Detection device and detection system suitable for pet equipment

Abstract

The application relates to a detection device and a detection system suitable for a PET device, comprising a support structure; a carrier body arranged in the support structure, the carrier body being configured with a containing cavity, the containing cavity being configured to embed a packaging piece, and the packaging piece being wrapped with a radiation point source; the radiation point source installed in the containing cavity can coincide with the center point of the carrier body; wherein the carrier body is divided into at least two halves which can be opened and closed along a first direction; the first direction is consistent with the direction in which the carrier body deviates from the support structure. The application embeds the packaging piece wrapped with the radiation point source in the containing cavity which is matched with the size of the packaging piece, and the part area of the carrier body is configured as a spherical segment with the radiation point source as the center, so that the problem of radiation anisotropy caused by the traditional irregular shape packaging can be eliminated.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and in particular to testing devices and testing systems applicable to PET equipment. Background Technology

[0002] Quality control (QC) of positron emission tomography (PET) systems is a crucial step in ensuring stable and reliable imaging performance. Currently, common QC methods in the industry include active and passive QC. Active QC typically uses radioactive sources, which can take the form of point sources, line sources, and barrel sources, and can be in solid or liquid form.

[0003] Solid-state barrel sources are a widely used quality control tool for measuring system uniformity, quantitative correction factors, and detector response consistency. However, barrel sources have significant limitations in measuring system sensitivity and time-of-flight (TOF) resolution. Current standard methods for measuring system sensitivity (such as NEMA NU2-2018) require the use of a 70cm long line source combined with multiple acquisitions using multi-layer sheathing. However, this method is complex, time-consuming, and places certain requirements on the system's axial field of view. Utility Model Content

[0004] Therefore, it is necessary to provide a detection device and a detection system suitable for PET equipment to address the problems of traditional detection methods for imaging equipment being complex, time-consuming, and requiring a certain axial field of view.

[0005] In a first aspect, embodiments of this application provide a detection device for use in an imaging apparatus, the detection device comprising:

[0006] Support structure;

[0007] A carrier body is disposed on the supporting structure. The carrier body is constructed with a receiving cavity, which is configured to embed an encapsulation component. A radiation point source is encapsulated within the encapsulation component. The radiation point source installed in the receiving cavity can coincide with the center point of the carrier body.

[0008] The carrier body comprises at least two openable halves along a first direction; the first direction is consistent with the direction of the carrier body away from the supporting structure.

[0009] In one embodiment, the outer surface of the carrier includes a first region, a second region, and a third region arranged sequentially along a first direction, wherein any point on the surface of the second region is equidistant from the center point.

[0010] In one embodiment, the second region has a first loop connected to the first region and a second loop connected to the third region; along the first direction, the orthographic projection of the first loop and the orthographic projection of the second loop coincide.

[0011] In one embodiment, the plane containing the first loop is parallel to the plane containing the second loop and perpendicular to the first direction;

[0012] And / or, the orthographic projection shape of the first loop or the second loop along the first direction is circular.

[0013] In one embodiment, the carrier includes a first base and a second base that are detachably connected, at least one of the first base and the second base being configured with a receiving groove to form the receiving cavity between the first base and the second base;

[0014] The outer surface of the first substrate includes the first region and a portion of the second region, and the outer surface of the second substrate includes the third region and another portion of the second region.

[0015] In one embodiment, the first substrate and the second substrate have a docking boundary, and the center point does not coincide with the plane containing the docking boundary.

[0016] In one embodiment, the shortest distance between the inner wall of the receiving cavity and the outer surface of the carrier is 1mm-20mm;

[0017] And / or, the density difference between the carrier and the package is 0.01 kg / m³. 3 -0.1kg / m 3 ;

[0018] And / or, the density of the carrier is the same as the density of the package;

[0019] And / or, the material of the carrier is the same as the material of the package.

[0020] Secondly, embodiments of this application provide a detection system suitable for PET equipment, the PET equipment having a scanning cavity, the detection system comprising:

[0021] Support structure;

[0022] A carrier body is disposed on the support structure. The carrier body is divided into two halves and is snapped together. The two halves form a receiving cavity after being snapped together. An encapsulation component is embedded in the receiving cavity. The encapsulation component contains a radiation point source for the PET device. An adjustment mechanism is connected to the support structure to adjust the carrier body to the target position of the scanning cavity.

[0023] In one embodiment, the PET device includes:

[0024] An imaging device includes a detection assembly defining a scanning cavity whose axis extends along a first direction;

[0025] A moving mechanism, connected to the adjusting mechanism, is configured to drive the carrier to move within the scanning cavity along the first direction.

[0026] In one embodiment, the adjustment mechanism includes:

[0027] The base is provided with a guide groove extending in a second direction, and the sidewall of the guide groove is provided with positioning holes;

[0028] A movable component is slidably disposed in the guide groove; the movable component is configured to form a guide channel extending in a third direction;

[0029] The first fastener passes through the positioning hole and abuts against the moving part;

[0030] The support structure is located at the guide channel via a second fastener.

[0031] The aforementioned detection device and detection system for PET equipment, by constructing a receiving cavity within the carrier that matches the size of the package, adapts and embeds the package containing the radiation point source within the package. Furthermore, by constructing a portion of the carrier as a spherical segment centered on the radiation point source, the anisotropy problem caused by traditional irregularly shaped packages can be eliminated. The carrier configuration in this example ensures a uniform and stable radiation field within the effective field of view of the imaging device. Moreover, this embodiment integrates the carrier and its internal package into a single reference source, facilitating direct placement into an activity meter for measurement. The measurement results can be directly used as the reference activity, greatly simplifying the sensitivity measurement process and significantly improving the accuracy and repeatability of sensitivity data. Attached Figure Description

[0032] Figure 1 This is a perspective structural diagram of a detection device provided in some embodiments of this application.

[0033] Figure 2 This is a schematic diagram of the overall structure of a detection device provided in some embodiments of this application.

[0034] Figure 3 This is a schematic diagram of the overall structure of another detection device provided in some embodiments of this application.

[0035] Figure 4This is a schematic diagram showing the maximum coincidence angle of the detection device provided in some embodiments of this application within an imaging device.

[0036] Figure 5 Geometric schematic diagrams of the first, second, and third regions of a carrier provided in some embodiments of this application.

[0037] Figure 6 This is a side view structural diagram of another carrier provided in some embodiments of this application.

[0038] Figure 7 This is a schematic diagram of the split structure of the detection device provided in some embodiments of this application.

[0039] Figure 8 This is a schematic diagram of the adjustment mechanism of the detection system provided in some embodiments of this application.

[0040] Figure 9 This is a side view of the adjustment mechanism of the detection device provided in some embodiments of this application.

[0041] Figure 10 This is a top view of the adjustment mechanism of the detection device provided in some embodiments of this application.

[0042] Figure 11 The present invention provides a schematic diagram of the structure of a detection system including an imaging device and a moving mechanism, which is provided in some embodiments of the present application.

[0043] Icon labels:

[0044] 100. Supporting structure;

[0045] 200, Support body; 201, First zone; 202, Second zone; 203, Third zone; 204, Receiving cavity; 205, Center point; 206, Dating boundary; 210, First substrate; 220, Second substrate; 207, Receiving groove;

[0046] 300. Imaging equipment; 310. Detection components; 301. Scanning cavity;

[0047] 400. Adjustment mechanism; 410. Base; 411. Guide groove; 412. Positioning hole; 420. Moving part; 421. Guide channel; 430. Second fastener;

[0048] 500. Mobile mechanism;

[0049] First direction - Z direction; Second direction - X direction; Third direction - Y direction. Detailed Implementation

[0050] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0051] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0052] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0053] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0054] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0055] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0056] As mentioned in the background section, compared to current detection methods using solid-state or line sources, point sources (such as the Na-22 solid point source) offer advantages such as emitting 511 keV gamma photons, a long half-life, low radiation dose, and exemption from inspection, making them particularly suitable for verifying parameters such as spatial resolution. However, due to their low activity, limited irradiation range, and the anisotropy and non-uniform attenuation caused by conventional packaging forms (such as disc-shaped or square-shaped), point sources have not been fully utilized in system-level quality control (such as sensitivity and TOF resolution measurements).

[0057] To address the aforementioned problems, this embodiment constructs a receiving cavity within the carrier that matches the size of the package, allowing the package containing the radiation point source to be fitted and embedded within it. Furthermore, by constructing a portion of the carrier as a spherical segment centered on the radiation point source, the anisotropy problem caused by traditional irregularly shaped packages is eliminated. The carrier configuration in this example ensures a uniform and stable radiation field within the effective field of view of the imaging device. Additionally, this embodiment integrates the carrier and its internal package into a single reference source, facilitating direct placement into an activity meter for measurement. The measurement results can then be directly used as the reference activity. This configuration significantly simplifies the sensitivity measurement process and substantially improves the accuracy and repeatability of sensitivity data.

[0058] See Figure 1 and Figure 2 , Figure 1 This is a perspective structural diagram of a detection device provided in some embodiments of this application. Figure 2This is a schematic diagram of the overall structure of a detection device provided in some embodiments of this application. One embodiment of this application first provides a detection device for quality control of an imaging device 300 to ensure that the imaging device 300 operates under expected performance conditions. The imaging device 300 in this example may include PET (Positron Emission Tomography), PET / CT equipment, and PET / MR equipment, etc., which include PET, and is not limited thereto. The detection device provided in this embodiment may include a support structure 100 and a carrier 200, the carrier 200 being used to mount a package with a radiation point source.

[0059] The carrier 200 is disposed on the support structure 100. The carrier 200 is constructed with a receiving cavity 204, which is configured to embed a package, and a radiation point source is encapsulated inside the package. The radiation point source installed in the receiving cavity 204 can coincide with the center point 205 of the carrier 200. The carrier 200 is divided into at least two openable halves along a first direction (Z direction). The first direction (Z direction) is consistent with the direction of the carrier 200 away from the support structure 100.

[0060] It is understood that the support structure 100 can be a support rod, one end of which is used to fix the carrier 200, for example, by adhesive bonding, threaded connection, integral formation, etc., or by a quick-release clamp, to facilitate frequent removal and placement of the carrier 200 for activity measurement; the other end of the support rod can be fixed to the scanning bed of the imaging device 300, or fixed to a specific fixture, which can be a multi-directional adjustment mechanism 400, capable of achieving precise position adjustment and fixation of the carrier 200 in two-dimensional space or circumferential angle. The structure of the specific adjustment mechanism 400 can be understood with reference to the following example.

[0061] In this example, the carrier 200 has an internal cavity 204, the shape of which matches the external geometry of the package to accommodate and fix the package. In other words, the carrier 200 can encapsulate the package. The package contains a solid or liquid radiation point source, whose radioactive nuclides include, but are not limited to, Na-22, Ge-68, and F-18. It should be noted that the package in this example is a purchased finished product, and the shape and size of the cavity 204 within the carrier 200 need to be designed and manufactured according to the purchased package.

[0062] In this example, the center point 205 of the carrier 200 can be a region within a certain range, not an absolute point; while the coincidence between the radiation point source and the center point can be completely coincident. Of course, those skilled in the art will understand that there is a certain error in the coincidence, and this error is negligible to them. For example, all or at least part of the structure of the carrier 200 is a sphere, then the center point is the center of the sphere of the carrier 200. When the package is correctly installed in the carrier 200, the center point 205 coincides with the radiation center of the radiation point source. Of course, to achieve effective coincidence, the processing accuracy of the receiving cavity 204 needs to meet the requirement that the deviation between its geometric center and the center point 205 should be at least less than 0.5 mm. For example, the design of the carrier 200 and its internal receiving cavity 204 can be realized through engineering modeling software, and then the carrier 200 can be formed by 3D printing.

[0063] Understandably, to facilitate the installation of the encapsulation component, the carrier 200 can be designed as a two-part structure. Only one part of the two parts may have a groove for accommodating the encapsulation component, or both parts may have grooves. During installation, the encapsulation component is inserted into the groove, and then the two parts are snapped together to fit the encapsulation component onto the carrier 200. Alternatively, the two parts can be locked together with a snap-fit ​​or interference fit to ensure a secure connection, thus preventing the radiation point source from shifting during detection. Furthermore, the two-part design of the carrier 200 also facilitates the replacement of encapsulation components with different activities or nuclides.

[0064] It should be noted that the plane (cut surface) at the joint of the split-type carrier 200 should be offset from the center point 205 (radiation point source) to prevent the rays of the radiation point source from escaping directly from the gap of the cut surface.

[0065] In this embodiment, the first direction (Z-direction) is defined to be consistent with the direction of the carrier 200 away from the support structure 100. This first direction (Z-direction) can also be understood as the axial direction of the scanning cavity 301 of the imaging device 300. In some embodiments, the outer surface of the carrier 200 includes a first region 201, a second region 202 and a third region 203 arranged sequentially along the first direction (Z-direction). The distance from any point on the surface of the second region 202 to the center point 205 is equal.

[0066] Specifically, the outer surface of the carrier 200 is divided into a first region 201, a second region 202, and a third region 203 along the first direction (Z-direction). The second region 202 is a spherical surface encircling the first direction (Z-direction), meaning that the distance from any point on the second region 202 to the center point 205 is equal. Further, the second region 202 is a spherical segment with the center point 205 as its sphere. Since the radiation source is also located at the center of the sphere, it can be ensured that the gamma photons emitted from the radiation source pass through this spherical segment region with approximately the same or identical thickness of the encapsulation material (consistent attenuation), thereby eliminating attenuation differences caused by the encapsulation geometry and ensuring isotropic radiation within the effective solid angle.

[0067] It is further important to understand that the division of the first zone 201, the second zone 202, and the third zone 203 in this embodiment is mainly based on the angular range of the second zone 202 (the angle from the center point 205 to the opposite ends of the second zone 202, for example, the following 2...). The maximum coincidence angle needs to be satisfied, and the calculation of the maximum coincidence angle requires consideration of the axial length and aperture of the imaging device 300. In other words, when the detection device moves to the center of the axial field of view of the imaging device 300, photons emitted from the radiation point source and exiting through the second region 202 can ensure that the radiation is uniform and isotropic within the effective coincidence angle. Conversely, photons emitted from the first region 201 and the third region 203 cannot form an effective coincidence event. Of course, for design and manufacturing convenience, the first region 201 and the third region 203 can be designed as spheres, that is, the first region 201, the second region 202, and the third region 203 form a complete sphere. Alternatively, the shapes of the first region 201 and the third region 203 can be designed separately, for example, as planar, to save materials; tungsten or lead layers capable of absorbing photons can also be designed in the first region 201 and the third region 203 to absorb photons that exceed the maximum coincidence angle and cannot form an effective coincidence event, thereby reducing scattering coincidence and accidental recombination noise and improving the signal-to-noise ratio of the detection data.

[0068] It should be noted that the material density of the carrier 200 in this embodiment can be the same as or very close to the material density of the package. Of course, the same material as the package can also be used to form the carrier 200. The actual processing also needs to consider the range of materials that 3D printing can cover. For example, the material of the carrier 200 is acrylic, epoxy resin, etc.

[0069] Furthermore, the structure volume after being packaged by the carrier 200 provided in this embodiment is relatively small, slightly larger than the size of the package. Therefore, the smaller carrier 200 can be placed in a radiation activity meter to directly measure the overall activity after packaging. Since the activity has already taken into account the attenuation of the carrier 200, it can be used as the reference activity for subsequent measurement of the sensitivity of the imaging device 300 without the need for complex attenuation correction calculations.

[0070] When using this detection device to detect various parameters of the imaging device 300 (including sensitivity, TOF resolution, energy spectrum, and uniformity), the carrier 200 is first fixed and adjusted to a predetermined starting position in the axial field of view of the imaging device 300 via the support structure 100. The scanning program of the imaging device 300 is then initiated, and the detection device is continuously moved axially to allow the moving point source to traverse the entire axial field of view. During this process, the detectors of the imaging device 300 record all coincidence events. Regarding sensitivity calculation, the introduction of a reference activity simplifies and improves sensitivity measurement; the specific calculation formula can be understood using the following embodiments. As for the calculation of TOF resolution, the moving point source can be equated to a long line source, and the timestamp data of coincidence events can be analyzed according to current standard methods to calculate the TOF resolution. The acquired data can generate a detector count 2D map to analyze the energy spectrum, photoelectric peak position, and channel changes of the imaging device 300, thereby evaluating the energy spectrum and uniformity of the imaging system.

[0071] In summary, the detection device provided in this application eliminates the radiation anisotropy problem caused by irregularly shaped packages by constructing a receiving cavity 204 within the carrier 200 that matches the size of the package. This allows the package containing the radiation point source to be fitted and embedded within the package. Furthermore, the second region 202 of the carrier 200 is constructed as a spherical segment centered on the radiation point source. The arrangement of the carrier 200 in this example ensures a uniform and stable radiation field within the effective field of view of the imaging device 300. Additionally, this embodiment integrates the carrier 200 and its internal package into a single reference source, facilitating direct placement into the activity meter for measurement. The measurement results can then be directly used as the reference activity. This arrangement greatly simplifies the sensitivity measurement process and significantly improves the accuracy and repeatability of the sensitivity data. Based on the isotropic radiation source and accurate reference activity provided by the detection device, multiple key performance parameters of the imaging device 300, such as sensitivity, TOF resolution, and energy spectrum characteristics, can be acquired simultaneously through a single continuous scanning process. This integrated measurement is not only highly efficient, but also ensures that all parameter data are obtained at the same time and under the same conditions, which is conducive to achieving efficient, comprehensive, and reliable monitoring of the performance of the imaging device 300.

[0072] Below, we will combine the appendix Figure 1-Appendix Figure 7 The specific structure of the detection device provided in the embodiments of this application will be described in detail.

[0073] like Figure 2 and Figure 3 As shown, Figure 3 This is a schematic diagram of the overall structure of another detection device provided in some embodiments of this application. In some embodiments, the second region 202 has a first loop connected to the first region 201 and a second loop connected to the third region 203; along the first direction (Z direction), the orthographic projection of the first loop and the orthographic projection of the second loop coincide.

[0074] Understandably, region 202, as the core effective emission region for radiated photons, forms a first loop connecting to region 201 and a second loop connecting to region 203 at its two axial ends. In other words, the first loop serves as the boundary between region 202 and region 201, and the second loop serves as the boundary between region 202 and region 203. Of course, these loops can be virtual lines, merely used to distinguish region 202 from regions 201 and 203. As a curve in space, the above-mentioned loop can be completely projected along the first direction (Z direction). That is, the projections of the first loop and the second loop on the plane perpendicular to the first direction (Z direction) completely overlap. Then, the second region 202 is a surface that is rotationally symmetric about an axis (which is consistent with the first direction (Z direction) and passes through the center point 205). Combined with the fact that the distance from any point on the second region 202 to the center point 205 is equal, the second region 202 is a spherical ring.

[0075] This embodiment defines the first and second ring lines as having coincident orthographic projections to ensure that the spherical segment of the second region 202 is completely symmetrical within a 360° radial range. When photons emitted by the radiation point source pass through the second region 202, the thickness of the carrier 200 material they pass through is consistent regardless of the radial direction, thereby eliminating the attenuation differences caused by traditional irregular packaging and ensuring uniform radiation field within the effective solid angle.

[0076] like Figure 6 As shown, in some embodiments, the plane containing the first loop is parallel to the plane containing the second loop and is perpendicular to the first direction (Z direction).

[0077] For example, the spherical annulus of the second region 202 is presented as a spherical segment between two parallel planes, with its radial section being an arc centered at the center point 205, and its axial section also being a symmetrical arc, forming a perfectly circular spherical annulus around an axis (parallel to the first direction (Z-direction) and passing through the center point 205). In one example, the orthographic projection shape of the first or second annulus along the first direction (Z-direction) is circular. For example, the center of the first or second annulus coincides with the center point 205. In this example, the radial contour of the perfect circle avoids the problem of photon scattering easily at the corners of the polygonal annulus, which helps to reduce scattering coincidence and accidental coincidence noise. In addition, by adjusting the radius of the annulus and the plane spacing, it can be adapted to imaging devices 300 with different apertures and axial lengths, making it highly versatile.

[0078] like Figure 4 and Figure 5 As shown, Figure 4 This is a schematic diagram showing the maximum coincidence angle of the detection device provided in some embodiments of this application within an imaging device. Figure 5 This is a geometrical schematic diagram of the first, second, and third regions of a carrier provided in some embodiments of this application. In some embodiments, a point M is defined on the first ring line, and a point N is defined on the second ring line. The line connecting point M and point N is parallel to the first direction (Z direction). The angle between the line connecting point M and center point 205 and the line connecting point N and center point 205 is 2°. ;in:

[0079] (1)

[0080] Where L is the axial length of the imaging device 300; D is the aperture of the imaging device 300;

[0081] The shortest distance from the first or second loop to the center point 205 is h, where:

[0082] (2)

[0083] Where r is the distance from any point on the second zone 202 to the center point 205.

[0084] It is understood that this embodiment is based on the axial length L and aperture D of the imaging device 300, and the solid angle range of the second region 202 is quantified through geometric formulas to ensure that its coverage effectively conforms to the angle. If the center point 205 is defined as O, then the angle between line segments OM and ON is 2°. That is, the solid angle half-angle of zone 202 is The distance from any point on the second zone 202 to the center point 205 is R, and the shortest distance from the first loop to the center point 205 is equal to the shortest distance from the second loop to the center point 205, which is h. The above formula (1) is the calculation logic for the effective coincidence angle of the imaging device 300. The total axial length of the detector of the imaging device 300 is L, that is, the half length of the axial effective field of view is L / 2; the total radial aperture is D, that is, the half aperture of the radial effective field of view is D / 2, thus 2 This is the maximum effective coincidence angle of the imaging device 300 (detector). In other words, photons exceeding this angle cannot be received in pairs by the detector, thus failing to form a valid coincidence event.

[0085] Equation (2) can be derived through trigonometric relationships, thereby determining h. Determining h is beneficial for dividing the first region 201, the second region 202, and the third region 203. That is, it is sufficient to ensure that the second region 202 is a spherical ring, and the shapes of the first region 201 and the third region 203 are not restricted. Of course, the shapes of the first region 201 and the second region 202 can also be specially designed to avoid interference from invalid photons.

[0086] like Figure 6 As shown, in some embodiments, the first region 201 is a plane, and the plane containing the first region 201 is perpendicular to the first direction (Z direction).

[0087] In one example, the second zone 202 is a plane, and the plane containing the second zone 202 is perpendicular to the first direction (Z direction).

[0088] like Figure 2 As shown, in one example, the first region 201 is an arc surface, and the distance from any point on the first region 201 to the center point 205 is equal to the distance from any point on the second region 202 to the center point 205; or, the distance from any point on the first region 201 to the center point 205 is greater than the distance from any point on the second region 202 to the center point 205.

[0089] In one example, the third zone 203 is an arc surface, and the distance from any point on the third zone 203 to the center point 205 is equal to the distance from any point on the second zone 202 to the center point 205; or, the distance from any point on the third zone 203 to the center point 205 is greater than the distance from any point on the second zone 202 to the center point 205.

[0090] It is understandable that the shape design of Zone 201 and Zone 203 may include at least the following methods:

[0091] Method 1, such as Figure 3As shown, the first area 201 and the third area 203 are both planes perpendicular to the first direction (Z direction). Combined with the shape of the second area 202, the first area 201 and the third area 203 can be circles of the same size, and the circle of the circle coincides with the center point 205. This arrangement can save materials and reduce the weight of the support 200, which is beneficial to the stability during the movement.

[0092] Method 2, such as Figure 1 As shown, the first zone 201 and the third zone 203 are designed as curved surfaces, and these curved surfaces are spherical. The distance from any point on the first zone 201 and the third zone 203 to the center point 205 is equal, and also equal to the distance from any point on the second zone 202 to the center point 205. In other words, the first zone 201, the second zone 202, and the third zone 203 form a complete sphere. This design facilitates processing and manufacturing, and improves production efficiency.

[0093] Method 3: The shapes of the first region 201 and the third region 203 are designed as curved surfaces. The distance from any point on the first region 201 and the third region 203 to the center point 205 is greater than the distance from any point on the second region 202 to the center point 205. The paths from the first region 201 and the third region 203 to the center point 205 are extended, resulting in a longer path for the radiation source photons through the first region 201 and the third region 203, enhancing attenuation and reducing invalid photons emitted from the first region 201 and the third region 203, thereby reducing noise.

[0094] Method 4: The first zone 201 and the third zone 203 are designed as curved surfaces, the first zone 201 is a sphere, and the distance from any point in the first zone 201 to the center point 205 is equal to the distance from any point in the second zone 202 to the center point 205. The distance from the second zone 202 to the center point 205 is greater than the distance from any point in the second zone 202 to the center point 205.

[0095] Method 5: Zone 201 is a plane, and Zone 202 is an arc surface. The arc surface can be the arc surface in Method 2 or Method 3.

[0096] Of course, the shapes in the above examples can be combined in various ways, and are not limited to the five methods mentioned above. In this embodiment, the first region 201 and / or the second region 202 are designed as planes, which can reduce the processing difficulty. In particular, in 3D printing, there is no need to print complex curved surfaces for calibration, and the flat surface of the plane is conducive to directly pasting the absorber or positioning mark in the example below, which facilitates subsequent positioning and other functions. In addition, designing the first region 201 and / or the second region 202 as curved surfaces can eliminate the step effect at the junction of the plane and the curved surface, which helps to reduce the scattering of photons at the step and ensures that the outer surface of the carrier 200 is continuous and smooth.

[0097] like Figure 7 As shown, Figure 7 This is a schematic diagram of a split structure of a detection device provided in some embodiments of this application. In some embodiments, the carrier 200 includes a first base 210 and a second base 220 that are detachably connected. At least one of the first base 210 and the second base 220 is provided with a receiving groove 207 to form a receiving cavity 204 between the first base 210 and the second base 220. The outer surface of the first base 210 includes a first region 201 and a portion of a second region 202, and the outer surface of the second base 220 includes a third region 203 and another portion of the second region 202.

[0098] It is understood that the first base 210 and the second base 220 can be detachably connected by snap-fit, thread, or interference fit. For example, the first base 210 may have a protrusion on its edge, and the second base 220 may have a slot, resulting in no obvious gap after fastening. Furthermore, the surface of the first base 210 (facing the second base 220) has a receiving groove 207 that perfectly matches the shape of the package, and the surface of the second base 220 (facing the first base 210) is flat. After fastening, the receiving groove 207 and the surface of the second base 220 form a closed receiving cavity 204. Alternatively, the first base 210 and the second base may have receiving grooves 207, forming the receiving cavity 204 after fastening.

[0099] To minimize the design volume of the carrier 200, both the first substrate 210 and the second substrate 220 are provided with partial second regions 202, so that after being fastened together, they can be seamlessly connected to form a complete second region 202, creating a continuous spherical ring. This split design allows for quick replacement of encapsulation components with different nuclides or different activities.

[0100] like Figure 1 and Figure 3 As shown, in some embodiments, the first substrate 210 and the second substrate 220 have a docking boundary 206, and the center point 205 does not coincide with the plane where the docking boundary 206 is located.

[0101] Specifically, based on the aforementioned split design, the first substrate 210 and the second substrate 220, after being fastened together, form a mating boundary 206. That is, the plane containing the gap between the first substrate 210 and the second substrate 220 needs to be offset from the center point 205. This is to prevent some photons emitted by the radiation point source from directly escaping through the gap, causing the radiation intensity in that direction to be higher than in other directions, thus disrupting isotropy. This offset arrangement ensures that all photons must pass through the carrier material 200 before exiting, guaranteeing a uniform radiation field.

[0102] In some embodiments, the shortest distance between the inner wall of the receiving cavity 204 and the outer surface of the carrier 200 is 1mm-20mm. For example, the shortest distance between the inner wall of the receiving cavity 204 and the outer surface of the carrier 200 is 1mm, 3mm, 5mm, 10mm, 15mm, 20mm, etc., and can be set according to the size of the package and the measurable size of the activity meter; no specific limitation is made here. In this example, the distance should not be too small to ensure that the carrier 200 has sufficient structural strength and can effectively attenuate photons; nor should it be too large to control the overall volume of the carrier 200 so that it can be directly placed into a conventional radiation activity meter to measure the overall activity without the need for complex attenuation correction after disassembly.

[0103] In one example, the density difference between the carrier 200 and the package is 0.01 kg / m³. 3 -0.1kg / m 3 .

[0104] In one example, the density of the carrier 200 is the same as the density of the package.

[0105] In one example, the material of the carrier 200 is the same as that of the package.

[0106] Specifically, the density of the carrier 200 is made close to or the same as that of the package, so that the attenuation coefficient of photons passing through them is the same. This avoids the problem of greater attenuation in the package and less attenuation in the carrier 200 due to differences in material density, and further enhances the isotropic radiation. At the same time, the consistent density makes the overall activity measurement results more accurate.

[0107] Since the photons emitted from region 201 (first region) and region 203 (third region) are invalid photons, that is, photons in the invalid angle region are not only useless but also harmful. These photons may be scattered by planar materials, change direction, and fly into the effective coincidence angle, where they are recorded by the detector. These scattered photons distort the energy spectrum and reduce image contrast. Although these photons cannot form true coincidences, they can form accidental coincidences with other unrelated photons, increasing background noise.

[0108] Based on the same concept, this application also provides a detection system suitable for PET equipment, such as... Figure 8 and Figure 11 As shown, Figure 8 This is a schematic diagram of the adjustment mechanism of the detection system provided in some embodiments of this application. Figure 11The diagram below illustrates the structure of a detection system, including an imaging device and a moving mechanism, provided in some embodiments of this application. The PET device has a scanning cavity 301. The detection system may include a support structure 100, a carrier 200, and an adjustment mechanism 400. The carrier 200 is disposed on the support structure 100 and is divided into two halves that are interlocked. When the two halves are interlocked, they form a receiving cavity 204. An encapsulation component is embedded within the receiving cavity 204, and the encapsulation component contains a radiation point source for the PET device. The adjustment mechanism 400 is connected to the support structure 100 to adjust the carrier 200 to a target position within the scanning cavity 301.

[0109] It is understood that the detection system is used for comprehensive performance quality control of imaging equipment 300 such as PET and SPECT. The specific structure of the support structure 100 and the carrier 200 can be understood with reference to the above embodiment. The carrier 200 is equipped with a package, and the package contains a radiation point source, such as a Na-22 point source.

[0110] The adjustment mechanism 400 is connected to the support structure 100, for example, to the other end of the support rod. It can adjust the up and down and left and right positions of the detection device manually or electrically so that the radiation point source can be stabilized at any target position, for example, so that the radiation point source is aligned with the axis of the imaging device 300.

[0111] More specifically, such as Figures 8 to 10 As shown, Figure 9 This is a side view of the adjustment mechanism of the detection device provided in some embodiments of this application. Figure 10 This is a top view schematic diagram of the adjustment mechanism of the detection device provided in some embodiments of this application. In some embodiments, the adjustment mechanism 400 includes a base 410, a movable member 420, a first fastener, and a second fastener 430. The base 410 is configured with a guide groove 411 extending in a second direction (X direction), and the sidewall of the guide groove 411 is configured with a positioning hole 412; the movable member 420 is slidably disposed in the guide groove 411; the movable member 420 is configured with a guide channel 421 extending in a third direction (Y direction); the first fastener passes through the positioning hole 412 and abuts against the movable member 420; wherein, the support structure 100 is disposed at the guide channel 421 via the second fastener 430.

[0112] Understandably, the base 410, as the mounting base, can be fixed to the scanning bed or the moving mechanism 500 by bolts, snap-fits, etc., thereby providing stable support for the entire adjustment mechanism 400. The guide groove 411 is a groove or slide rail machined on the base 410 extending in the second direction (X direction), and its side wall is machined with multiple positioning holes 412. The guide groove 411 is configured to provide guidance and a preliminary moving path for the moving part 420, while the positioning holes 412 are used to cooperate with the first fastener to position and lock the moving part 420. The first fastener can be a bolt, screw, or quick clamp. If it is a bolt, it passes through the positioning holes 412 on the side wall of the guide groove 411, and the end of the bolt abuts against the moving part 420. When tightened, friction or mechanical interlocking is used to firmly fix the moving part 420 in the current position of the guide groove 411, realizing positioning and locking in the second direction (X direction).

[0113] The movable member 420 can be a slider or bracket that slides in the guide groove 411 along the second direction (X direction). Its upper part has a guide channel 421 extending along the third direction (Y direction), which can be a through hole or a guide rail. A support structure 100 of the detection device passes through the guide channel 421 of the movable member 420. When tightened, the support structure 100 is secured to the movable member 420; when loosened, the support structure 100 is allowed to move along the third direction (Y direction). More specifically, the end of the support rod is connected to the guide channel 421 of the movable member 420 via a second fastener 430 (bolt or screw), thereby fixing it to the adjustment mechanism 400. The other end of the support rod is fixed to the carrier 200.

[0114] In this embodiment, the adjustment mechanism 400 can accurately position and fix the radiation point source at any target location within the scanning field of view of the imaging device 300, thereby providing a basis for accurate quality control measurements. For example, the adjustment mechanism 400 can accurately position the carrier 200 so that it is always at the center of the scanning cavity 301, avoiding radial photon flux differences caused by eccentricity.

[0115] like Figure 11 As shown, in some embodiments, the PET device further includes an imaging device 300, a moving mechanism 500, and a processing unit. The imaging device 300 includes a detection component 310 defining a scanning cavity 301, the axis of which extends along a first direction (Z-direction); the moving mechanism 500 is connected to an adjustment mechanism 400 and configured to move the detection device within the scanning cavity 301 along the first direction (Z-direction); the processing unit is connected to the detection component 310 and the moving mechanism 500 and outputs the sensitivity S of the imaging device 300.

[0116] (3)

[0117] in, It is the total count after removing random matching data at time T, corresponding to The count needs to be deducted for the influence of transient photon events from the radiation point source. The specific deduction method is based on the threshold method in the chord graph domain. Further, please refer to the relevant content of NECR (noise equivalent counts rate) in NEMA NU-2018 regarding the method of obtaining true coincidence counts after deduction, which will not be described in detail here. It is the total number of measurements obtained within time T; A is the random coincidence data obtained through a delay window; A is the activity measured by an activity meter, and the effect of single-ended decay has been corrected. The decay path is the sphere radius r, and the corresponding coincidence time count is obtained; D is the decay correction coefficient.

[0118] Regarding the correction of activity measured by an activity meter, it can be further understood that the purpose of the activity meter is to measure the amount of decay. This measurement is based on inferring the number of decays from the total count of individual photons. In the absence of attenuation, the number of decays C can be directly inferred from the aforementioned decay laws and the measured number of individual photons. However, because the carrier material experiences attenuation (the attenuation radius is the radius r of the sphere), the true number of decays needs to be determined by considering the total count after attenuation correction. The correction factor is... The corrected count is .

[0119] In this embodiment, the detection process of the imaging device 300 is to measure a pair of coincidence events. If the total attenuation path traversed by this pair of photons is 2r, then the corresponding count of the coincidence event is:

[0120]

[0121] The above formula is based on the formula for converting single-photon activity to two-photon activity measured by the activity meter, which means that the above description requires an additional single-end attenuation effect on the measured activity level.

[0122] It is understood that the imaging device 300 includes a detection component 310, such as a PET detector ring, which is used to collect the timestamp, energy, and position data of gamma photons. The detection component 310 encloses a scanning cavity 301, and the axis of the scanning cavity 301 extends along a first direction (Z-direction). The moving mechanism 500 is connected to the base 410 of the aforementioned adjustment mechanism 400 to drive the entire detection device to move continuously and smoothly within the scanning cavity 301 along the first direction (Z-direction), thereby traversing the entire axial field of view of the scanning cavity 301, that is, the stroke covers the axial length L of the imaging device 300. The moving mechanism 500 can be the original scanning bed of the imaging device 300 and the drive motor that drives the scanning bed to move, or it can be an additional linear drive module integrated into the adjustment mechanism 400, such as a linear motor, etc., without limitation. In addition, the moving mechanism 500 can drive the entire detection device to move back and forth along the first direction (Z-direction) or move once in a single stroke to cover the entire axial field of view.

[0123] The processing unit can acquire the movement information of the moving mechanism 500, including the moving speed, starting position and ending position, etc., and receive and process the raw coincidence event data collected by the detection component 310, and calculate and output the sensitivity S of the imaging device 300 according to formula (3). Of course, it can also calculate the TOF resolution and other performance parameters of the imaging device 300 according to the above data.

[0124] More specifically, this embodiment controls the movement range of the moving mechanism 500 to simulate the 70cm wire source required by the NEMA standard or other wire sources of arbitrary length, making the system applicable to PET systems of various shaft lengths. Furthermore, the processing unit uses the overall activity A, which is directly measured by an activity meter and already includes attenuation, as a benchmark for sensitivity calculation, thereby avoiding complex and potentially inaccurate attenuation correction calculations and significantly improving the accuracy of sensitivity data.

[0125] The detection system provided in this embodiment can simultaneously acquire all the data required for calculating sensitivity, TOF resolution, energy spectrum, and uniformity in a single scan, enabling the acquisition of key parameters under identical conditions in one go, thus enhancing the consistency and reliability of the results. The TOF resolution is calculated by equating a moving point source to a dynamic line source, analyzing the time difference of coincidence events at different locations, and fitting the time-resolved standard deviation.

[0126] Based on the same concept, this application also provides a detection method, which is applied to the detection system described above. The detection method may include:

[0127] Step S101: Install the package into the detection device and obtain the overall activity of the detection device measured by the activity meter as a reference value;

[0128] Step S102: Adjust the adjustment mechanism 400 to the target position. The adjustment mechanism 400 is used to support the detection device.

[0129] Step S103: Control the moving mechanism 500 to move in the scanning cavity 301 of the imaging device 300 along a set direction. The moving mechanism 500 is used to support the adjustment mechanism 400.

[0130] Step S104: Continuously receive the measurement values ​​sent by the detection component 310 and compare the measurement values ​​with the reference values ​​to complete the detection of the imaging device 300.

[0131] Understandably, regarding step S101, by installing the encapsulation containing a radiation point source (e.g., Na-22) within the receiving cavity 204 of the carrier 200 of the detection device, it is ensured that the radiation center of the point source coincides with the center point 205 (center of the sphere) of the carrier 200. Subsequently, the entire carrier 200 with the encapsulation installed is removed from the support structure 100 and placed in an activity meter to measure its overall radioactivity A. It should be noted that the activity A measured in this step already includes the attenuation of photons by the encapsulation material of the carrier 200. Therefore, this value can be directly used as the absolute reference value for subsequent calculations of system sensitivity without any further attenuation correction calculations. Of course, this step can be performed at the beginning of the detection process or after the detection process is completed. This flexible design allows users to verify the source strength before detection or to accurately measure the activity after detection for retrospective calculations, thus adapting to different workflows and quality control specifications.

[0132] Regarding step S102, the carrier 200 and the radiation point source on it are precisely moved and fixed to the target position by adjusting the adjustment mechanism 400. The target position is usually the center point of the scanning field of view of the imaging device 300, or it can be the off-center point of the scanning field of view of the imaging device 300.

[0133] Regarding step S103, the detection program is initiated, and the moving mechanism 500 is controlled to drive the entire adjustment mechanism 400 and the detection device to move continuously and at a constant speed along the axial direction of the scanning cavity 301 of the imaging device 300. The starting and ending points of the movement can be set as needed, for example, simulating the 70cm line source length required by the NEMA NU2-2018 standard. During this process, the point source is equivalent to an ideal long line source with uniform activity distribution, passing through the entire axial field of view. The setting direction in this embodiment can be understood as a direction parallel to the first direction (Z direction).

[0134] Regarding step S104, during the scanning movement, the detection component 310 (e.g., detector ring) of the imaging device 300 continuously collects coincidence event data and sends the raw count data (i.e., measured values) to the processing unit. The processing unit synchronously records the position information of the moving mechanism 500 and performs real-time or post-processing on the received data. This includes calculating the sensitivity of the imaging device 300 according to the above formula (3), comparing the calculated sensitivity and other parameters with preset performance standards, and determining whether the imaging device 300 is in a qualified state. For example, the processing unit can generate a quality control report containing multiple results such as sensitivity, TOF resolution, energy spectrum characteristics, and uniformity, thereby completing the inspection of the imaging device 300.

[0135] This embodiment directly measures the overall baseline activity A in step S101, thus eliminating the complex, indirect, and error-prone process of traditional NEMA methods, which requires five data acquisitions using multiple layers of tubing and then calculating the attenuation-free sensitivity through exponential fitting. This embodiment directly substitutes A into the formula for calculation, making sensitivity measurement extremely simple, fast, and more accurate.

[0136] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0137] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A detection device, characterized in that, For an imaging device (300), the detection device includes: Support structure (100); A carrier (200) is disposed on the support structure (100). The carrier (200) is constructed with a receiving cavity (204). The receiving cavity (204) is configured to embed an encapsulation, and the encapsulation contains a radiation point source. The radiation point source installed in the receiving cavity (204) can coincide with the center point (205) of the carrier (200). The carrier (200) is divided into at least two openable halves along a first direction; the first direction is consistent with the direction of the carrier (200) away from the support structure (100).

2. The detection device according to claim 1, characterized in that, The outer surface of the carrier (200) includes a first region (201), a second region (202) and a third region (203) arranged sequentially along a first direction. The distance from any point on the surface of the second region (202) to the center point (205) is equal.

3. The detection device according to claim 2, characterized in that, The second region (202) has a first loop connected to the first region (201) and a second loop connected to the third region (203); along the first direction, the orthographic projection of the first loop and the orthographic projection of the second loop coincide.

4. The detection device according to claim 3, characterized in that, The plane containing the first loop is parallel to the plane containing the second loop and perpendicular to the first direction; And / or, the orthographic projection shape of the first loop or the second loop along the first direction is circular.

5. The detection device according to any one of claims 2-4, characterized in that, The carrier (200) includes a first base (210) and a second base (220) that are detachably connected, and at least one of the first base (210) and the second base (220) is provided with a receiving groove (207) to form the receiving cavity (204) between the first base (210) and the second base (220). The outer surface of the first substrate (210) includes the first region (201) and a portion of the second region (202), and the outer surface of the second substrate (220) includes the third region (203) and another portion of the second region (202).

6. The detection device according to claim 5, characterized in that, The first substrate (210) and the second substrate (220) have a docking boundary (206), and the center point (205) does not coincide with the plane where the docking boundary (206) is located.

7. The detection device according to any one of claims 1-4, characterized in that, The shortest distance between the inner wall of the receiving cavity (204) and the outer surface of the carrier (200) is 1mm-20mm; And / or, the density difference between the carrier (200) and the package is 0.01 kg / m³. 3 -0.1kg / m 3 ; And / or, the density of the carrier (200) is the same as the density of the package; And / or, the material of the carrier (200) is the same as the material of the package.

8. A detection system suitable for PET equipment, said PET equipment having a scanning chamber (301), characterized in that, The detection system includes: Support structure (100); A carrier (200) is provided on the support structure (100). The carrier (200) is divided into two halves and is snapped together. The two halves are snapped together to form a receiving cavity (204). A package is embedded in the receiving cavity (204). The package contains a radiation point source for the PET equipment. An adjustment mechanism (400) is connected to the support structure (100) to adjust the carrier (200) to the target position of the scanning cavity (301).

9. The detection system according to claim 8, characterized in that, The PET equipment includes: An imaging device (300) includes a detection assembly (310) defining a scanning cavity (301) whose axis extends along a first direction; A moving mechanism (500) is connected to the adjusting mechanism (400), and the moving mechanism (500) is configured to drive the carrier (200) to move in the scanning cavity (301) along the first direction.

10. The detection system according to claim 9, characterized in that, The adjustment mechanism (400) includes: The base (410) is provided with a guide groove (411) extending in a second direction, and the sidewall of the guide groove (411) is provided with a positioning hole (412). A movable element (420) is slidably disposed in the guide groove (411); the movable element (420) is configured with a guide channel (421) extending in a third direction. The first fastener passes through the positioning hole (412) and abuts against the moving part (420); The support structure (100) is located at the guide channel (421) via a second fastener (430).

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