Spectrally generated stereoscopic x-ray imaging

Abstract

This invention relates to X-ray imaging. An X-ray apparatus (100) is provided. The X-ray apparatus (100) includes an X-ray generator (10) and an X-ray detector (12). The X-ray generator (10) is configured to generate a multicolor X-ray beam within the frequency range of the object to be imaged. The multicolor X-ray beam is configured to have an energy-dependent angle relative to the X-ray detector (20). The X-ray detector (20) is configured to acquire multiple energy-resolved absorption images of the object, which can be used to generate a stereoscopic absorption image of the object. This novel imaging modality can be considered as an intermediate between pure projection imaging and full 3D modality. Therefore, it can be used in the early stages of the diagnostic process to clarify indications without the need to acquire a full 3D image. The X-ray apparatus can relax the requirement for precise patient positioning for detailed examinations (e.g., lateral ankle) because radiologists can compensate for misalignment after image acquisition.

Description

Technical Field

[0001] This invention relates to X-ray imaging, and more particularly to X-ray equipment, X-ray systems, and X-ray imaging methods. Background Technology

[0002] X-ray imaging is often the starting point in a patient's diagnostic path. Subsequent three-dimensional (3D) examinations such as computed tomography (CT) and magnetic resonance imaging (MR) can frequently be scheduled to resolve ambiguities present in interpreting findings from two-dimensional (2D) X-ray images. Such examinations can be expensive and provide additional doses to the patient in the case of CT.

[0003] Spectroscopic CT systems are currently under development, opening up a wide range of novel and previously unforeseen diagnostic imaging applications through the resolution of X-ray photons of different energies. This ability to resolve different wavelengths enables a deeper understanding of anatomy and physiology, as it reveals the fundamental physical properties of tissue processes and bone anatomy in different parts of the human body's spectrum. A relatively simple example of using such techniques in planar radiography is the application of dual-energy imaging in chest X-rays for bone suppression. Summary of the Invention

[0004] An improved X-ray device may be required.

[0005] The object of the invention is achieved through the subject matter of the independent claims, wherein further embodiments are incorporated in the dependent claims. It should be noted that the aspects described below also apply to X-ray apparatus, X-ray systems, and X-ray imaging methods.

[0006] According to a first aspect of the present invention, an X-ray apparatus is provided. The X-ray apparatus includes an X-ray generator and an X-ray detector. The X-ray generator is configured to generate a multicolor X-ray beam within a frequency range of an object to be imaged. The multicolor X-ray beam is configured to have an energy-dependent angle relative to the X-ray detector. The X-ray detector is configured to acquire multiple energy-resolved absorption images of the object, the multiple energy-resolved absorption images being usable for generating a stereoscopic absorption image of the object.

[0007] Therefore, a novel X-ray device is proposed that can fill the gap between pure 2D X-rays and 3D CT or 3D MR modalities, while being less technically complex than CT or MR scanners and easier to use compared to conventional X-ray tomography. The proposed X-ray device utilizes the energy-correlation angle of X-rays relative to a spectral detector to generate stereoscopic absorption images of objects. Different implementations of such energy-correlation X-ray angles are described in detail below. All implementations share the commonality of being based on a single X-ray source and a single detector, where no parts are set to move, unlike, for example, C-arm systems or CT scanners. Therefore, the setup is relatively simple and can be implemented more cost-effectively compared to, for example, C-arm systems. Furthermore, its use can be seamlessly integrated into conventional X-ray workflows.

[0008] As will be described below, some of the proposed implementations allow for changes in the central beam relative to the spectral detector (i.e., the viewing direction) after image acquisition. Therefore, radiologists can retrospectively adjust the viewing direction to a certain extent to address ambiguities present in a single 2D projection image or to correct suboptimal patient positioning. Furthermore, the proposed techniques could potentially be used to accelerate and / or enhance CT or C-arm systems.

[0009] Therefore, the proposed X-ray device, for example Figure 1 and Figure 2 The exemplary X-ray device shown can solve one or more of the following problems:

[0010] Conventional X-ray imaging produces purely 2D projection images, which may have ambiguity that can only be resolved in 3D. Furthermore, the quality of X-ray images can depend heavily on the patient's positioning relative to the detector and X-ray source. The X-ray device disclosed herein offers a novel imaging modality that can be considered between purely projection imaging (e.g., X-ray) and a full 3D modality (e.g., CT). Moreover, the proposed X-ray device can relax the requirement for precise patient positioning for detailed examinations (e.g., lateral ankle) because radiologists can compensate for misalignment after image acquisition.

[0011] 3D imaging modalities can resolve this ambiguity, but they are costly, technically complex, and may involve additional patient doses in the case of CT. X-ray devices, as disclosed herein, can be used to generate pseudo-3D images of joints for the detection and classification of fractures that would otherwise require CT scans.

[0012] Existing stereoscopic X-ray / tomography synthesis techniques may involve several detectors and / or sources, or be based on moving parts (e.g., a C-arm). Some X-ray systems can be upscaled to stereoscopic modality, but this can lead to further configuration time, which is less advantageous in efficient workflows. Existing stereoscopic X-ray / tomography synthesis with a single tube and detector may involve at least two or more image acquisitions, where the tube is oriented differently relative to the detector. Existing stereoscopic X-ray / tomography synthesis techniques also result in higher patient radiation doses. The X-ray device disclosed herein can be used to generate pseudo-3D images of joints for the detection and classification of fractures that would otherwise require CT scans. Typically, the proposed X-ray device allows radiologists to retrospectively change the viewing orientation of projected X-ray images to address ambiguities present in a single 2D projected image. The proposed X-ray device can be integrated into a C-arm system or CT scanner to reduce scan time, for example, by simultaneously acquiring multiple viewing orientations from a single detector source location.

[0013] In addition to stereoscopic examination, different views of the same anatomical structures (e.g., chest PA and side views) are routinely acquired, resulting in higher radiation doses. X-ray equipment as disclosed herein allows for simultaneous acquisition of multiple observation directions from a single detector source location.

[0014] Current CT / C-arm systems acquire only a single view from each detector source location. The X-ray equipment disclosed herein allows for simultaneous acquisition of multiple viewpoints from a single detector source location.

[0015] According to an embodiment of the invention, the X-ray apparatus further includes an X-ray optics device configured to redirect the multicolor X-ray beam such that the multicolor X-ray beam is angled in an energy-dependent manner.

[0016] X-ray optical equipment may include wavelength dispersing elements, such as... Figure 1 The X-ray prism is shown. X-ray optical devices can alternatively be provided as diffraction gratings, optical devices configured to redirect polychromatic X-ray beams by utilizing Compton scattering, or combinations of one or more of these elements. Such configurations will be described in detail below, particularly regarding... Figure 1 The example shown.

[0017] According to embodiments of the present invention, an X-ray optical device includes one or more of the following: an X-ray prism, an optical device configured to redirect a polychromatic X-ray beam by utilizing Bragg scattering, and an optical device configured to redirect a polychromatic X-ray beam by utilizing Compton scattering.

[0018] According to embodiments of the present invention, the X-ray detector includes: a dual-layer or multi-layer sandwich detector or a photon counting detector.

[0019] In other words, a planar spectral detector is then used to acquire energy-resolved absorption images. This can be achieved using a two- or multi-layer sandwich detector or a photon-counting detector. In the case of a two-layer detector, stereo images are obtained directly from the signals of the detector layers. If more than two layers of detectors are involved, or a photon-counting detector is used, multiple stereo images with different relative angles of the central beam are acquired in a single image. In other words, more 3D information is imaged in this case. Furthermore, using a photon-counting detector allows for quasi-continuous changes in the angle (within a specific range) by comparing the absorption images of two selected bands.

[0020] According to an embodiment of the present invention, the X-ray detector includes multiple tilted detector layers, each of which is sensitive to a corresponding energy range.

[0021] In this configuration, the energy-dependent beam angle relative to the X-ray detector is achieved by a detector cover housing two or more tilted detector layers, each sensitive to a range of energies. This configuration will be described in detail below, particularly regarding... Figure 2 and Figure 3 The example shown.

[0022] According to an embodiment of the invention, the X-ray detector further includes a mechanical extender, which is combined with a rotation axis attached to the boundary of one or more detector layers for adjusting the tilt angle of one or more detector layers.

[0023] The mechanical extender, combined with a rotational axis attached to the boundary of each layer, can be used to symmetrically adjust the tilt angle of the layers. This allows for the achievement of different energy-related angles. This configuration will be described in detail below, particularly regarding... Figure 2 The example shown.

[0024] According to a second aspect of the invention, an X-ray system is provided. The X-ray system includes an X-ray apparatus and a computing device according to the first aspect and any associated examples. The X-ray apparatus includes an X-ray generator and an X-ray detector configured to acquire multiple energy-resolved absorption images of an object. The computing device is configured to perform image processing on the acquired multiple energy-resolved absorption images of the object.

[0025] Examples of X-ray systems in Figure 6 As shown in the image.

[0026] According to an embodiment of the invention, the computing device is configured to determine the observation direction in different energy bands of a multicolor X-ray beam and associate the observation direction with the corresponding energy-resolved absorption image.

[0027] Therefore, the detected energy or band is converted into the corresponding observation direction, that is, the angle of the central beam of X-rays within a given energy or band.

[0028] According to an embodiment of the present invention, the computing device is configured to fuse two or more energy-resolved absorption images from the plurality of energy-resolved absorption images to continuously or quasi-continuously change the observation direction.

[0029] Therefore, even if the photon energy is not continuously resolved, the absorption images of the detector layer can be fused within a physical approximation, for example, by linear or nonlinear combinations, to continuously change the observation direction within a certain range.

[0030] According to an embodiment of the invention, the computing device is configured to apply a deep learning model trained on a given anatomical structure to estimate a 3D reconstruction based on one or more energy-resolved absorption images of the object.

[0031] 2D-3D reconstruction can be performed using a 3D statistical shape model (SSM) or a general model. A 2D projection of the 3D SSM or general model computed from a training dataset can be compared to an X-ray image to generate a similarity score, and the shape parameters of the SSM or general model can be optimized to maximize similarity. Alternatively, a convolutional neural network (CNN) can be used to perform 2D-3D reconstruction to extract anatomical landmarks, and 3D modeling can be performed based on the extracted anatomical landmarks.

[0032] According to an embodiment of the present invention, the X-ray detector includes a plurality of tilted detector layers, each sensitive to a corresponding energy range. The computing device is configured to perform image processing to compensate for distortions caused by the geometric arrangement of the tilted detector layers.

[0033] The geometric arrangement of tilted detector layers can lead to distortion. Given a source-detector coverage distance, each detector layer actually has a slightly different source-to-image distance (SID), which can be compensated for after the fact (e.g., approximately by isotropic scaling).

[0034] According to an embodiment of the present invention, the computing device is configured to perform image processing to compensate for differences in the energy-related decay behavior of different materials.

[0035] For example, image-to-image translation can be performed using machine learning algorithms that have been trained to compensate for differences in energy-related decay behavior. Image-to-image translation can be achieved in an unpaired manner using, for example, recurrent generative adversarial networks (GANs) or large models fine-tuned in a self-supervised manner.

[0036] According to an embodiment of the invention, the X-ray system further includes a display configured to display a stereoscopic absorption image of the generated object.

[0037] According to an embodiment of the present invention, the X-ray system is a C-arm system or a CT system.

[0038] According to a third aspect of the present invention, an X-ray imaging method is provided, comprising:

[0039] A multicolor X-ray beam is generated by an X-ray generator within the frequency range of the object to be imaged, wherein the multicolor X-ray beam has an energy-dependent angle relative to the X-ray detector; and

[0040] Multiple energy-resolved absorption images of the object are acquired by an X-ray detector, and these multiple energy-resolved absorption images can be used to generate a stereoscopic absorption image of the object.

[0041] This will be described in detail below, especially regarding Figure 7 The flowchart shown.

[0042] These and other aspects of the invention will become apparent and will be elucidated with reference to the embodiments described below. Attached Figure Description

[0043] These and other aspects of the invention will become apparent and further clarified with reference to the embodiments described by way of example in the following description and the accompanying drawings, in which...

[0044] Figure 1 An exemplary X-ray device is shown.

[0045] Figure 2 Another exemplary X-ray device is shown.

[0046] Figure 3 A perspective view of an exemplary X-ray detector with three tilted detector layers is shown.

[0047] Figure 4 Another example of an X-ray device is shown.

[0048] Figure 5A An exemplary conventional X-ray image of a virtual bone model is shown.

[0049] Figure 5B A stereo X-ray image showing the spectra generated by the central beams of two photon energies at different angles is shown.

[0050] Figure 6 An exemplary X-ray system is shown.

[0051] Figure 7 A flowchart describing an X-ray imaging method is shown.

[0052] It should be noted that the accompanying drawings are purely schematic and not drawn to scale. In the drawings, elements corresponding to those already described may have the same reference numerals. Examples, embodiments, or optional features, whether or not indicated as non-limiting, should not be construed as limiting the claimed invention. Detailed Implementation

[0053] Figure 1 An exemplary X-ray device 100 is shown. The X-ray device 100 includes an X-ray generator 10, an X-ray detector 20, and an X-ray optical device 30.

[0054] exist Figure 1 In the exemplary X-ray apparatus 100 shown, the X-ray generator 10 is an X-ray tube. The X-ray tube 10 includes a vacuum housing 2 having a vacuum interior. The X-ray tube 10 also includes a cathode 4 with a filament coil and an anode 6 with a target 8. The cathode 4 and anode 6 are arranged within the vacuum housing 2, with the anode 6 facing the filament coil of the cathode 4. A potential difference (e.g., 20 to 150 kV) is applied between the electrodes by a high-voltage power supply 12. Electrons emitted from the cathode 4 are accelerated through the vacuum by the tube potential to strike the anode 6. Upon impact with the target 8, electrons arriving near the atomic nuclei in the target material are slowed by the positive charge of the nuclei, resulting in the conversion of energy into heat (e.g., 99%) and X-ray photons (e.g., 1%). The X-ray photons are released from a window (not shown) of the X-ray tube 10 as a multicolor X-ray beam with a defined energy range (also known as an X-ray spectrum), forming the basis for X-ray image formation. The multicolor X-ray beam can be a cone beam, a rectangular beam, a fan beam, or other shapes of X-ray beam.

[0055] X-ray optics 30 is adapted to receive a multicolor X-ray beam from X-ray tube 10 and split the X-ray beam into multiple energies of X-rays, each energy being guided along a corresponding direction. X-ray optics 30 is also operable to guide multiple energies of X-rays in multiple angular directions and / or displacements relative to the central beam axis 14 of the multicolor X-ray beam. Thus, the multicolor X-ray beam is angular in an energy-dependent manner. In some examples, X-ray optics 30 may include wavelength-dispersing elements, such as… Figure 1 The X-ray prism shown. The X-ray optical device 30 may alternatively be provided as a diffraction grating, an optical device configured to redirect a polychromatic X-ray beam by utilizing Compton scattering, or a combination of one or more of these elements.

[0056] X-ray optics 30 guides X-rays of different energies along a path angled relative to the central beam axis 14. Each angle is determined by X-ray optics 30. For example, such as Figure 1As shown, the X-ray optical device 30 performs spectral separation and generates two X-ray beams, including a first X-ray beam 16 with a first energy (e.g., 80 keV) and a second X-ray beam 18 with a second energy (e.g., 140 keV). The first X-ray beam 16 has a central beam 16a, and the second X-ray beam 18 has a central beam 18a. Figure 1 As shown, the central beams 16a and 18a are at different angles relative to the X-ray detector 20, thus creating two viewing directions to acquire X-ray images of the object. The object can be a human body or a part of a human body. In other words, the angle between these two central beams represents the difference between the angles at which two planar X-ray images or monocular views are captured. This angle can be used to construct two views with binocular parallax.

[0057] X-ray detector 20 can be a planar spectroscopic detector for acquiring energy-resolved images. A planar spectroscopic detector can be implemented using a two-layer or multi-layer sandwich detector or a photon-counting detector. In the case of a two-layer detector, stereo images are obtained directly from the signals of the detector layers. If more than two layers are involved or a photon-counting detector is used, multiple stereo images with different relative angles of the central beam are acquired in a single image. In other words, more 3D information is imaged in this case. Using a photon-counting detector allows the angle to vary quasi-continuously within a certain energy range, thereby allowing comparison of absorption images from two or more selected energy bands. For example, a photon-counting detector can be configured to classify photons passing through an object into multiple energy bins based on their energy, and the angle can be quasi-continuously varied within a specific energy range by selecting different energy bins.

[0058] Typically, the imaging device is configured such that the central beam strikes the detector at a 90° angle. Figure 1 In the example shown, there is no longer a single central beam. In one example, the X-ray device 100 can be configured to symmetrically offset the central beam perpendicular to the detector plane, such that X-ray images can be observed symmetrically from "both sides" relative to the detector normal. For example, the X-ray generator 10 can be configured to generate a multicolor X-ray beam in which the central beam axis 14 has a small tilt angle relative to the normal of the detector plane of the X-ray detector 20.

[0059] Figure 2 Another exemplary X-ray device 100 is shown. Figure 2 In the example shown, X-ray device 100 includes an X-ray generator 10 and an X-ray detector 20. Figure 2 The X-ray generator 10 shown and Figure 1 The X-ray generator 10 shown may have similar components. Figure 1 The exemplary X-ray equipment shown is different. Figure 2The X-ray apparatus 100 shown does not include X-ray optical devices suitable for splitting an X-ray beam into multiple X-ray energies. Instead, in Figure 2 In the exemplary X-ray device 100 shown, two or more tilted detector layers (such as...) are accommodated. Figure 2 The detector covers of the first tilt detector layer 22a and the second tilt detector layer 22b (shown) achieve angularity of the energy-correlated beam relative to the X-ray detector 20. Each of the two or more tilt detector layers is sensitive to a certain energy range. For example, the first tilt detector layer 22a may be sensitive to an energy range of approximately 80 keV, and the second tilt detector layer 22b may be sensitive to an energy range of approximately 100 keV.

[0060] although Figure 2 A dual-layer tilted detector can be illustrated by way of example; however, it should be understood that the X-ray detector 20 may include three or more detector layers, each sensitive to a range of energies. For example, Figure 3 A perspective view of an exemplary X-ray detector 20 having three detector layers: a first detector layer 20a, a second detector layer 20b, and a third detector layer 20c is shown. Each of the three layers is sensitive to a range of energies. For example, the first detector layer 20a is sensitive to X-rays with an energy of 80 keV, the second detector layer 20b is sensitive to X-rays with an energy of 100 keV, and the third detector layer 20c is sensitive to X-rays with an energy of 140 keV. Figure 3 In the exemplary X-ray detector 20 shown, the first detector layer 20a is parallel to the detector cover 24 of the X-ray detector 20 and therefore orthogonal to the orthogonal axis 26 of the X-ray detector 20. The second detector layer 20b and the third detector layer 20c are tilted relative to the orthogonal axis 26 of the X-ray detector 20 and relative to each other, such that no pair of detector layers 20a, 20b, and 20c are parallel. In other words, detector layer 20a is neither parallel to detector layer 20b nor parallel to detector layer 20c, and detector layer 20b is not parallel to detector layer 20c. This exemplary X-ray detector 20 can allow the generation of stereoscopic images with a retrospectively adjustable viewing orientation. Note that... Figure 3 The exemplary X-ray detector 20 shown is provided by way of example. It should be understood that the X-ray detector 20 may include four or more detector layers, and each layer may be tilted at any suitable angle relative to the detector cover 24 and / or the orthogonal axis 26.

[0061] Return to Figure 2In some embodiments, the mechanical extender 28 may be provided in conjunction with a rotation axis 30 attached to the boundary of one or more detector layers for symmetrically or alternatively asymmetrically adjusting one or more detector layers (e.g., Figure 2 The tilt angles of the first and second detector layers 22a and 22b are shown. This allows for different energy-related angles to be achieved.

[0062] Using X-ray equipment, such as Figure 1 and Figure 2 The exemplary X-ray device 100 shown can acquire multiple energy-resolved absorption images at different angles. The acquired energy-resolved absorption images at two different angles can be used as left-eye and right-eye views and can be horizontally merged into a single left-right 3D image. Stereoscopic vision can be achieved by observing the merged image using virtual reality (VR) glasses (e.g., a simple VR headset). Alternatively, the acquired energy-resolved absorption images at two different angles can be converted into a single red-blue 3D image, and the edited image can be observed using red-blue glasses to generate stereoscopic vision. As another option, the acquired energy-resolved absorption images at two different angles can be converted into interlaced X-ray stereoscopic images and displayed using a glasses-free 3D device.

[0063] Figure 4 Another example of an X-ray imaging apparatus 100 is shown. Figure 4 In the example shown, X-ray device 100 includes an X-ray generator 10 and an X-ray detector 20. Figure 4 The X-ray generator 10 shown and Figure 1 and Figure 2 The X-ray generator 10 shown may have similar components.

[0064] and Figure 1 and Figure 2 The exemplary X-ray equipment shown is different. Figure 4 The X-ray device 100 shown includes Figure 1 The X-ray optical device 30 shown and Figure 2 The X-ray detector 20 and X-ray optical device 30 shown are adapted to split an X-ray beam into multiple energies. The X-ray detector 20 has two or more tilted detector layers, for example... Figure 4 The first detector layer 22a and the second detector layer 22b are shown. In other words, in this illustrated example, the energy-dependent beam angle relative to the X-ray detector 20 is determined by the X-ray optics 30 and the tilted detector layer (e.g., Figure 4 The first detector layer 22a and the second detector layer 22b shown are both implemented. (And...) Figure 1Compared to the embodiment shown without using tilted detector layers, each detector layer, sensitive to specific energy bands, is tilted in such a manner that the resulting energy-correlated absorption images cover a wider range of observation directions. For example, as... Figure 4 As shown, a first X-ray beam 16 of first energy enters the X-ray detector 20 at an incident angle β. The incident angle β is the angle between the central beam 16a of the first X-ray beam 16 and a line perpendicular (at a 90-degree angle) to the detector surface at the point of incidence. The detector layer 22a is sensitive to the first energy and is tilted relative to the detector surface at an angle α (where α ≠ 0°). The effective observation direction of the first X-ray beam 16 is measured by the angle between its central beam 16a and the normal to the detector layer sensitive to that energy (i.e., detector layer 22a). Figure 4 As shown, the interaction between the X-ray optical device 30 and the tilted detector layer 22a thus produces an effective observation direction at an angle of α+β for acquiring X-ray images of the object. Detector layer 22b can be used to adjust the effective viewing angle of the second X-ray beam 18 in a similar manner. In summary, considering the energy-related redirection of the X-ray optical device 30 for different energy bands, the first tilted detector layer 22a and the second tilted detector layer 22b can be configured such that the minimum incident angle and the maximum (signed) incident angle are less than and greater than the angles of incidence, respectively. Figure 1 The minimum and maximum incident angles in the corresponding embodiments. In this way, with... Figure 1 and Figure 2 Compared to the embodiment shown, multiple observation directions can be acquired simultaneously over a larger area at a single detector source location.

[0065] Despite Figure 4 Not shown, but should be understood. Figure 2 The mechanical extender 28 shown can also be used in Figure 4 In the embodiments used, it is used to symmetrically or alternatively asymmetrically adjust the tilt angle of one or more detector layers, for example... Figure 2 The first detector layer 22a and the second detector layer 22b are shown in the diagram. This allows for different energy-related angles to be achieved.

[0066] Figure 5A An exemplary conventional X-ray image of a virtual bone model is shown. Figure 5B This shows a stereoscopic X-ray image generated by the spectra of two central beams with different angles, representing two photon energies. The angle is expressed as relative to... Figure 1 and Figure 2 The angle of the center beam axis 14 shown (e.g., Figure 5B (As shown in 1°, 2°, 4°, 6°, and 8°). Figure 5B Each stereoscopic X-ray image is a single red-blue 3D image, and red-blue glasses are likely to provide the clearest view of the colors used to observe these stereoscopic X-ray images. Although Figure 5B The stereoscopic X-ray images in the images are presented in black and white; however, it should be understood that these spectral-generated stereoscopic X-ray images can also be presented in color. For example, in Figure 5B In this study, a stereoscopic X-ray image generated by the spectra of two central beams with different photon energies at different angles can be represented by red-green coding. Color coding can be used to distinguish X-ray images acquired at different angles (i.e., different energies).

[0067] The X-ray device disclosed in this article may have one or more of the following potential clinical applications:

[0068] This novel imaging modality can be viewed as somewhere between pure projection imaging (e.g., X-ray) and full 3D modality (e.g., CT). Therefore, it can be used early in the diagnostic process to clarify indications without requiring the acquisition of a full 3D image. For example, it can be used to generate pseudo-3D images of joints to detect and classify fractures that would otherwise require a high-dose, costly CT scan. Typically, the proposed X-ray device allows radiologists to retrospectively change the viewing orientation of the projection X-ray image to address ambiguities present in a single 2D projection image.

[0069] The proposed X-ray device can relax the requirements for precise patient positioning in fine examinations (e.g., lateral ankle) because radiologists can compensate for misalignment after image acquisition.

[0070] The proposed X-ray device may be particularly useful in mobile X-ray systems, where positioning is more difficult (e.g., for bedside patients), making retrospective correction of the direction of observation highly valuable.

[0071] In addition to facilitating pseudo-3D views, spectral information can also be used to analyze material composition for diagnostic purposes. For example, energy resolution can enable the differentiation of specific properties of soft tissues (e.g., distinguishing edema from pathological tissue swelling), properties that can currently only be differentiated through indirect inference during radiological interpretation.

[0072] The proposed X-ray device can also be integrated into a C-arm system or CT scanner, for example, by simultaneously acquiring multiple observation directions from a single detector source location to reduce scanning time.

[0073] Figure 6 An exemplary X-ray system 200 is illustrated. Examples of the X-ray system 200 may include, but are not limited to, C-arm systems and CT systems. The exemplary X-ray system 200 includes an X-ray device 100 and a computing device 110. The exemplary X-ray system may optionally include a display 120.

[0074] X-ray device 100 includes an X-ray generator and an X-ray detector configured to acquire multiple energy-resolved absorption images of an object. Figure 1 and Figure 2 Two exemplary X-ray devices 100 are shown in the figure.

[0075] Computing device 110 can be implemented in various ways (e.g., using dedicated hardware) to perform the functions described herein. A “processor” is an example of computing device 110 that employs one or more microprocessors that can be programmed using software (e.g., microcode) to perform the various functions described herein. Computing device 110 can be implemented with or without a processor, and can also be implemented as a combination of dedicated hardware performing some functions and processors (e.g., one or more programmed microprocessors and associated circuitry) performing other functions. Examples of computing device components that can be employed in various embodiments of this disclosure include, but are not limited to, conventional microprocessors, application-specific integrated circuits (ASICs), and field-programmable gate arrays (FPGAs). In various embodiments, the processor can be associated with one or more storage media (collectively referred to herein as “memory,” such as volatile and non-volatile computer memory). In some embodiments, the storage media can be encoded with one or more programs that, when executed on one or more processors and / or controllers, perform at least some of the functions described herein. Various storage media can be fixed within the computing device or can be transportable, such that one or more programs stored thereon can be loaded into the computing device to implement the various aspects of this disclosure described herein. The terms “program” or “computer program” are used in the general sense herein to refer to any type of computer code (e.g., software or microcode) that can be used to program one or more processors.

[0076] The computing device 110 is configured, for example, from Figure 1 and Figure 2 The X-ray detector 20 shown receives multiple acquired energy-resolved absorption images of an object and performs image processing on these images to generate a stereoscopic absorption image of the object. For example, the computing device 110 may perform one or more processing steps, including but not limited to compensating for perspective distortion, compensating for energy-dependent attenuation behavior of different materials, denoising the energy-resolved absorption images (particularly for photon-counting detectors), correlating the energy-resolved absorption images with the observation direction, identifying material composition, and rendering a stereoscopic image. These exemplary processing steps will be described in detail below.

[0077] In some examples, computing device 110 can perform image processing to compensate for perspective distortion. For example, in Figure 2In the exemplary X-ray apparatus 100 shown, the X-ray detector 20 includes multiple tilted detector layers, each sensitive to a corresponding energy range. The geometric arrangement of these detector layers can lead to distortion. In this case, the computing device 110 can be configured to perform image processing to compensate for the distortion caused by the geometric arrangement of the tilted detector layers. For example, given a source-detector-coverage distance, each detector layer actually has a slightly different SID, which can be compensated for afterward, for example, approximately by isotropic scaling.

[0078] In some examples, computing device 110 can perform imaging processing to compensate for differences in the energy-related decay behavior of different materials, for example, via an optoelectronic scale such as (Z / E) having atomic number Z and energy E. 3 The attenuation. For example, machine learning algorithms can be used for image-to-image translation, trained to compensate for differences in energy-related attenuation behavior. This is feasible because the observation direction changes only slightly in different energy bands, thus obtaining redundant image information. Image-to-image translation can be achieved unpaired using, for example, recurrent GANs or finely tuned large models trained in a self-supervised manner. If the X-ray detector is in Figure 1 The photon counting detector used in the X-ray apparatus 100 shown can quasi-continuously select small energy bands and change the observation direction accordingly. This allows for iterative compensation of energy-related attenuation behavior by sliding it within a small chamber over the measured energy range.

[0079] Because the number of photons per energy cell is much smaller than that in a conventional X-ray image used to define the radiation dose to a patient, the signal-to-noise ratio of an energy-resolved absorption image may be lower than that of a conventional X-ray image. In some examples, the computing device 110 can perform imaging processing to denoise the energy-resolved absorption image. This can be achieved, for example, by classical denoising algorithms that take into account the physical properties of noise, or by a machine learning model (e.g., a deep neural network) trained to denoise X-ray images in a supervised manner.

[0080] In some examples, computing device 110 can be configured to determine the observation direction in different energy bands of a multicolor X-ray beam and associate the observation direction with the corresponding energy-resolved absorption image. Depending on the implementation details, such as... Figure 1 and Figure 2 The implementation shown converts the detected energy or band into a corresponding observation direction, i.e., the angle of the central beam of X-rays within a given energy or band. This conversion can be based on a mathematical-physical model, taking into account source and detector configurations, and... Figure 1 In the case of the implementation options shown, the physical characteristics of the X-ray optical equipment used should be considered.

[0081] In some examples, computing device 110 can be configured to perform stereoscopic image rendering. For example, as described above, multiple energy-resolved absorption images can be acquired from different angles. The images obtained at these angles can be used as left-eye and right-eye views and can be horizontally merged into a single left-right 3D image displayed on display 120. VR glasses can be used to achieve stereoscopic vision. Observation using VR glasses can produce realistic stereoscopic views of the anatomical structure of an object. In some examples, display 120 can be a glasses-free device, and the images obtained at these angles can be converted by computing device 110 into interlaced X-ray stereoscopic images and displayed together with a glasses-free 3D device.

[0082] In some examples, radiologists can retrospectively tune the viewing direction to resolve ambiguities present in a single 2D projection image or to correct suboptimal patient positioning. For instance, if the X-ray detector is a dual-layer or multi-layer sandwich detector, the photon energy is not continuously resolved. In this case, the absorption images of the detector layers of the X-ray detector can be fused by computing device 110 within physical approximations, for example, through linear or nonlinear combinations, to continuously or quasi-continuously change the viewing direction. If the X-ray detector has a dual-angle detector layer configuration, such as... Figure 3 The X-ray detector shown can change the observation direction by rotating it around two axes within certain limitations. The observation direction can be continuously adjusted afterward by combining absorption images from three energy bands. If the X-ray detector is a photon counting detector configured to classify photons passing through an object into multiple energy boxes based on photon energy, the computing device 110 can be configured to continuously or quasi-continuously change the observation direction by selecting different energy boxes.

[0083] In some examples, computing device 110 may apply a deep learning model trained for a given anatomical structure to estimate a 3D reconstruction based on one or more acquired energy-resolved absorption images of the object. In other words, the 3D shape of an anatomical structure can be estimated and constructed based on one or more 2D energy-resolved absorption images. For example, in an exemplary method for estimating the 3D bone shape under X-ray images, a 2D projection of a 3D statistical shape model (SSM) or a general model computed from a training dataset can be compared with the X-ray images to generate a similarity score, and the shape parameters of the SSM or general model can be optimized to maximize similarity. 2D-3D reconstruction can also be performed using a CNN to extract anatomical landmarks, and 3D modeling can be performed based on the extracted anatomical landmarks.

[0084] In some examples, computing device 110 can perform material composition analysis using spectral information in slightly angled views. Regular material composition analysis for a single view can also be supported, for example, by algorithmic compensation of different views corresponding to different energies via a machine learning model trained for a specific anatomical structure.

[0085] Figure 7 A flowchart describing the X-ray imaging method 300 is shown.

[0086] At frame 310, the X-ray generator produces a multicolor X-ray beam within the frequency range of the object to be imaged. The multicolor X-ray beam has an energy-dependent angle relative to the X-ray detector. This energy-dependent angle can be determined by… Figure 1 and Figure 2 The exemplary configuration shown is used to implement this.

[0087] At box 320, the X-ray detector acquires multiple energy-resolved absorption images of the object, which can be used to generate a stereoscopic absorption image of the object.

[0088] exist Figure 1 In the exemplary X-ray apparatus shown, the X-ray detector can be a planar spectrometer for acquiring energy-resolved absorption images. The planar spectrometer is then used to acquire energy-resolved absorption images. The planar spectrometer can be implemented using a two-layer or multi-layer sandwich detector or a photon-counting detector. In the case of a two-layer detector, stereo images are obtained directly from the signals of the detector layers. If more than two layers are involved or a photon-counting detector is used, multiple stereo images with different relative angles of the central beam are acquired in a single image. In other words, in this case, more 3D information is imaged. Furthermore, using a photon-counting detector allows for quasi-continuous changes in the angle (within a specific range) by comparing the absorption images of two selected energy bands.

[0089] exist Figure 2 In the exemplary X-ray device shown, the X-ray detector may include two or more tilted detector layers, each of which is sensitive to a range of energies. Figure 2 An exemplary X-ray detector with two tilted detector layers is shown in the figure, and Figure 3 An exemplary X-ray detector layer with three tilting detector layers is shown in the figure.

[0090] In another exemplary embodiment of the present invention, a computer program or computer program unit is provided, characterized in that it is adapted to perform method steps of the method according to one of the foregoing embodiments on a suitable system.

[0091] Therefore, computer program elements can be stored on a computer unit, which may also be part of an embodiment of the present invention. The computing unit can be adapted to perform or cause the steps of the described methods. Furthermore, it can be adapted to operate components of the described apparatus. The computing unit can be adapted to automatically operate and / or execute user commands. The computer program can be loaded into the working memory of a data processor. Therefore, a data processor can be configured to perform the methods of the present invention.

[0092] This exemplary embodiment of the invention covers computer programs that use the invention from the outset and computer programs that convert existing programs into programs that use the invention through updates.

[0093] Furthermore, the computer program unit may be able to provide all the necessary steps to implement the exemplary embodiments of the method described above.

[0094] According to another exemplary embodiment of the present invention, a computer-readable medium, such as an optical disc, is provided, wherein the computer-readable medium has computer program units stored thereon, the computer program units being described in the preceding portion.

[0095] Computer programs may be stored and / or distributed on suitable media, such as optical or solid-state media provided with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunications systems.

[0096] However, computer programs can also be presented via networks such as the World Wide Web, and can be downloaded from such networks to the working memory of a data processor. According to another exemplary embodiment of the invention, a medium is provided for making a computer program unit downloadable, the computer program unit being arranged to perform a method according to one of the foregoing embodiments of the invention.

[0097] It should be noted that embodiments of the invention are described with reference to different subject matter. In particular, some embodiments are described with reference to method-type claims, while other embodiments are described with reference to device-type claims. However, those skilled in the art will understand from the above and below description that, unless otherwise stated, any combination of features related to different subject matter is also considered to be disclosed with this application, except for any combination of features belonging to one type of subject matter. However, all features can be combined together to provide synergies, rather than simply being the sum of features.

[0098] While the invention has been detailed and described in the accompanying drawings and the foregoing description, such description is to be considered illustrative or exemplary, and not restrictive. The invention is not limited to the disclosed embodiments. Other variations of the disclosed embodiments will be understood and implemented by those skilled in the art in practicing the claimed invention upon study of the drawings, the disclosure, and the dependent claims.

[0099] In the claims, the word "comprising" does not exclude other elements or steps, and the quantifiers "a" or "an" do not exclude a plurality. A single processor or other unit can perform the functions of several items referenced in the claims. The fact that certain measures are re-referenced in mutually different dependent claims does not mean that a combination of these measures cannot be advantageous. Any reference numerals in the claims should not be construed as limiting the scope.

Claims

1. An X-ray device (100), comprising: X-ray generator (10); and X-ray detector (20); The X-ray generator is configured to generate a multicolor X-ray beam within the frequency range of the object to be imaged; The multicolor X-ray beam is configured to have an energy-dependent angle relative to the X-ray detector; and The X-ray detector is configured to acquire multiple energy-resolved absorption images of the object, which can be used to generate a stereoscopic absorption image of the object.

2. The X-ray device according to claim 1, further comprising: X-ray optical apparatus (30), the X-ray optical apparatus being configured to redirect the multicolor X-ray beam such that the multicolor X-ray beam is angled in an energy-dependent manner.

3. The X-ray device according to claim 2, wherein, The X-ray optical device includes one or more of the following: X-ray prism; An optical device configured to redirect the multicolor X-ray beam by utilizing Bragg scattering; as well as An optical device configured to redirect the multicolor X-ray beam by utilizing Compton scattering.

4. The X-ray apparatus according to claim 2 or 3, wherein, The X-ray detector includes: Double-layer or multi-layer sandwich detectors; or Photon counting detector.

5. The X-ray apparatus according to any one of claims 1 to 3, wherein, The X-ray detector comprises multiple tilted detector layers (22a, 22b, 22c), each of which is sensitive to a corresponding energy range.

6. The X-ray device according to claim 5, in, The X-ray detector also includes a mechanical extender (28) which is combined with a rotation axis (30) attached to the boundary of one or more detector layers for adjusting the tilt angle of the one or more detector layers.

7. An X-ray system (200), comprising: X-ray device (100) according to any one of the preceding claims; and Computing device (10); The X-ray device includes an X-ray generator and an X-ray detector, the X-ray detector being configured to acquire multiple energy-resolved absorption images of the object; and The computing device is configured to perform image processing on the plurality of energy-resolved absorption images of the acquired object.

8. The X-ray system according to claim 7, in, The computing device is configured to determine the observation direction in different energy bands of the multicolor X-ray beam and associate the observation direction with the corresponding energy-resolved absorption image.

9. The X-ray system according to claim 8, in, The computing device is configured to fuse two or more energy-resolved absorption images from the plurality of energy-resolved absorption images to continuously or quasi-continuously change the observation direction.

10. The X-ray system according to any one of claims 7 to 9, in, The computing device is configured to apply a deep learning model trained on a given anatomical structure to estimate a three-dimensional 3D reconstruction based on one or more energy-resolved absorption images of the object.

11. The X-ray system according to any one of claims 7 to 9, in, The X-ray detector comprises multiple tilted detector layers, each sensitive to a corresponding energy range; and The computing device is configured to perform image processing to compensate for distortion caused by the geometric arrangement of the tilted detector layer.

12. The X-ray system according to any one of claims 7 to 9, in, The computing device is configured to perform image processing to compensate for differences in the energy-related decay behavior of different materials.

13. The X-ray system according to any one of claims 7 to 9, further comprising: A display (120) is configured to display a stereoscopic absorption image of the generated object.

14. The X-ray system according to any one of claims 7 to 9, in, The X-ray system is a C-arm system or a computed tomography (CT) system.

15. An X-ray imaging method (300), comprising: An X-ray generator generates a (310) multicolor X-ray beam within the frequency range of the object to be imaged, wherein the multicolor X-ray beam has an energy-dependent angle relative to the X-ray detector; and Multiple energy-resolved absorption images of the object are acquired by the X-ray detector (320), and the multiple energy-resolved absorption images can be used to generate a stereo absorption image of the object.

Images