Positioning of an object relative to an X-ray detector

Abstract

X-ray imaging system 100 includes an X-ray source 110, an X-ray detector 120, a depth camera 130, and a processor 140. Processor 140 receives depth camera image data from the depth camera, projects the depth camera image data from the perspective of X-ray source 110 onto a radiation receiving surface of X-ray detector 120, and generates an image representation 170 of the depth camera image data projected onto the radiation receiving surface of X-ray detector 120 from the perspective of depth camera 130.

Description

Technical Field

[0001] The present disclosure relates to the positioning of an object with respect to an X-ray detector. An X-ray imaging system, a computer-executed method, and a computer program product are also disclosed.

Background Art

[0002] An X-ray imaging system includes an X-ray source and an X-ray detector. The X-ray source and the X-ray detector are separated by an examination region. In order to perform an X-ray imaging operation on an object, the object is placed in the examination region. It is important that the object to be imaged is correctly positioned with respect to the X-ray detector in order to avoid the need to repeat X-ray images and the associated increase in X-ray dose.

[0003] More specifically, the X-ray detector includes a radiation-sensitive region that is used to generate X-ray image data, and it is important that the object is correctly positioned with respect to these radiation-sensitive regions in order to generate an X-ray image of the object.

[0004] Some X-ray detectors further include a radiation dose measurement region that is used to generate dose data during X-ray image data generation. The dose data may also be used to automatically control the duration of the emission of X-ray radiation, thereby resulting in a desired signal-to-noise ratio in the resulting X-ray image. This operation is sometimes referred to as automatic exposure control "AEC". The correct positioning of the patient with respect to these radiation dose measurement regions is also important, especially when performing X-ray imaging methods on objects that include density variations.

[0005] For example, when performing lateral thoracoscopic imaging, it is important to first position the patient's thoracic cavity so that it overlaps with the radiosensitive area of ​​the X-ray detector, and then position the dose measurement area of ​​the X-ray detector behind the spine, with little to no overlap. If the spine obscures the dose measurement area, the X-ray attenuation caused by the dense spine will suppress the measured dose data. If dose data is used to automatically control the duration of X-ray radiation emission by automatic exposure control, the resulting extension of this duration may worsen the contrast of the X-ray image, making it inaccurate for diagnostic purposes.

[0006] The positioning of an object relative to an X-ray detector is conventionally performed visually or via a monitor displaying a visible or red-green-blue (RGB) camera image of the object. Depth images generated by a depth camera are similarly displayed on a monitor and used to position objects relative to the X-ray detector. The radiosensitive region and its dose-measuring region of the X-ray detector are typically marked on the radiation-receiving surface of the detector. During use, the operator positions the object relative to the detector visually or via a monitor using the markings on the detector's surface. [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, conventional approaches to positioning objects relative to X-ray detectors have drawbacks. To avoid obscuring the path between the X-ray source and the X-ray detector, cameras, and similarly the human eye, typically view the inspection area between the X-ray source and the X-ray detector from an offset position relative to the X-ray source. With a depth camera in such an offset position, especially when the offset is large, it is difficult for the operator to determine whether the X-ray radiation emitted by the X-ray source will produce the desired projection image of the object on the X-ray detector. Moreover, the object may obscure the markings on the radiation-receiving surface of the detector. Such problems can lead to the object being suboptimally positioned relative to the detector, necessitating the retaking of the X-ray image. This disrupts the workflow and increases the radiation dose to the object.

[0008] Therefore, the method by which objects are positioned relative to the X-ray detector needs to be improved. [Means for solving the problem]

[0009] According to one aspect of this disclosure, an X-ray imaging system is provided. The X-ray imaging system includes an X-ray source, an X-ray detector, a depth camera, and a processor. The X-ray source and X-ray detector are separated by the inspection area to perform an X-ray imaging operation on an object when the object is received within the inspection area. The depth camera is configured to view the inspection area to generate depth camera image data representing the object as it is received within the inspection area. The processor, Receiving depth camera image data, From the perspective of the X-ray source, depth camera image data is projected onto the radiation receiving surface of the X-ray detector, From the perspective of the depth camera, to generate an image representation of the depth camera image data projected onto the radiation receiving surface of the X-ray detector. It was configured to perform the following actions.

[0010] Further aspects, features, and advantages of this disclosure will become apparent from the following example, made with reference to the accompanying drawings. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram illustrating a first viewpoint of an example X-ray imaging system 100 including an X-ray source and an X-ray detector 120, according to certain aspects of the present disclosure. [Figure 2] This is a schematic diagram illustrating a second viewpoint of an example X-ray imaging system 100 including an X-ray source and an X-ray detector 120, according to certain aspects of the present disclosure. [Figure 3] This is a schematic diagram illustrating an example of a configuration including an X-ray source, an X-ray detector 120, and a depth camera 130, by comparing them. [Figure 4] This is a schematic diagram illustrating an example arrangement of an X-ray source, an X-ray detector 120, a depth camera 130, and a processor 140 according to certain aspects of the present disclosure. [Figure 5] This is a schematic diagram illustrating a first example of an image representation 170 of depth camera image data projected onto the radiation receiving surface of the X-ray detector 120 from the viewpoint of the depth camera 130, according to certain aspects of this disclosure. [Figure 6] This schematic diagram illustrates a second example of an image representation 170 of depth camera image data projected onto the radiation receiving surface of the X-ray detector 120 from the viewpoint of the depth camera 130, according to certain aspects of this disclosure. [Figure 7] This schematic diagram illustrates a third example of an image representation 170 of depth camera image data projected onto the radiation receiving surface of the X-ray detector 120 from the viewpoint of the depth camera 130, according to certain aspects of this disclosure. [Figure 8] This schematic diagram illustrates a fourth example of an image representation 170 of depth camera image data projected onto the radiation receiving surface of the X-ray detector 120 from the viewpoint of the depth camera 130, according to certain aspects of this disclosure. [Figure 9] This schematic diagram illustrates a fifth example of an image representation 170 of depth camera image data projected onto the radiation receiving surface of the X-ray detector 120 from the viewpoint of the depth camera 130, according to certain aspects of this disclosure. [Modes for carrying out the invention]

[0012] Examples of this disclosure are provided with reference to the following description and figures. For illustrative purposes, this description will describe numerous specific details of a particular example. References herein to “example,” “implementation,” or similar terms mean that the features, structures, or characteristics described in the example are included in at least one example. It should also be noted that features described in relation to one example may be used in another example, and for the sake of brevity, not all features are necessarily repeated in every example. For example, features described in relation to an X-ray imaging system are implemented in a corresponding manner in a computer execution method and in a computer program product.

[0013] The following description refers to an X-ray imaging system, such as the DigitalDiagnost C90, commercially available from Philips Healthcare in Best, Netherlands, or another type of X-ray imaging system. In some example configurations, the X-ray source of the X-ray imaging system is mounted on the ceiling via a gantry, and the corresponding X-ray detector is mounted on a stand and held in a vertical position. However, it should be noted that the examples in this disclosure are not limited to this particular configuration, and the X-ray source and X-ray detector may, alternatively, be mounted in different ways and held in different positions.

[0014] The following description refers to various methods implemented by processors, i.e., computers. It is noted that the computer execution methods disclosed herein, when executed by at least one processor, are provided as a non-temporary computer-readable storage medium containing stored computer-readable instructions that cause at least one processor to implement the method. In other words, the computer execution methods are implemented in computer program products. Computer program products can be provided by dedicated hardware or hardware capable of running software together with appropriate software. When provided by a processor, the functionality of the features of the method can be provided by a single dedicated processor, a single shared processor, or a number of individual processors, some of which are shared. The express use of the terms “processor” or “controller” should not be interpreted as an exclusive reference to hardware capable of running software, and may implicitly include, but are not limited to, digital signal processor ("DSP") hardware, read-only memory ("ROM") for storing software, random access memory ("RAM"), non-volatile storage devices, and the like. Furthermore, examples of the disclosure may take the form of a computer program product accessible from a computer-usable storage medium or a computer-readable storage medium, the computer program product providing program code for use by, or in conjunction with, a computer or any instruction execution system. For the purposes of this description, a computer-usable storage medium or a computer-readable storage medium may be any device capable of housing, storing, communicating, propagating, or transporting a program for use by, or in conjunction with, an instruction execution system, apparatus, or device. The medium may be electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system or device or propagation medium.Examples of computer-readable media include semiconductor or solid-state memory, magnetic tape, removable computer disks, random-access memory (RAM), read-only memory (ROM), rigid magnetic disks, and optical disks. Current examples of optical disks include compact discs—read-only memory (CD-ROM), compact discs—read / write (CD-R / W), Blu-ray™, and DVD.

[0015] As mentioned above, in order to avoid the need for repeated X-ray imaging and the associated increase in X-ray dose, it is important that the object to be imaged is correctly positioned relative to the X-ray detector.

[0016] Figure 1 is a schematic diagram illustrating a first viewpoint of an exemplary X-ray imaging system 100, including an X-ray source and an X-ray detector 120, according to certain aspects of the present disclosure. The X-ray imaging system 100 further includes a depth camera 130 and a processor 140. The X-ray source 110 and the X-ray detector 120 are separated by an inspection area 150 to perform an X-ray imaging operation on an object 160 when the object is received within the inspection area. The X-ray source and the X-ray detector are typically maintained in stationary positions during the imaging operation. The object is, for example, a part of the human body, or actually any object. In the exemplary example, the X-ray source is mounted on the ceiling via a gantry, and the X-ray detector is mounted on a stand and held in a vertical position. Alternative arrangements, mounting arrangements, and positions of the X-ray source 110 and the X-ray detector 120 are also used.

[0017] FIG. 2 is a schematic diagram illustrating a second perspective of an exemplary X-ray imaging system 100 including an X-ray source and an X-ray detector 120, according to some aspects of the present disclosure. Compared to FIG. 1, the perspective of FIG. 2 more clearly illustrates the positions of the X-ray source 110 and the depth camera 130. Also, in FIG. 2, an object 160 in the shape of a patient is received within an examination region 150 to perform an X-ray imaging operation, which in the exemplary case is a chest X-ray imaging operation, on the patient. The solid line extending between the X-ray source 110 and the X-ray detector 120 in FIGS. 1 and 2 indicates an overlapping volume measurement range between the X-ray beam emitted by the X-ray source 110 and the X-ray radiation sensitive region of the X-ray detector 120, within which X-ray image data is generated. This overlapping volume measurement range defines the examination region 150. The periphery of the X-ray radiation sensitive region 180 of the X-ray detector, as illustrated by a rectangular contour on the X-ray detector in FIG. 1, is marked on the radiation receiving surface of the X-ray detector. In some examples, the X-ray detector 120 further includes one or more radiation dose measurement regions 190 for generating radiation dose measurement data. These may be referred to as automatic exposure control "AEC" chambers. The exemplary example of FIG. 1 has five circular radiation dose measurement regions, but in other examples, these may have different shapes, there may be a different number of radiation dose measurement regions, or in some cases, there may be none at all.

[0018] In use, it is desirable for the object 160 to be correctly positioned relative to the X-ray detector 120, or more particularly, relative to the X-ray radiation sensitive region 180 and / or one or more radiation dose measurement regions 190, in order to obtain a reliable X-ray image of the object 160.

[0019] The depth camera 130 illustrated in FIGS. 1 and 2 is configured to view an inspection area 150 in order to generate depth camera image data representing an object 160 when the object is received within the inspection area 150. In other words, the depth camera 130 has a field of view that overlaps a portion of the inspection area 150. Generally, depth camera image data generated by a depth camera represents the distance between the depth camera and points on the surface of an object within the field of view of the depth camera. Referring to FIGS. 1 and 2, the depth camera image data thus represents the three-dimensional shape of the surface of the object 160. In the example arrangement illustrated in FIGS. 1 and 2, the minimum extent of the field of view of the depth camera is indicated by the dashed line extending between the depth camera 130 and the X-ray detector 120.

[0020] The depth camera 130 in the example arrangement illustrated in FIGS. 1 and 2 is mechanically coupled to the X-ray source 110. However, the depth camera 130 may alternatively be positioned elsewhere in order to view the inspection area 150. The depth camera may be mechanically coupled, for example, to a wall, or to the ceiling of the room in which the X-ray imaging system 100 is placed, or to a stand placed on the floor of the room. The depth camera may alternatively be mobile. In some examples, the depth camera may thus have the ability to move around within the room in which the X-ray imaging system 100 is placed. In each of these alternative arrangements, the depth camera can view the inspection area 150.

[0021] Various types of depth cameras are envisioned for use as depth camera 130. These cameras may employ, for example, time-of-flight, LiDAR, structural optics, or binocular stereoscopic principles. In time-of-flight, or LiDAR, the time it takes for an emitted light pulse to travel from the camera's position to an object in the scene and back is used to generate depth camera image data representing the distance to the object. The Azure Kinect DK depth camera and the Intel RealSense™ LiDAR camera L515 are examples of depth cameras employing this principle. In the structural optics principle, an optical pattern is projected onto the surface of an object in the scene, and the difference between the original projected pattern and the pattern deformed by the object's surface is imaged by one or more cameras. In the binocular stereoscopic principle, different views of the scene are used to calculate a depth map of the scene.

[0022] In some examples, the depth camera 130 also generates optical image data representing the object 160 when it is received within the inspection area 150. This optical image data may be provided by the aforementioned camera in addition to the depth camera image data provided by the aforementioned camera. Such a camera is called an RGB-D camera. The optical image data represents the visible or infrared portion of the light spectrum.

[0023] The processor 140 illustrated in Figure 1 is configured to receive depth camera image data. The processor receives depth camera image data via any form of digital communication. The processor 140 receives depth camera image data from the depth camera 130. The communication path can be direct or indirect. The processor 140 and the depth camera 130 may communicate via a direct wired or wireless communication path, such as an electrical cable or Ethernet, or a wireless infrared or RF communication path, such as Bluetooth, as illustrated by the arrows connecting these items in Figures 1 and 2. Alternatively, the communication path may be indirect, and the processor 140 and the depth camera 130 may communicate with each other via the internet, the cloud, or computer-readable storage memory.

[0024] Furthermore, the 140 processor is From the perspective of the X-ray source 110, depth camera image data is projected onto the radiation receiving surface of the X-ray detector 120, To generate an image representation 170 of the depth camera image data projected onto the radiation receiving surface of the X-ray detector 120 from the viewpoint of the depth camera 130. It was configured to perform the following actions.

[0025] In doing so, an image representation 170 is provided that prevents one or more problems associated with the positioning of an object relative to the X-ray source. These will be explained with reference to Figures 3 and 4.

[0026] Figure 3 is a schematic diagram illustrating an example of a configuration including an X-ray source, an X-ray detector 120, and a depth camera 130. In Figure 3, the X-ray source and X-ray detector are separated by an inspection area 150. The X-ray source and X-ray detector are used to perform X-ray imaging operations on an object 160 placed in the inspection area 150. The solid angle of the X-ray source 110 is Ω x X-ray radiation is generated within a volumetric measurement beam defined by the X-ray source 110, and the X-ray radiation is detected by the X-ray detector 120 to generate X-ray image data. A depth camera 130, or alternatively an optical camera, is positioned offset with respect to an axis 200 passing through the center of the X-ray source 110 and the center of the X-ray detector. The depth camera 130 is positioned to view the inspection area 150 and further the object 160. The depth camera image, or in fact the optical camera image, generated from this offset position somewhat assists the operator in positioning the object 160 relative to the detector 120 to generate an X-ray image of the object 160. However, with the depth camera in this offset position, especially when the offset is large, it is difficult for the operator to determine whether the X-ray radiation emitted by the X-ray source will produce the desired projection image of the object 160 on the X-ray detector 120. The arrangement in Figure 3, therefore, results in the object 160 being mispositioned relative to the X-ray detector, requiring the object 160 to be repositioned and the X-ray image to be retaken.

[0027] To address this problem, one conventional approach has proposed deforming the depth camera image data and viewing the depth camera image data from the viewpoint of the X-ray source. However, this approach produces an intuitive view of object 160. Moreover, this approach suffers from the disadvantage that the depth camera image data is lost within the occluded region of the detector surface. Referring to the arrangement illustrated in Figure 3, the solid angle Ω c The intermittent lines extending from the depth camera 130 define the extent of the boundary of object 160 on the surface of the X-ray detector as seen from the viewpoint of the depth camera. The solid line extending from the X-ray source indicates the extent of the boundary of object 160 on the surface of the detector 120 as viewed from the viewpoint of the X-ray source 110. When viewed from this viewpoint, the depth camera image data disappears from the shaded occluded region in Figure 3. To compensate for the loss of depth camera image data within the occluded region, the occluded region is restored with data acquired in the absence of object 160. This adds further complexity to the approach regarding viewing the depth camera image data from the viewpoint of the X-ray source.

[0028] Figure 4 is a schematic diagram illustrating an example configuration including an X-ray source, an X-ray detector 120, a depth camera 130, and a processor 140, according to certain aspects of the present disclosure. As in the comparative example in Figure 3, in Figure 4, the depth camera 130 is positioned to view the inspection area 150. In contrast to the comparative example described with reference to Figure 3, in the approach of the present disclosure, depth camera image data is projected from the viewpoint of the X-ray source 110 onto the radiation-receiving surface of the X-ray detector 120. Then, an image representation 170 of the depth camera image data projected onto the radiation-receiving surface of the X-ray detector 120, from the viewpoint of the depth camera 130, is generated. The projection is performed mathematically based on the relative positions of the X-ray source 110, the X-ray detector 120, and the depth camera 130. Referring to Figure 4, this is illustrated as a portion of the surface 210 of an object 160, which is seen by the depth camera 130 and projected onto the radiation-receiving surface of the X-ray detector 120 to provide image data 220. Subsequently, an image representation of the projected image data 220 is generated from the viewpoint of the depth camera 130. This image representation is more intuitive than the view of the depth camera image data from the viewpoint of the X-ray source. Therefore, the use of this image representation reduces the chance of the object 160 being mispositioned relative to the X-ray detector 120 and reduces the need to retake the X-ray image. Moreover, since the image representation is provided from the viewpoint of the depth camera, it does not need to be restored because it has the same viewpoint from which the depth camera image data was acquired.

[0029] The projection of depth camera image data onto the radiation receiving surface of the X-ray detector 120, and the generation of an image representation 170 of the projected depth camera image data, are generally performed based on a predetermined spatial relationship between the X-ray source 110, the X-ray detector 120, and the depth camera 130. This predetermined spatial relationship is used to calculate the spatial transformation applied to the relevant data in order to perform the projection.

[0030] The predetermined spatial relationship between the X-ray source 110, the X-ray detector 120, and the depth camera 130 may be determined in a different manner.

[0031] In some examples, one or more of the X-ray source 110, X-ray detector 120, and depth camera 130 are fixed positions, and a predetermined spatial relationship is determined using calibration data representing the fixed positions. In some examples, the positions of all three—X-ray source 110, X-ray detector 120, and depth camera 130—are fixed. In these examples, a predetermined spatial relationship between the X-ray source 110, X-ray detector 120, and depth camera 130 is determined based on calibration data representing the relative positions of the X-ray source 110, X-ray detector 120, and depth camera 130.

[0032] The positions of the X-ray source 110, the X-ray detector 120, and the depth camera 130 are fixed by, for example, mechanically attaching related items to a reference position such as a wall, ceiling, or floor. In some examples, it is assumed that one or more of these items can be positioned at one of several selectable fixed positions, and that calibration data representing each of these fixed positions is provided. For example, the X-ray source 110 and / or the X-ray detector 120 are moved to one of several selectable fixed positions. Calibration data representing the position or relative position is stored in a database, for example, as a lookup table, and is accessed by the processor to calculate the aforementioned spatial transformation.

[0033] In some examples, the position of one or more of the X-ray source 110, X-ray detector 120, and depth camera is movable to any position, and a predetermined spatial relationship between the X-ray source 110, X-ray detector 120, and depth camera 130 is determined using a position sensor. In this regard, various types of position sensors are envisioned, including position sensors employing optical radio frequency (RF) or ultrasonic tracking techniques. Examples of suitable position sensors include laser-based optical rangefinders, RF and ultrasonic ranging transponders, and optical cameras configured to track the position of a reference marker placed in one or more of the X-ray source 110, X-ray detector 120, and depth camera 130. In one example, an additional depth camera is used to track the position of one or more of the X-ray source 110, X-ray detector 120, and depth camera 130.

[0034] In one example, the spatial relationship between the depth camera 130 and the X-ray detector 120 is determined from depth camera image data generated by the depth camera 130. In this example, the depth camera 130 is further configured to view at least a portion of the radiation-receiving surface of the X-ray detector 120, and the depth camera 130 is further configured to generate depth camera image data representing at least a portion of the radiation-receiving surface of the X-ray detector 120. The processor 140 determines the spatial relationship between the depth camera 130 and the X-ray detector 120 from the generated depth camera image data representing at least a portion of the radiation-receiving surface of the X-ray detector 120, and is further configured to use the determined spatial relationship between the depth camera 130 and the X-ray detector 120 to determine the spatial relationship between the X-ray source 110, the X-ray detector 120, and the depth camera 130.

[0035] In this example, the depth camera 130 either observes a portion of the surface of the X-ray detector 120 while the object 160 is received within the inspection area 150, or observes it in the absence of the object 160. In the latter case, the spatial relationship between the depth camera 130 and the X-ray detector 120 is determined before the object 150 is received within the inspection area. For example, the spatial relationship may be determined immediately before the object is received within the inspection area 150, or once an hour, once a day, or at different time intervals. As in the example above, calibration data representing the determined spatial relationship is stored in a database, for example, as a lookup table, and accessed by the processor 140 to calculate the spatial transformation described above.

[0036] Continuing this example, the spatial relationship between the X-ray source 110, the X-ray detector 120, and the depth camera 130 is determined using the spatial relationship between the depth camera 130 and the X-ray detector 120 determined from the generated depth camera image data, and further based on calibration data representing the relative positions of the X-ray source 110 and the depth camera 130, and / or the relative positions of the X-ray source 110 and the X-ray detector 120. By using this calibration data in combination with the spatial relationship between the depth camera 130 and the X-ray detector 120 determined from the generated depth camera image data, the relative positions of all three—the X-ray source 110, the X-ray detector 120, and the depth camera 130—are determined. The calibration data is stored in a database and accessed by the processor 140 to determine the aforementioned spatial transformations.

[0037] Continuing this example, in Figure 4, the depth camera 130 is mechanically coupled to the X-ray source 110, and the calibration data represents the relative position between the X-ray source 110 and the depth camera 130. Alternatively, the depth camera 130 may be mechanically coupled to the X-ray source 110 and movable to one of several selectable fixed positions. In this example, the calibration data represents multiple relative positions. Calibration data representing the fixed relative positions of the X-ray source 110 and the X-ray detector 120 is stored and used in a similar manner, combined with the spatial relationship between the depth camera 130 and the X-ray detector 120 determined from the generated depth camera image data, in order to determine the relative positions of all three: the X-ray source 110, the X-ray detector 120, and the depth camera 130.

[0038] Figures 5 to 9 illustrate various examples of image representations provided in this disclosure. Generally, image representations are provided as two-dimensional or three-dimensional images.

[0039] Figure 5 is a schematic diagram illustrating a first example of an image representation 170 of depth camera image data projected onto the radiation-receiving surface of the X-ray detector 120 from the viewpoint of the depth camera 130, according to certain aspects of the present disclosure. In Figure 5, the image representation 170 includes projected depth camera image data corresponding to the patient's surface and a portion of the radiation-receiving surface of the X-ray detector 120. The image representation in Figure 5 allows the operator to position the patient relative to the outer periphery of the X-ray detector.

[0040] In some examples, the X-ray detector 120 includes one or more radiosensitive regions 180 for generating X-ray image data and / or one or more radiation dose measurement regions 190 for generating X-ray dose measurement data. In one example, the processor 140 is configured to generate an overlay image representation including one or more X-ray radiosensitive regions 180 and / or a representation of one or more X-ray radiation dose measurement regions 190, as well as an image representation 170 of the projected depth camera image data. This is illustrated in Figure 6, which is a schematic diagram illustrating a second example of an image representation 170 of depth camera image data projected onto the radiation receiving surface of the X-ray detector 120 from the viewpoint of the depth camera 130, according to some aspect of the present disclosure.

[0041] In comparison with Figure 5, Figure 6 shows the projected depth camera image data superimposed on the five example X-ray dose measurement areas 190 and radiosensitivity areas 180. In Figure 6, the patient is displayed semi-transparently. The X-ray detector 120 is visible in the background, and the projected object 160, i.e., the patient, is provided as a semi-transparent overlay on top of the background. Alternatively, the projected object 160, i.e., the patient, is visible in the background, and the X-ray radiosensitivity areas 180 and / or X-ray dose measurement areas 190 are superimposed on top of the patient. The image representation in Figure 6 allows the operator to position the patient relative to the X-ray radiosensitivity areas 180 and the five example X-ray dose measurement areas 190.

[0042] Referring to the example in Figure 6, the overlay of the X-ray radiosensitive area 180 and / or the X-ray dose measurement area 190, as well as the projected depth camera image data, is performed by i) detecting the radiation-receiving surface of the X-ray detector in the projected depth camera image data, and ii) mapping the positions of the X-ray radiosensitive area 180 and / or the X-ray dose measurement area 190 to the detected radiation-receiving surface of the X-ray detector, based on knowledge of the position of the X-ray detector 120 relative to its radiation-receiving surface. The positions of the X-ray radiosensitive area 180 and / or the X-ray dose measurement area 190 relative to the radiation-receiving surface of the X-ray detector 120 are determined by generating a reference depth camera image that includes the radiation-receiving surface of the X-ray detector 120 without the object 160, i.e., the exemplary patient, and determining the positions of the X-ray radiosensitive area 180 and the X-ray dose measurement area 190 relative to the reference depth camera image from the corresponding RGB image. Alternatively, the positions of the X-ray radiation-sensitive region 180 and the X-ray radiation dose measurement region 190 with respect to the radiation-receiving surface of the X-ray detector 120 can be determined from calibration data representing the geometric model of those positions.

[0043] Figure 7 is a schematic diagram illustrating a third example of an image representation 170 of depth camera image data projected onto the radiation receiving surface of the X-ray detector 120 from the viewpoint of the depth camera 130, according to some aspect of this disclosure. Compared with Figure 6, in the image representation 170 of Figure 7, the patient's surface is replaced by its silhouette on the surface of the X-ray detector 120.

[0044] Figure 8 is a schematic diagram illustrating a fourth example of an image representation 170 of depth camera image data projected onto the radiation receiving surface of the X-ray detector 120 from the viewpoint of the depth camera 130, according to some aspect of this disclosure. Compared with Figure 6, in the image representation 170 of Figure 8, the patient's surface is replaced by its contour that overlaps with the surface of the X-ray detector.

[0045] Figure 9 is a schematic diagram illustrating a fifth example of an image representation 170 of depth camera image data projected onto the radiation receiving surface of the X-ray detector 120 from the viewpoint of the depth camera 130, according to some aspect of this disclosure. Compared with Figure 8, in Figure 9, the image representation 170 schematically visualizes the position of the object 160 relative to the X-ray radiation-sensitive region 180 and the X-ray radiation dose measurement region 190. In the schematic visualization, the object is identified in the depth camera image data and replaced by a schematic diagram of the object.

[0046] In one example, one or more corrective actions are further generated to obtain a more optimal position of the patient relative to the X-ray detector 120. In this example, the processor 140 is further configured to calculate the displacement between the position of one or more features in the image representation 170 of the projected depth camera image data and the expected position of one or more features relative to i) one or more representations of X-ray radiosensitive regions 180 and / or ii) one or more representations of X-ray radiation dose measurement regions 190. The processor 140 is further configured to generate outputs representing one or more corrective actions to reduce the displacement, based on the calculated displacement.

[0047] In this example, image processing techniques are used to identify features such as the patient's silhouette, limb position, or head on the surface of the X-ray detector from depth camera image data. The expected position of the features is determined based on user input of the type of imaging operation to be performed, automatic detection of the current position of the patient's anatomical landmarks or regions, classification of the patient's view, or a combination of these factors. For example, if a chest imaging operation is performed, the silhouette of the patient's torso on the surface of the detector is identified, and the corrective action includes "moving the torso 5 centimeters to the right" to align the patient's torso with the X-ray radiosensitive area 180. The corrective action is output in the form of an audio command or displayed on a monitor. For example, a directional arrow indicating the distance the object should be moved is superimposed on the relevant part of the image representation 170.

[0048] In one example, the depth camera 130 further generates optical image data. In this example, the processor 140 generates an image representation 170 of the projected depth camera image data so that the image representation includes the optical image data. For example, an RGB-D camera is used to provide optical image data in addition to the depth camera image data. The optical image data is in the visible or infrared portion of the electromagnetic spectrum. The optical image data is included in the image representation 170 by generating an overlay of the optical image data and the representation of the projected depth camera image data. The overlay further assists the user in positioning the patient relative to the X-ray detector 120.

[0049] Returning to Figure 4, in most situations, a portion of the surface 210 of object 160, "visible" from the viewpoint of the X-ray source 110 and projected onto the surface of the X-ray detector 120, can be determined with a very good approximation from the depth camera image data, regardless of its offset position. However, when the offset is large, the projection plane of the object is incomplete on the opposite side of the X-ray source from the offset, i.e., the lower portion of the projected image data 220 in Figure 4. In such situations, a more complete projection of the depth camera image data from the viewpoint of the X-ray source 110 onto the radiation receiving surface of the X-ray detector 120 can be obtained by combining projection data acquired from different rotational positions of the depth camera relative to the X-ray source 110. Therefore, in one example, the depth camera is mechanically coupled to the X-ray source 110, and the depth camera 130 is radially offset with respect to an axis 200 passing through the centers of the X-ray source 110 and the X-ray detector 120, or the depth camera 130 is radially offset with respect to an axis passing through the center of the radiation beam emitted by the X-ray source 110. The depth camera 130 is rotatable around the axis 200 to generate depth camera image data from different rotational positions with respect to the axis.

[0050] In this example, both the depth camera 130 and the X-ray source are capable of rotating together around an axis, meaning there is no relative movement between the X-ray source and the X-ray detector during rotation, or the depth camera 130 is capable of rotating independently of the X-ray source, in which case the X-ray detector remains stationary while the depth camera rotates. In this example, the depth camera is freely rotated to any angular position, or in practice, the depth camera is rotated to one of several selectable fixed rotation positions. The rotation positions are distinguished, for example, in increments of 90 degrees, or 180 degrees, or at other angular intervals. Doing so achieves a more precise positioning of the object 160 relative to the X-ray detector 110.

[0051] In one example, a further image representation of the projected depth camera image data is provided. In this example, the processor 140 generates an image representation 170 of the projected depth camera image data from the viewpoint of the X-ray source 110. This projection is determined based on the predetermined spatial relationship between the X-ray source 110, the X-ray detector 120, and the depth camera 130. This further image representation is further used to assist the operator in positioning an object relative to the X-ray detector.

[0052] In one example, an X-ray image is further generated. In this example, the X-ray detector 120 is configured to generate X-ray image data representing the attenuation of X-ray radiation emitted by the X-ray source 110 within the examination area 150, and the processor 140 is further configured to generate an X-ray image representation of the X-ray image data.

[0053] Another example provides a computer execution method for use with an X-ray imaging system 100. The computer execution method generates an image representation 170 using an X-ray imaging system comprising an X-ray source 110, an X-ray detector 120, and a depth camera 130, wherein the X-ray source 110 and the X-ray detector 120 are separated by an inspection area 150 to perform an X-ray imaging operation on an object when the object is received within the inspection area, and the depth camera 130 is configured to view the inspection area 150 to generate depth camera image data representing the object as it is received within the inspection area, and the method is as follows: Receiving depth camera image data, From the perspective of the X-ray source 110, depth camera image data is projected onto the radiation receiving surface of the X-ray detector 120, To generate an image representation 170 of the depth camera image data projected onto the radiation receiving surface of the X-ray detector 120 from the viewpoint of the depth camera 130. It holds.

[0054] In another example, a computer program product for use with an X-ray imaging system 100 is provided. The computer program product comprises instructions that, when executed by one or more processors 140, cause one or more processors 140 to perform a method for generating an image representation 170 using an X-ray imaging system comprising an X-ray source 110, an X-ray detector 120, and a depth camera 130, wherein the X-ray source 110 and the X-ray detector 120 are separated for each inspection area 150 to perform an X-ray imaging operation on an object when the object is received within the inspection area, and the depth camera 130 is configured to look at the inspection area 150 to generate depth camera image data representing the object when the object is received within the inspection area. The method is as follows: The steps include receiving depth camera image data and From the viewpoint of the X-ray source 110, the depth camera image data is projected onto the radiation receiving surface of the X-ray detector 120. The steps include generating an image representation 170 of the depth camera image data projected onto the radiation receiving surface of the X-ray detector 120 from the viewpoint of the depth camera 130, and It holds.

[0055] The above examples are to be understood as illustrative and non-limiting of the present disclosure. Further examples are anticipated. For example, the examples described relating to X-ray imaging systems are further provided in a corresponding form by computer execution methods, computer program products, or computer-readable storage media. It should be understood that features described in any one example can be used alone or in combination with other described features, in combination with another or more features of the example, or in combination with other examples. Furthermore, equivalents and modifications not described above may be adopted without departing from the scope of the invention as defined in the appended claims. In the claims, the word “equipped with” does not exclude other elements or actions, and singular elements do not exclude plurals. The mere fact that certain features are enumerated in mutually different dependent claims does not indicate that combinations of these features cannot be used advantageously. No reference numeral in the claims should be taken to mean limiting its scope.

Claims

1. X-ray source and An X-ray detector separated from the X-ray source by the inspection area to perform an X-ray imaging operation on the object when the object is received within the inspection area, A depth camera that observes the inspection area in order to generate depth camera image data representing the object when the object is received within the inspection area, Receiving the aforementioned depth camera image data, From the perspective of the X-ray source, the depth camera image data is projected onto the radiation receiving surface of the X-ray detector, From the viewpoint of the depth camera, an image representation of the depth camera image data projected onto the radiation receiving surface of the X-ray detector is generated. The processor that performs the task An X-ray imaging system equipped with [the following features].

2. The X-ray imaging system according to claim 1, wherein the processor projects the depth camera image data from the viewpoint of the X-ray source onto the radiation receiving surface of the X-ray detector, and / or generates the image representation of the depth camera image data projected onto the radiation receiving surface of the X-ray detector from the viewpoint of the depth camera.

3. The depth camera is viewing at least a portion of the radiation receiving surface of the X-ray detector, The depth camera generates depth camera image data representing at least a portion of the radiation receiving surface of the X-ray detector, The aforementioned processor, From the generated depth camera image data representing at least a portion of the radiation receiving surface of the X-ray detector, the spatial relationship between the depth camera and the X-ray detector is determined. Using the determined spatial relationship between the depth camera and the X-ray detector, the spatial relationship between the X-ray source, the X-ray detector, and the depth camera is determined. The X-ray imaging system according to claim 2, which performs the following.

4. The X-ray imaging system according to claim 3, wherein the processor determines the spatial relationship between the X-ray source, the X-ray detector, and the depth camera based on calibration data representing the relative positions of the X-ray source and the depth camera, and / or the relative positions of the X-ray source and the X-ray detector.

5. The X-ray imaging system according to claim 2, wherein the predetermined spatial relationship between the X-ray source, the X-ray detector, and the depth camera is determined based on calibration data representing the relative positions of the X-ray source, the X-ray detector, and the depth camera.

6. The X-ray detector comprises one or more radiation-sensitive regions for generating X-ray image data, and / or one or more radiation dose measurement regions for generating X-ray dose measurement data. The X-ray imaging system according to claim 1, wherein the processor generates an overlay representation including one or more X-ray radiation-sensitive regions, and / or a representation of one or more X-ray radiation dose measurement regions, and the image representation of the projected depth camera image data.

7. The X-ray imaging system according to claim 6, wherein the processor calculates a displacement between the position of one or more features in the image representation of the projected depth camera image data and the expected position of the one or more features relative to i) the representation of the one or more X-ray radiation-sensitive regions and / or ii) the representation of the one or more X-ray radiation dose measurement regions, and the processor generates an output representing one or more corrective measures to reduce the displacement, based on the calculated displacement.

8. The depth camera generates optical image data, The X-ray imaging system according to claim 1, wherein the processor generates the image representation of the projected depth camera image data such that the image representation includes the optical image data.

9. The depth camera is mechanically connected to the X-ray source, The depth camera is radially offset with respect to an axis passing through the center of the X-ray source and the X-ray detector, or the depth camera is radially offset with respect to an axis passing through the center of the radiation beam emitted by the X-ray source. The X-ray imaging system according to claim 1, wherein the depth camera is rotatable around the axis to generate depth camera image data from different rotational positions with respect to the axis.

10. The X-ray imaging system according to claim 1, wherein the processor generates an image representation of the depth camera image data projected from the viewpoint of the X-ray source.

11. The X-ray detector generates X-ray image data representing the attenuation of X-ray radiation emitted by the X-ray source within the inspection area. The X-ray imaging system according to claim 1, wherein the processor generates an X-ray image representation of the X-ray image data.

12. The X-ray imaging system according to claim 1, wherein the depth camera image data represents the shape of the surface of the object.

13. The X-ray imaging system according to claim 1, wherein the image representation of the projected depth camera image data includes an overlay on the radiation receiving surface of the X-ray detector of a portion of the surface of the object, a portion of the silhouette of the object, or a portion of the contour of the object.

14. A method for operating an X-ray imaging system, The X-ray imaging system comprises an X-ray source, an X-ray detector, and a depth camera, wherein the X-ray source and the X-ray detector are separated by the inspection area to perform an X-ray imaging operation on the object when the object is received within the inspection area, and the depth camera observes the inspection area to generate depth camera image data representing the object when the object is received within the inspection area. The processor of the X-ray imaging system receives the depth camera image data, The processor performs the steps of projecting the depth camera image data onto the radiation receiving surface of the X-ray detector from the viewpoint of the X-ray source, The processor generates an image representation of the depth camera image data projected onto the radiation receiving surface of the X-ray detector from the viewpoint of the depth camera. A method for operating an X-ray imaging system, comprising the following:

15. A non-temporary computer-readable medium for storing executable instructions, wherein the executable instructions cause a computer to perform a method for generating an image representation using an X-ray imaging system. The X-ray imaging system comprises an X-ray source, an X-ray detector, and a depth camera, wherein the X-ray source and the X-ray detector are separated by the inspection area to perform an X-ray imaging operation on the object when the object is received within the inspection area, and the depth camera observes the inspection area to generate depth camera image data representing the object when the object is received within the inspection area. The aforementioned method, The steps include receiving the depth camera image data, From the viewpoint of the X-ray source, the depth camera image data is projected onto the radiation receiving surface of the X-ray detector. The steps include generating an image representation of the depth camera image data projected onto the radiation receiving surface of the X-ray detector from the viewpoint of the depth camera, and A non-temporary computer-readable medium having [a certain characteristic].

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