Spiral SPECT with flexible and adaptive detector array

Abstract

An imaging system for gamma ray imaging, comprising: a gantry having an opening configured to receive a patient to be imaged; and a plurality of imaging arms. The arms each include a detector head having an imaging plane that receives and detects gamma radiation from a patient and an arm coupled to the gantry using a plurality of actuators, the plurality of actuators are configured to move the probe heads radially within the gantry, tilt the imaging faces relative to the axes of the arms, and adjust the spacing between the probe heads on adjacent imaging arms. The processor is configured to coordinate movement of the imaging arms such that the imaging planes of the plurality of imaging arms together selectively form one of a plurality of predetermined imaging surfaces within the gantry. One of the predetermined imaging surfaces is a flat plane having a uniform pitch of the plurality of detector heads suitable for planar imaging. Other surfaces are suitable for tomography imaging.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 478,519, filed January 5, 2023, which is incorporated herein by reference in its entirety. Technical Field

[0003] The present application relates generally to the field of emission imaging and more particularly to SPECT imaging, in which both tomographic and planar imaging are used to image a patient. Background Art

[0004] Single photon emission computed tomography (SPECT) is a nuclear medicine (NM) tomographic imaging technique that uses gamma ray emissions from patient tissue. Standard computed tomography (CT) images the transmission of radiation (e.g., x-rays). SPECT and CT imaging are typically performed in a single imaging system, allowing flexible radiological scanning of patients from a single machine. Many current clinical SPECT / CT systems deployed in industry use large field of view (FOV) gamma cameras, resulting in the machine occupying a large footprint (e.g., more than 20 m2). 2 ). For example, the Symbia Pro.Specta SPECT / CT system is a room size optimized system requiring a minimum room size of 5.6m x 3.7m. The basic technical problem is the use of an Anger camera (a gamma camera using NaI scintillator plates and photomultiplier tubes) that uses a multi-channel collimator to form a projection image (2D) of the 3D activity distribution at a certain viewing angle relative to the patient. If only planar scintigraphy is clinically indicated, a few angular exposures may be sufficient for the scan. If tomography is required, multiple exposures must be acquired that sample at least a 180 degree arc around the long axis of the patient. The axial dimension (parallel to the patient axis) of a large FOV anger camera is typically about 40 cm and the transaxial (meaning the non-radial axis normal to the axial direction) dimension is about 50 cm, enabling the evaluation of anatomically relevant features in one scintigraphy exposure. Such detectors are large (2000 cm 2), must typically be shielded from stray gamma radiation, and weigh more than 200 kg. The support gantry is designed accordingly to enable the required rotational and translational motion of the detector. Other designs using room temperature semiconductor detectors (RTSDs), such as cadmium zinc telluride (CZT) crystals (instead of photomultipliers), require multi-channel collimation, which still leads to large room size requirements. That is, in order to enable sufficient tomographic observation coverage for multiple surrounding detector elements, a slewing motion is typically required in addition to the rotational and translational motion. Other designs with smaller coverage areas (including dedicated organ cameras) use fixed pinhole-based tomographic imaging methods with a fixed arc and pinhole distribution, and are only able to image the specific (however incomplete) organ in question (e.g. the heart), and do not fully cover the entire torso.

[0005] These conventional designs utilize gamma detectors, which are typically large and expensive, making adding more than a few detectors impractical. Furthermore, these detectors tend to be relatively large in the axial direction to increase particle counts and thus ensure image quality. The small number of detectors and long axial length mean that helical imaging, while theoretically possible, is impractical in a medical setting. Summary of the Invention

[0006] This document describes systems and methods for capturing gamma-ray images of a patient by utilizing imaging arms with several degrees of freedom to reposition and rearrange gamma-ray cameras to form imaging surfaces of different shapes from the face of the cameras. These arms allow a single set of imaging arms to capture different imaging types, including planar and helical imaging.

[0007] According to one embodiment, an imaging system includes: a gantry having an opening configured to receive a patient to be imaged and a ring configured to orbit the patient under processor control; a plurality of detector heads having imaging surfaces configured to receive and detect gamma radiation from the patient; and a plurality of extendable radial arms. The radial arms are each coupled to the ring at a plurality of locations along the ring and are configured to radially translate one of the plurality of detector heads and orient the imaging surface of each detector head under processor control. The processor is configured to coordinate the movement of the plurality of extendable radial arms so that the imaging surfaces together form a plurality of predetermined imaging surfaces within the gantry. At least one of the predetermined imaging surfaces comprises a flat plane having uniform spacing of the plurality of detector heads.

[0008] According to another embodiment, an imaging system includes: a gantry having an opening configured to receive a patient to be imaged; and a plurality of imaging arms. Each arm includes a detector head having an imaging surface for receiving and detecting gamma radiation from the patient and an arm coupled to the gantry using a plurality of actuators. The plurality of actuators are configured to move the detector heads radially within the gantry, tilt the imaging surface relative to the axis of the arm, and adjust the spacing between the detector heads on adjacent imaging arms. A processor is configured to coordinate the movement of the plurality of imaging arms such that the imaging surfaces of the plurality of imaging arms together selectively form one of a plurality of predetermined imaging surfaces within the gantry. At least one of the predetermined imaging surfaces includes a flat plane having uniform spacing of the plurality of detector heads.

[0009] According to one aspect of some embodiments, at least one of the predetermined imaging surfaces comprises two orthogonal flat planes, wherein there is uniform spacing of the plurality of detector heads within each plane. According to another aspect of some embodiments, at least one of the predetermined imaging surfaces comprises a curved surface, wherein there is uniform spacing of the plurality of detector heads within each plane. According to another aspect of some embodiments, there are no significant gaps in the spacing of the plurality of detector heads within the flat planes. According to another aspect of some embodiments, the size of each imaging surface is in the range of 7 to 12 cm by 10 to 16 cm. According to another aspect of some embodiments, at least one predetermined imaging surface comprises a subset of the plurality of detector heads, and another subset of the plurality of detector heads is retracted.

[0010] According to another aspect of some embodiments, the processor is further configured to control the movement of the ring and capture a spiral image of the patient. According to another aspect of some embodiments, the processor is further configured to control the movement of the plurality of extendable radial arms so that the plurality of detector heads orbit in a non-circular orbit. According to another aspect of some embodiments, the processor is further configured to capture a stationary planar image of the patient. According to another aspect of some embodiments, the processor is further configured to capture a tomographic image of the patient. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The accompanying drawings, which are incorporated in and form a part of the specification, illustrate embodiments of the present invention and, together with the written description, serve to explain the principles, characteristics, and features of the present invention. In the drawings:

[0012] Figure 1 is a schematic diagram of an extendable radial arm and a detector head used in some embodiments;

[0013] Figures 2A-2B is a schematic diagram of an extendable radial arm and a detector head used in some embodiments;

[0014] Figure 3 is a schematic diagram of an extendable radial arm and a detector head used in some embodiments;

[0015] Figures 4A-4B is a schematic diagram of an extendable radial arm and a detector head used in some embodiments;

[0016] Figures 5A-5D is an axial view of an exemplary gantry and arm arrangement used in some embodiments;

[0017] Figures 6A-6C is an axial view of an exemplary arm and detector arrangement used in some embodiments;

[0018] Figure 7 is a system diagram of an imaging system that may be used in some embodiments; and

[0019] Figure 8 is a perspective view of an exemplary imaging system that may be used in some embodiments. DETAILED DESCRIPTION

[0020] The present disclosure is not limited to the particular systems, devices, and methods described, as these may vary. The terminology used in the description is for the purpose of describing the particular versions or embodiments only and is not intended to limit the scope.

[0021] As used herein, the terms "algorithm," "system," "module," or "engine," if used herein, are not intended to limit any particular embodiment to implement and / or perform the actions, steps, processes, etc. attributable thereto and / or performed by it. An algorithm, system, module, and / or engine may be, but is not limited to, software, hardware, and / or firmware, or any combination thereof, that performs the specified functions, including but not limited to any combination of general-purpose and / or special-purpose processors and appropriate software loaded or stored in a machine-readable memory and executed by the processor. Furthermore, unless otherwise noted, any names associated with a particular algorithm, system, module, and / or engine are for ease of reference and are not intended to limit to a particular embodiment. Additionally, any functionality attributed to an algorithm, system, module, and / or engine may be equally performed by multiple algorithms, systems, modules, and / or engines, incorporated into and / or combined with the functionality of another algorithm, system, module, and / or engine of the same or different type, or distributed across one or more algorithms, systems, modules, and / or engines in various configurations.

[0022] Embodiments of a SPECT / CT scanner address one or more of these challenges by including multiple movable detectors in a circumferential gantry surrounding a patient on a slidable couch. The detectors can be moved circumferentially along the gantry (in some embodiments, individually or as a group) to create a given detection / image. Simultaneously, the patient is positioned axially by sliding the couch (typically aligned parallel to the sagittal plane) through the plane of the gantry (aligned parallel to the patient's transverse plane). In some embodiments, the couch can translate in three directions. In addition to moving along a circumferential orbit within the gantry, the detectors can be independently positioned radially by linear actuators under processor control to selectively position the imaging head closer to the patient, thereby improving collimation resolution and gamma ray collection. Furthermore, the detector head (the detector positioned near the patient at the distal end of the arm) can be swiveled relative to the linear actuators (under processor control). In some embodiments, the detector head and arm include additional degrees of freedom to aid in proper placement and orientation of the detector head. This allows for off-radius focusing of one or more detectors. This can be used to focus tomographic imaging at locations within the patient that are either centered within the gantry or off-center. Furthermore, this arrangement can be used to selectively place the planes of the individual detector heads in the same plane to capture planar images. Thus, a single machine can be used for 2D planar imaging or tomography using only a few radially extendable gamma detectors.

[0023] US Patent 9,213,110 describes a SPECT system that uses a series of radially extendable detector columns that can be attached to a gantry at predetermined circumferential positions, allowing them to orbit at a fixed angular distance from each other. These columns have gamma detectors that are elongated in the patient axial direction but very narrow in the transaxial direction (using <4×4 cm detector elements arranged in rows of up to seven elements). This narrow shape is necessary to allow the detector head of each column to be tilted along an axis parallel to the patient and gantry plane axes within a narrow, elongated housing. Tilting the detector heads is used to adjust the field of view of each detector head.

[0024] While the form factor of the detector array disclosed in U.S. Patent 9,213,110 requires narrow transversely axial detector heads, the embodiments disclosed herein use a different approach, employing detector heads that are intentionally wider than those. An advantage of this arrangement is that the detector heads can slide radially and tilt to form a flat row of detector plates for planar imaging. Exemplary detector heads used in some embodiments utilize a more square-like aspect ratio, such as 8-10 cm x 12-14 cm detectors. These less slender (in the axial direction) and wider (in the transversely axial direction) detectors have certain advantages. The shorter axial dimension results in less reuse of axial slices of the anatomy, which makes helical imaging possible. At the same time, the wider transversely axial dimension allows for more gamma ray collection within a given anatomical slice, for faster imaging at a given axial position. It also facilitates the placement of adjacent detectors with little gap between them. When the detector arms are extended radially so that the detector pivot points are in line, the detector heads can be tilted to form a single plane with minimal gap. This is suitable for 2-D planar imaging. Thus, by using a wider, less elongated detector head, the detector can be tiled for planar imaging, or formed into a circle or ellipse (or an arc thereof) for 3D tomography. By configuring the detector head into an arc (or orthogonal planes), helical (by axially translating the patient) or 4D imaging is possible.

[0025] For example, these more rectangular gamma detectors for the detector head can be achieved by using a 2-D tiling of the gamma detector / Compton camera explained in U.S. Patent 11,647,973, which is incorporated herein in its entirety. These detectors include a collimating pinhole plate, a scintillation crystal, and a plurality of solid-state light detectors or photomultiplier tubes. The detector head can be divided into an array of tiles or formed into a single unit with a single collimating plate. It should be noted that any suitable configuration of collimating plates can be used, such as a grating with parallel holes or with slightly non-parallel holes that produce a lens focusing effect.

[0026] The collimator plate of the gamma detector includes multiple pinholes that can be parallel or multiplexed, focused / amplified. A wider detector allows for parallel or multiplexed / focused collimators. An exemplary detector head includes an imaging surface having a total of 8-10 cm by 12-14 cm of collimator, scintillator, and solid-state photodetector array. In some embodiments, the exemplary detector head is 7-12 cm by 10-16 cm.

[0027] Figure 1is a block diagram illustrating exemplary features for an extendable radial arm that can support a detector head and provide at least two degrees of freedom (in this case, radial distance and one degree of freedom of tilt). The radial arm is coupled to a ring within the gantry of an imaging device. The arm extends inward from the gantry at a central opening toward a patient lying on a bed within the opening in the gantry where the cantilevered arm extends. The ring can rotate within the gantry to allow the detector head at the distal end of each radial arm to orbit around the patient to collect gamma ray radiation to image the patient's anatomy. A radial arm 10 includes a body 12 coupled to the ring of the gantry (not shown, but understood to be at the top of the page) and a linear actuator 14 including an extension rod 16 (e.g., a piston or ball screw) that can be extended away from the proximal end of the arm (top of the page) under control of a processor. An example of such extension is shown in dashed lines. Any suitable linear actuation mechanism can be used, including a linear motor, a motor driving a ball screw, or a pneumatic or hydraulic piston. The linear actuator should be suitable for processor control, including encoding so that the processor can determine the extension of the linear actuator. This allows precise radial distance control of the probe head to be achieved by the processor. The linear actuator also includes an appropriate drive for the motion mechanism.

[0028] At the distal end of the rod 16, a pivot point 18 provides a pivot axis for a probe head 20. Any suitable gamma camera may be used with the probe head 20. Within the housing of the probe head 20, a motor or other suitable drive mechanism may pivot the probe head 20 relative to the rod 16 at the pivot point 18 under processor control. Figure 1 In the example of FIG. 1 , the processor actuates linear actuator 14 to radially extend rod 16, thereby extending the distal end of the rod and thereby extending pivot point 18 (thereby reducing the radial distance from the center of the gantry as it extends). A motor (e.g., a stepper motor) within the housing of detector head 20 allows the processor to rotate detection surface 21 (the base of the exemplary trapezoid) to angle the collimation plates of the detector head toward the desired target. This is shown in posture 20a. Thus, the processor controlling radial arm 10 can control the distal position and orientation of the detector's imaging surface 21 relative to the proximal base of the radial arm coupled to the gantry.

[0029] Although the body 12 and rod 16 are shown as being substantially wider than one another, any suitable arrangement may be used. For example, the drive components of the linear actuator 14 may be housed within a radially movable housing rather than as a housing. Figure 1The radial arm is shown as being located in a fixed portion of the radial arm. Additionally, a shield can be placed around any portion of the radial arm to protect the mechanical and electronic components from the hospital environment. Note that these illustrative embodiments are not to scale, and the arms can be wider / narrower or longer / shorter, depending on design needs. Similarly, the exact shape of the detector head can be very different without changing the illustrative functionality.

[0030] Figure 2A An alternative embodiment of a radial arm 10a is shown having an additional degree of freedom to translate the detector head relative to the centerline of the linear actuator. Similar to radial arm 10, radial arm 10a includes a body 12 and actuator 14, as well as an extension rod 16 and a pivot point 18. However, this embodiment adds a sliding slot 22 within the detector 20. This allows the body of the detector 20 to translate to the right or left relative to the pivot point 18. This translation can be accomplished under processor control using a linear actuator or a motor with a rack and pinion transmission. Posture 20b provides an example of how the processor can orient the imaging plane of the detector 20. In this example, the rod 16 extends radially and the pivot point translates laterally relative to the body of the detector head 20. This allows for extension, tilt, and offset of the imaging plane 21 for more precise placement. Specifically, slot 22 provides an additional degree of freedom to allow the center of the imaging plane to move laterally from the centerline of the radial arm 10a. This allows the processor to adjust the spacing of the imaging planes on adjacent radial arms.

[0031] Figure 2B Two additional postures 20c and 20d are shown. In these postures, the linear actuator is extended and the detector head is pivoted about the pivot point 18 and slides relative to the pivot point using the slot 22. This can be achieved by using a drive in the linear actuator 14 (e.g., a motor and ball screw) to extend the rod 16; using a motor in the detector head 20 to pivot the body of the detector head relative to the pivot point 18; and using an actuator or motor in the detector head 20 to provide additional translation of the imaging plane 21 relative to the pivot point 18.

[0032] Figure 3Another embodiment of a radial arm 10b having additional degrees of freedom compared to the radial arm 10 is shown. In this example, the body 12 and the actuator 14 are similar, but the rod 16 is connected to an intermediate member 26, which is connected to the distal end of the rod 16 via a pivot 24. The intermediate member includes a pivot point 18 at its distal end, thereby allowing the body of the detector head 20 to move relative to the pivot point 24. The pivot point 24 can be managed by a stepper motor within the member 26, the rod 16 (or mounted thereon), or within the detector head 20 (and can be driven via a belt or gear drive). Alternatively, the intermediate member 26 can be connected to two linear actuators (instead of a single actuator as shown). If the member 26 is connected to the two actuators at an offset pivot point (instead of a single pivot point 24), any difference in the actuator length will result in an angular difference between the rod 16 and the member 26. In some embodiments, the intermediate member 26 is within the body of the detector head 20, thereby allowing a more compact arrangement. In some embodiments, the pivot point 24 may be offset from center in the probe head 20 to increase the offset effect.

[0033] Posture 20e illustrates how the intermediate member 26 can be used to change both the orientation of the face of the detector head and the offset of the face relative to the centerline of the rod 16. In posture 20e, an "a" will be added to each component to explain how they result in posture 20e. The rod 16a extends, causing the pivot point 24a to extend radially toward the patient. The intermediate body 26a pivots relative to the rod 16a, causing the pivot point 18a to be offset relative to the centerline actuator. The detector head pivots relative to the position, causing the detector head to be oriented in posture 20e. This results in extension (via rod 16a), tilt (via pivot point 18a), and offset from the centerline of the linear actuator 14 (via intermediate body 26a). The intermediate body 26 and the additional pivot point 18 provide additional degrees of freedom to allow the center of the imaging plane to move laterally from the centerline of the radial arm 10a. This allows the processor to adjust the spacing of the imaging planes on adjacent radial arms.

[0034] Figure 4A An additional way of adding another degree of freedom in the radially extending arm 10c is shown. A pivot point 28 at the base of the actuator 14 provides a degree of freedom that allows the face 21 to move relative to the normal centerline. This pivot point can be driven by a motor, or it can be a natural result of two linear actuators replacing the actuator 14, where the bases of the two karts have offset pivot points at the proximal ends and share a common pivot point 18. Any difference in the length of the two actuators will naturally cause the pivot point 18 to move left or right. In some embodiments, for example, Figure 4BIn the embodiment shown, the housing 12 of the arm may be secured with a hollow opening large enough to allow left or right movement of the pivot point 18 to occur without interference between the body 12 and the actuator 14. In some embodiments, the housing 12 pivots with the actuator 14. Figure 4A Posture 20f is shown in which the actuator 14 is extended, allowing the face of the detector 20 to move closer to the patient and away from the normal centerline. Figure 4B A similar embodiment of arm 10d is shown, where housing 12a is fixed, but with an opening large enough to allow posture 20f to be achieved without interference between housing 12a and rod 16. The pivot provides an additional degree of freedom to allow the center of the imaging plane to be moved laterally from the radial centerline of radial arm 10c. Note that these previous examples place the radial arms along radial lines of the imaging gantry (not shown, but assumed to be at the top of the page). Thus, the radial centerlines of the radial arms are directly below the page, forming an imaginary line from the gantry circumference to the gantry center. This allows the processor to adjust the spacing of the imaging planes on adjacent radial arms.

[0035] The reason for these additional degrees of freedom in the aforementioned embodiments is generally to allow the detector imaging plane to be offset relative to the natural centerline of the radially extending arms under processor control. When different radially extending arms have different degrees of radial extension, this offset allows for uniform spacing between the planes of adjacent detector heads for non-circular imaging arrangements. This can be an important feature in the case of planar imaging, as 2D imaging benefits from a uniform arrangement of detector heads without significant gaps between adjacent detectors. Figures 2A-4B The embodiments in FIGURE 1 show a radial detector arm with three degrees of freedom: radial extension (e.g., via a linear actuator), tilt of the detector head body relative to the axis of the radial arm (e.g., via a rotary actuator), and one additional degree of freedom that varies depending on the embodiment (which allows adjustment of the spacing between adjacent detector head imaging planes). Note that adjusting the spacing between adjacent detector heads does not necessarily refer to adjusting the radial extension, which naturally changes the spacing because the closer the ends of the arms are to each other, the closer the ends move to the center point. Rather, adjusting the spacing refers to offsetting the center of the imaging plane from a radial line of the gantry, while allowing for both radial extension and tilt (orientation) of the imaging plane.

[0036] Figure 5A An axial view of an imaging system 30 is shown. An annular gantry 32 includes an inner ring 33 that can swivel relative to the gantry housing. This allows a detector head coupled to the inner ring 33 to orbit around the patient during tomographic imaging or for placement of stationary 2-D views. In this example, the inner ring 33 includes a plurality of available detector position slots 34. Radial arms 36 can be removable and selectively placed into these positions prior to imaging. These arms can be Figure 1-4B . In this example, twelve arms are placed in every other slot of the twenty-four possible slots 34. The radial arm can be connected to the slot at any one of these positions. The slot 34 may include mechanical and electrical connection components, which are suitable for removably holding the radial arm and for providing power, control signals and image data paths to the arm and its detector head. In some embodiments, the slots 34 or fixed positions in the ring 33 allow for selective installation of the radial arm. In some embodiments, the slots 34 are movable relative to each other within the ring 33. The bed 38 is located near the middle of the opening, allowing the patient to be selectively placed within the ring. The bed 38 can slide and translate at least in the vertical direction (in some embodiments, left / right).

[0037] Figure 5B An exemplary arrangement of seven radial arms 40 within a slot 34 is shown. In this example, the radial length of each arm 40 has been adjusted for planar imaging. To illustrate the length, the detector head is not shown, but Figure 6A Figure 2-C provides additional illustration of how the detector heads can be arranged. Note that the spacing between the distal ends of the arms 40 can vary when the distal ends are aligned. This can be addressed with the additional degree of freedom shown in Figures 2-4B, which allows the face of the detector head to translate to selectively change or remove the gap under processor control.

[0038] Figure 5C A related example is shown in which the arms are arranged in slot 34 in several different groups. Group 41 includes five radial arms arranged for planar imaging below the patient. Group 42 is arranged and extended to provide planar imaging in an orthogonal direction to the patient's side. At the same time, arm 43 has been fully retracted by the processor to prevent mechanical interference between the detector heads. The detector heads attached to the distal ends of arms 42 and 43 can be tilted to provide two orthogonal planar imaging surfaces.

[0039] Figure 5D An example is shown in which the radial arms form half of an elliptical imaging surface. Note that the ends of the arms form a non-circular arc facing the patient. The detector heads on the distal ends of these arms can form a generally continuous semi-elliptical imaging surface. In some embodiments, as the gantry 32 orbits around the patient, the arms automatically extend and retract under processor control so that the detector heads follow the elliptical imaging surface around the patient (of which only half exists at a given time). In this example, some arms (e.g., arm 45) are extended to participate in the imaging surface, while some arms (e.g., arm 46) are fully retracted to avoid mechanical interference. This is particularly important in areas where the arms are almost fully extended.

[0040] Figures 6A-6C are axial views of different arrangements of imaging surfaces that can be created under processor control, such as in Figures 5A-5D In the example shown in . In arrangement 50, arm 54 is extended and detector head 52 is further translated to form a planar imaging surface. In this example, the detector heads are translated to substantially contact so that this forms a continuous planar surface without significant gaps. Although gaps should be minimized in the case of a planar imaging surface, if the gap is less than 5 mm, the gap is insignificant.

[0041] In arrangement 50a, the detector head 52 is formed as an arcuate imaging surface with small uniform gaps. These gaps can provide spacing to avoid mechanical interference, especially when the arm can move during gantry orbiting to maintain the imaging surface shape relative to the patient reference frame during orbiting.

[0042] In arrangement 50b, the arm 54 is extended and the detector head 52 is further translated to form two planar imaging surfaces.

[0043] Medical Imaging System Architecture:

[0044] Figure 7 A SPECT system 400 is shown that can implement the process 300 described above. The system 400 includes a gantry 402 to which two or more gamma cameras 404a, 404b are attached, although any number of gamma cameras can be used. A detector within each gamma camera detects gamma photons (i.e., emission data) emitted by a patient on a bed 408 or a radioisotope within a phantom 406.

[0045] The couch 408 is capable of moving the patient or phantom 406 along axis A and / or axis B. At a corresponding couch position (i.e., imaging position), a portion of the patient 406 is positioned between the gamma cameras 404A, 404B to capture emission data from the body portion. The gamma cameras 404a, 404b may include multi-focal cone beam collimators or parallel hole collimators as are known in the art. The cameras 404a and 404b are merely illustrative, and in some embodiments their mechanical arrangement may be understood as being used in a Figure 1-6C institutions discussed in .

[0046] The camera typically includes a collimator, a scintillation crystal, and a photosensor array. The scintillation crystal may include a thallium-doped sodium iodide crystal that generates photons in response to gamma radiation received from the patient.

[0047] Conventionally, a radioisotope is administered to a patient. While in the patient's body, the radioisotope emits gamma photons, which subsequently leave the patient. The gamma photons are collimated by a collimator in each camera / detector head to define their line of response and filter out scattered or stray gamma radiation. The collimated photons are received at various locations in scintillation crystals, which convert the gamma radiation into visible light photons that can be detected by the sensor array.

[0048] The sensor array may include a photomultiplier tube (PMT) array. A typical PMT of a sensor array may include a translucent photocathode, a focusing grid, dynodes, and an anode. The sensor array converts visible photons emitted by the scintillation crystals into an electronic signal representing the number of collected visible photons. A signal processing unit receives the electronic signal from the sensor array and processes the electronic signal to generate an image of the patient's anatomical structure. Solid-state photodetectors may also be used in the sensor array.

[0049] Control system 420 may include any general-purpose or special-purpose computing system. Thus, control system 420 includes: one or more processing units 422 configured to execute processor-executable program code to cause system 420 to operate as described herein; and a storage device 430 for storing the program code. Storage device 430 may include one or more fixed disks, solid-state random access memory, and / or removable media (e.g., a thumb drive) installed in a corresponding interface (e.g., a USB port).

[0050] The storage device 430 stores program code for a system control program 432. The one or more processing units 422 can execute the system control program 432 in conjunction with the SPECT system interface 440 to control the motors, servos, and encoders to rotate the gamma cameras 404a, 404b along the gantry 402 and acquire two-dimensional emission data (i.e., projection images) at defined imaging positions during rotation. The acquired data 434 can be stored in the memory 430. As is known, the control program 432 can also be executed to reconstruct a volume 436 from the emission data 434.

[0051] The control program 432 may also be executed to cause the control system 420 to perform the process 300 , including acquiring class standard images 438 , managing a comparison between the test image and each class standard image 438 , and evaluating the test part based on the comparison.

[0052] The terminal 450 may include a display device and an input device coupled to the system 420 via the terminal interface 448. The terminal 450 may display any one of the two-dimensional emission data 434 and the reconstructed volume 436. The terminal 450 may also display a test image alongside the class standard image 438 and receive user input indicating a selection of one displayed image over another. In some embodiments, the terminal 450 is a separate computing device such as, but not limited to, a desktop computer, a laptop computer, a tablet computer, and a smartphone.

[0053] Each component of system 400 may include other elements necessary for its operation, as well as additional elements for providing functionality other than those described herein. It will be understood by those skilled in the art that the systems described herein may be implemented in hardware, firmware, or software encoded on a non-transitory computer-readable storage medium (e.g., as instructions executable by a processor).

[0054] Figure 8 The invention relates to a method for using multiple radial arms and a distal probe head according to an embodiment disclosed herein. Figure 7 3D illustration of the imaging system.

[0055] In the above detailed description, reference is made to the accompanying drawings, which form a part thereof. In the accompanying drawings, similar symbols generally identify similar parts, unless the context dictates otherwise. The illustrative embodiments described in this disclosure are not intended to be limiting. Other embodiments may be used, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that the various features of the present disclosure, as generally described herein and shown in the accompanying drawings, may be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are expressly contemplated herein.

[0056] Various aspects of the present technical solution are described herein with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the technical solution. It will be understood that each block of the flowcharts and / or block diagrams, and combinations of blocks in the flowcharts and / or block diagrams, can be implemented by computer-readable program instructions.

[0057] These computer-readable program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device for producing a machine, so that the instructions executed by the processor of the computer or other programmable data processing device create a device for implementing the functions / actions specified in one or more blocks of the flowchart and / or block diagram. These computer-readable program instructions can also be stored in a computer-readable storage medium, which can direct the computer, programmable data processing device, and / or other equipment to operate in a specific manner, so that the computer-readable storage medium having the instructions stored therein includes an article of manufacture, which includes instructions for implementing various aspects of the functions / actions specified in one or more blocks of the flowchart and / or block diagram.

[0058] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus, or other device to produce a computer-implemented process, so that the instructions executed on the computer, other programmable apparatus, or other device implement the functions / actions specified in one or more boxes of the flowchart and / or block diagram.

[0059] The flow charts and block diagrams in the accompanying drawings illustrate the architecture, functions and operations of the possible implementation schemes of the system, method and computer program product according to the various embodiments of the present technical solution. In this regard, each frame in the flow chart or block diagram can represent a module, segment or part of an instruction, which includes one or more executable instructions for realizing the specified logical function. In some alternative embodiments, the functions noted in the frame may not occur in the order noted in the figure. For example, the two frames shown in succession can actually be performed substantially simultaneously, or these frames can sometimes be performed in reverse order, depending on the functions involved. It will also be noted that each frame of the block diagram and / or flow chart illustration and the combination of the frames in the block diagram and / or flow chart illustration can be realized by a dedicated hardware-based system that performs a specified function or action or performs a combination of special-purpose hardware and computer instructions.

[0060] A second action can be said to be "responsive to" a first action, regardless of whether the second action is caused directly or indirectly by the first action. The second action can occur at a substantially later time than the first action and still be responsive to the first action. Similarly, the second action can be said to be responsive to the first action even if intermediate actions occur between the first and second actions, and even if one or more of the intermediate actions directly cause the second action to be performed. For example, a second action can be responsive to the first action if the first action sets a flag, and a third action can later initiate the second action whenever the flag is set.

[0061] The present disclosure should not be limited in terms of the specific embodiments described in this application, which are intended to illustrate various features. It will be apparent to those skilled in the art that many modifications and variations may be made without departing from the spirit and scope of the present invention. In addition to those listed herein, functionally equivalent methods and devices within the scope of the present disclosure will be apparent to those skilled in the art based on the foregoing description. It should be understood that the present disclosure is not limited to specific methods, reagents, compounds, compositions or biological systems, which may of course vary. It should also be understood that the terms used herein are only for the purpose of describing specific embodiments, rather than being intended to be restrictive.

[0062] Regarding the use of substantially any plural and / or singular terms herein, those skilled in the art can convert the plural to the singular and / or the singular to the plural according to the needs of the context and / or application. For the sake of clarity, various singular / plural permutations can be explicitly described herein.

[0063] Those skilled in the art will understand that, in general, the terms used herein are generally intended to be "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "comprising" should be interpreted as "including but not limited to," etc.). Although various compositions, methods, and apparatus are described as "comprising" various components or steps (interpreted to mean "including but not limited to"), the compositions, methods, and apparatus may also "consist essentially of" or "consist of" the various components and steps, and such terms should be interpreted as defining substantially closed groups of components.

[0064] As used herein, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Nothing in this disclosure should be construed as an admission that the embodiments described in this disclosure are not entitled to antedate such disclosure by virtue of prior invention.

[0065] In addition, even if specific numbers are explicitly recited, those skilled in the art will recognize that such recitation should be interpreted as meaning at least the recited number (e.g., the mere recitation of "two recitations" without other modifiers means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention similar to "at least one of A, B, and C, etc." is used, such construction is generally intended to mean that a person skilled in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but is not limited to systems having only A, only B, only C, A and B, A and C, B and C, and / or A, B, and C, etc.). In those instances where a convention similar to "at least one of A, B, or C, etc." is used, such construction is generally intended to mean that a person skilled in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but is not limited to systems having only A, only B, only C, A and B, A and C, B and C, and / or A, B, and C, etc.). Those skilled in the art will also understand that any disjunctive conjunction "and / or" phrase that actually presents two or more alternative terms, whether in the specification, sample examples, or figures, should be understood to include the possibility of one, either, or both of these terms. For example, the phrase "A or B" will be understood to include the possibility of "A" or "B" or "A and B."

[0066] In addition, where features of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

[0067] As will be understood by those skilled in the art, for any and all purposes, such as in providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations thereof. Any listed range can easily be considered to fully describe and enable the same range to be divided into at least equal halves, thirds, quarters, fifths, tenths, etc. As non-limiting examples, each range discussed herein can easily be decomposed into lower third, middle third, and upper third, etc. It will also be understood by those skilled in the art that all languages ​​such as "up to," "at least," etc. include the enumerated numbers and refer to the ranges that can subsequently be decomposed into subranges as described above. Finally, as will be understood by those skilled in the art, a range includes each individual member. Therefore, for example, a group having 1-3 components refers to a group having 1, 2, or 3 components. Similarly, a group having 1-5 components refers to a group having 1, 2, 3, 4, or 5 components, etc.

[0068] Various of the above-disclosed and other features and functions or their alternatives may be combined into many other different systems or applications. Those skilled in the art may subsequently make various currently unforeseen or unanticipated substitutions, modifications, variations or improvements, each of which is also intended to be encompassed by the disclosed embodiments.

[0069] Independent of the use of the grammatical term, individuals with either male or female identities are included within the term.

[0070] The following is a list of non-limiting illustrative embodiments disclosed herein:

[0071] Illustrative Embodiments 1. An imaging system comprises: a gantry having an opening configured to receive a patient to be imaged and a ring configured to orbit the patient under processor control; a plurality of detector heads having imaging surfaces configured to receive and detect gamma radiation from the patient; and a plurality of extendable radial arms. The radial arms are each coupled to the ring at a plurality of locations along the ring and are configured to radially translate one of the plurality of detector heads and orient the imaging surface of each detector head under processor control. The processor is configured to coordinate movement of the plurality of extendable radial arms such that the imaging surfaces together form a plurality of predetermined imaging surfaces within the gantry. At least one predetermined imaging surface comprises a plane having uniform spacing of the plurality of detector heads.

[0072] Illustrative embodiment 2. An imaging system includes: a gantry having an opening configured to receive a patient to be imaged; and a plurality of imaging arms. Each arm includes: a detector head having an imaging surface for receiving and detecting gamma radiation from the patient; and an arm coupled to the gantry using a plurality of actuators. The plurality of actuators are configured to move the detector heads radially within the gantry, tilt the imaging surface relative to the axis of the arm, and adjust the spacing between the detector heads on adjacent imaging arms. A processor is configured to coordinate the movement of the plurality of imaging arms so that the imaging surfaces of the plurality of imaging arms together selectively form one of a plurality of predetermined imaging surfaces within the gantry. At least one of the predetermined imaging surfaces includes a flat plane having uniform spacing of the plurality of detector heads.

[0073] According to one of the aforementioned embodiments, at least one of the predetermined imaging surfaces comprises two orthogonal flat planes with uniform spacing of the plurality of detector heads within each plane. According to one of the aforementioned embodiments, at least one of the predetermined imaging surfaces comprises a curved surface with uniform spacing of the plurality of detector heads within each plane. According to one of the aforementioned embodiments, the spacing of the plurality of detector heads in the flat planes has no significant gaps. According to another aspect of some embodiments, the size of each imaging surface is in the range of 7 to 12 cm by 10 to 16 cm. According to one of the aforementioned embodiments, at least one predetermined imaging surface comprises a subset of the plurality of detector heads, and another subset of the plurality of detector heads is retracted.

[0074] According to one of the foregoing embodiments, the processor is further configured to control the movement of the ring and capture a helical image of the patient. According to one of the foregoing embodiments, the processor is further configured to control the movement of the plurality of extendable radial arms such that the plurality of detector heads orbit in a non-circular orbit. According to one of the foregoing embodiments, the processor is further configured to capture a stationary planar image of the patient. According to one of the foregoing embodiments, the processor is further configured to capture a tomographic image of the patient.

Claims

1. An imaging system comprising: a gantry (32) having an opening configured to receive a patient to be imaged and a ring (33) configured to orbit relative to the patient under processor control; a plurality of detector heads (20) having imaging surfaces (21) configured to receive and detect gamma radiation from the patient; a plurality of extendable radial arms (54), each coupled to the ring at a plurality of locations (34) along the ring and configured to radially translate one of the plurality of detector heads and orient the imaging plane of each detector head under processor control; as well as a processor (422) configured to coordinate movement of the plurality of extendable radial arms such that the imaging surfaces together form a plurality of predetermined imaging surfaces within the gantry, Wherein, at least one of the predetermined imaging surfaces comprises a flat plane (50) having a uniform spacing of the plurality of detector heads.

2. The imaging system according to claim 1, wherein At least one of the predetermined imaging surfaces includes two orthogonal planar planes (50b) with uniform spacing of the plurality of detector heads within each plane.

3. The imaging system according to claim 1, wherein: At least one of the predetermined imaging surfaces comprises an arcuate surface (50a) having uniform spacing of the plurality of detector heads in each plane.

4. The imaging system according to claim 1, wherein: The plurality of detector heads are spaced apart within the flat plane (50) without significant gaps.

5. The imaging system according to claim 1, wherein: The size of each imaging surface (21) is set to be in the range of 7 cm to 12 cm by 10 cm to 16 cm.

6. The imaging system according to claim 1, wherein: At least one of the predetermined imaging surfaces includes a subset of the plurality of detector heads, and another subset of the plurality of detector heads is retracted.

7. The imaging system according to claim 1, wherein: The processor is further configured to control the movement of the ring and capture helical images of the patient.

8. The imaging system according to claim 1, wherein: The processor is further configured to control movement of the plurality of extendable radial arms such that the plurality of detector heads orbit in a non-circular orbit.

9. The imaging system according to claim 1, wherein: The processor is further configured to capture a still planar image of the patient.

10. The imaging system of claim 1, wherein: The processor is further configured to capture tomographic images of the patient.

11. An imaging system comprising: a gantry (32) having an opening configured to receive a patient to be imaged; a plurality of imaging arms (54), each imaging arm including a detector head (20) having an imaging surface (21) for receiving and detecting gamma radiation from the patient, and an arm (10a-10d) coupled to the gantry using a plurality of actuators (14, 18, 22, 24, 28) configured to move the detector head radially within the gantry, tilt the imaging surface relative to the axis of the arm, and adjust the spacing between detector heads on adjacent imaging arms; as well as a processor (422) configured to coordinate movement of the plurality of imaging arms so that the imaging surfaces of the plurality of imaging arms together selectively form one of a plurality of predetermined imaging surfaces within the gantry, Wherein, at least one of the predetermined imaging surfaces comprises a flat plane (50) having a uniform spacing of the plurality of detector heads.

12. The imaging system according to claim 11, wherein: At least one of the predetermined imaging surfaces includes two orthogonal planar planes (50b) with uniform spacing of the plurality of detector heads within each plane.

13. The imaging system of claim 11, wherein: At least one of the predetermined imaging surfaces comprises an arcuate surface (50a) having uniform spacing of the plurality of detector heads in each plane.

14. The imaging system of claim 11, wherein: The plurality of detector heads are spaced apart within the flat plane (50) without significant gaps.

15. The imaging system of claim 11, wherein: The size of each imaging surface (21) is set to be in the range of 7 cm to 12 cm by 10 cm to 16 cm.

16. The imaging system of claim 11, wherein: At least one of the predetermined imaging surfaces includes a subset of the detector heads of the plurality of imaging arms, and another subset of the detector heads are retracted.

17. The imaging system of claim 11, wherein: The processor is further configured to control the motion of the gantry and capture helical images of the patient.

18. The imaging system of claim 11, wherein: The processor is further configured to control movement of the plurality of imaging planes such that the plurality of detector heads orbit in a non-circular orbit.

19. The imaging system of claim 11, wherein: The processor is further configured to capture a still planar image of the patient.

20. The imaging system of claim 11, wherein: The processor is further configured to capture tomographic images of the patient.

Images