of the image will be reduced, but the drop is still within an acceptable range. In this case, the rotational movement The openness of one side of the structure will be greatly improved, that is, the operable space on one side becomes larger, which is convenient for operation in some special applications (such as surgery). When the two detection parts 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 measured object on the premise that the measured object does not move, which is convenient for alignment. Manipulate a different site, or verify/supplement the results obtained from the initial scan.

Fig. 8 is a schematic diagram of the 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 device provided by the present invention can form a circular arrangement after being moved, that is, the detection part 10 and 15 form a ring shape without gaps after similar motion and bending motion. It should be understood by those skilled in the art that the PET device can also be reversely changed from a ring-shaped arrangement to a double-arc arrangement, which will not be repeated here. The advantage brought by this structural change is that the required detection accuracy can be selected according to actual needs or whether further operations are required. For example, when the operation is completed and the postoperative results need to be checked, the double-arc arrangement can be used. Immediately change to a circular arrangement to obtain high-precision imaging results and facilitate real-time effect judgments.

Fig. 9 is a schematic diagram of the shape change of PET according to another embodiment of the present invention. In the embodiment of Fig. 9, in order to keep the angle of the opening angle δ on both sides unchanged before and after the shape change, the PET device provided by the present invention passes through After similar movement and bending movement, it is necessary to remove several detection modules at both ends of each detection part, for example, remove the two detection modules 12, 13 and the detection module 12 at both ends of the first detection part 10 after the movement. , 13 adjacent to the two detection modules, while removing the two detection modules 22, 23 at both ends of the second detection part 20 and the two detection modules adjacent to the detection modules 22, 23. Those skilled in the art should pay attention to that when the PET device undergoes reverse separation and stretching movements, the opening angle δ on both sides will become larger. In order to keep the angle relatively stable, it can also be adjusted after each A corresponding number of detection modules are added to both ends of the detection part, 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 the operator or the space required for operating the device, and at the same time can ensure that the detection coverage angle is consistent, so as to take into account the convenience of operation and the quality of imaging results.

Fig. 10 is a schematic diagram of shape change of PET according to another embodiment of the present invention. In the embodiment of Fig. 10, 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 at this time. In order to make the opening angle larger, the C-type PET needs to be stretched, and the stretching motion makes the shape of the PET device change in two ways: the first change is that the diameter of the circle where the detection part 20 is located changes, from the dotted line in Figure 10 Part of it is changed to the corresponding part of the solid line. 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 The relative angle 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 shown that the detection modules 21/22 are all facing The direction of the arrow in the figure is compressed and the detection modules become relatively compact. At this time, the opening angle _δ2 becomes larger. The advantage brought by this structural change is that a fixed opening angle on one side can be selected according to actual needs, which is convenient for the operator or the space required for operating the device, and at the same time can ensure that the detection coverage angle is consistent, thus taking into account the convenience of operation and the quality of imaging results , this is because C-type PET will cover a larger solid angle and have higher sensitivity when the number of detection modules is the same compared to double-arc PET and flat-panel PET.

Fig. 11 is a schematic diagram of the shape change of PET according to another embodiment of the present invention. Compared with the embodiment shown in Fig. 10, the PET device in Fig. 11 can also perform a bending movement opposite to the stretching movement, as shown in Fig. As indicated by the middle arrow, the opening angle decreases from δ ₁ indicated by the initial dotted line to δ ₂ indicated by the solid line. Those skilled in the art should note that, in order to keep the opening angle relatively stable, a corresponding number of detection modules 21 / 22 at both ends can be removed after the movement, so details will not be repeated here. The advantage brought by this structural change is that a fixed opening angle on one side can be selected according to actual needs, which is convenient for the operator or the space required for operating the device, and at the same time can ensure that the detection coverage angle is consistent, thus taking into account the convenience of operation and the quality of imaging results , this is because C-type PET will cover a larger solid angle and have higher sensitivity when the number of detection modules is the same compared to double-arc PET and flat-panel PET.

Fig. 12 is a schematic diagram of the shape change of PET according to an embodiment of the present invention. In the embodiment of Fig. 12, the PET device provided by the present invention is initially in a C-shaped arrangement, and after movement, it can form a double-arc arrangement, that is, to detect The parts can form the double-arc arrangement shown in Figure 5 and Figure 6 after separation and stretching, and the opening also changes from one opening to openings on both sides. Those skilled in the art should understand that the PET device can also reversely change from a double-arc arrangement to a C-shaped arrangement, and the circular, double-arc and C-shaped arrangements can also change each other, as shown in Fig. The embodiment shown in 12 is only an example rather than a limitation, and details are not repeated here. The advantage brought by this structural change is that the openness of the structure is greatly improved under the premise of ensuring the required detection accuracy or sensitivity, and the shape can be changed rapidly, which is suitable for various application scenarios.

The above-mentioned separation movement, approach movement and rotation movement can be realized by any driving unit capable of linear movement or rotation movement, such as driving each detection module to move or driving the whole detection part to move by a hydraulic drive unit. The hydraulic drive unit can also be connected with a computer to facilitate accurate control of the distance of the moving or approaching movement. How to set up the drive unit and how to connect the drive unit to the detection part and other technical means can be easily realized by those skilled in the art according to the technical content disclosed in the present invention, and will not be repeated here.

The above stretching and bending movements can be realized by setting a drive unit between adjacent detection modules, for example, in the embodiment of Figure 13, a hinge 2 can be arranged between adjacent detection modules 11/21, and the hinge 2 It can allow rotation between two adjacent detection modules 11/21, so that the arc change of the entire detection part can be changed through multiple hinges or through multiple hinges in cooperation with other drive units, so that the detection part after shape change can still Located on the same circumference; in the embodiment of Fig. 14, a motor 3 can be arranged between adjacent detection modules 11/21, and the motor 3 can directly drive the occurrence between two adjacent detection modules 11/21. Rotate, thereby changing the radian change 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; in the embodiment of Figure 15, multiple detection modules 11 of the same detection part A plurality of mutually hinged connecting rods 5/6 can be arranged between /21, and these connecting rods 5/6 are hinged at the hinge point 4/7/8, thereby allowing the occurrence of Rotate, and then change the arc change of the entire detection part, so that the detection part after the shape change can still be located on the same circumference. Specifically, how to drive the detection module to rotate around the hinge through the drive unit/motor and how to connect the drive unit to the detection part/detection module/hinge/connecting rod and other technical means belong to those skilled in the art that can be easily realized according to the technical content disclosed in the present invention. , which will not be repeated here.

In addition to the above-mentioned embodiments, the shape change of the detection part in the present invention can also be realized in the manner shown in FIG. 16 . In the embodiment of FIG. 16, in the initial state, the PET device includes a first detection part 30 and a second detection part 40, and the shapes and relative positions of the first detection part 30 and the second detection part 40 may be the same as those in the above-mentioned embodiments. , the difference is that the number of detection modules 31/41 contained in the first detection part 30 and the second detection part 40 can be different, and at the same time, each/multiple detection modules in each detection part are connected with the support Connected by rods 32, these support rods 32 can be movably arranged on one/a plurality of ring supports 33, the extension direction of these support rods 32 passes through the center of circle formed by the detection part and can do linear motion on the ring support 33 and Rotational motion, 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 circular motion. The circumferential direction of the holder 33 moves. When the state needs to be changed, several detection modules 31/41 can be respectively selected from the first detection part 30 and the second detection part 40, so that the selected detection modules 31/41 undergo linear motion and/or rotational motion, For example, the detection module shown by the dotted line in FIG. 16 can be moved to the corresponding solid line position, thereby forming 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 as each other. The opposite double arc structure is still on the same circumference.

The embodiment in Figure 16 is especially 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 quality of the image will be reduced, the drop 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 the operation in some special applications. When the detection part rotates, 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 measured object under the premise that the measured object does not move, which is convenient for different parts. operation, or to verify/supplement the results obtained from the initial scan.

In all the above-mentioned 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 shows one of the calibration methods provided by the present invention. The method includes the following steps:

Step 1: randomly select two groups of detection modules located on the circumference diameter of the detection part, and mark the intersection point O of the vertical line in the detection surface of these two groups of detection modules;

Step 2: Randomly select another group of detection modules, and mark the perpendicular line of the detection surface of the detection module;

Step 3: If the perpendicular line 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 line in step 2 does not pass through the intersection point O in step 1 , then 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 at this time;

Step 4: After the shape of the detection part changes, repeat the above steps 1-3 until it is determined that the detection modules are located on the same circle.

The present invention also provides a method for positron emission computed tomography, the method comprising the following steps:

Step S1: Imaging with a PET device;

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

Step S3: Imaging is performed using the PET device that has passed through step S2.

In the above step S1, the initial shape of the detection part of the PET device can be a circle, a double arc or a C shape, wherein the circle, double arc or C shape refers to each of the polygons formed by connecting the detection surfaces of the detection part. One side is tangent to the same circle, or the midpoint of each detection surface is on the same circle.

In the above step S2, changing the shape of the PET device includes the following:

The first type: if the PET device in step S1 is circular, then the shape of the PET device in step S2 can be changed to double arc or C-shaped, and the double-arc or C-shaped circumference can also be accompanied by the change process. Diameter change or rotation.

The second type: if the PET device in step S1 is double-arc, then the shape of the PET device in step S2 can be changed to a circle, double-arc or C-shaped, and double-arc or C-shaped can also occur during the change process. The diameter of the circle where the shape is located changes or rotates.

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 a circle, double-arc or C-shaped, and double-arc or C-shaped can also occur during the change process The diameter of the circle on which it is located changes or rotates.

The above-mentioned shape changes of the PET device are included in the embodiments shown in FIGS. 5-16 , and will not be described again here.

In the above step S2, changing the shape of the PET device in step S1 can be performed through the embodiments shown in Fig. 14-Fig. 16, and the description will not be repeated here.

Before the above step S1 or step S3, the PET device can also be calibrated, and the specific calibration steps are consistent with the calibration steps described in FIG. 17 .

Fig. 18 is a schematic diagram of the comparison of imaging results of different shapes of PET according to an embodiment of the present invention, wherein the parameters of the measured object and the detection module in each embodiment are consistent, and the upper left corner is the imaging result of a circular PET device. 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. The imaging result is compared with the imaging result in the upper left corner The quality has not decreased significantly; 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. The imaging result is the same as the imaging result in the upper left corner Although the specific quality has declined, it is still within an acceptable range, and the resolution of the simulated lesion is still clearly discernible, which proves that the PET device has a good effect in terms of imaging quality, system sensitivity and operability.

Fig. 19 is a schematic diagram showing the comparison of imaging parameters of PET with 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 restoration coefficient and the background variation rate, CRC represents the contrast restoration coefficient, and BV represents the background Mutation rate, circular black block corresponds to the relevant parameters of the circular PET device, triangular black block corresponds to the relevant parameters when the number of detectors is 3/4 of the circular PET, and the quadrilateral black block corresponds to the number of detectors 1/ of the circular PET The relevant parameters at time 2, as can be seen from Figure 19, when the number of detectors decreases, that is, when the PET device changes from circular to double-arc, both CRC and BV will decrease, but the background variation rate will only decrease by 4.5 % to 6.1%, while the contrast of the hot area (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 the lesion, and can take into account the openness, adjustability, sensitivity and response uniformity of the system.

The above are only preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Various changes can also be made to the above embodiments of the present invention. For example, according to the specific embodiments described above, those skilled in the art Technicians can also design the shape of the detection part as a plurality of circular arcs located on the same circumference, wherein at least two groups of circular arcs are in one-to-one correspondence. That is to say, all simple and equivalent changes and modifications made according to the claims and description of the application for the present invention fall within the protection scope of the claims of the patent of the present invention. What is not described in detail in the present invention is conventional technical content.

Claims (33)

1. A positron emission computed tomography device, characterized in that it comprises:

   The detection part, the detection part includes several detection modules, the detection surfaces of the detection modules are distributed along the first circumference, wherein the detection surfaces of at least two groups of the detection modules are arranged opposite and located on the second In the diameter direction of a circle, at least one opening is formed on the first circle; the detection surface of the detection part changes to be distributed along the second circle during detection, and the first circle and the first circle The diameters of the two circles are different.
2. The positron emission computed tomography apparatus according to claim 1, wherein there are two detection parts and two openings respectively, and the openings and the detection parts are arranged at intervals and together form the circumference.
3. The positron emission computed tomography apparatus according to claim 1, wherein there is one detection part and one opening respectively, and the openings and the detection part are arranged at intervals and jointly form the circumference.
4. The positron emission computed tomography apparatus according to claim 2 or 3, characterized in that, all the detection modules in the detection part are in one-to-one correspondence in the circumferential diameter direction.
5. The positron emission computed tomography apparatus according to claim 2 or 3, wherein a part of the detection modules in the detection part correspond to each other in the diameter direction of the circumference.
6. The positron emission computed tomography apparatus 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 computed tomography apparatus according to claim 2 or 3, characterized in that, after the detection part moves, the diameter of the first circle is larger than the diameter of the second circle.
8. The positron emission computed tomography apparatus according to claim 1, wherein after the detection part moves, the angle of the central angle corresponding to the opening remains unchanged, and the detection module in the detection part decrease in number.
9. The positron emission computed tomography apparatus according to claim 1, wherein after the detection part moves, the angle of the central angle corresponding to the opening remains unchanged, and the detection module in the detection part increase in number.
10. The positron emission computed tomography apparatus according to claim 1, wherein there are at least two openings and the detection part, and after the detection part moves, the number of the opening changes to one.
11. The positron emission computed tomography apparatus according to claim 1, wherein there are two openings before the movement, and the openings disappear after the detection part moves.
12. The positron emission computed tomography apparatus according to claim 1, wherein there is one opening, and after the detection part moves, the number of openings and the number of detection parts both change to two .
13. The positron emission computed tomography apparatus according to claim 1, wherein the at least one detection part rotates along the second circumference after the movement, and there are at least two groups of the detection modules after the rotation. The detection surfaces are still relatively arranged and located on the same straight line.
14. The positron emission computed tomography apparatus according to claim 13, characterized in that, the two detection parts rotate at the same angle at the same time.
15. A positron emission computed tomography device, characterized in that it comprises:

    At least one detection part, the detection part includes several detection modules, the detection surfaces of the detection modules are distributed along the same circumference, at least one opening is formed on the circumference, and at least one detection part is along the With the angular displacement of the circumference, the detection surfaces of at least two groups of the detection modules are arranged opposite to each other and located in the diameter direction of the circumference before and after the movement.
16. The positron emission computed tomography apparatus according to claim 15, characterized in that there are two detection parts, and the two detection parts simultaneously undergo the same angular displacement during detection.
17. The positron emission computed tomography apparatus according to claim 15, wherein there are two detection parts, and the angular displacements of the two detection parts are different during detection.
18. The positron emission computed tomography apparatus according to claim 15, characterized in that there are two detection parts, one of which is angularly displaced during detection.
19. The positron emission computed tomography apparatus according to claim 15, characterized in that, after the detection part moves, the number of the detection modules in one of the detection parts decreases.
20. The positron emission computed tomography apparatus according to claim 15, characterized in that, after the detection part moves, the number of the detection modules in one of the detection parts increases.
21. A positron emission computed tomography device, characterized in that it comprises:

    The detection part, the detection part includes several detection modules, the detection surfaces of the detection modules are distributed along the first circumference, and the detection surfaces of the detection modules are arranged opposite and located in the diameter direction of the first circumference Above; the detection surface of the detection part changes in motion during detection so as to be distributed along the second circumference and form at least one opening.
22. The positron emission computed tomography apparatus according to claim 21, wherein the detection part is split into at least two parts opposite to each other after being moved, and the opening and the detection part are jointly along the Second circular distribution.
23. The positron emission computed tomography apparatus according to claim 21, wherein a part of the detection part is still arranged opposite to each other after moving, and the opening and the detection part are jointly along the second Circumferential distribution.
24. A method for positron emission computed tomography, characterized in that it at least comprises the following steps:

    Step S1: Using a PET device for imaging, the PET device includes several detection modules and at least one opening, the detection surface of the detection module and the opening are distributed along the first circumference, wherein at least two groups of detection modules The detection surfaces are arranged opposite and located in the diameter direction of the first circumference;

    Step S2: changing the shape of the PET device in the step S1 so that the detection surface of the detection module is relatively arranged along the second circumference;

    Step S3: Imaging with the PET device that has passed through the step S2.
25. The positron emission computed tomography method according to claim 24, characterized in that, in the step S2, changing the shape of the PET device includes moving a part of the detection module along the first circumference or The second circle rotates.
26. The positron emission computed tomography method according to claim 24, wherein the detection module calibration is performed before the step S1 or the step S3.
27. The positron emission computed tomography method according to claim 24, characterized in that, in the step S2, the PET devices distributed along the second circumference have no opening or have at least one opening.
28. The positron emission computed tomography method according to claim 24, characterized in that, in the step S2, the shape change of the PET device is realized by a driving device and/or increasing or decreasing the number of the detection modules.
29. A method for positron emission computed tomography, characterized in that it at least comprises the following steps:

    Step S1: Using a PET device for imaging, the PET device includes several detection modules, the detection surfaces of the detection modules are distributed along the first circumference, and the detection surfaces of the detection modules are arranged opposite and located at in the diameter direction of the first circumference;

    Step S2: changing the shape of the PET device in the step S1 so that there is an opening between the detection surfaces of the detection module, and the opening and the detection surface are arranged opposite to each other along the second circumference;

    Step S3: Imaging with the PET device that has passed through the step S2.
30. The positron emission computed tomography method according to claim 29, wherein in the step S2, changing the shape of the PET device includes moving a part of the detection module along the first circumference or The second circumferential direction rotates.
31. The positron emission computed tomography method according to claim 29, characterized in that, before the step S1 or the step S3, the detection module calibration is performed.
32. The positron emission computed tomography method according to claim 29, characterized in that, in the step S2, the PET devices distributed along the second circumference have no opening or have at least one opening.
33. The positron emission computed tomography method according to claim 29, characterized in that, in the step S2, the shape change of the PET device is realized by a driving device and/or increasing or decreasing the number of the detection modules.

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