General purpose phantom for calibration and verification of optical and radiation systems

Abstract

One or more embodiments of this disclosure relate to a universal phantom for calibration and verification of optical and radiation systems. The universal phantom includes a first phantom and a second phantom. The first phantom includes a plurality of radiation markers. The second phantom includes a plurality of optical markers. The second phantom is fixedly attached to the first phantom at a predetermined location. A calibration method employs the universal phantom to combine the tasks of determining the isogonal point of a radiation machine, calibrating optical devices, and registering the optical devices with their origin at that isogonal point in a radiation coordinate system.

Description

Technical Field

[0001] This application generally relates to radiation therapy and imaging. In particular, various embodiments of phantom devices and methods for calibrating and validating optical and radiation systems are described. Background Technology

[0002] Optical devices such as stereo (3D) cameras, 2D cameras, time-of-flight (ToF) cameras, lidar, or structured light cameras are commonly used in radiation systems to assist with patient setup, verify patient identification, monitor treatment, or provide guidance, for example, in surface-guided radiation therapy (SGRT). Using optical devices in a radiation system requires calibrating them in a radiation coordinate system.

[0003] Traditionally, calibrating optical devices in a radiometric coordinate system requires multiple calibration tools to perform various calibration steps to ensure that the optics are calibrated, aligned with each other, and registered to the radiometric coordinate system. For example, to calibrate a stereo camera in a therapeutic or diagnostic coordinate system, conventional techniques use calibration plates to calibrate the stereo camera and use a separate, x-ray-detectable three-dimensional (3D) object to register the stereo camera to the therapeutic or diagnostic coordinate system. Registering a camera to a radiometric coordinate system requires a complex computer model of the 3D object combined with a geometrically accurate phantom, or geometric matching based on a CT scan-based treatment plan (in the case of therapeutic applications), where the x-ray image to be aligned typically shows a 3D object slightly smaller than what the stereo camera is viewing. The latter is caused by edge artifacts, which do not allow for clear detection of the object's outline. Traditional calibration tools are expensive. The entire calibration and registration process is labor-intensive and provides limited accuracy.

[0004] Therefore, there is a need to address the problems or limitations of traditional calibration techniques. The aim is to provide a universal phantom that integrates several tools into a single solution, allowing for more efficient and effective calibration and registration of optical devices in a radiative coordinate system. Summary of the Invention

[0005] In one aspect, embodiments of this disclosure are characterized by a universal phantom or apparatus for calibrating optical and / or radiation systems. Typically, embodiments of this apparatus include a first phantom and a second phantom. The first phantom includes a plurality of radiation markers. The second phantom includes a plurality of optical markers. The second phantom is fixedly attached to the first phantom at a predetermined location.

[0006] In various embodiments of this aspect, the first phantom includes a three-dimensional (3D) body, and the plurality of radiating markers are distributed within the 3D body.

[0007] In various embodiments of this aspect, the second phantom includes a plate member having a flat surface, and the plurality of optical marks are arranged in a two-dimensional (2D) pattern on the flat surface.

[0008] In various embodiments of this aspect, the second phantom also includes one or more radiation markers.

[0009] In various embodiments of this aspect, the plate components of the second body mold are generally radially transparent.

[0010] In various embodiments of this aspect, the second phantom includes modular units that allow the second phantom to be fixedly attached to the first phantom in a first orientation and a second orientation different from the first orientation.

[0011] In various embodiments of this aspect, the first phantom includes a three-dimensional (3D) body, and the plurality of radiating marks are distributed within the 3D body. The second phantom includes a plate member having a flat surface, and the plurality of optical marks are arranged in a two-dimensional (2D) pattern within the flat surface. The plate member of the second phantom is fixedly attached to the 3D body of the first phantom in a first orientation and a second orientation different from the first orientation. In a particular embodiment, the 3D body of the first phantom is generally in the form of a cylinder, a partial cylinder, or a cuboid, the plate member of the second phantom has a cutout, and at least a portion of the 3D body of the first phantom is disposed within the cutout of the plate member. In a particular embodiment, the second phantom further includes a plurality of radiating marks.

[0012] In various embodiments of this aspect, the device further includes a radiation generator capable of operating at megavolt-level energy and includes a first source configured to generate radiation suitable for treating a patient. In a particular embodiment, the radiation generator further includes a second source capable of operating at kilovolt-level energy to generate radiation suitable for imaging an object. In another specific embodiment, the device further includes one or more optical devices.

[0013] In various embodiments of this aspect, the device includes a radiation source operable to produce X-rays, protons, heavy ions, electrons, and any other type of radiation.

[0014] In another aspect, embodiments of this disclosure are characterized by a method for calibrating a system including a radiometer and one or more cameras. Typically, embodiments of this method include the following steps: positioning a phantom device at or approximately at an isoangular point of the radiometer, wherein the phantom device includes a first phantom and a second phantom, the first phantom including a plurality of radiometric markers, the second phantom including a plurality of optical markers, and the second phantom being fixedly attached to the first phantom at a predetermined position; acquiring an image including the radiometric markers of the first phantom using radiation from the radiometer; determining the isoangular point of the radiometer using the image including the radiometric markers of the first phantom; defining the position of the first phantom in a first coordinate system, the origin of which is at the isoangular point, and defining the position of the second phantom in the first coordinate system based on a predetermined position of the second phantom relative to the first phantom; calibrating the one or more cameras relative to the second phantom in the second coordinate system using an image including the optical markers of the second phantom acquired by the one or more cameras; and mapping the positions of the one or more cameras to the first coordinate system.

[0015] In various embodiments of this aspect, a plurality of optical markers of the second phantom are arranged in a two-dimensional (2D) pattern, and an image including the optical markers arranged in a 2D pattern is used to calibrate one or more cameras in a second coordinate system.

[0016] In various embodiments of this aspect, the second phantom also includes one or more radiating markers, and when defining the position of the second phantom in the first coordinate system, an image including one or more radiating markers of the second phantom can be used to verify the predetermined position of the second phantom relative to the first phantom.

[0017] In various embodiments of this aspect, the calibration of the one or more cameras includes verifying the inherent calibration of the one or more cameras using images of optical markers including a second phantom acquired by the one or more cameras.

[0018] In various embodiments of this aspect, the radiation machine includes a source and an image detector, the source being operable at megavolt (MV) level energy, the image detector being operable to acquire an image of a radiation marker including the first phantom using radiation from the source, and the method further includes the steps of: using the image of the radiation marker including the first phantom to determine an imaging isogonal point between the source and the image detector, and adjusting the position of the image detector if the imaging isogonal point is not aligned with the isogonal point of the radiation machine.

[0019] In various embodiments of this aspect, the radiation machine includes a source and an image detector, the source being operable at kilovolt (kV) level energy, the image detector being operable to acquire an image of a radiation marker including the first phantom using radiation from the source, and the method further includes the steps of: using the image of the radiation marker including the first phantom to determine an imaging isogonal point between the source and the image detector, and adjusting the position of the image detector if the imaging isogonal point is not aligned with the isogonal point of the radiation machine.

[0020] This overview is provided to present selected aspects and embodiments of this disclosure in a simplified form and is not intended to identify key or essential features of the claimed subject matter, nor is it intended to help determine the scope of the claimed subject matter. The selected aspects and embodiments are merely intended to provide the reader with a brief overview of certain forms the invention may take and are not intended to limit the scope of the invention. Other aspects and embodiments of this disclosure are described in the detailed description sections.

[0021] These and various other aspects, embodiments, features, and advantages of this disclosure will be better understood after reading the following detailed description in conjunction with the accompanying drawings. Attached Figure Description

[0022] Figure 1 This is a simplified illustration of a radiation system according to an embodiment of the present disclosure.

[0023] Figure 2 This is a simplified illustration of a radiation system according to an embodiment of the present disclosure.

[0024] Figures 3A-3F An example phantom apparatus according to an embodiment of the present disclosure is depicted.

[0025] Figure 4 An example labelboard according to an embodiment of the present disclosure is depicted. Figure 4A and Figure 4B An exemplary optical mark is depicted.

[0026] Figure 5 This is a flowchart illustrating an example method according to an embodiment of the present disclosure.

[0027] Figure 6 The coordinate system associated with the phantom device in the radiation system according to an embodiment of the present disclosure is shown.

[0028] Figure 7 This is a diagram showing the computing system. Detailed Implementation

[0029] refer to Figures 1-7Similar elements with similar structures or functions are indicated by similar numbers. Various embodiments of the phantom apparatus and methods for calibrating and inspecting optical and / or radiation systems will now be described. It should be noted that the accompanying drawings are intended to illustrate the embodiments and not to exhaustively describe or limit the scope of this disclosure. Alternative structures and functional steps will readily be considered feasible without departing from the principles of the claimed invention.

[0030] Overview

[0031] Typically, embodiments of this disclosure combine several phantoms into a single solution, allowing for more efficient and effective calibration and verification of optics in a radiation coordinate system. The combination of a radiation phantom and optical markers allows for the determination of the isogonal point of the radiation machine and the calibration and registration of optics in a radiation coordinate system whose origin is at the isogonal point. This combined solution enables a fully automated process for identifying the isogonal point of the radiation machine, calibrating MV imaging systems, kV imaging systems, and optics in the radiation coordinate system, with minimal or no human interaction.

[0032] Figure 1This is a simplified illustration of a radiation therapy system 100 in which embodiments of the present disclosure may be implemented. As shown, system 100 includes a radiation machine 101, a treatment bed 150, and one or more cameras 160. A computer system 170 is connected to the radiation machine 101, the treatment bed 150, and the one or more cameras 160 and controls their operation. In use, a patient (not shown) may be positioned on a top 152 of the treatment bed, which may move relative to or be moved by the treatment bed 150 in multiple degrees of freedom, including translation and rotation in different directions, to align the treatment target in the patient with an isogonal point 120 of the treatment machine 101. One or more cameras 160 acquire images of the patient, the radiation machine 101, and / or the treatment bed 150, and transmit the images to the computer system 170 for processing and observation. The images may be used to assist patient setup, verify patient identification, monitor treatment, and / or provide treatment planning, etc. In some embodiments, one or more cameras 160 may be a stereoscopic (3D) camera system operable to provide surface-guided radiation therapy (SGRT). Stereo cameras are known in the art and typically comprise a pair of cameras and a projector or structured light source. According to embodiments of this disclosure, a phantom device 300 may be located on a treatment bed 150 or a treatment bed top 152 for calibrating and / or validating one or more cameras 160 and / or a radiation machine 101. The phantom device 300 may be moved by the treatment bed 150 and / or the treatment bed top 152 with multiple degrees of freedom, including translation and rotation in different directions, to allow at least one of the one or more cameras 160 to observe all or part of the phantom device 300, providing a large field of view (FOV) at least within the range of motion of the treatment bed or the treatment bed top.

[0033] refer to Figure 1 The radiation machine 101 may include: a linear accelerator ( Figure 1(Not shown in the image), which is capable of operating at high energy levels such as megavolt (MV) voltages to generate high-energy electrons; and source 102, such as a metallic target (MV source) suitable for generating, for example, X-rays or other types of radiation suitable for therapeutic treatment. Radiation machine 101 may include various collimating devices to limit, define, or modify the characteristics of the radiation beam as it travels away from source 102. The collimating device may include a multi-leaf collimator (MLC) 104 operable to shape or dynamically shape the beam according to the treatment plan. MLC 104 may rotate about a central beamline 106, thereby placing MLC 104 in various orientations. The linear accelerator, source 102, various collimating devices including MLC 104, and other devices or components may be encapsulated in a gantry 108, which may be in the form of a C-arm and rotate about a horizontal axis 110. Therefore, as gantry 108 steps or sweeps around the patient according to the treatment plan, radiation machine 101 can deliver radiation to the treatment target from various angles. Any movement of the patient, radiation machine 101, and treatment bed 150 can be monitored and / or guided by one or more cameras 160.

[0034] The radiation machine 101 may include an electronic entry imaging device (EPID) 112, which, together with the MV source 102, provides MV imaging capability to the radiation machine 101. The MV imaging systems 102 and 112 can be used to assist patient setup, verify patient identification, and monitor treatment. The radiation machine 101 may also include an X-ray tube 114 and an image detector 115 capable of operating at kV-level energy (kV source), providing kV imaging capability to the radiation machine 101. The kV imaging systems 114 and 115 provide better contrast, resolution, and other image quality, and can be used to guide treatment and execute treatment plans. The EPID 112, kV source 114, and image detector 115 are supported by and rotate with the gantry 108.

[0035] It should be noted that although the combination has such Figure 1 The radiation machine 101 with a gantry structure in the form of a C-arm shown describes an embodiment of the present disclosure, but the principles of the present disclosure can be applied to radiation machines with a gantry structure in the form of an O-ring, or to robotic arms in which the radiation source and / or patient can move with multiple degrees of freedom. Figure 2A radiation therapy system 200 is shown, comprising a radiator 201 with a rack configuration in the form of an O-ring. As shown, the system 200 includes the radiator 201, a treatment bed 250, and one or more cameras 160. A computer system 170 is connected to and controls the operation of the radiator 201, the treatment bed 250, and the one or more cameras 160. The radiator 201 includes a housing 208 defining an opening or aperture 210 that allows a patient or a portion of a patient on the treatment bed to be positioned within the aperture to receive radiation. A linear accelerator (not shown), a source 212, an MLC (not shown), and other devices may be supported and rotated or rotated on the annular rack 214 in the housing 208, thereby allowing radiation to be directed at the patient's treatment target from multiple angles. The one or more cameras 160 acquire images of the patient, the radiator 201, and / or the treatment bed 250, and transmit the images to the computer system 170 for processing and observation. The images can be used to assist patient setup, verify patient identification, monitor treatment, provide treatment planning, and / or treatment guidance.

[0036] It should be noted that although embodiments of this disclosure have been described in conjunction with treatment machines 101 or 201, the principles of this disclosure can also be applied to diagnostic systems, such as systems for computed tomography (CT), cone-beam computed tomography (CBCT), CT simulation, MRI, etc. Furthermore, it should be understood that embodiments of this disclosure can be applied to various types of radiation systems, including systems that generate X-rays, protons, heavy ions, electrons, and any other type of radiation.

[0037] refer to Figure 1 The radiation machine 101 has an isogonal point or radiation isogonal point 120, a small-volume point or center where the radiation beam or the axis of the radiation beam intersects at all points of rotation of the source 102 during beam opening. Precise positioning of the treatment target at the isogonal point 120 allows radiation to be delivered to the target while avoiding unnecessary radiation to surrounding healthy organs or tissues. Therefore, determining or validating the isogonal point of the radiation machine is critical, particularly in stereotactic radiosurgery (SRS) and stereotactic body radiation therapy (SBRT), where high doses of radiation are delivered in single or smaller fractions to small-sized treatment targets, allowing for smaller error tolerances. Determining or validating the radiation isogonal point also allows for the calibration of MV and kV imaging systems in a treatment coordinate system with the origin at the isogonal point.

[0038] Optical devices160 operating at various wavelengths, such as stereo (3D) cameras, 2D cameras, time-of-flight (ToF) cameras, lidar, or structured light cameras, are increasingly used in radiation systems for patient setup, patient identification, treatment monitoring, treatment planning, and / or guidance. Using optical devices in radiation systems requires calibration of the optical devices in a radiation coordinate system. Traditionally, various different tools are used to separately perform the determination of isocenters of the radiation machine, the calibration and verification of the optical devices, and the registration of the optical devices in the radiation coordinate system. Calibration of optical devices in the radiation coordinate system requires numerous calibration tools to perform various calibration steps. For example, to calibrate a stereo camera in a treatment or diagnostic coordinate system, conventional techniques use calibration plates to calibrate the stereo camera and use a separate x-ray-detectable three-dimensional (3D) object to register the stereo camera to the treatment or diagnostic coordinate system.

[0039] According to embodiments of this disclosure, a phantom device or a universal phantom 300 is provided. For example... Figures 1-2 As shown, the universal phantom 300 can be used to determine or verify the isogonality of a radiation machine, calibrate the MV imaging system and / or kV imaging system mounted on the radiation machine, and perform other quality assurance tasks. Furthermore, the universal phantom 300 can be used to calibrate optical devices and register them in a radiation coordinate system. The universal phantom 300 of this disclosure combines several phantoms into a single solution, allowing for more efficient and effective determination of the isogonality of the radiation machine, calibration of the radiation imaging system, and calibration of the optical system in the radiation coordinate system.

[0040] General Phantom

[0041] refer to Figures 3A-3B A general phantom or phantom device or apparatus 300 according to embodiments of the present disclosure will now be described. As shown, the phantom device 300 includes a first phantom 310 and a second phantom 320. The first phantom 310 includes a plurality of radiation markers 312. The second phantom 320 includes a plurality of optical markers 322, 322A. The second phantom 320 is fixedly attached to the first phantom 310 at a predetermined position, allowing the position and / or orientation of the second phantom 320 relative to the first phantom 310 to be fixed during use.

[0042] As used herein, the term "phantom" broadly refers to an object, structure, or tool designed to evaluate, analyze, and / or tune the performance of various devices or systems, including X-ray, optical, MRI, or ultrasound devices or systems. As used herein, the term "radiation marker" refers to an object that can be imaged by a radiation imaging detector when irradiated or exposed to radiation. A radiation marker can be an object made of a metal such as tungsten, titanium, steel, or other metals or metal alloys that attenuates radiation to allow a radiation imaging detector to detect the effects of attenuation. As used herein, a radiation marker can also refer to radioactive materials or tracers used in positron emission tomography (PET).

[0043] As used herein, the term "optical mark" refers to any mark, pattern, code, or any combination thereof that can be imaged by an optical image detector. Exemplary optical marks include marks arranged in patterns such as circles or squares, checkerboards, ArUco marks, QR codes, three-dimensional objects, active or passive reflectors, or any combination thereof. Figure 4 An exemplary optical mark according to an embodiment of the present disclosure is shown, comprising a combination of circular marks 322 and ArUco marks 322A arranged in a predetermined pattern. Figure 4 As shown, multiple circular markers 322 (also referred to as "reference discs") can be grouped according to a predetermined pattern (also referred to as "reference disc patterns") to divide the marker plate into areas or zones, such as six areas at the corners and sides of the marker plate. Each reference disc pattern may also include ArUco markers 322A (six shown) for representing a specific reference disc pattern. Figure 4A An exemplary ArUco mark 322A is shown. Figure 4B An example reference disk pattern 322B is shown, comprising multiple circular markings 322 and an ArUco marking 322A. It should be noted that... Figure 4 , Figure 4A and Figure 4B The optical marks 322 and 322A and pattern 322B shown are for illustrative purposes. The principles of this disclosure are not limited to any particular type, number, and / or pattern of optical marks.

[0044] Reference Figures 3C-3D The first phantom 310 and the second phantom 320 can each be in modular form and can be assembled into a unit during use. The modular design of the first phantom 310 and the second phantom 320 allows the position and / or orientation of the second phantom 320 relative to the first phantom 310 to be adjustable for different applications. Figure 3A This illustrates that the second phantom 320 can be fixedly attached to the first phantom 310 in an orientation at an angle to the longitudinal axis 318 of the first phantom, for example, suitable for use with, for example, having, Figure 1The radiator 101 with the C-arm frame shown is used together. Figure 3B This illustrates that the second phantom 320 can be fixedly attached to the first phantom 310 in an orientation generally parallel to the longitudinal axis 318 of the first phantom, for example, suitable for use with a phantom having... Figure 2 The radiator 201 with the O-ring frame shown is used together.

[0045] refer to Figures 3C-3D The first phantom 310 may include a body 314, such as a three-dimensional (3D) subject, and a plurality of radiation markers 312 distributed within the 3D subject. For example, the 3D subject 314 may be in the form of a cylinder or partial cylinder, cuboid, cube, or other regular or irregular shape. The 3D subject 314 may be made of a radiolucent material such as polyoxymethylene. The radiation markers 312 may be distributed or asymmetrically distributed within the 3D subject 314 and precisely positioned at predetermined locations. Examples of the first phantom 310 include cylindrical and cuboid phantoms available from Varian Medical Systems, Palo Alto, California.

[0046] refer to Figures 3C-3D The second phantom 320 may include a plate member 324 and a plurality of optical marks 322, 322A disposed on or within the plate member. The plate member 324 may be in the form of a plate or member having a flat surface that allows the optical marks 322, 322A to be arranged in a two-dimensional (2D) pattern. The plate member 324 may be made of a radiolucent material such as polyoxymethylene. Alternatively, the plate member 324 may be made of any other suitable material. As described above, the optical marks 322, 322A may be in the form of circles, rectangles, checkerboards, ArUco marks, QR codes, or any combination thereof. In this disclosure, the term "second phantom" may be used interchangeably with the term "marker plate." As an example, the second phantom 320 may include a plurality of ArUco marks 322A and a plurality of circular marks 322 arranged in a 2D pattern on the surface of the plate member 324. Figure 4 Another example of a marking board is shown, which includes multiple ArUco marks 322A and multiple circular marks 322 arranged in a 2D pattern.

[0047] In some embodiments, the second phantom 320 may include a plurality of radiation markers. The radiation markers may be distributed at predetermined locations within the plate member 324 and serve as a reference for verifying the position and / or orientation of the second phantom 320 relative to the first phantom 310 using radiation imaging. The radiation markers of the second phantom 320 may also be used to check the integrity of the marking plate 320 by determining a desired distance between precisely positioned radiation markers. For illustrative purposes, Figure 4Nine radiation markers 323 are shown distributed at the corners and in the middle of the marking plate. It should be understood that the marking plate 320 may include more or fewer radiation markers.

[0048] refer to Figures 3E-3F The second mold 320 can be securely attached to the first mold 310 by any suitable means. For example, slots 316a and 316b can be provided on one side of the 3D body 314 of the first mold 310, allowing the plate member 324 of the second mold 320 to be received in the slot. Holes 317 can be provided in the 3D body 314, allowing the plate member 324 of the second mold 320 to be secured to the 3D body 314 of the first mold 310 by suitable fasteners such as screws, nuts, pins, clips, latches, etc. 319.

[0049] exist Figures 3E-3F In the specific embodiment shown, slots 316a and 316b are disposed near the upper and lower sides of one end of the 3D body 314 of the first body mold 310. The slot 316b adjacent to the lower side of the 3D body 314 of the first body mold 310 can be configured to allow the plate member 324 of the second body mold 320 to be positioned at an angle to the longitudinal axis 318 of the 3D body 314, such as... Figure 3E As shown. Fasteners 319, such as screws, nuts, pins, and clips, can be used to secure the plate member 324 of the second mold 320 to the 3D body 314 of the first mold. A groove 316a adjacent to the upper side of the 3D body 314 of the first mold 310 can be configured to allow the plate member 324 of the second mold 320 to be positioned in an orientation generally parallel to the longitudinal axis 318 of the 3D body 314, such as... Figure 3F As shown. Fasteners 319 such as screws and nuts and interface plates 321 can be used to fix the plate components 324 of the second body mold 320 to the 3D body 314 of the first body mold 314.

[0050] refer to Figures 3E-3F In a particular embodiment, the plate member 324 of the second body mold 320 may have, for example, a cutout 328 in the middle portion of the plate member 324, allowing the 3D body 314 or a portion of the 3D body 314 of the first body mold 310 to be disposed therein. The cutout 328 in the plate member 324 allows the second body mold 320 to be securely attached to the first body mold 310 in a relatively compact manner.

[0051] The fixed attachment of the second phantom 320 to the first phantom 310 allows the position and / or orientation of the second phantom 320 relative to the first phantom 310 to be predetermined or known. Because the first phantom 310 can be used to determine or verify the isogonal point of the radiation system, and therefore the position and / or orientation of the first phantom 310 can be defined in a radiation coordinate system with its origin at the isogonal point, the position and / or orientation of the second phantom 320 in the radiation coordinate system can also be determined based on the known relationship between the second phantom 320 and the first phantom 310. One or more cameras 160 that can be calibrated or verified using the second phantom 320 can then be mapped or registered to the radiation coordinate system with its origin at the isogonal point.

[0052] refer to Figures 3A-3F The phantom device 300 may include a frame or interface plate 304 for attaching the phantom device 300 to a treatment bed or the top of a treatment bed. The interface plate 304 may have suitable features for attaching to the side of the 3D body 314 of the first phantom 310 and the treatment bed or the top of the treatment bed. In some embodiments, the phantom device 300 may include a micrometer movement mechanism (not shown) that allows for precise adjustment of the position of the phantom device 300.

[0053] Calibration method

[0054] refer to Figure 5 Now, calibration method 500 is described. Typically, this method employs a phantom apparatus to combine the tasks of determining the isogonal point of the radiation machine, calibrating the optics, and registering the optics in a radiation coordinate system with the origin at the isogonal point, thereby allowing for efficient and effective calibration of the optics in the radiation coordinate system. Method 500 can be used in, for example... Figures 1-2 The radiation system shown is 100, 200, or any other suitable treatment, diagnostic, simulation, research, and development system. A suitable radiation system includes a radiation machine, a treatment bed or support structure, one or more optical devices or cameras, and a computer system connected to the radiation machine, treatment bed, and one or more cameras. The radiation machine includes a frame and a radiation source supported by the frame. The frame or radiation source is rotatable about an axis of rotation.

[0055] refer to Figure 5Method 500 may begin at step 502, in which the phantom device is positioned at or approximately at the isoangular point of the radiator. The phantom device may be mounted on a treatment bed or the top of a treatment bed capable of movement in multiple degrees of freedom. The phantom device may be roughly aligned to the isoangular point of the radiator by a clinical staff member using an orientation aid (such as an indoor laser). The phantom device may include a first phantom and a second phantom, the first phantom having multiple radiation markers and the second phantom having multiple optical markers. The second phantom may optionally include multiple radiation markers. The second phantom is fixedly attached to the first phantom at a predetermined location. The phantom device may be combined with... Figures 3A-3F The general phantom 300 described is identical or similar. As an example, the first phantom may include a 3D body (e.g., a hollow cylinder) having a plurality (e.g., 16) of metal spheres or spherical supports (BBs) asymmetrically distributed within the 3D body. The second phantom may include a plate member having a flat surface and a plurality of optical markers arranged in a 2D pattern. The second phantom may also include a plurality of radiation markers.

[0056] In step 504, the method continues to acquire images of the radiation markers, including the first phantom, using radiation from the radiometer. Images of the radiation markers, including the first phantom, can be acquired using the MV imaging system and / or kV imaging system of the radiometer. For example, in a treatment room, images of the first phantom can be acquired using the MV imaging system of a treatment machine equipped with an EPD. Alternatively or additionally, images of the first phantom can be acquired using a kV imaging system comprising a kV source and an image detector mounted on the treatment machine. Multiple images of the first phantom can be captured at different gantry angles or source angles between 0 degrees and 360 degrees. In cases involving MLC rotation, an additional plate comprising radiation markers, such as metal pins, can be inserted into an auxiliary slot in the gantry head. The MLC can be rotated to multiple orientation angles, and at each orientation angle, multiple MV images and / or kV images of the first phantom can be acquired at different gantry angles or source angles between 0 degrees and 360 degrees.

[0057] In step 506, the method continues to use images of the first phantom acquired using radiation from the radiometer to determine or verify the radiation isogonality or the radiometer's isogonality. Determining or verifying the radiometer's isogonality using radiation images of the phantom is generally known. The Winston-Lutz (WL) method is one such known method. IsoCal TM This is another known method developed and available from Varian Medical Systems, Inc., Palo Alto, California. WL and IsoCal TM The methods are incorporated herein by reference. Briefly and generally, in IsoCal... TMIn the routine, MV and / or kV images are analyzed to identify the locations of radiation markers on the phantom and / or metal pins on the MLC plate within the images. The identified locations of the radiation markers are used to perform a geometric analysis to calculate the intersections of the axes of radiation beams from multiple rack angles, or the radiation isogonal points of the radiator. U.S. Patent No. 7,844,094, issued November 30, 2010, describes a method for determining the geometric parameters of a radiator using radiation images of a phantom, the disclosure of which is incorporated herein by reference.

[0058] According to embodiments of this disclosure, MV images and / or kV images are analyzed, and geometric analysis is performed to calculate the imaging isogonality of the MV imaging system and / or the kV imaging system. This allows for the identification of any misalignment between the MV image detector and the MV source and / or between the kV image detector and the kV source, and allows for the correction or adjustment of the positions of the MV image detector and / or the kV image detector based on the gantry angle, thereby allowing the imaging isogonality of the MV imaging system and / or the kV imaging system to align with the radiation isogonality of the treatment machine.

[0059] In an alternative embodiment where the method is implemented in a diagnostic system such as a CT scanner or CT simulator, the method may be performed in steps 504 and 506 to acquire images of a first phantom in a CT room using the CT scanner or CT simulator, and to use the CT images to determine or verify the isogonal points of the CT scanner or CT simulator. In this way, CT images can be acquired and a frame of reference (FOR) can be stored as a structure set in, for example, a DICOM file format. Optical markers in the second phantom can be used to correlate the position of the second phantom relative to the reference frame using a reference CT from the CT room.

[0060] In step 508, the method further defines or determines the position of the first phantom in the first coordinate system or the radial coordinate system in which the origin is at an isogonal point, and defines or determines the position of the second phantom in the radial coordinate system. For illustration, Figure 6A first coordinate system or radiation coordinate system 600, with its origin 602 located at the isoangular point of the radiometer, and a second coordinate system or common optical coordinate system 620, with its origin 622 relative to the second phantom or marker plate, are shown for calibrating one or more optical devices. The location of the center 612 of the radiation marker pattern of the first phantom and a coordinate system 610 with its origin at the center 612 are also shown. It should be noted that, for clarity, the separation distances between the origins 602, 612, and 622 of coordinate systems 600, 610, and 620 are enlarged. For phantom devices comprising a first and a second phantom used in this method, located or approximately at the isoangular point of the radiometer, the origins 602, 612, and 622 of coordinate systems 600, 610, and 620 may coincide or approximately coincide. The origin 622 of the common optical coordinate system 620 is preferably set at or near the radiation isoangular point 602, allowing one or more cameras to easily observe the optical markers of the second phantom. As described above, the isogonal point 602 of the radiometer can be determined or verified using the radiation image of the first phantom. Consequently, the position of the center 612 and the orientation of the first phantom can be defined or determined in the radiation coordinate system 600. Because the second phantom is fixedly attached to the first phantom in a predetermined relationship, the position and orientation of the second phantom can also be defined or determined in the radiation coordinate system 600. In an alternative embodiment, the second phantom may additionally include a plurality of radiation markers, and the position and orientation of the second phantom relative to the first phantom can be verified using a radiation image including the radiation markers in the second phantom. In defining the position of the second phantom in the radiation coordinate system 600, step 508 may provide a first transformation matrix to transform the location or position and orientation of the first phantom to the radiation coordinate system, and a second transformation matrix to establish a relationship between the positions of the second phantom and the positions of the first phantom.

[0061] refer to Figure 5 In step 510, the method continues to use images including optical markers acquired by one or more cameras in a second coordinate system ( Figure 6 One or more cameras are calibrated relative to the second phantom in an optical coordinate system 620. For example, the one or more cameras may be 3D cameras, and images of optical markers including the second phantom are obtained using the 3D cameras or cameras within the 3D cameras. Using a 2D pattern of optical markers arranged on a marker plate, the 3D cameras can be aligned with each other and can be scaled to the second coordinate system or an optical coordinate system shared by each of the one or more 3D cameras relative to the marker plate. The relative positions of the 3D cameras in the second coordinate system can be represented by individual or third transformation matrices. Calibration of cameras or 3D cameras using optical markers is generally known, and various methods have been developed. Therefore, a detailed description of the calibration steps is omitted herein to focus on the description of embodiments of this disclosure.

[0062] In some embodiments, step 510 may optionally be performed to verify the inherent parameters of the factory-calibrated cameras. For example, one or more cameras may be structured light 3D cameras, which may include a pair of cameras and a light projector. Factory calibration is typically performed to align the two cameras with each other and with the projector, and to calculate distortion and scaling errors (“inherent calibration”). A second phantom, including plate components and optical markers arranged in a 2D pattern, can be used to verify the inherent calibration by describing the relationship between the cameras in a matrix structure, before merging them, by evaluating brightness and pattern contrast, epipolar quality, and the scale of the individual cameras. Minor adjustments to the calibration file are possible if mechanical adjustment is not required to correct the deviations.

[0063] In step 512, the method proceeds to register or map the positions of one or more cameras to a first coordinate system. Using the transformation matrix from step 508 and the transformation matrix from step 510, any point in the common optical coordinate system can be mapped to a radiation coordinate system with the origin at an isogonal point.

[0064] It should be pointed out that, in combination Figure 5 When describing the functional steps of the calibration method, the arrangement of the blocks shown and described does not imply a specific order. Furthermore, it should be understood that more or fewer steps, actions, or processes can be incorporated into the method without departing from the scope of this disclosure. For example, the method can be implemented in a radiation system without an optical system, and the universal phantom of this disclosure can still be used to calibrate and validate radiation machines. In another example, the method can be implemented to calibrate other types of cameras, such as ToF, LiDAR, and structured light cameras typically used for coarse positioning on patient settings or treatment tables, and the universal phantom of this disclosure can still be used to calibrate these types of cameras. In some embodiments, the universal phantom of this disclosure can also be used to calibrate 2D cameras for patient identification, thereby eliminating the need for additional phantoms or strips on top of the treatment table for 2D camera registration, as is the case in conventional patient identification techniques.

[0065] Advantageously, the use of a universal phantom according to embodiments of the present disclosure integrates the tasks of calibration and registration of optical devices in a radiation coordinate system. Conventional methods use separate calibration tools to calibrate and register cameras in a radiation coordinate system, such as calibration plates for calibration and separate calibration cuboids for registration to a radiation therapy system. In registration with a radiation therapy system, a 3D computer model of the reference surface of the physical calibration cuboid is used, and surface matching and modeling of the physical calibration cuboid are performed. According to embodiments of the present disclosure, calibration of the 3D camera can be performed using optical marks arranged in a 2D pattern on a marker plate, and registration from the marker plate to the radiation coordinate system can be achieved based on prior knowledge or by using radiation imaging.

[0066] Combination Figure 5 The methods described in this disclosure can be implemented in a computer system according to embodiments of this disclosure. The invention can take the form of a computer product including a computer-readable medium that stores or carries instructions, which, when executed by a computer processor, cause the computer processor to perform the methods described in this disclosure. The instructions can be implemented as software code and executed by a processor using any suitable computer language, such as Java, C++, C#, Perl, Python, or other computer languages ​​and techniques. The computer-readable medium can include any suitable medium capable of storing or encoding a sequence of instructions for execution by a computer processor and causing the computer processor to perform any method of the invention. Therefore, computer-readable media will include, but are not limited to, solid-state memory, optical discs, and magnetic disks. Examples of computer-readable media include volatile and non-volatile, removable and non-removable media for storing computer-readable instructions. As a non-limiting example, computer-readable media includes random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), flash memory or other memory technologies, optical disc ROM (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic tape cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and be accessible for retrieval of that information. In some embodiments, instructions or software programs may be encoded and transmitted using carrier signals suitable for transmission over wired, optical, and / or wireless networks conforming to various protocols, including the Internet. Thus, computer-readable media can be created using data signals encoded with such programs. Computer-readable media encoded with program code may be packaged with compatible devices or provided separately from other devices, for example, via Internet download. Furthermore, any such computer-readable media may reside on or within a computer product (e.g., a hard disk drive, CD, or an entire computer system).

[0067] refer to Figure 7 , Figures 1-2 The computer system 170 shown typically includes a processor 702, a memory 704, a user interface 706, and a network interface 708, each of which is coupled to a system bus 710.

[0068] Processor 702 may include a central processing unit (CPU) known in the art, such as processor or Processor, or graphics processing unit (GPU), for example GPU, or other types of processing units. Processor 702 may retrieve and execute computer-executable instructions from memory 704, which may cause processor 702 to perform any of the methods and / or steps according to the embodiments of this disclosure described above.

[0069] Memory 704 may include any one or a combination of volatile and non-volatile storage elements. Memory 704 may include random access memory (RAM) or other dynamic storage devices for storing information and instructions to be executed by processor 702, as well as for storing temporary variables or other intermediate information during the execution of instructions by processor 702. Memory 704 may also include read-only memory (ROM) or other static storage devices for storing static information and instructions of processor 702. Memory 704 may also include data storage devices such as magnetic disks or optical disks for storing information and instructions. Memory 704 (e.g., a non-transitory computer-readable medium) may include programs (logic) for operating computer systems and for performing applications or other treatment planning applications, including calculations involving radiation and / or optical systems as described above. Additionally, memory 704 may include a database storing any information selectable by a user (e.g., a radiation oncologist or radiation therapist).

[0070] User interface device 706 may include components for user interaction with computer system 170, such as keyboard, pointing device, pen, touch input device, voice input device, etc. Output devices such as display device, printer, speaker, etc., may also be included in computer system 170.

[0071] Network interface 708 allows computer system 170 to communicate with radiation machine 101 / 201, treatment bed 150 / 251, camera 160, and other devices or systems via a communication network 712 such as the Internet or an intranet (e.g., a local area network). Network interface 708 may include a Wi-Fi interface, Ethernet interface, Bluetooth interface, or other wireless or wired interface. Network interface 708 allows computer system 170 to receive and transmit electrical signals, electromagnetic signals, and / or optical signals carrying data streams representing various types of information.

[0072] Various embodiments of the universal phantom and methods for calibrating optical devices in a radiation coordinate system have been described with reference to the accompanying drawings. It should be noted that the drawings are intended for illustrative purposes, and some drawings are not necessarily drawn to scale. Furthermore, specific details are set forth in the drawings and description to provide a thorough understanding of this disclosure. It will be apparent to those skilled in the art that some of these specific details may not be used in practicing the embodiments of this disclosure. In other instances, well-known components or process steps may not be shown or described in detail to avoid unnecessarily obscuring the embodiments of this disclosure.

[0073] Unless otherwise specifically defined, all technical and scientific terms used herein have the meanings commonly understood by one of ordinary skill in the art. As used in the specification and appended claims, the singular forms “a,” “an,” and “the” include plural references unless the context clearly indicates otherwise. The term “or” means “or” in a non-exclusive sense unless the context clearly specifies otherwise. Furthermore, the terms “first” or “second,” etc., may be used to distinguish one element from another when describing various similar elements. It should be noted that the terms “first” and “second” as used herein include references to two or more. Moreover, the use of the terms “first” or “second” should not be construed as in any particular order unless the context clearly indicates otherwise. The terms “coupled,” “supported,” “connected,” “mounted,” and variations thereof are widely used and include direct and indirect coupling, support, connection, and mounting.

[0074] Those skilled in the art will understand that various other modifications can be made. All such or other changes and modifications are contemplated by the inventors and are within the scope of this invention.

Claims

1. An apparatus comprising a phantom, the phantom comprising: A first phantom, the first phantom comprising a plurality of radiometric markers; as well as The second mold has a flat surface and includes a plurality of optical marks disposed on the flat surface. The second mold also has a cut formed in the flat surface, wherein the cut is surrounded by the plurality of optical marks, and at least a portion of the first mold is disposed in the cut such that the second mold is fixedly attached to the first mold at the location of the cut.

2. The apparatus of claim 1, wherein the first phantom comprises a three-dimensional body, and the plurality of radiation markers are distributed in the three-dimensional body.

3. The apparatus of claim 1, wherein the second phantom comprises a plate member having the flat surface, and the plurality of optical marks are arranged in a two-dimensional pattern on the flat surface.

4. The apparatus of claim 3, wherein the second phantom further comprises a plurality of radiation markers.

5. The apparatus of claim 3, wherein the plate member of the second body mold is generally radially transparent.

6. The apparatus of claim 1, wherein the second phantom includes a modular unit that allows the second phantom to be fixedly attached to the first phantom in a first orientation and a second orientation different from the first orientation.

7. The apparatus according to claim 1, wherein The first phantom includes a three-dimensional body, and the plurality of radiation markers are distributed in the three-dimensional body; The second phantom includes a plate member having the flat surface, and the plurality of optical marks are arranged in a two-dimensional pattern on the flat surface; and The plate members of the second model are fixedly attached to the three-dimensional body of the first model in a first orientation and a second orientation different from the first orientation.

8. The apparatus according to claim 7, wherein The three-dimensional main body of the first model is generally in the form of a cylinder, a partial cylinder, or a cuboid; The plate member of the second mold has the cutout; and At least a portion of the three-dimensional body of the first model is arranged in the cutout of the plate member.

9. The apparatus of claim 8, wherein the second phantom further comprises a plurality of radiation markers.

10. The apparatus of claim 1, further comprising a radiation generator including a source operable to generate radiation of X-rays, protons, heavy ions, or electrons.

11. The apparatus of claim 10, further comprising one or more optical devices.

12. The apparatus of claim 11, further comprising a positioning device for supporting the first phantom and the second phantom, wherein the positioning device is movable relative to the source, allowing at least one of the one or more optical devices to observe all or a portion of the first phantom and the second phantom.

13. The apparatus of claim 10, wherein the radiation generator is capable of operating at megavolt-level energy, and the source is configured to generate radiation suitable for treatment and / or imaging.

14. The apparatus of claim 10, wherein the radiation machine is capable of operating at kilovolt-level energy, and the source is configured to generate radiation suitable for imaging and / or treatment.

15. A method for calibrating a system comprising a radiation machine and one or more cameras, the method comprising: The phantom assembly is positioned or approximately positioned at an isoangular point of the radiator. The phantom assembly includes a first phantom and a second phantom. The first phantom includes a plurality of radiation marks. The second phantom has a flat surface and includes a plurality of optical marks disposed on the flat surface. The second phantom also has a cut formed in the flat surface, wherein the cut is surrounded by the plurality of optical marks, and at least a portion of the first phantom is disposed in the cut such that the second phantom is fixedly attached to the first phantom at the location of the cut. An image of the radiation markers, including the first phantom, is acquired using radiation from the radiation machine; The isogonal point of the radiometer is determined using the image including the radiation markers of the first phantom; The position of the first model is defined in a first coordinate system, the origin of which is located at the isogonal point. The position of the second model is defined in the first coordinate system based on a predetermined position of the second model relative to the first model. Using images of the optical markers of the second phantom acquired by the one or more cameras, the one or more cameras are calibrated relative to the second phantom in a second coordinate system; as well as Map the positions of the one or more cameras to the first coordinate system.

16. The method of claim 15, wherein the plurality of optical marks of the second phantom are arranged in a two-dimensional pattern, and an image including the optical marks arranged in the two-dimensional pattern is used to calibrate the one or more cameras in the second coordinate system.

17. The method of claim 16, wherein the second phantom further comprises a plurality of radiating markers, and when defining the position of the second phantom in the first coordinate system, an image including the plurality of radiating markers of the second phantom is used to verify the predetermined position of the second phantom relative to the first phantom.

18. The method of claim 16, wherein the calibration of the one or more cameras comprises: The inherent parameters of the one or more cameras are verified using images of the optical markers of the second phantom acquired by the one or more cameras.

19. The method of claim 15, wherein the radiation machine comprises a source and an image detector, the source being operable at a megavolt (MV) level of energy, the image detector being operable to acquire an image comprising the radiation marker of the first phantom with radiation from the source, the method further comprising: The image of the radiation markers, including the first phantom, is used to determine the imaging isogonal point between the source and the image detector, and if the imaging isogonal point is not aligned with the isogonal point of the radiation machine, the position of the image detector is adjusted.

20. The method of claim 15, wherein the radiation machine comprises a source and an image detector, the source being operable at kilovolt (kV) level energy, the image detector being operable to acquire an image comprising the radiation signature of the first phantom with radiation from the source, the method further comprising: The image of the radiation markers, including the first phantom, is used to determine the imaging isogonal point between the source and the image detector, and if the imaging isogonal point is not aligned with the isogonal point of the radiation machine, the position of the image detector is adjusted.

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