SPECT multi-pinhole collimator, combined collimator and detection device
By designing a SPECT multi-pinhole collimator with a single pinhole and multi-pinhole collimator module, combining programming operations and guide structure, the cumbersome problems of collimator replacement and adjustment in SPECT detection in small animals are solved, and the operation is simplified and cost reduction is achieved.
Patent Information
- Application Number
- CN202421198943.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-29
- Publication Date
- 2025-06-03
- Estimated Expiration
- 2034-05-29
AI Technical Summary
SPECT detection in small animals requires frequent replacement and adjustment of collimator, which leads to cumbersome operation and high cost, and the existing technology is difficult to effectively solve this problem.
A SPECT multi-pinhole collimator is designed, including a single-pinhole collimator module and at least two multi-pinhole collimator modules. The coordination detection of different collimators is achieved through programming operations, and a combined structure of transverse guide rails and threaded screws is adopted to realize the synchronous movement of the collimator and the detector.
It realizes simplification of operation of replacing the collimator and adjusting the detection distance, reduces equipment costs, and can detect and collect four types of image data at one time, providing comprehensive data support.
Smart Images
Figure CN222929771U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of SPECT multi-pinhole collimators, and specifically relates to an SPECT multi-pinhole collimator, a combined collimator and a detection device. Background Technique
[0002] SPECT (Single-Photon Emission Computed Tomography) is one of the two ECT (Emission Computed Tomography) techniques in nuclear medicine imaging. It uses a radioactive drug that emits only a single photon per decay for tomographic imaging, and reflects the functions, metabolism and physiological conditions in the organism by showing the distribution of the drug in the organism. Compared with PET, SPECT has both advantages and disadvantages. Generally speaking, it is one of the relatively important nuclear medicine imaging detection methods at present and is widely used in clinical detection.
[0003] In addition to being used clinically, SPECT is currently very common in small animal drug research. Due to the improvement of the safety margin, more radiation / irradiation can be tolerated in small animal research than in human medicine, and SPECT is less restricted in small animal drug research. Therefore, small animal SPECT is widely used in the research of new drugs clinically and is often used for the detection and research of experimental animals. Since the photons emitted by the drug in the organism are isotropic, a collimator is needed to restrict the direction of the photons incident on the detector, and the performance of the collimator directly determines the quality of the finally obtained image. In the prior art, the collimator of a small animal SPECT device uses the magnification effect of pinhole imaging combined with a large detector area to achieve the purpose of high resolution, which is a common type of collimator configuration.
[0004] However, different from human body detection, the detectors and collimators for human body detection are generally relatively fixed after debugging. The detector collects data in a relatively fixed manner for medical analysis. For example, each time, it is only necessary to collect data for one of the patient's chest, abdomen, and head. The collection method is relatively fixed, and the collimator generally does not need to be replaced or moved (its position is fixed relative to the detector). For experimental small animals, the requirements for collecting SPECT data are more flexible. For example, the small animal (mouse) detected this time, and the next detected animal is much larger (such as a rabbit). Or although the detection is aimed at the animal's liver, for research purposes, it is also desired to see the whole body image of the animal. Or more generally, for imaging of the liver region, it is hoped to have image results with different resolutions to select the most suitable one for subsequent analysis and processing. Subsequently, when different conditions are met, appropriate resolution images can be selected according to the requirements for research or analysis. Due to the flexibility of small animal drug research, it is often necessary to cooperate with different collimators to detect and obtain data. However, changing the collimator each time is very troublesome and laborious because replacing the collimator also requires adjusting the distance (FOV). The frequent need to cooperate with different collimators for small animal SPECT detection and the cumbersome operation of replacing the collimator are obvious contradictions. There are few technical solutions to solve such problems in the prior art. If different multiple devices are used to solve it, although it is simple, the equipment cost increases significantly, and the technical solution is very uneconomical. Summary of the Invention
[0005] The purpose of the present invention is to provide a device, which mainly solves the problem that the frequent need to cooperate with different collimators for small animal SPECT detection and the cumbersome operation of replacing the collimator are obvious contradictions. This method is unique to this application and there is no inspiration from the prior art. With the careful design of the device, the operation method of this application is simple and convenient, and the cost is low. Moreover, the cooperative detection with different collimators can be realized through programming operations, and the accessory cost is not high. At most, for one small animal / small animal region of interest, the replacement detection imaging of a single pinhole and three multi-pinhole collimators can be realized, and four kinds of image data can be collected in one detection, providing simple but comprehensive data support for subsequent analysis and research.
[0006] To achieve the above object, the present invention provides the following technical solution: A SPECT multi-pinhole collimator, characterized in that: it includes a single pinhole collimator module and at least two multi-pinhole collimator modules; the single pinhole collimator module and the at least two multi-pinhole collimator modules are integrally made on a substrate, or are embedded and fixed side by side on a frame substrate.
[0007] Further, the SPECT multi-pinhole collimator includes a single-pinhole collimator module and 2-3 multi-pinhole collimator modules; the magnification factors and FOVs of each multi-pinhole collimator module are all different from each other.
[0008] Further, the fact that the FOVs are all different from each other means that at least one of the theoretical axial FOV and the theoretical radial FOV is different from each other.
[0009] A SPECT multi-pinhole combined collimator, characterized in that: it includes two SPECT multi-pinhole collimators as described above that are arranged in parallel and opposite to each other.
[0010] Further, the two SPECT multi-pinhole collimators are respectively installed on a transverse guide rail that can make the SPECT multi-pinhole collimator move horizontally; each transverse guide rail is installed on a combination of a threaded lead screw and a guide rail, and under the control of the rotation of the threaded lead screw, the SPECT multi-pinhole collimator approaches or moves away from the detection position.
[0011] A SPECT detection device, characterized in that: it also has two opposed detectors, each detector is fixed in a detector frame, which includes the SPECT multi-pinhole combined collimator as described above, and the two transverse guide rails are respectively fixed on the inner sides of the two detector frames.
[0012] Each detector and the SPECT multi-pinhole collimator on the same side approach or move away from the detection position together under the control of the rotation of the threaded lead screw.
[0013] Further, the threaded lead screw is a left-right bidirectional lead screw, and the rotation of the threaded lead screw drives the opposed detector pair and collimator pair to move synchronously towards each other.
[0014] Further, the inner embedded shape of each pinhole of the single-pinhole collimator module and the multi-pinhole collimator is in the shape of a frustum of a pyramid, and the through-hole shape of each pinhole is circular, square or rectangular.
[0015] One proximity sensor is installed on each of the two SPECT multi-pinhole collimators arranged in parallel and opposite to each other and facing inwards.
[0016] Compared with the prior art, the present application has many non-obvious advantages: First, it avoids the situation that the collimator part / detector part / overall device needs to be disassembled or replaced every time the collimator is changed. Only lateral translation and position adjustment are needed to achieve the replacement of the collimator and imaging; Second, it is very easy to adjust from the structural setting. First, the collimator is an integrated lateral plate combination, or is arranged horizontally and embedded in the frame to form a plate combination, and then the plate combination is fixed on the detector frame with a lateral guide rail. In this way, as long as the detector frame is driven by the lead screw to move in the Z-axis direction, the detector can move with the collimator, which is an effective measure to ensure detection. Then, using different collimators means that the FOV is different (generally different in radial and circumferential directions). At this time, the appropriate detection distance can be adjusted by the rotation of the lead screw. This adjustment can be driven by a preset program to accurately move and execute. Third, the use and switching of different collimators is easy to operate. You only need to move the lateral guide rail, and then fine-tune the lead screw according to the preset OFV corresponding distance to make it meet the predetermined detection distance of the current collimator, and then detection can be carried out. Moreover, the fourth advantage is that this operation is perfectly adapted to programmed automatic control. For example, according to the control distance of the lead screw and the transverse guide rail measured in advance, it is programmed to automatically shoot according to the single pinhole collimator - the first multi-pinhole collimator - the second multi-pinhole collimator - the third multi-pinhole collimator, all automatically completed. Fourth, the multi-pinhole collimator generally has three pinholes, each pinhole is embedded in a quadrangular pyramid shape, and the through hole shape of each pinhole is circular or square, rectangular. This setting has outstanding advantages over the prior art. Compared with a simple square hole or circular hole in the prior art, it can effectively reduce image overlap and the influence of cone artifacts, improve imaging quality, and according to the optical path design, the quadrangular prism design does not block rays. Fifth, it can also be convenient to adjust the adaptation FOV. Under the premise that the cross-section of the square cone hole is a rectangle, the axial FOV direction is the longer side, which can increase the axial FOV. Conversely, the radial side is the longer side, which can increase the radial FOV. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 Schematic diagram of the SPECT detection device.
[0018] Figure 2 Schematic diagram of the detector composition.
[0019] Figure 3 This is a single pinhole collimator style diagram.
[0020] Figure 4 This is a multi-pinhole collimator style diagram.
[0021] Figure 5 Schematic diagram of the detection device's shape changes to cope with four different collection positions.
[0022] Figure 6 It is a schematic diagram of the multi-pinhole imaging principle.
[0023] Reference numerals: 1, combined collimator; 2, detector; 21, detector frame; 22, crystal; 23, light guide; 24, FEE board / SiPM array board; 31, transverse guide rail; 32, rigid coupling; 33, servo motor bracket; 34, second ball screw support; 35, second ball screw; 36, second rigid coupling; 37, second servo motor; 38, fixing ring; 39, microswitch; 40, vertical guide rail; 41, left-right threaded screw. 51, hole 1; 52, hole 2; 53, hole 3; 54, actual detector area, 55, theoretical detector area. Detailed implementation manners
[0024] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.
[0025] Embodiment 1
[0026] A SPECT multi-pinhole collimator, characterized in that: it includes a single-pinhole collimator module and at least two multi-pinhole collimator modules. Common examples here are a single-pinhole collimator and three multi-pinhole collimators. A plurality of multi-pinhole collimators are very necessary. In many cases, especially during the experimental stage, it is not easy for mice to determine whether they only care about a certain organ, a certain area of a certain organ, or also care about the areas of adjacent organs. Therefore, it is very necessary to continuously sample with different multi-pinhole collimators. Continuous sampling can also better ensure that the situation during sampling is basically the same. If the collimator is replaced and then detected, it is not only troublesome but also takes too long, and the state of the experimental animals cannot be guaranteed.
[0027] The parameters of the single-pinhole collimator are, for example: magnification: M = 0.833, opening angle: 90.6°, hole (through hole) diameter: 2.5 mm, theoretical axial FOV: 121.2 mm, theoretical radial FOV: 121.2 mm.
[0028] The parameters of the multi-pinhole collimator are, for example: magnification: M = 0.833, radial central opening angle: 53.1°, radial two-side opening angles: 46.1°, axial opening angle: 90.6°, hole diameters: 0.5, 1, 1.5 mm, theoretical axial FOV: 121.2 mm, theoretical radial FOV: 60 mm. This collimator configuration is suitable for imaging rats (120*60), for example.
[0029] The parameters of the multi-pinhole collimator are, for example: magnification: M = 1.25, radial central opening angle: 53.1°, radial side opening angles: 43.2°, axial opening angle: 90.6°, aperture: 0.5, 1, 1.5 mm, theoretical axial FOV: 80.8 mm, theoretical radial FOV: 40 mm. This collimator configuration is, for example, suitable for mouse (80*40) imaging.
[0030] The parameters of the multi-pinhole collimator are, for example: magnification: M = 1.67, radial central opening angle: 53.1°, radial side opening angles: 41°, axial opening angle: 90.6°, aperture: 0.5, 1, 1.5 mm, theoretical axial FOV: 60.6 mm, theoretical radial FOV: 30 mm. This collimator configuration is, for example, suitable for mouse (60*30) imaging. It should be noted that the concept of this application does not limit the specifications of the collimator. The above example configuration is just a set of usable configuration values, and it does not mean that the collimator must be arranged in the above configuration. The collimator can, for example, be configured according to axial opening angles of 87.5°, 90°, 92.5°, and 85°. The collimators in these configurations can also complete sampling of different specifications of mice.
[0031] A single-pinhole collimator module and at least two multi-pinhole collimator modules are integrally fabricated on a substrate, or are embedded and fixed side by side on a frame substrate. Both of these methods can be adopted, each having its own advantages and disadvantages. The former is more stable in use and more reassuring for lateral movement, but the disadvantage is that it cannot be adjusted or replaced. The latter can easily adjust and replace one or more collimators, but its fixed fit is not as firm as the former, and more considerations need to be given to the fixing means.
[0032] The SPECT multi-pinhole collimator includes a single-pinhole collimator module and 2 - 3 multi-pinhole collimator modules.
[0033] The magnification and FOV of each multi-pinhole collimator module are all different from each other. Basically, for the purpose of obtaining different images, there is no need to set the same multi-pinhole collimator. Of course, two of them can be the same, and data can be collected using one of them.
[0034] That the FOVs are all different from each other means that at least one of the theoretical axial FOV and the theoretical radial FOV is different from each other. A more preferred way is that the radial and axial FOVs of multiple multi-pinholes are all different from each other, but it is also possible that some remain unchanged, for example, the theoretical axial FOV remains basically unchanged or changes little.
[0035] Example 2
[0036] A SPECT multi-pinhole combined collimator, characterized in that: it includes two SPECT multi-pinhole collimators as described in Embodiment 1 that are arranged in parallel and opposite to each other. In this application, two opposite collimators are used, and the two collimators are mirror-symmetrical. In this way, the detectors on both sides can be detected simultaneously as long as a mirror operation is performed.
[0037] Both of the two SPECT multi-pinhole collimators are respectively installed on a transverse guide rail that can make the SPECT multi-pinhole collimator move horizontally; the transverse guide rail is, for example, a double guide rail in the front and back, so as to ensure the stability of movement and fixation.
[0038] Each transverse guide rail is installed on a combination of a threaded lead screw and a guide rail, and under the control of the rotation of the threaded lead screw, the SPECT multi-pinhole collimator is brought closer to or away from the detection position. The threaded lead screw is, for example, two lead screws with a mirror-image spiral pattern up and down, which can achieve opposite movement, or it is a single lead screw with opposite threads up and down, and the midpoint / midline corresponds to the center position of the detected animal / detection imaging hole (circular or square). In this way, the rotation of one lead screw can achieve the opposite approach or separation of the two collimators.
[0039] Embodiment 3
[0040] A SPECT detection device, characterized in that: it further includes two opposite detectors, each detector is fixed in a detector frame, which includes the SPECT multi-pinhole combined collimator of Embodiment 2, and the two transverse guide rails are respectively fixed to the inner sides of the two detector frames. Here, the inner side refers to the side close to the detected animal / detection position / imaging hole. Such a setting can ensure a fixed distance between the collimator and the detector, and the detector and the collimator can also be adjusted together in the radial distance (distance from the detection center) to adapt to different detection conditions.
[0041] The two detectors are similarly (mirror-image) installed on a combination of a threaded lead screw and a guide rail, and each detector and the SPECT multi-pinhole collimator on the same side are brought closer to or away from the detection position under the control of the rotation of the threaded lead screw.
[0042] The threaded lead screw is a left-right bidirectional lead screw (the threads are opposite from the midpoint upward and downward), and the rotation of the threaded lead screw drives the opposite detector pair and collimator pair to move synchronously in opposite directions. In this way, when the lead screw rotates left and right, the upper and lower detector pairs and collimator pairs will approach or move away from each other in opposite directions, rather than moving in the same direction.
[0043] The inner-embedded shape of each pinhole of the single-pinhole collimator module and the multi-pinhole collimator is in the shape of a frustum of a pyramid (it can also be a similar shape, such as a frustum of a cone, but the frustum of a pyramid shape does not affect the optical path, is easy to process, and is also easy to measure). The through-hole shape of each pinhole is circular, square, or rectangular. The large base (square cross-section) of the frustum of the pyramid is on the side close to the detection center, the small base is on the side far from the detection center, and the through-hole is located on the small base. The frustum of the pyramid shape is generally a hollow shape.
[0044] Each of the two SPECT multi-pinhole collimators arranged in parallel and opposed is provided with a proximity sensor arranged inward. Since the lateral direction of the collimator combination may be very long, this proximity sensor can be two or more. Its function is to prevent the collimators from getting too close to each other in the middle, for example, colliding with an animal or other components.
[0045] For example, as Figure 1 shown in the combined collimator, it can be seen that there is one detector at each of the upper and lower parts. The detector is housed in a cuboid-shaped frame. A transverse guide rail is fixed inside the detector frame. The combined collimator is fixed on the transverse guide rail. The combined collimator can move left and right to adapt different collimators (holes) to the detector. The left and right movement of the combined collimator is driven by a second servo motor, for example. When applying different collimators, the applicable distances are often different, and the distance between the collimator and the detection position needs to be adjusted. At this time, the main servo motor drives the left and right bidirectional lead screw to simultaneously move the two detectors and the collimator closer / farther away.
[0046] As Figure 2 shown, the detector is a three-layer structure. Typically, for example, it is composed of a crystal, a light guide layer, and a PMT layer, or for example, it is composed of a crystal layer, a light guide layer, and an FEE (array SiPM layer). The crystal can be a common crystal used in SPECT, for example.
[0047] As Figure 3 shown, it is a single-hole collimator. As Figure 4 shown, from top to bottom are the first, second, and third multi-hole collimators respectively. The parameters of typical collimators can be the parameters in Embodiment 1, or other different valid parameters, as long as the parameter sets that can enable the collimator to work properly are acceptable. The values in Embodiment 1 should not be regarded as a limitation to the application.
[0048] As Figure 5What is shown is a specific diagram of a single pinhole collimator and three multi-pinhole collimators being in the detection state. The distance between the collimators on both sides is also different, because the FOV of different collimators may be different. For example, the single pinhole acquisition position has an effective aperture of 112mm and a radial FOV of 121.2mm. The multi-pinhole acquisition position has an effective aperture of 112mm and a radial FOV of 60mm. The multi-pinhole acquisition position has an effective aperture of 72mm and a radial FOV of 40mm. The multi-pinhole acquisition position has an effective aperture of 52mm and a radial FOV of 30mm. The FOV etc. here are specifically implementable, and the numerical values should not be considered as limitations on the application.
[0049] from Figure 6 It can be seen that the advantages of this application are that the pinhole collimator adopts a square cone hole design, which can reduce image overlap and the influence of cone artifacts and improve imaging quality. The cross-section of the square cone hole is a rectangle, and the axial FOV direction is the longer side, which can increase the axial FOV (square, for example, refers to a quadrangular prism). For the outermost two holes of the three pinholes (such as hole 1 and hole 3), the actual imaging area is half of the theoretical imaging area. The imaging area of the middle hole is increased at the same position, thereby increasing the magnification.
[0050] Description of how to implement: A SPECT imaging method is used to implement detection using a SPECT detection device, which is characterized by: (1) Debugging step: By controlling the rotation of the threaded screw, each detector on the upper and lower sides is controlled to move closer to or farther away from the detection position together with the SPECT multi-pinhole collimator on the same side under the control of the rotation of the threaded screw, and the test is carried out, and the two SPECT multi-pinhole collimators are controlled to move left and right on the transverse guide rail so that each collimator on them is located at the detection position at least once; debugging is completed.
[0051] (2) Test steps: After debugging, place the test object or calibration object at the test position and perform the following test: move the single pinhole collimator horizontally to align with the detector, adjust it according to its preset FOV, control the rotation of the lead screw, adjust the distance between the current collimator and the test position to the preset distance, and perform the test; repeat the above steps for the other three collimators in the order of left and right adjacent, and complete the test in sequence.
[0052] Description of how to implement: A SPECT imaging method is used to implement detection using a SPECT detection device, which is characterized by: (1) Debugging step: By controlling the rotation of the threaded screw, each detector on the upper and lower sides is controlled to move closer to or farther away from the detection position together with the SPECT multi-pinhole collimator on the same side under the control of the rotation of the threaded screw, and the test is carried out, and the two SPECT multi-pinhole collimators are controlled to move left and right on the transverse guide rail so that each collimator on them is located at the detection position at least once; debugging is completed.
[0053] (2) Test steps: After debugging, place the test object or calibration object at the detection position and perform the following detections: Randomly select a collimator and move it horizontally to align with the detector. Adjust it according to its preset FOV, control the rotation of the lead screw, and adjust the distance between the current collimator and the detection position to the preset distance for detection; Repeat the above steps for the other three collimators in random order to complete the detections in sequence.
[0054] The above are only the embodiments of the present invention, and common knowledge such as the specific structures and characteristics known in the solutions is not described in detail here. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claims involved.
Claims
1. A SPECT multi-pinhole collimator, characterized in that: including a single pinhole collimator module and at least two multi-pinhole collimator modules; The single pinhole collimator module and the at least two multi-pinhole collimator modules are integrally manufactured on a substrate, or are embedded and fixed in parallel on a frame substrate.
2. A SPECT multi-pinhole collimator according to claim 1, characterized in that: The SPECT multi-pinhole collimator includes a single pinhole collimator module and 2-3 multi-pinhole collimator modules; The magnification and FOV of each multi-pinhole collimator module are different from each other.
3. A SPECT multi-pinhole collimator as claimed in claim 2, characterized in that: The FOVs are different in pairs, which means that at least one of the theoretical axial FOV and the theoretical radial FOV is different in pairs.
4. A SPECT multi-pinhole combined collimator, characterized in that: The method comprises two parallel and opposing SPECT multi-pinhole collimators as claimed in any one of claims 1 to 3.
5. A SPECT multi-pinhole combined collimator as claimed in claim 4, characterized in that: The two SPECT multi-pinhole collimators are respectively mounted on transverse guide rails capable of causing the SPECT multi-pinhole collimators to move transversely; Each transverse guide rail is mounted on a combination of a threaded lead screw and the guide rail, and the SPECT multi-pinhole collimator is moved close to or away from a detection position under the rotation control of the threaded lead screw.
6. A SPECT detection device, characterized in that: Also provided are two opposing detectors, each detector being fixed in a detector frame, which comprises the SPECT multi-pinhole combination collimator as claimed in claim 5, and two transverse guide rails being fixed on the inner sides of the two detector frames respectively; Each detector, together with the SPECT multi-pinhole collimator on the same side, is moved closer to or farther from the detection position under the rotation control of the threaded lead screw.
7. A SPECT detection device as claimed in claim 6, characterized in that: The threaded screw is a left-right bidirectional screw, and the rotation of the threaded screw drives the opposite detector pair and collimator pair to move synchronously in opposite directions.
8. A SPECT detection device according to claim 6 or 7, characterized in that: The embedded shape of each pinhole of the single pinhole collimator module and the multi-pinhole collimator is a quadrangular pyramid shape, and the through hole shape of each pinhole is circular, square or rectangular; Each of the two parallel and opposing SPECT multi-pinhole collimators is equipped with an inwardly arranged proximity sensor.