A method of SPECT arrangement for increasing the field of view of detection

Abstract

A method for increasing the detection field of view of a SPECT arrangement, which is implemented by using a SPECT system (1) comprising one or more detection groups (11), each detection group comprising a detector (21), coincidence circuit (22), computer (23), the detector is arranged in a circumferentially uniform manner with the detection surface facing the detection area, first in a first position; the center of the detection surface of each detector is displaced laterally by a distance of not less than 3 cm or not less than 10% of the width of the detection surface of the detector to reach a second position; under the premise that the distance between the center of the detection surface of each detector and the center of the detection area is d, all detectors are rotated by a plurality of turns under the drive of the gantry, and the received detection signals are transmitted to the computer through the coincidence circuit, and the SPECT system controls all computers to complete image reconstruction. The detector is composed of a collimator layer (211), a scintillation crystal layer (212), a light guide layer (213), and a PMT array layer (214).

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of SPECT detection probe technology improvement, and particularly to a SPECT arrangement method for increasing a detection field of view. BACKGROUND

[0002] A SPECT machine is a nuclear medicine imaging device developed on the basis of a gamma camera. Its basic structure consists of three parts: a probe, a rotating motion machine frame, a computer and its auxiliary equipment. The probe of the SPECT device is the core of SPECT imaging. The main components of a gamma camera imaging are a collimator, a large-area NaI(Tl) scintillation crystal, a light guide and a PM tube array. Two features different from the traditional NaI(Tl) counting detector are crucial for image formation. The first is that the imaging collimator is used to define the direction of the detected gamma rays. The collimator is most commonly composed of a lead plate containing a large number of holes. By controlling which gamma rays are accepted, the collimator forms a projection image of the gamma ray distribution at the surface of the NaI(Tl) crystal. The second is that the NaI(Tl) crystal is observed by a PM tube array rather than a single PM tube. The signals from the PM tubes are fed to electronic or digital position logic circuits, which determine the XY position of each scintillation event by using a weighted average of the PM tube signals when each scintillation event occurs.

[0003] The output of each photomultiplier tube is amplified and digitized using an analog-to-digital converter (ADC). The XY position of each gamma ray that interacts in the NaI(Tl) crystal is calculated from the digitized signals. The energy E deposited by the gamma ray is proportional to the total measured pulse amplitude and is also calculated by summing the individual PM tube signals. If E falls within a selected energy window, the event is accepted and placed in the appropriate XY position in the image.

[0004] By summing the signals from all PM tubes, the energy E of a single event can also be analyzed. When the pulse amplitude of an event falls within a selected energy window, it is accepted, and the X and Y values are merged into a discrete two-dimensional array of image elements or pixels. The image is formed by a histogram of the number of events at each possible XY position. A large number of events are required to form an interpretable image, because each pixel must have a sufficient number of counts to reach an acceptable signal-to-noise level.

[0005] The image is displayed on a computer monitor, where the image brightness and contrast can be controlled, and different color representations can be used.

[0006] But the existing problems in the prior art is that the price of SPECT whole machine is difficult to reduce, for example, in the four probe rotating mode, generally, the detection surface area of each probe is significantly larger than the cross-sectional area of the center of the region of interest, for example, the waist of a person is placed in the region of interest, and the region of interest is at least a cuboid region of 50cm*30cm*30cm, then the probe generally has an area of at least 60*60cm to basically meet the detection needs, and the cost of four probes is multiplied by 4, especially the scintillation crystal is very expensive, according to this setting mode, the cost of the SPECT whole machine is high.

[0007] How to effectively reduce the cost of the instrument, and reducing the probe cross-sectional area is a direct way, but if it is reduced in the same way, the probe is aligned with the center of the region of interest to detect, which will significantly reduce the scope of the effective detection area, even if the side length of the probe is reduced by 10cm, the effective detection volume may be reduced by 1 / 3 or even more, because the reduction of the general probe area is equivalent to the reduction of the detection area of the four sides (due to the symmetrical distribution). Only reducing the area of the probe, although the cost is reduced, but the effective detection volume is reduced too much.

[0008] The prior art does not have such a technology, that is, although the area of the probe is reduced, how to assist through other means or adjust the detection method so that the adverse effects of reducing the area of the probe can be offset or offset partially, so that the same detection area can be detected with a lower cost instrument configuration. SUMMARY

[0009] The purpose of the present application is to solve the problem that the prior art does not assist in reducing the area of the probe with other technologies to alleviate the adverse effects of reducing the area of the probe, the device of the present application enables the same detection area to be detected with a lower cost instrument configuration, that is, even if the area of the probe is reduced, the detection image quality is not significantly reduced, or the degree of reduction of the image quality is much lower than the general detection method, and this method does not need to increase the cost of the instrument to complete.

[0010] A SPECT arrangement method for increasing the detection field of view, characterized in that: it is implemented by using a SPECT system 1, which includes one or more detection groups 11, each detection group including a detector 21, a coincidence circuit 22, and a computer 23.

[0011] (1) All detectors are arranged in a circumferentially uniform manner with the detection surface facing the detection area, and are first located at a first position.

[0012] (2) Each detector is displaced laterally by a distance of not less than 3 cm or not less than 10% of the width of the detection surface of the detector at the center of the detection surface to a second position.

[0013] (3) Each second position is at a distance d from the center of the detection region, and under the premise that the center of the detection surface of each detector is at a distance d from the center of the detection region, all detectors are rotated by the gantry for multiple turns, and the received detection signals are transmitted to the computer through the coincidence circuit, and the SPECT system controls all computers to complete image reconstruction.

[0014] Further, the detector is sequentially composed of a collimator layer 211, a scintillation crystal layer 212, a light guide layer 213, and a PMT array layer 214.

[0015] The detection surface of each detector is planar and rectangular in shape.

[0016] The number of detection groups is 1-4, and when the number of detection groups is one, the detectors are arranged in a manner parallel to the surface of the detection bed, and when the number of detectors is 2-4, the detectors are arranged in a circumferentially uniform manner with the detection surface facing the detection region, and the included angle between adjacent detectors is about 180°, 120°, or 90°.

[0017] Each detector is displaced laterally by a distance of 5-25 cm or 15-35% of the width of the detection surface of the detector at the center of the detection surface.

[0018] The collimator layer is a parallel hole collimator with uniformly arranged holes, a pinhole collimator, a diverging hole collimator, or a focusing hole collimator.

[0019] The material of the scintillation crystal layer is NaI(Tl) or CsI(Tl), and the PMT array layer is SiPMT; each PMT in the PMT array layer is connected to the coincidence circuit.

[0020] Further, the detection surface of each detector is a square with the same area.

[0021] Each detector is displaced laterally by a distance of 15-20 cm or 20-25% of the width of the detection surface of the detector at the center of the detection surface.

[0022] A SPECT arrangement method for increasing the detection field of view is also claimed, characterized in that it is implemented using a SPECT system 1 comprising one or more detection groups 11, each detection group comprising one detector 21, one coincidence circuit 22, and one computer 23.

[0023] (1) All detectors are arranged in a circumferentially uniform manner with the detection surface facing the detection region.

[0024] (2) For the axis of symmetry at the center of the detection surface of each detector, the shortest distance between the center point of the detection area and the axis of symmetry shall be no less than 3 cm or no less than 10% of the width of the detection surface of the detector.

[0025] (3) The distance between the center of the detection surface of each detector and the center of the detection area is d. Under the premise of keeping the distance between the center of the detection surface of each detector and the center of the detection area d, all detectors rotate multiple times under the drive of the frame and transmit the received detection signals to the computer through the coincidence circuit. Under the control of the PECT system, all computers complete the image reconstruction.

[0026] Furthermore, the detector is composed of a collimator layer 211, a scintillation crystal layer 212, a light guide layer 213, and a PMT array layer 214 in sequence.

[0027] All detectors have planar detection surfaces, and all of them are rectangular in shape.

[0028] The detection group consists of 1 to 4 detectors. When there is only one detector, the detectors are arranged parallel to the surface of the detection bed. When there are 2 to 4 detectors, the detectors are arranged with the detection surfaces facing the detection area in a circumferentially uniform distribution. The included angle between adjacent detectors is approximately 180°, 120°, or 90°.

[0029] The shortest distance between the center point of the detection area and the axis of symmetry shall be no less than 5-25 cm or no less than 15-35% of the detection surface width of the detector.

[0030] The collimator layer consists of a parallel-hole collimator, a pinhole collimator, a diverging-hole collimator, or a focusing-hole collimator with uniformly arranged holes.

[0031] The scintillation crystal layer is made of NaI(Tl) or CsI(Tl), and the PMT array layer is made of SiPMT; each PMT in the PMT array layer is connected to a coincidence circuit.

[0032] Furthermore, the detection surfaces of all detectors are squares with the same area.

[0033] The shortest distance between the center point of the detection area and the axis of symmetry shall be no less than 15-20 cm or no less than 20-25% of the detection surface width of the detector.

[0034] Another SPECT arrangement method for increasing the detection field of view is characterized by the use of a SPECT system 1, which includes one or more detection groups 11, each of which includes a detector 21, a coincidence circuit 22, and a computer 23.

[0035] (1) All detectors are arranged with their detection surfaces facing the detection area in a circumferentially uniform distribution.

[0036] (2) A straight line passing through the center of the detection area is perpendicular to the detection surface at point P, and the shortest distance from point P to the center of the detection surface of the detector is not less than 3 cm or not less than 10% of the width of the detection surface of the detector.

[0037] (3) The distance from the center of each detector to the center of the detection area is d, and under the premise that the distance from the center of each detector to the center of the detection area is d, all detectors are rotated multiple times under the drive of the gantry, and the received detection signals are transmitted to the computer through the coincidence circuit, and under the control of the PECT system, all computers complete image reconstruction.

[0038] Further, the detector is sequentially composed of a collimator layer 211, a scintillation crystal layer 212, a light guide layer 213, and a PMT array layer 214.

[0039] The detection surface of all detectors is planar and rectangular in shape.

[0040] The detection group is 1-4, when the detection group is one, the detector is arranged in parallel to the surface of the detection bed, when the detector is 2-4, the detection surface of the detector is arranged in a circumferentially uniform distribution, and the included angle between adjacent detectors is about 180° or 120° or 90°; a straight line passing through the center of the detection area is perpendicular to the detection surface at point P, and the shortest distance from point P to the center of the detection surface of the detector is not less than 5-25 cm or not less than 15-35% of the width of the detection surface of the detector.

[0041] The collimator layer is a parallel hole collimator with uniformly arranged holes, a pinhole collimator, a diverging hole collimator, or a focusing hole collimator.

[0042] The material of the scintillation crystal layer is NaI(Tl) or CsI(Tl), and the PMT array layer is SiPMT; each PMT in the PMT array layer is connected to a coincidence circuit.

[0043] The detection surface of all detectors is a square with the same area.

[0044] A straight line passing through the center of the detection area is perpendicular to the detection surface at point P, and the shortest distance from point P to the center of the detection surface of the detector is not less than 15-20 cm or not less than 20-25% of the width of the detection surface of the detector.

[0045] The method for arranging SPECT as in the preceding claim, characterized in that the multiple detection groups are all carried by a whole rotating gantry 4, and for each detection group, the rotating gantry has a positioning frame 41 corresponding thereto, the positioning frame is in the shape of a rectangular frame or a "N" shape, and each positioning frame has a pair of oppositely arranged 42 sliding grooves on the inner side, and the detector can slide left and right in the positioning frame and be fixed, and the position of the detector in claims 1-9 is adjusted in the positioning frame.

[0046] The advantages of the present application are mainly as follows: first, the cost is effectively reduced, for the SPECT detection required, the device of the present application can enable the same detection area to be detected by a lower-cost instrument, the setting mode of the present application makes the image intensity at the center of the region of interest still guaranteed although the signal of the edge part of the region of interest is weaker, and the image clarity at the edge is reduced, which generally has little effect on the actual detection, or is within an acceptable range; second, a problem-solving way different from the prior art is proposed, the prior art generally does not consider that the detector area can be greatly reduced, because it is by default that the center is symmetrically placed, so it does not have the enlightenment of the setting of the present application, the setting mode of the present application is the result of careful consideration and repeated testing, and the technical analysis of why the present application can not be too weak is given below. BRIEF DESCRIPTION OF DRAWINGS

[0047] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced below, and obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0048] Figure 1 is a schematic diagram of the setting mode of general SPECT.

[0049] Figure 2 is a typical effect schematic diagram of the embodiment of the present application.

[0050] Figure 3 is a schematic diagram of the cooperation mode of the detector and the positioning frame.

[0051] Figure 4 is a lateral alignment related schematic diagram of the positioning frame.

[0052] Figure 5 is a schematic diagram of the moving / fixing mode of the sliding column of the detector.

[0053] Reference numerals: SPECT system, 1, detection group, 11, detector, 21, coincidence circuit, 22, computer, 23, rectifier layer, 211, scintillation crystal layer, 212, light guide layer, 213, PMT array layer, 214, object to be detected, rotating frame, 4, positioning frame, 41, chute, 42, 5, region of interest, 6, first intensity detection area, A, second intensity detection area, B, third intensity detection area, C, first position, P1, second position, P2, laser lamp mount, 71, laser lamp, 72, detection bed. 421, sliding column, 43, marking part, 44, blind hole group, 441, fixing sleeve, 442, protrusion. Detailed Implementation

[0054] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.

[0055] Figure 1 This illustrates a typical SPECT setup, the most common and standard method. First, a cube (or a square-shaped region of interest when viewed from the side) is defined, ensuring the object being detected is roughly centered within the region of interest. For example, four detection groups are used on four sides, with the region of interest forming a cube. The data from the four detection groups are reconstructed in a manner corresponding to the cube region. This method guarantees detection quality, but the instrument is expensive. On one hand, switching to a three-probe or two-probe setup (e.g., three probes spaced 120° apart, two probes spaced 180° apart) significantly reduces image quality. On the other hand, reducing the detection area by 20% (e.g., reducing the side length by 20%) reduces the effective detection area by 36%, also significantly impacting image clarity. In summary, current technologies haven't addressed how to effectively control costs without significantly reducing the detected area or image quality.

[0056] Figure 2A typical embodiment of the present application is given, still taking the example of arranging four probes, the lateral area of the probes on each side is reduced by about 40%, but the overall detector moves to the side, in the figure, it is about 15-20% of the original detector width, from the figure, it can be seen that the actual imaging area involved here is not greatly reduced compared to the original area of interest, about still 85% of the original area of interest, but it can be roughly divided into three cases, in the central region of the object, the four directions can still be received by the collimator, that is, region A still maintains the original signal strength and imaging clarity, region B is roughly changed to be able to be received by three-direction collimator, such as the right B region, it can be detected by the left upper right three directions, region CB is roughly changed to be able to be received by two-direction collimator, roughly speaking, the image clarity exists from A-B-C slightly decreased situation, but overall, the detection area is not much reduced than the original, if seen from the side, if the detector width is reduced to 60%, the central detection area is about 36% of the original, but the actual effective monitoring area of the present application is much larger than 36%, at least reaches 75-80% of the original, it can be seen that the positive value of the present application concept is obvious.

[0057] Embodiment 1

[0058] A SPECT system 1 is implemented, which includes one or more detection groups 11, each detection group including a detector 21, coincidence circuit 22, computer 23. The same as the general SPECT system, the present application can adopt 2 / 3 / 4 three probe arrangement modes. 2 probes are 180° apart, 3 probes are 120° apart, 4 probes are 90° apart, which are distributed circumferentially.

[0059] (1) All detectors are arranged in a circumferentially uniform manner with the detection surface facing the detection area, first in the first position. This first position is generally the same as the general spect system, the detection surface is aligned with the center of the area of interest, the present application is also arranged from this position, so based on this adjustment, the influence on subsequent arrangement and calculation is based, and it is more accurate. The alignment of this position can be based on the alignment of the rotating gantry and the area of interest, and on this basis, the 0 point position is provided on the positioning frame, which can facilitate the adjustment of the detector to the first position.

[0060] (2) Each detector is displaced laterally by a distance of not less than 3 cm or not less than 10% of the width of the detection surface of the detector, to a second position. A typical operation here is to move the detector laterally by a distance according to the scale of the positioning frame, so as to achieve the required lateral movement accurately and conveniently. For the coincidence circuit, on the one hand, it is mounted on the rotating gantry, and on the other hand, the circuit has a certain length, which allows the detector to move while still being connected.

[0061] (3) Each second position is at a distance d from the center of the detection region, and under the premise that the center of the detection surface of each detector is at a distance d from the center of the detection region, all detectors are rotated by the gantry for multiple turns, and the received detection signals are transmitted to the computer through the coincidence circuit, and the SPECT system controls all computers to complete image reconstruction. Based on the previous principle analysis, the signals for image reconstruction here are not all four-direction signals, and two algorithms can be adopted here, one is to assume that all four-direction signals are present, but in image reconstruction, the image clarity of the B and C regions will be slightly insufficient due to only 3 / 2-direction signals. The second is to set different algorithms according to different regions, and then splice the three different images into one image result. Both of these two ways are operable by those skilled in the art.

[0062] Further, the detector is sequentially composed of a collimator layer 211, a scintillation crystal layer 212, a light guide layer 213, and a PMT array layer 214. The collimator is, for example, a parallel array plate made of a lead plate or a lead-containing plate, which only accepts vertically incident rays. The scintillation crystal is one or more corresponding to one PMT, and the PMT is, for example, a silicon PMT.

[0063] The detection surface of each detector is planar and rectangular in shape. The detector can be a front-shaped surface, or a rectangular shape that is longer in the horizontal direction or the vertical direction, with the horizontal and vertical directions being relative to the direction in which the patient lies.

[0064] The detection group is 1-4, when the detection group is one, the detectors are arranged in a manner parallel to the surface of the detection bed, and when the detectors are 2-4, the detectors are arranged in a circumferentially uniform manner with the detection surfaces facing the detection region, and the included angle between adjacent detectors is correspondingly about 180° or 120° or 90°.

[0065] Each detector is displaced laterally by a distance of 5-25 cm or 15-35% of the width of the detection surface of the detector at the center of the detection surface. Each detector is displaced laterally by a distance of 15-20 cm or 20-25% of the width of the detection surface of the detector at the center of the detection surface. In this embodiment, this movement is performed in a specific distance or a proportion of the width of the detection surface, which is a relatively simple and easy way to operate in practice.

[0066] The collimator layer is a parallel hole collimator with holes uniformly arranged, a pinhole collimator, a diverging hole collimator or a focusing hole collimator.

[0067] The material of the scintillation crystal layer is NaI(Tl) or CsI(Tl), and the PMT array layer is a SiPMT; each PMT in the PMT array layer is connected to a coincidence circuit.

[0068] Further, the detection surfaces of all the detectors are squares with the same area.

[0069] Embodiment 2

[0070] The difference between this embodiment and Embodiment 1 is that the expression of the detector offset is different.

[0071] For the symmetry axis at the center of the detection surface of each detector, the shortest distance of the center point of the detection area from the symmetry axis is not less than 3 cm or not less than 10% of the width of the detection surface of the detector.

[0072] The shortest distance of the center point of the detection area from the symmetry axis is not less than 5-25 cm or not less than 15-35% of the width of the detection surface of the detector.

[0073] The shortest distance of the center point of the detection area from the symmetry axis is not less than 15-20 cm or not less than 20-25% of the width of the detection surface of the detector.

[0074] In some cases, it may be inconvenient to describe the distance of the detector offset itself, because, for example, there may be no convenient positioning point on the detector, or a button or an identification point for positioning itself has a width, which may cause errors. Here, the distance from the symmetry axis is described, which may be more accurate than the method of Embodiment 1 in some cases.

[0075] Embodiment 3

[0076] The difference between this embodiment and Embodiment 1 is that the expression of the detector offset is different.

[0077] A straight line through the center of the detection area is perpendicular to the detection surface at point P, and the shortest distance of point P from the center of the detection surface of the detector is not less than 3 cm or not less than 10% of the width of the detection surface of the detector.

[0078] A straight line through the center of the detection area is perpendicular to the detection surface at point P, and the shortest distance of point P from the center of the detection surface of the detector is not less than 5-25 cm or not less than 15-35% of the width of the detection surface of the detector.

[0079] The straight line perpendicular to the detection surface at P point is detected at the center of the region, and the shortest distance between P point and the center of the detection surface of the detector is not less than 15-20 cm or not less than 20-25% of the width of the detection surface of the detector.

[0080] In some cases, the distance describing the deviation of the detector itself can be constant, because for example there can be no convenient positioning point on the detector, or the positioning of a button or the identification point itself has a width, which can cause errors, and here the distance from the projection position is described, which can be more accurate than the manner of embodiment 1 in some cases.

[0081] Embodiment 4

[0082] As the previous SPECT arrangement method, characterized in that: one or more detection groups are carried by a whole rotating gantry 4, and for each detection group, the rotating gantry has a positioning frame 41 corresponding thereto, which is in the shape of a rectangular frame or a "n" shape, and each positioning frame has a pair of oppositely arranged 42 sliding grooves on the inside, and the detector has a sliding column 421 on both sides, which can slide left and right in the positioning frame and be fixed, and the position of the detector in claims 1-9 is adjusted in the positioning frame. As shown in the figure. The sliding column is, for example, in the middle position of the side of the detector, one on each side, which is convenient for subsequent positioning. Figure 3

[0083] The specific positioning here can be operated as follows: the positioning frame is at a position where the detector is in the first position, and in the shape of a rectangular frame, it is at the middle position in front and behind the frame, and in the shape of a "n", it is at a position where the detector is vertically above the region of interest. Here, each of the front is provided with a laser lamp holder 71, which can insert two laser lamps 72 and vertically irradiate downward, and at this time, the two lamps are aligned with the center line on the examination bed 73, which can ensure that the detector is in the first position. On this basis, in the shape of a rectangular frame, each detector can be adjusted to the second position to the left or right, and in the shape of a "n", it can basically only move to one side, such as the right side. Because of the influence of the later rotation of the gantry, the laser lamp here is detachable, and after alignment, it is detached, and the detector is moved to the second position in one of the manners of embodiments 1-3. As shown in the figure. The side of the positioning frame has a scale, which allows the specific length to be moved according to the scale, and the scale is, for example, in mm. Figure 4

[0084] Embodiment 5

[0085] Further, in order to cooperate with the left and right movement of the present application and facilitate positioning, another convenient operation moving / fixed manner can be provided.

[0086] ​​First, the common operation mode of the present application is that the detector needs to be centered, first move to the left by x times of L, L is a fixed distance, for example, between 5-12 cm, then return to the center, and then move to the right by x times of L. In this way, how to make the detector directly locate to a specific position without measurement, a simple operation mode is needed, and the embodiment provides such a mode. L is for example 5 / 6 / 7 / 8 / 9 / 10 / 11 / 12 cm.

[0087] First, one side of the detector has a plurality of blind holes on its shell (such as hard polypropylene, polytetrafluoroethylene, hard modified polyurethane, etc.) for fixation, and the sliding groove 42 has a plurality of identification parts 43, the distance between each identification part and the adjacent one is L (for easy identification and positioning), and the identification part 43 has a blind hole group 44 arranged close to the identification part on the outside of the sliding groove. The sliding column has a polytetrafluoroethylene fixing sleeve 441, and the fixing sleeve has one or more protrusions 442 adapted to the blind hole group. According to such a setting, the sliding column can be conveniently fixed at a distance of x*L offset to the left for detection, and further moved to a distance of x*L offset to the right for detection.

[0088] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any change or replacement without creative labor should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be limited by the protection scope defined in the claims.

Claims

1. A SPECT arrangement method to increase the detection field of view, characterized in that: It is implemented using a SPECT system (1) comprising one or more detection groups (11), each detection group comprising a detector (21), a coincidence circuit (22), and a computer (23). (A) All detectors are arranged with their detection surfaces facing the detection area in a circumferentially uniform distribution, and are initially located in the first position; (B) The center of the detection surface of each detector is displaced laterally by no less than 3 cm or by a distance of no less than 10% of the width of the detection surface of the detector to reach the second position; (C) The distance from each second position to the center of the detection area is d. While keeping the distance from the center of the detection surface of each detector to the center of the detection area d, all detectors rotate multiple times under the drive of the frame, and transmit the received detection signals to the computer through the coincidence circuit. The SPECT system controls all computers to complete image reconstruction. There are 4 detectors in the detection group. When there are 4 detectors, the detectors are arranged in a circumferentially uniform manner with the detection surfaces facing the detection area, and the included angle between adjacent detectors is 90°. The collimator layer consists of parallel-hole collimators or pinhole collimators with evenly distributed holes.

2. The SPECT arrangement method for increasing the detection field of view as described in claim 1, characterized in that: The detector is composed of a collimator layer (211), a scintillation crystal layer (212), a light guide layer (213), and a PMT array layer (214) in sequence; All detectors have planar detection surfaces, and all of them are rectangular in shape. The center of the detection surface of each detector is displaced laterally by 5-25 cm or by a distance of 15-35% of the width of the detection surface; The scintillation crystal layer is made of NaI(Tl) or CsI(Tl), and the PMT array layer is made of SiPMT; each PMT in the PMT array layer is connected to a coincidence circuit.

3. The SPECT arrangement method for increasing the detection field of view as described in claim 2, characterized in that: All detectors have a square detection surface with the same area; The center of the detection surface of each detector is displaced laterally by 15-20 cm or by a distance of 20-25% of the width of the detection surface.

4. A SPECT arrangement method to increase the detection field of view, characterized in that: It is implemented using a SPECT system (1) comprising one or more detection groups (11), each detection group comprising a detector (21), a coincidence circuit (22), and a computer (23). (D) All detectors are arranged with their detection surfaces facing the detection area in a circumferentially uniform distribution. (E) For the axis of symmetry at the center of the detection surface of each detector, the shortest distance between the center point of the detection area and the axis of symmetry shall be no less than 3 cm or no less than 10% of the width of the detection surface of the detector; (F) The distance between the center of the detection surface of each detector and the center of the detection area is d. Under the premise of keeping the distance between the center of the detection surface of each detector and the center of the detection area d, all detectors rotate multiple times under the drive of the frame and transmit the received detection signals to the computer through the coincidence circuit. Under the control of the SPECT system, all computers complete the image reconstruction. There are 4 detectors in the detection group. When there are 4 detectors, the detectors are arranged in a circumferentially uniform manner with the detection surfaces facing the detection area, and the included angle between adjacent detectors is 90°. The collimator layer consists of parallel-hole collimators or pinhole collimators with evenly distributed holes.

5. The SPECT arrangement method for increasing the detection field of view as described in claim 4, characterized in that: The detector is composed of a collimator layer (211), a scintillation crystal layer (212), a light guide layer (213), and a PMT array layer (214) in sequence; All detectors have planar detection surfaces, and all of them are rectangular in shape. The shortest distance between the center point of the detection area and the axis of symmetry shall be no less than 5-25 cm or no less than 15-35% of the detection surface width of the detector; The scintillation crystal layer is made of NaI(Tl) or CsI(Tl), and the PMT array layer is made of SiPMT; each PMT in the PMT array layer is connected to a coincidence circuit.

6. The SPECT arrangement method for increasing the detection field of view as described in claim 5, characterized in that: All detectors have a square detection surface with the same area; The shortest distance between the center point of the detection area and the axis of symmetry shall be no less than 15-20 cm or no less than 20-25% of the detection surface width of the detector.

7. A SPECT arrangement method to increase the detection field of view, characterized in that: It is implemented using a SPECT system (1) comprising one or more detection groups (11), each detection group comprising a detector (21), a coincidence circuit (22), and a computer (23). (G) All detectors are arranged with their detection surfaces facing the detection area in a circumferentially uniform distribution; (H) A straight line passing through the center of the detection area is perpendicular to the detection surface at point P. The shortest distance between point P and the center of the detector's detection surface is not less than 3 cm or not less than 10% of the width of the detector's detection surface. (I) The distance between the center of the detection surface of each detector and the center of the detection area is d. Under the premise of keeping the distance between the center of the detection surface of each detector and the center of the detection area d, all detectors rotate multiple times under the drive of the frame and transmit the received detection signals to the computer through the coincidence circuit. Under the control of the SPECT system, all computers complete the image reconstruction. There are 4 detectors in the detection group. When there are 4 detectors, the detectors are arranged in a circumferentially uniform manner with the detection surfaces facing the detection area, and the included angle between adjacent detectors is 90°. The collimator layer consists of parallel-hole collimators or pinhole collimators with evenly distributed holes.

8. The SPECT arrangement method for increasing the detection field of view as described in claim 7, characterized in that: The detector is composed of a collimator layer (211), a scintillation crystal layer (212), a light guide layer (213), and a PMT array layer (214) in sequence; All detectors have planar detection surfaces, and all of them are rectangular in shape. A straight line passing through the center of the detection area is perpendicular to the detection surface at point P. The shortest distance between point P and the center of the detector's detection surface is not less than 5-25 cm or not less than 15-35% of the width of the detector's detection surface. The scintillation crystal layer is made of NaI(Tl) or CsI(Tl), and the PMT array layer is made of SiPMT; each PMT in the PMT array layer is connected to a coincidence circuit.

9. A SPECT arrangement method for increasing the detection field of view as described in claim 7, characterized in that: All detectors have a square detection surface with the same area; A straight line passing through the center of the detection area is perpendicular to the detection surface at point P. The shortest distance between point P and the center of the detector's detection surface is no less than 15-20 cm or no less than 20-25% of the width of the detector's detection surface.

10. A SPECT arrangement method for increasing the detection field of view as described in any one of claims 1-9, characterized in that: Multiple detection groups are supported by an integral rotating frame (4). For each detection group, the rotating frame has a corresponding positioning frame (41). The positioning frame is rectangular or U-shaped. Each positioning frame has a pair of oppositely arranged sliding grooves (42) on its inner side. The detector can slide left and right within the positioning frame and be fixed. The position of the detector in any of claims 1-9 is adjusted within the positioning frame.

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