Variable FOV four-probe SPECT detector and detection method

Abstract

A variable FOV four-probe SPECT detector comprises a detector part group (1) and a supporting device (2). The detector part group comprises four detector parts (11), and the supporting device is composed of a rotating device (21) and four connecting rods (22); one ends of the four connecting rods are rotatably connected with the side surface of the detector through pivots, and the other ends of the four connecting rods are rotatably connected with different positions of the side surface of the rotating device through pivots (23); each detector part is provided with a detector plate (111), a detector (112) and a guide rail (113); each detector plate has at least one recess (114) cooperating with another detector portion. The detector group is switched between two different forms of FOV, wherein the FOV in one form is larger than the FOV in the other form. The detector is used for executing a variable FOV four-probe SPECT detection method.

Description

Technical Field

[0001] The present invention relates to the technical field of SPECT devices with adjustable FOV, and in particular to a variable FOV four-probe SPECT detector and a detection method. Background Art

[0002] SPECT (Single-Photon Emission Computed Tomography) is one of the two ECT (Emission Computed Tomography) techniques used in nuclear medicine. It uses radioactive drugs that emit only a single photon per decay to perform tomographic imaging. By showing the distribution of the drug within a living organism, SPECT reflects the body's function, metabolism, and physiological status. Compared to PET, SPECT has both advantages and disadvantages. Overall, it is one of the more important nuclear medicine imaging methods and is widely used in clinical testing.

[0003] In addition to its clinical applications, SPECT is currently widely used in small animal drug research. Due to its increased safety margin, small animals can withstand greater radiation exposure than humans, making its use in small animal drug research less restrictive. Consequently, small animal SPECT is widely used in the research of novel drugs and is frequently used for testing and studying laboratory animals (particularly mice of varying sizes).

[0004] However, unlike human imaging, the detectors and collimators used in human imaging are typically fixed after debugging. The examiner collects data in a relatively fixed manner for medical analysis. For example, data can be collected from only one of the patient's chest, abdomen, or head. The acquisition method is relatively fixed, and the detector collimator generally does not need to be replaced or moved, or may only move between fixed A / B positions. However, the requirements for acquiring SPECT data for small animal experiments are more flexible. For example, one acquisition may involve a small animal (a mouse) while the next acquisition may involve a much larger animal (a rat). Alternatively, while imaging the animal's liver, research may also require full-body images. More commonly, imaging the liver region requires images at different resolutions to select the most appropriate for subsequent analysis and processing. Subsequently, the appropriate resolution can be selected for research or analysis based on the specific conditions. Due to the flexibility of small animal drug research, not only full-body data is required, but also data from specific areas or higher resolution data is often needed to better analyze drug conditions.

[0005] Taking specific detection as an example, sometimes a 60*60mm FOV (cube field of view) between detectors is sufficient, but sometimes a clearer image is needed, or for example, the experimental mice are smaller, so it is hoped to obtain data with a 40*40mm or even smaller 30*30mm FOV.

[0006] However, current SPECT technology does not have such a configuration on a single machine, that is, the detector is made variable in a specific way, and the same set of detector boards can provide several detection modes with different FOVs. In the existing technology, if different FOVs are needed for experimental animals (the same or different animals), different SPECT devices are generally used, such as an 80*80mm, a 60*60mm, and a 40*40mm device, to obtain images based on the size of the experimental animal and the required resolution (whole body or focus on specific organs). Summary of the Invention

[0007] The purpose of the present invention is to provide a device that primarily addresses the practical need for small animal spectroscopy (SPECT) imaging, which often requires images of varying resolutions to better analyze the test results. While existing technologies typically address this need for varying FOVs using two or more devices, we attempt to address this issue with a single SPECT. Specifically, we provide a variable support mechanism for the detector slice, enabling it to switch between larger and smaller resolutions, achieving the function of two devices with a single device. Through sophisticated design, this application achieves the functionality of two devices with a single device. Furthermore, the sophisticated support structure prevents damage to the detector during adjustment.

[0008] To achieve the above-mentioned object, the present invention provides the following technical solution: a variable FOV four-probe SPECT detector, characterized in that it comprises a detector assembly and a supporting device.

[0009] The detector part group includes four detector parts, and the supporting device consists of a rotating device and four connecting rods.

[0010] One end of the four connecting rods is rotatably connected to the side of the detector, and the other ends of the four connecting rods are rotatably connected to the side of the rotating device at different positions.

[0011] Each detector part comprises a detector plate, a detector and a guide rail; the detector is fixed to the end of the corresponding detector plate, and the detector plate is clamped into the guide rail and can reciprocate on the guide rail.

[0012] Each detector plate has at least one recess that mates with another detector portion.

[0013] When the rotating device rotates, the position of the detector part is driven to change through the connecting rod, and the detector part group switches between two different forms of FOV, wherein the FOV of one form is larger than the FOV of the other form.

[0014] Furthermore, the support device is fixedly supported, and the rotating device is annular in shape when viewed from the side and can rotate about its center in a plane perpendicular to the multiple detectors. The four connecting rods' pivotal connections on the rotating device are evenly distributed on the rotating device when viewed from the side. The detectors include a scintillation crystal layer, a photoelectric converter layer, a signal processing circuit, and a collimator; the signal processing circuit's wiring is led out from the detector board.

[0015] A variable FOV four-probe SPECT detection method is implemented using the above variable FOV four-probe SPECT detector.

[0016] The method is implemented in the following steps: 1) The detector assembly is placed in an initial state with a large FOV; a power-on test is performed, and SPECT detection is performed on the detection object, collecting detection data; 2) After the detection in step 1 is completed, the detection object is removed and replaced with another detection object, or the detection object remains unchanged. The rotating device rotates counterclockwise or clockwise, driving each detector unit along a curve and retracting via a connecting rod, changing the detector assembly to a small FOV configuration. At least a portion of each detector unit mates with a recessed portion on an adjacent detector unit, and detection is performed again. Furthermore, in the small FOV configuration, only the received signals of a portion of the detection units on each detector are collected and transmitted to generate an image.

[0017] A variable FOV four-probe SPECT detection method is implemented using the above variable FOV four-probe SPECT detector.

[0018] The method is implemented in the following steps: 1) The detector assembly is placed in an initial state with a small FOV, with at least a portion of each detector unit mating with a recess on an adjacent detector unit; a power-on test is performed, and SPECT detection is performed on the test object, collecting detection data; 2) After the detection in step 1 is completed, the test object is removed and replaced with another one, or the test object remains unchanged. The rotating device rotates counterclockwise or clockwise, driving each detector unit along a curve and outward through a connecting rod, changing the detector assembly to a large FOV configuration, and performing detection again. Furthermore, in the small FOV configuration, only the received signals of a portion of the detection units on each detector are collected and transmitted to generate an image.

[0019] A variable FOV four-probe SPECT detector is characterized by comprising a detector assembly and a supporting device.

[0020] The detector assembly includes four detector parts, and the supporting device consists of a rotating device, four cross bars and a limiting plate.

[0021] One end of the four cross bars is fixedly connected to the detector side, and the other ends of the four cross bars are fixedly connected to different positions of the side surface of the rotating device. The four cross bars are perpendicular to the side surface of the detector to which they are connected, and the four cross bars are all perpendicular to the side surface of the rotating device; the four cross bars pass through the four arc grooves on the limit plate respectively.

[0022] Each detector part comprises a detector plate, a detector and a guide rail; the detector is fixed to the end of the corresponding detector plate, and the detector plate is clamped into the guide rail and can reciprocate on the guide rail.

[0023] Each detector plate has at least one recess that mates with another detector portion.

[0024] When the rotating device rotates, the position of the detector part is driven to change through the cross bar, and the detector part group switches between two different forms of FOV, wherein the FOV of one form is larger than the FOV of the other form.

[0025] Furthermore, the support device is supported and fixed, and the rotating device can rotate around the center in a plane perpendicular to the multiple detectors. The limit plate is fixed separately, and the four arc-shaped grooves on the limit plate correspond to the large FOV position and the small FOV position at both ends respectively.

[0026] The connection positions of the four cross bars on the rotating device are evenly distributed on the rotating device when viewed from the side.

[0027] The detector includes a scintillation crystal layer, a photoelectric converter layer, a signal processing circuit and a collimator; the circuit of the signal processing circuit is led out from the detector board.

[0028] A variable FOV four-probe SPECT detection method is implemented using the above variable FOV four-probe SPECT detector.

[0029] The method is implemented in the following steps: 1) The detector assembly is placed in an initial state with a large FOV; a power-on test is performed, and SPECT detection is performed on the detection object, collecting detection data; 2) After the detection in step 1 is completed, the detection object is removed and replaced with another detection object, or the detection object remains unchanged. The rotating device rotates counterclockwise or clockwise, driving each detector unit along the curved arc groove to move inward via the crossbar, changing the detector assembly to a small FOV configuration. At least a portion of each detector unit mates with the recessed portion of an adjacent detector unit, and detection is performed again. Furthermore, in the small FOV configuration, only the received signals of a portion of the detection units on each detector are collected and transmitted to generate an image.

[0030] A variable FOV four-probe SPECT detection method is implemented using the above variable FOV four-probe SPECT detector.

[0031] The method is implemented in the following steps: 1) The detector assembly is placed in an initial state with a small FOV, with at least a portion of each detector assembly aligned with a recess on an adjacent detector assembly; a power-on test is performed, and SPECT detection is performed on the test object, collecting detection data; 2) After the detection in step 1 is completed, the test object is removed and replaced with another one, or the test object remains unchanged. The rotating device rotates counterclockwise or clockwise, driving each detector assembly along the curved arc groove through the crossbar, causing the detector assembly to change to a large FOV configuration, and detection is repeated. Furthermore, in the small FOV configuration, only the received signals of a portion of the detection units on each detector are collected and transmitted to generate an image.

[0032] The above are two device compositions and implementation methods of this application, each with similar principles but slightly different actual implementations. The principles are similar in that "each detector plate has at least one recess that mates with another detector portion," and the rotational inward-retraction method allows the already compact SPECT four-sided detector to be further retracted, forming a smaller FOV. This configuration is unique to this application and is not inspired by prior art. This is based on three premises: first, each detector plate supporting the detector is inherently inclined; second, this further retraction is a rotational inward retraction, rather than a direct inward squeeze of the four sides; and third, each detector plate leaves a portion of space for one or two adjacent detector portions. These two and three methods work together to make this retraction possible. A second feature is that a more practical implementation method is provided through two methods: one in which a rotating device drives the connecting rod connected by the two pivots to retract / pull inward / outward; the other in which a crossbar is used to connect the rotating device to achieve retraction / pull outward. However, for the proper and safe position conversion, a limit plate is provided. These two settings have been proven to be more reliable and easier to use, with a lower risk of damaging the equipment.

[0033] What is significantly different from the prior art is that there are SPECTs with adjustable FOV in the prior art, but that generally adopts a method of common inward retraction along the normal, that is, the detectors on all four sides are retracted and pulled outward to achieve FOVs of different sizes. However, this method is completely different from the present application. Its typical disadvantage is that if the inward FOV is relatively compact, then conversely, when it is in a larger FOV state, the detectors are not tightly surrounded. Although the FOV is relatively large, the edge resolution is low, and the signal in the peripheral area of the detection is not very clear, and the results are not very reliable. For example, if this simple outward pull is very tight when the FOV is 40*40cm, then when it is 60*60cm, the distance between the detectors is larger. At this time, for example, the corners of the two detector plates have a distance of 10*1.414=14.14cm. If it is further pulled out, for example to 80*80cm, the distance is even larger.

[0034] The present application is different from this. First, it is very compact in the 40*40cm state. After switching to 20*20cm, it is also very compact. At this time, for the detector part that does not actually collect signals, it is possible to further save system energy by not collecting / collecting / transmitting its signals. It is clear that in the state of small FOV, some detection units on the left / right side of the detector do not actually collect signals, or cannot collect meaningful signals.

[0035] Compared to the prior art, this application offers numerous non-obvious advantages: First, it eliminates the need for separate SPECT instruments to switch between different fields of view, saving costs. Second, compared to the simple inward and outward FOV adjustment method, the present application's setup provides better image quality assurance. The simple inward and outward FOV adjustment method, however, lacks image quality assurance in large FOV modes, particularly at the edges of the image. In contrast, the present application's detectors are tightly integrated, ensuring image quality in both large and small FOV modes. Third, through a unique implementation method, where "each detector plate has at least one recess that mates with another detector portion," and a rotational inward-inward coupling mechanism, the already compact SPECT four-sided detector can be further retracted, resulting in a smaller FOV configuration. Both configurations are very compact, ensuring image quality. Fourth, it conserves system resources by pre-determining which detector units will not be able to capture valid data in a small FOV state and eliminating them during the acquisition phase, saving computing and power resources. Fifth, for a detection object, two images with different FOVs (with improved resolution) can be given on a SPECT without changing or taking it, saving time and efficiency, and the results can also be compared and analyzed. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1This is a schematic diagram of the first form of the variable FOV four-probe device.

[0037] Figure 2 This is a schematic diagram of the device status switching of the first form.

[0038] Figure 3 Schematic diagram of the second form of the variable FOV four-probe device.

[0039] Figure 4 This is a schematic diagram of the second form device status switching.

[0040] Figure 5 Schematic diagram of the limiting plate.

[0041] Figure numerals: 1. Detector assembly; 2. Support device; 11. Detector part; 21. Rotating device; 22. Connecting rod; 23. Pivot; 111. Detector plate; 112. Detector; 113. Guide rail; 114. Recess, 215. Limiting plate; 216. Arc groove; 217. Small FOV position; 218. Large FOV position. DETAILED DESCRIPTION

[0042] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without doing creative work are within the scope of protection of the present invention. The present application is groundbreaking in the variable FOV setting, and the examples given should not be considered as necessary limitations to the present application, such as the numerical value of the FOV field of view.

[0043] Example 1

[0044] A variable FOV four-probe SPECT detector characterized by comprising a detector assembly and a support device. The detector assembly specifically refers to a combination of four detectors that detect SPECT signals from four sides, all perpendicular to the normal to the detection center. The support device is responsible for supporting and moving the four detectors to achieve simple FOV change.

[0045] In the prior art, the FOV of general four-sided SPECT is not adjustable, or it only has a simple adjustment function of inward / outward along the vertical normal direction, which cannot achieve compatibility with two FOVs as in the present application, and clear resolution of both forms.

[0046] The detector assembly consists of four detector sections, and the supporting device consists of a rotating device and four connecting rods. The rotating device and connecting rods support the detector sections from the side, and this arrangement allows the detector sections to rotate with the rotating device, allowing for quick adjustment of the FOV.

[0047] One end of each of the four connecting rods is rotatably connected to a pivot on the side of the detector, while the other end is rotatably connected to a pivot at different locations on the side of the rotating device. The pivot itself is fixed to the rotating device and can rotate while maintaining perpendicularity to the rotating device surface. To balance the weight, the other end of the pivot extends from the other side / inside of the rotating device and can be equipped with a counterweight or other object.

[0048] Each detector part has a detector plate, a detector and a guide rail; the detector is fixed to the end of the corresponding detector plate, and the detector plate is snapped into the guide rail and can reciprocate on the guide rail. Due to the unique setting of the present application, the detector plate as a whole is, for example, in the shape of a long strip. The detector is set at the top. In order to facilitate inward and outward pulling, the detector plate is generally tilted, and the surface of the top is inclined at an angle of 20-70° to the normal. This also makes it convenient to set a recess, which cooperates with an adjacent detector part, for example, on the shorter side of the edge of the detector plate. The guide rail is usually set on the side close to the rotating device. In order to prevent collisions, it can also be set on the opposite side. In order to avoid collisions, the signal lines and power lines of general detectors are set inside the hollow detector plate. If it is set on the surface of the detector plate, it needs to be fixed at a certain distance with a buncher.

[0049] Each detector plate has at least one recessed portion that mates with another detector unit. A recessed portion of the detector plate allows for the insertion of a portion of an adjacent detector plate (including a detector) to address the situation where the detector plate lacks sufficient space when retracted. In this case, the detection signals of the detector units that enter or approach the recessed portion are not collected, or if collected, are not used in the calculations. The recessed portion can be any suitable shape, including a triangle, a quadrilateral, a circle, a sector, or even a portion of an ellipse.

[0050] When the rotating device rotates, the connecting rod drives the detector unit to change position, switching the detector unit assembly between two different FOVs, one of which is larger than the other. The specific values selected for the small and large FOVs should not be considered as limitations of the present invention. Here, for example, the small FOV is between 15mm and 60mm, and the large FOV is between 40-120mm. If the target is mice, the small and large FOVs are 60mm and 40mm, respectively. If the target object changes, the data may change. For example, the value will increase for squirrels and monkeys.

[0051] Furthermore, the supporting device is supported and fixed, and the rotating device is annular in shape when viewed from the side and can rotate around the center in a plane perpendicular to the multiple detectors. The rotating device is preferably annular, but can also be other shapes. The annular shape is relatively simple to use and maintain. The pivot connection positions of the four connecting rods on the rotating device are evenly distributed on the rotating device when viewed from the side. The connecting rods are, for example, metal or a metal core wrapped with other materials. The detector includes a scintillation crystal layer, a photoelectric converter layer, a signal processing circuit and a collimator; the circuit of the signal processing circuit is led out from the detector board. The detector module itself has no significant difference from other similar SPECTs.

[0052] Example 2

[0053] A variable FOV four-probe SPECT detection method is implemented using the above variable FOV four-probe SPECT detector.

[0054] The method is implemented in the following steps: 1) The detector assembly is placed in an initial state with a large FOV; a power-on test is performed, and SPECT detection is performed on the detection object, collecting detection data; 2) After the detection in step 1 is completed, the detection object is removed and replaced with another detection object, or the detection object remains unchanged. The rotating device rotates counterclockwise or clockwise, driving each detector unit along a curve and retracting via a connecting rod, changing the detector assembly to a small FOV configuration. At least a portion of each detector unit mates with a recessed portion on an adjacent detector unit, and detection is performed again. Furthermore, in the small FOV configuration, only the received signals of a portion of the detection units on each detector are collected and transmitted to generate an image.

[0055] This is one of the ways in which the apparatus of Example 1 is used to perform the detection. Its characteristic is that the large FOV form is detected first, and then the small FOV form is detected. The detection object can be the same or different.

[0056] For the situation where some detector units cannot receive data in a small FOV mode, there are three ways to solve it: turn on the power, but do not collect data from these detection units, or collect data but do not use it. You can also pre-set it and turn off some useless detection units in a small FOV mode. Although this saves power and resources, it is a bit troublesome to set up.

[0057] Example 3

[0058] A variable FOV four-probe SPECT detection method is implemented using the above variable FOV four-probe SPECT detector.

[0059] The method is implemented in the following steps: 1) The detector assembly is placed in an initial state with a small FOV, with at least a portion of each detector unit mating with a recess on an adjacent detector unit; a power-on test is performed, and SPECT detection is performed on the test object, collecting detection data; 2) After the detection in step 1 is completed, the test object is removed and replaced with another one, or the test object remains unchanged. The rotating device rotates counterclockwise or clockwise, driving each detector unit along a curve and outward through a connecting rod, changing the detector assembly to a large FOV configuration, and performing detection again. Furthermore, in the small FOV configuration, only the received signals of a portion of the detection units on each detector are collected and transmitted to generate an image.

[0060] This is one of the ways in which the apparatus of Example 1 is used to perform the detection. Its characteristic is that the small FOV form is detected first, and then the large FOV form is detected. The detection object can be the same or different.

[0061] For the situation where some detector units cannot receive data in a small FOV mode, there are three ways to solve it: turn on the power, but do not collect data from these detection units, or collect data but do not use it. You can also pre-set it and turn off some useless detection units in a small FOV mode. Although this saves power and resources, it is a bit troublesome to set up.

[0062] Example 4

[0063] A variable FOV four-probe SPECT detector, characterized by comprising a detector assembly and a support device. The detector assembly here specifically refers to a combination of four detector sections, which detect SPECT signals from four sides, all perpendicular to the normal of the detection center. The support device is responsible for supporting and moving the four detector sections to achieve a simple change of FOV. In the prior art, the FOV of a general four-sided SPECT is not adjustable, or it only has a simple adjustment function of inward / outward retraction along the perpendicular normal direction, which cannot achieve compatibility with two FOVs as in the present application, and clear resolution of both morphologies.

[0064] The detector assembly consists of four detectors, and the support assembly consists of a rotating device, four crossbars, and a limit plate. The rotating device and crossbars support the detectors from the sides and are designed so that the detectors can rotate with the rotating device, allowing for quick adjustment of the FOV.

[0065] One end of each of the four crossbars is fixedly connected to the detector side, and the other ends are fixedly connected to different positions on the side of the rotating device. The four crossbars are perpendicular to the side of the detector to which they are connected, and all four crossbars are perpendicular to the side of the rotating device. The four crossbars pass through the four arc-shaped slots on the limit plate. The crossbars themselves are fixed to the rotating device and can ensure a stable connection between the detector and the rotating device while maintaining perpendicularity to the surface of the rotating device. To balance the weight, a counterweight or other object can be placed on the other side of the crossbar where it passes through the limit slot. The crossbars themselves must have a certain weight and strength, for example, made of metal or with a metal core.

[0066] Each detector part has a detector plate, a detector and a guide rail; the detector is fixed to the end of the corresponding detector plate, and the detector plate is snapped into the guide rail and can reciprocate on the guide rail. Due to the unique setting of the present application, the detector plate as a whole is, for example, in the shape of a long strip. The detector is set at the top. In order to facilitate inward and outward pulling, the detector plate is generally tilted, and the surface of the top is inclined at an angle of 20-70° to the normal. This also makes it convenient to set a recess, which cooperates with an adjacent detector part, for example, on the shorter side of the edge of the detector plate. The guide rail is usually set on the side close to the rotating device. In order to prevent collisions, it can also be set on the opposite side. In order to avoid collisions, the signal lines and power lines of general detectors are set inside the hollow detector plate. If it is set on the surface of the detector plate, it needs to be fixed at a certain distance with a buncher.

[0067] Each detector plate has at least one recess that mates with another detector unit. A recess is a recessed portion of the detector plate that allows for the insertion of a portion of an adjacent detector plate (including a detector). This addresses the situation where the detector plate lacks sufficient space when retracted. In this case, the detection signals of the detector units that enter or approach the recess are not collected, or if collected, are not used for calculations.

[0068] When the rotating device rotates, the crossbar drives the detector unit to change position, switching the detector unit assembly between two different FOVs, one of which is larger than the other. The specific values selected for the small and large FOVs should not be considered limitations of the present invention. Here, for example, the small FOV is between 15mm and 60mm, and the large FOV is between 40-120mm. For mice, the small and large FOVs are, for example, 60mm and 40mm. If the object of examination changes, the data may change. For example, the value will increase for squirrels or monkeys.

[0069] Furthermore, the support device is fixed and supported, and the rotating device can rotate around the center in a plane perpendicular to the multiple detectors. The rotating device is preferably annular, but other shapes are also possible. The annular shape is relatively simple to use and maintain. The limit plate is separately fixed, and the four arc-shaped slots on the limit plate correspond to the large FOV position and the small FOV position at both ends.

[0070] The connection positions of the four cross bars on the rotating device are evenly distributed on the rotating device when viewed from the side. The cross bars are, for example, metal or a metal core wrapped with other materials.

[0071] The detector consists of a scintillator crystal layer, a photoelectric converter layer, a signal processing circuit, and a collimator. The signal processing circuitry extends from the detector board. The detector module itself is not significantly different from other similar SPECT systems.

[0072] Example 5

[0073] A variable FOV four-probe SPECT detection method is implemented using the above variable FOV four-probe SPECT detector.

[0074] The method is implemented in the following steps: 1) The detector assembly is placed in an initial state with a large FOV; a power-on test is performed, and SPECT detection is performed on the detection object, collecting detection data; 2) After the detection in step 1 is completed, the detection object is removed and replaced with another detection object, or the detection object remains unchanged. The rotating device rotates counterclockwise or clockwise, driving each detector unit along the curved arc groove to move inward via the crossbar, changing the detector assembly to a small FOV configuration. At least a portion of each detector unit mates with the recessed portion of an adjacent detector unit, and detection is performed again. Furthermore, in the small FOV configuration, only the received signals of a portion of the detection units on each detector are collected and transmitted to generate an image.

[0075] This is one of the ways in which the apparatus of Example 4 is used to perform the detection. Its characteristic is that the large FOV form is detected first, and then the small FOV form is detected. The detection object can be the same or different.

[0076] For the situation where some detector units cannot receive data in a small FOV mode, there are three ways to solve it: turn on the power, but do not collect data from these detection units, or collect data but do not use it. You can also pre-set it and turn off some useless detection units in a small FOV mode. Although this saves power and resources, it is a bit troublesome to set up.

[0077] Example 6

[0078] A variable FOV four-probe SPECT detection method is implemented using the above variable FOV four-probe SPECT detector.

[0079] The method is implemented in the following steps: 1) placing the detector assembly in an initial state of a small FOV configuration, with at least a portion of each detector assembly cooperating with a recess on an adjacent detector assembly; powering on the test object for testing, performing SPECT testing on the test object, and collecting test data; 2) after the test in step 1 is completed, removing the test object and replacing it with another test object, or not changing the test object, rotating the rotating device counterclockwise or clockwise, and driving each detector assembly to move and pull outward along the arc-shaped groove curve through the crossbar, so that the detector assembly changes to a large FOV configuration, and testing is performed again.

[0080] This is one of the ways in which the apparatus of Example 4 is used to perform the detection. Its characteristic is that the small FOV form is detected first, and then the large FOV form is detected. The detection object can be the same or different.

[0081] For the situation where some detector units cannot receive data in a small FOV mode, there are three ways to solve it: turn on the power, but do not collect data from these detection units, or collect data but do not use it. You can also pre-set it and turn off some useless detection units in a small FOV mode. Although this saves power and resources, it is a bit troublesome to set up.

[0082] The principle of this application is explained below with reference to the accompanying drawings, and it can be seen that: Figure 1 In the first configuration, the device is in a small FOV configuration. At this point, the four connecting rods partially protrude from the sides, and the four detector sections fit tightly together. Each detector section partially protrudes into the recess of the adjacent detector section, preventing collisions. This makes compact assembly possible.

[0083] Figure 2 In the middle, the left picture is Figure 1 The detectors are positioned in a roughly symmetrical shape. To reduce the size, reverse the above steps.

[0084] Here, rotating left or right is just an example and is not a limitation of the present invention, because both left and right rotations are possible.

[0085] Figure 3-5 This is a representation of the second aspect of the present invention. Figure 3 It is a representation of a large FOV form. Figure 4The transformation in the second form is similar to the first form, except that the connecting rod is replaced by a crossbar and a limit plate. There is no follower component like the connecting rod. The moving path of the crossbar is fixed and limited by the arc groove. This also avoids collisions between different detector parts when retracting / pulling. Because of the obstruction of the limit plate, the rotating device at the rear side is Figure 3-5 It is not shown in the figure, but it is a mechanism similar to the optional device of the first form.

[0086] Figure 5 The shape of the limit plate is specifically given. The arc shape of the arc groove here can be a circular arc, an elliptical arc, an asymptote that meets certain conditions, etc., which can avoid device collision in processing design.

[0087] The above is only an embodiment of the present invention, and common sense such as the specific structure and characteristics of the scheme are 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 the present invention 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, and it is intended that all changes that fall within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claim involved.

Claims

1. A variable FOV four-probe SPECT detector, characterized by: It comprises a detector assembly (1) and a supporting device (2); The detector assembly comprises four detector parts (11), and the supporting device comprises a rotating device (21) and four connecting rods (22); One end of each of the four connecting rods is rotatably connected to a pivot shaft on the side of the detector, and the other end of each of the four connecting rods is rotatably connected to a pivot shaft (23) at different positions on the side of the rotating device. Each detector section comprises a detector plate (111), a detector (112) and a guide rail (113); the detector is fixed to the end of the corresponding detector plate, and the detector plate is snapped into the guide rail and can reciprocate on the guide rail; Each detector plate has at least one recess (114) that mates with another detector portion; When the rotating device rotates, the position of the detector part is driven to change through the connecting rod, and the detector part group switches between two different forms of FOV, wherein the FOV of one form is larger than the FOV of the other form.

2. The variable FOV four-probe SPECT detector according to claim 1, characterized in that: The supporting device is supported and fixed, and the rotating device is annular in shape when viewed from the side and can rotate around the center in a plane perpendicular to the multiple detectors; The pivotal connection positions of the four connecting rods on the rotating device are evenly distributed on the rotating device when viewed from the side; The detector includes a scintillation crystal layer, a photoelectric converter layer, a signal processing circuit and a collimator; the circuit of the signal processing circuit is led out from the detector board.

3. A variable FOV four-probe SPECT detection method, characterized by: It is implemented using a variable FOV four-probe SPECT detector as claimed in claim 1 or 2; It is implemented in the following steps: (1) Place the detector assembly in the initial state of large FOV; power on for testing, perform SPECT testing on the test object, and collect test data; (2) After the detection in step 1 is completed, the detection object is removed and replaced with another detection object, or the detection object is not changed. The rotating device rotates counterclockwise or clockwise, and each detector part is driven to move inward along the curve through the connecting rod, so that the detector part group is changed to a small FOV shape. At least a part of each detector part cooperates with the recess on an adjacent detector part, and the detection is performed again.

4. A variable FOV four-probe SPECT detection method, characterized by: It is implemented using a variable FOV four-probe SPECT detector as claimed in claim 1 or 2; It is implemented in the following steps: (1) The detector group is placed in an initial state with a small FOV, with at least a portion of each detector group being aligned with a recess on an adjacent detector group; powering on the test object, performing SPECT testing, and collecting test data; (2) After the detection in step 1 is completed, the detection object is removed and replaced with another detection object, or the detection object is not changed. The rotating device rotates counterclockwise or clockwise, and each detector part is driven to move and pull out along the curve through the connecting rod, so that the detector part group changes to a large FOV shape and the detection is carried out again.

5. The variable FOV four-probe SPECT detection method according to claim 3 or 4, characterized in that: In the small FOV mode, only the received signals of some detection units on each detector are collected and transmitted to generate the image.

6. A variable FOV four-probe SPECT detector, characterized by: It comprises a detector assembly (1) and a supporting device (2); The detector assembly includes four detector parts (11), and the supporting device is composed of a rotating device (21), four cross bars, and a limiting plate (215); One end of each of the four cross bars is fixedly connected to the detector side, and the other ends of each of the four cross bars are fixedly connected to different positions of the side surface of the rotating device. The four cross bars are perpendicular to the side surface of the detector to which they are connected, and the four cross bars are perpendicular to the side surface of the rotating device. The four cross bars pass through the four arc-shaped slots (216) on the limit plate. Each detector section comprises a detector plate (111), a detector (112) and a guide rail (113); the detector is fixed to the end of the corresponding detector plate, and the detector plate is snapped into the guide rail and can reciprocate on the guide rail; Each detector plate has at least one recess (114) that mates with another detector portion; When the rotating device rotates, the position of the detector part is driven to change through the cross bar, and the detector part group switches between two different forms of FOV, wherein the FOV of one form is larger than the FOV of the other form.

7. The variable FOV four-probe SPECT detector according to claim 6, characterized in that: The supporting device is supported and fixed, and the rotating device can rotate around the center in a plane perpendicular to the multiple detectors; The limiting plate is fixed separately, and the four arc-shaped grooves on the limiting plate have two ends corresponding to the large FOV position (218) and the small FOV position (217) respectively; The connection positions of the four cross bars on the rotating device are evenly distributed on the rotating device when viewed from the side; The detector includes a scintillation crystal layer, a photoelectric converter layer, a signal processing circuit and a collimator; the circuit of the signal processing circuit is led out from the detector board.

8. A variable FOV four-probe SPECT detection method, characterized by: It is implemented using a variable FOV four-probe SPECT detector as claimed in claim 6 or 7; It is implemented in the following steps: (1) Place the detector assembly in the initial state of large FOV; power on for testing, perform SPECT testing on the test object, and collect test data; (2) After the detection in step 1 is completed, the detection object is removed and replaced with another detection object, or the detection object is not changed. The rotating device rotates counterclockwise or clockwise, and the cross bar drives each detector part to move inward along the arc groove curve, so that the detector part group changes to a small FOV shape. At least a part of each detector part cooperates with the concave part on an adjacent detector part, and the detection is performed again.

9. A variable FOV four-probe SPECT detection method, characterized by: It is implemented using a variable FOV four-probe SPECT detector as claimed in claim 6 or 7; It is implemented in the following steps: (1) The detector group is placed in an initial state with a small FOV, with at least a portion of each detector group being aligned with a recess on an adjacent detector group; powering on the test object, performing SPECT testing, and collecting test data; (2) After the detection in step 1 is completed, the detection object is removed and replaced with another detection object, or the detection object is not changed. The rotating device rotates counterclockwise or clockwise, and the cross bar drives each detector part to move and pull outward along the arc groove curve, so that the detector part group changes to a large FOV shape and the detection is carried out again.

10. The variable FOV four-probe SPECT detection method according to claim 8 or 9, characterized in that: In the small FOV mode, only the received signals of some detection units on each detector are collected and transmitted to generate the image.

Images