Generation of cephalometric X-ray images based on panoramic imaging data

Abstract

Various aspects of systems, methods, and related embodiments for generating cephalometric (CEPH) radiographic images based on panoramic image data from an extraoral radiography system are described. [Solution] One exemplary method for generating a calculated CEPH image includes the steps of: obtaining panoramic image data generated from a panoramic X-ray scan; generating a representation of the panoramic image data in defined three-dimensional space; determining the geometric shape of the cephalometric view in defined three-dimensional space; modeling simulated X-rays in the geometric shape of the cephalometric view in order to identify the portion of the panoramic image data to be used in the calculated cephalometric image; and outputting the calculated cephalometric image.

Description

Background Art

[0004] , , ,

[0001] Cephalometric (CEPH) X-rays, also known as cephalograms, are commonly used by dentists, orthodontists, and other clinicians for diagnostic tasks and assessment of dental conditions. Cephalometric is used, for example, to determine the relative positions of a patient's jaws during orthodontic and dental treatment planning, implementation, and follow-up. In some setups, a dedicated device called a CEPH arm may be added as an extension of an extraoral X-ray system to capture cephalometric projections and generate cephalometric images ("CEPH images").

[0002] For example, the CEPH arm may be added to a panoramic X-ray (orthopantomography) X-ray device, such as an extraoral device that can only capture panoramic (PAN) views or a combined extraoral device that can capture PAN and 3D scans. The positioning and exposure procedures used to capture the CEPH view are different from those used for the PAN view. The focal detector distance for CEPH X-rays is approximately 1.5 to 2 meters between the source and the detector, and CEPH images are generally generated using linear scan or one-shot techniques. In addition to the significant cost of the additional equipment, the use of the CEPH arm increases the required installation space for the X-ray machine, requires additional adjustment and calibration, and requires specialized involvement of service and technicians when the machine is installed or maintained.

[0003] In drawings that are not necessarily drawn to scale, like reference numerals can describe like components in different figures. Like reference numerals with different subscripts can represent different examples of like components. The drawings generally, but not by way of limitation, show various embodiments described herein by way of example.

Brief Description of the Drawings

[0004] [Figure 1] A diagram showing a computerized extraoral X-ray system according to an example.

[0005] [Figure 2] This is a flowchart of an algorithm for calculating the CEPH view based on panoramic imaging data, as an example.

[0006] [Figure 3] This figure shows a panoramic configuration of X-ray emission and detection using an extraoral X-ray system, as an example.

[0007] [Figure 4] This figure shows the panoramic focus curve and focal layer in a cross-sectional view of a patient's anatomical structure, as an example.

[0008] [Figure 5] This is a technique for refining projected images used to reconstruct panoramic images, as exemplified by this method. [Figure 6] This is a technique for refining projected images used to reconstruct panoramic images, as exemplified by this method.

[0009] [Figure 7] This figure shows an example of mapping between three-dimensional space and a reconstructed panoramic image.

[0010] [Figure 8] This figure illustrates the creation of a virtual CEPH projection image based on simulated X-rays in a defined three-dimensional space, as an example.

[0011] [Figure 9] This is a flowchart illustrating an example of a method for generating a calculated cephalometric image.

[0012] [Figure 10] This is a block diagram of an example of a computing system capable of performing any one or more of the techniques described herein. [Modes for carrying out the invention]

[0013] The following relates to improvements in image processing techniques for generating computed CEPH images from panoramic X-ray image data without using specialized equipment such as CEPH arms, dedicated CEPH X-ray sensors, or mechanisms for repositioning sensors to acquire CEPH images. Specifically, the following methods can generate computed CEPH images, also referred to herein as computed, synthesized, simulated, or artificial CEPH images, based on imaging data acquired for a two-dimensional (2D) panoramic X-ray scan (e.g., an orthopantomography frontal X-ray). In the following methods, the 2D CEPH view can be generated from a full-frame panoramic (FFPAN) scan, such as imaging data acquired by a 2D or 2D / 3D panoramic X-ray machine that also creates orthopantomogram images from FFPAN imaging data. More than 4000 individual X-ray images are acquired from different angular positions of the patient's jaw to create an FFPAN-based orthopantomogram image. The pixel resolution of the FFPAN sensor corresponds to the resolution typically used in dedicated CEPH sensors and is significantly higher than the resolution of 3D (e.g., CBCT) sensors.

[0014] The method described herein includes a method for creating a 2D CEPH view based on the use of reconstructed FFPAN image data from a panoramic image represented in 3D space. Individual X-ray projection images in an FFPAN-based system are available after a full scan of the patient and are used to reconstruct an FFPAN-based panoramic image, which is then used to reconstruct a calculated CEPH image. This generation of a CEPH view based on FFPAN image data, specifically image data acquired from a CMOS digital X-ray sensor, eliminates the need for additional CEPH equipment and calibration. This means that it is no longer necessary to expand an existing extraoral PAN or PAN / 3D device by adding a separate CEPH arm extension, or to integrate a new mechanism for moving the panoramic X-ray sensor to the CEPH position. As a result, additional costs due to the cost of the sensor, machine installation, service, and the complexity of services associated with calibration, positioning, additional acquisition / dosing, and CEPH arm extensions can be avoided.

[0015] Therefore, the methods described herein enable the generation of CEPH images calculated directly based on 2D panoramic image data, and enable the generation of multiple types of calculated CEPH views, including, but not limited to, viewpoints corresponding to standardized lateral cephalometric radiographs (e.g., lateral views of the patient's head including the bones and soft tissues of the face and skull). Even when the quality of calculated CEPH views generated from FFPAN scan data is inferior compared to scans from dedicated CEPH sensors, the methods described herein enable the generation of CEPH views without the need for separate scanning equipment. This makes it possible to generate CEPH views in various dental and orthodontic evaluation settings without the need for modifications or new equipment. Furthermore, these methods enable the generation of CEPH views based on existing panoramic views.

[0016] Figure 1 shows a computerized extraoral X-ray system 100. As shown in Figure 1, the X-ray system 100 includes an X-ray apparatus 101 for performing patient imaging. Before exposure, the patient's head is preferably positioned at the center of the X-ray apparatus 101 using a bite block 107 and head fixation 106, etc. As will be described later, the X-ray apparatus 101 includes an X-ray emitter array 103 and an X-ray detector 104 that rotate around the patient's head to acquire X-ray images from different angles. The X-ray apparatus 101 may also include an operator apparatus 105 that includes a basic user interface or operator control unit (e.g., touchscreen, buttons, etc.) for activating and controlling various functions of the X-ray system 100.

[0017] As shown in Figure 1, the X-ray system 100 may operably connect the X-ray apparatus 101 to a separate computing system 110 (a set of one or more computers) and a separate output device 142, such as a display device for visualizing the dataset. The computing system 110 may be connected to the X-ray apparatus 101 via a local network (not shown) or alternatively via a wide area network (e.g., the Internet). The computing system 110 may be part of a cloud computing deployment. In other examples, the functions of the computing system 110 may be integrated into the X-ray apparatus 101. Thus, the data processing operations described herein may be performed on the X-ray apparatus 101, the computing system 110, or connected computing resources in the cloud.

[0018] For example, the computing system 110 can run various computer programs and manipulate the dataset to create different visualizations and representations of the image. In some examples, the computing system 110 can provide commands to control the X-ray apparatus 101 via the input device 144 or via program control. Alternatively, separate computers may be used for image processing and apparatus control operations. The datasets generated herein may be presented to clinicians (e.g., physicians, dentists, trained staff, etc.) for visualization, particularly for diagnostic purposes, by using the output device 142 or by communication to another type of output device such as a printer or screen.

[0019] The X-ray system 100 is adapted to perform a dental panoramic imaging procedure, which includes the step of generating panoramic and CEPH images using the techniques described below. As shown in Figure 1, the X-ray system 100 comprises an X-ray emitter array 103 having at least two individual X-ray emitters, each capable of emitting X-ray radiation (for example, as shown in Figure 3), the X-ray emitters being offset at least along a predetermined direction (for example, the height direction or the longitudinal direction of the patient). The X-ray apparatus 101 further comprises an X-ray detector 104 for at least partially detecting the X-ray radiation emitted by the individual X-ray emitters during one rotation. For example, the X-ray emitter array 103 and the X-ray detector 104 may be arranged to be movable relative to each other around an axis extending parallel to a predetermined direction, and the areas of the X-ray detector 104 irradiated by each individual X-ray emitter at least partially overlap.

[0020] The X-ray apparatus 101 may further include an aperture mechanism (not shown) for collimating the X-ray radiation emitted by each individual X-ray emitter into respective irradiation regions. The X-ray apparatus 101 may further include a control device or mechanism (not shown) for moving the X-ray emitter array 103 and the X-ray detector 104 around a parallel axis, controlling each individual X-ray emitter, and reading out a series of images of respective irradiation surfaces of the X-ray detector 104 during rotation. These and other features may be controlled by onboard logic and processing circuitry on the X-ray apparatus 101, which in some examples may be controlled by the operator device 105.

[0021] The computing system 110 is shown as including a processing circuit 112, a memory 114, and a storage device 116. The processing circuit 112 may execute machine-readable software instructions (e.g., provided from the memory 114 or the storage device), as described below, to perform operations implementing panoramic image data processing 122, cephalo image data processing 124, and a graphical user interface 126. The image processing method described herein may be a computer-implemented method and may be performed via adjustment of the X-ray system 100 including the X-ray apparatus 101, the computing system 110, or both subsystems. Further exemplary implementations of the processing circuit 112, the memory 114, and the storage device 116 are provided below with reference to FIG. 10.

[0022] The image processing method executed by the computing system 110 may include panoramic image data processing 122 and cephalo image data processing 124. Further details of the creation of the panoramic image via the panoramic image data processing 122 and the creation of the cephalo image via the cephalo image data processing 124 are described in FIGS. 2-9 below. The panoramic image and the cephalo image may be presented separately or together via a graphical user interface 126, such as an image display user interface, which is controlled via the input device 144 and presented via the output device 142. Other image data processing of the computing system 110 may be invoked via the graphical user interface 126 or the operator device 105.

[0023] The panoramic image data processing 122 may include creating a spatial panoramic image based on the projection images within the captured FFPAN image data. For example, each FFPAN image generated from an X-ray (e.g., the X-ray 320 shown in FIG. 3) can be reconstructed into a 2D spatial panoramic image (e.g., the panoramic image 720 shown in FIG. 7). The creation of this panoramic image represents a focal curve in 3D space (e.g., the focal curve 340 shown in FIG. 3) and can be assisted with a defined shape, such as a 3D mesh, used to establish a focal layer of a particular thickness (e.g., the default focal layer thickness 440 or the extended focal layer thickness 445 with a focal layer shown in FIG. 4). In some examples, this default focal layer in 3D space can be further locally optimized by an autofocus algorithm during the reconstruction of the panoramic image. A diagram of the relationship between the 3D mesh and the resulting 2D panoramic image is shown in FIG. 7.

[0024] In the first method, the cephalometric image data processing 124 may include the steps of: calculating one or more virtual CEPH projection images using data from a 2D spatial panoramic image; and then reconstructing a virtual CEPH image from these virtual CEPH projection images. For example, after a spatial panoramic image is represented in a defined 3D space, several virtual CEPH projection images can be recreated using simulated rays in the defined 3D space. In the second alternative method, the cephalometric image data processing 124 may include the steps of: calculating virtual CEPH projection images after defining the dimensions and resolution of the CEPH image in the defined 3D space; and using simulated X-ray beams in the defined 3D space (e.g., one beam per pixel) to create the calculated CEPH image. An exemplary geometric shape and a diagram of simulated X-rays used to create the calculated CEPH image are shown in Figure 8.

[0025] A method for calculating a CEPH view based on FFPAN image data from an extraoral X-ray system is not currently available in the present state of technology. Rather, in the present state of technology, CEPH images may be generated using a separate CEPH imaging device added to the extraoral X-ray system (e.g., using the CEPH arm described above), or based on special processing of 3D image data (e.g., volumetric images) generated from a 3D imaging system (e.g., a CBCT scanner). It will be understood that this method for calculating a CEPH view based on a reconstructed 2D panoramic image is distinguishable from conventional methods for generating a CEPH view based on 3D image volume. The use of CBCT and other 3D scanning procedures is associated with increased patient radiation dose and a decrease in the resolution of the resulting CEPH view, but there may be many scenarios in which only 2D panoramic images are acquired and only source FFPAN image data is available.

[0026] Panoramic and FFPAN image data are already acquired during standard evaluation procedures in many dental and orthodontic practices, and this method for calculating CEPH views based on these provides several technical and operational advantages. These advantages include, but are not limited to, reduced equipment requirements because a dedicated CEPH arm is not required, reduced patient radiation dose because separate exposures or 3D scans from the CEPH arm are not required, and the creation of images with a calculated CEPH view resolution similar to conventional CEPH images. The technique described herein can be used to avoid the acquisition of separate X-ray images, enabling radiation dose reduction closer to the ALARA (as low as reasonably achievable) goal. These and other advantages can be achieved while using the same patient positioning of panoramic shots used in existing panoramic X-ray acquisition workflows.

[0027] Figure 2 shows a flowchart of an exemplary algorithm for calculating the CEPH view based on panoramic imaging data. This flowchart illustrates a series of operations, some of which may be repeated or performed in alternative sequences.

[0028] Operation 201 represents the acquisition of raw imaging data (e.g., individual X-ray projection images) by panoramic X-ray scanning. For example, this may include the use of X-ray system 100 to acquire many FFPAN images at a pre-set frame acquisition rate (e.g., 300 frames per second). Figure 3, described below, shows an exemplary panoramic X-ray scanning procedure used to acquire each projection image, which can be performed by rotating the X-ray apparatus 101 around a human subject.

[0029] Operation 202 describes the correction of raw image data (e.g., X-ray projection image) acquired from a panoramic X-ray scan. This may include image correction techniques such as dark-field correction, gain or flat-field correction, defect correction, or other corrections (e.g., scatter removal, noise reduction, contrast enhancement, etc.). Other image correction techniques may be used.

[0030] Operation 203 demonstrates the reconstruction of a panoramic image from a corrected X-ray projection image. For example, the reconstruction of the panoramic image may use a focal layer with the default focal layer thickness in operation 204A. Alternatively, the reconstruction of the panoramic image may use a focal layer with an extended or enlarged focal layer thickness in operation 204B. A comparison between a focal layer with the default thickness and one with an extended thickness is shown in Figure 4 and described below.

[0031] Operation 205 includes the step of generating a representation of the panoramic image in a defined 3D space. As an example, this may include the step of generating a 3D shape, such as a surface mesh ("3D mesh") that represents the focal curve in three-dimensional space. A diagram illustrating how this 3D shape corresponds to the panoramic image is shown in Figure 7. Further detailed examples of methods for reconstructing a panoramic image and representing it in a defined 3D space are provided in European Patent Application Publication No. 4375928, “METHOD FOR LENGTH MEASUREMENT WITHIN DENTAL PANORAMIC IMAGES,” by inventor Stefan Eichner, which is incorporated herein by reference in its entirety.

[0032] Operation 206 includes defining the geometric shape of a CEPH view having simulated rays in a defined 3D space. As an example, this may include determining at least one new focal position and virtual focal layer of the CEPH view in the defined 3D space in order to define how the simulated X-ray beam passes through the representation of the panoramic image present in the defined 3D space. This is shown with reference to Figure 8, along with a depiction of the virtual focal position 852, the virtual focal layer 850, and the simulated X-ray beam 820.

[0033] Operation 207 includes the step of creating a virtual CEPH image or multiple virtual CEPH projection images using a CEPH view established from simulated X-rays moving through a mesh representation of a panoramic image in a defined 3D space. In the first example, the virtual CEPH image is created by intersecting simulated X-rays in a defined three-dimensional space through voxels of a three-dimensional mesh into a virtual cephalometric image, modeling one X-ray beam per pixel of the virtual cephalometric image. In the second alternative example, the virtual CEPH projection image is generated by intersecting simulated X-rays in a defined three-dimensional space through voxels of a three-dimensional mesh, creating a virtual cephalometric projection image from the intersecting voxels of the three-dimensional mesh.

[0034] An exemplary model of this defined 3D space is shown in Figure 8, where the pixel positions (e.g., pixel position 812) of the generated CEPH layer 810 corresponding to the simulated X-ray beam data are shown. Thus, as the simulated X-ray beam 820 passes through the 3D panoramic image 830, individual pixels from the panoramic image may be selected for use in a virtual CEPH image or virtual CEPH projection image.

[0035] If a virtual CEPH image is created, operation 208A may be used; if a virtual CEPH projection image is created, operation 208B may be used. Operation 208A is an optional procedure for weighting image information for overlapping points along the same X-ray beam in the virtual CEPH image. Operation 208B is an optional procedure for weighting image information for overlapping points in the new virtual CEPH projection image. This additional weighting of imaging information may be applied depending on the location of the calculated virtual CEPH image view. Operation 209 also describes a step of reconstructing a virtual CEPH image view from various virtual CEPH projection images to generate the calculated CEPH image. Additional image post-processing techniques (e.g., image correction techniques, changes in image brightness or contrast, etc.) may be performed on individual virtual CEPH projection images or on the calculated CEPH image. As understood, the same (or different) post-processing or image correction techniques may be used on the reconstructed panoramic image and the created CEPH image.

[0036] Operation 210 represents a step of outputting a computed CEPH image generated from a virtual CEPH image or reconstructed from a virtual CEPH projection image. This may include steps of saving the computed CEPH image in a 2D image format to computer memory or storage, providing the computed CEPH image data to another computing device over a network, or outputting the computed CEPH image to a display screen.

[0037] While the aforementioned operations refer to the acquisition of new images from a panoramic X-ray scan (e.g., operation 201), it will be understood that the remaining operations can be used to create panoramic and computed CEPH images from previously acquired FFPAN image data. Based on the acquisition geometry of the panoramic scan data acquired from the extraoral X-ray system used and the typical geometric ratio of classical CEPH images, a virtual CEPH projection image can be created and a computed CEPH image reconstructed using a virtual focal point, simulated X-rays, and mapped image data.

[0038] Figure 3 shows an exemplary panoramic arrangement of X-ray emission positions relative to sensing positions in an extraoral X-ray system. Specifically, Figure 3 shows how a series of hundreds or thousands of X-rays 320 are emitted along the emitter curve 310, starting at the emitter start position 311 and ending at the emitter end position 312. The X-rays 320 are received using at least one sensor that moves along the sensor curve 330, starting at the acquisition start position 331 and ending at the acquisition end position 332. The X-ray sensor moves in a circular or "U" shape along the sensor curve 330, but the focal region of the panoramic image changes optimally depending on the specific geometric shape of the patient's dentition. Thus, the X-ray apparatus can establish a focal curve 340 that has a different shape from the shapes of the X-ray emitter curve 310 and the sensor curve 330.

[0039] The shape of the focal curve 340 may be constructed in three-dimensional space and used for subsequent image processing. For example, the construction of a panoramic image (and the resulting computed CEPH image generated from the panoramic image) may be based on the use of a 3D mesh representing the focal curve 340 in three coordinates (x, y, z) in three-dimensional space.

[0040] Figure 4 shows a cross-sectional view of the patient's anatomical structure 410, illustrating how the shape of the panoramic scan's focal curve 430 corresponds to the patient's jawbone 420, an example of the patient's anatomical structure. The illustrated focal curve 430 follows the general contours of the inside of the bones and teeth and is used to form a focal layer that defines the objects to be displayed.

[0041] Figure 4 also shows the area incorporated into the patient's anatomical structure when shown with a default focal layer thickness of 440 compared to an extended focal layer thickness of 445. The focal layer thickness is the range around the focal layer (extending towards the tongue and cheek) that defines the amount of blurring of objects outside the focal layer. A greater focal layer thickness results in less sharpness of objects along the focal layer. A default focal layer thickness of 440 may be used in panoramic images to provide focus on the jawbone and the areas immediately medial to and surrounding the connected teeth. An extended focal layer thickness of 445 is used to provide a magnified view of the patient's anatomical structure in the calculated CEPH image and may reveal additional features of the patient's face.

[0042] In particular, the typical viewpoints and features of classical CEPH images can be achieved by extending the thickness of the focal layer. As two non-restrictive examples, the extension of the focal layer thickness can be created by omitting or skipping raw image frames (e.g., omitting the X-ray projection image as shown in Figure 5) or by using a weighted collimator beam profile (e.g., by applying weighting to the collimator beam profile of the projection image as shown in Figure 6).

[0043] Figure 5 illustrates a first technique for refining projection images used to reconstruct a panoramic image, based on excluding information from specific views. As shown, a series of X-rays 510 are emitted through the patient's anatomical structures to produce a series of raw image frames 530 (e.g., projection images). This is shown as the X-rays gradually cross the patient's jawbone 520. However, some of the raw image frames 530 may be skipped and excluded for use when reconstructing the panoramic image. Certain frames may be skipped, for example, because the image corresponds to a beam angle that is not available in the CEPH view, or to further increase the thickness of the focal layer.

[0044] Figure 6 shows a second technique for refining the projection image used to reconstruct the panoramic image based on weighting information represented in the projection image. For example, the normal collimator beam profile 610 may be changed to a weighted collimator beam profile 620 within the raw projection image or image frame used to construct the panoramic scan. The beam profile shown in Figure 6, for example, is similar to a Gaussian shape and defines the amount of radiation acquired during the scan. If the beam profile is reduced in size on both sides (e.g., condensed), less information is provided about the reconstruction result.

[0045] Reducing the beam profile reduces the beam angle covered per projection frame. This increases the thickness of the focal layer as fewer pixels are combined with each other in the reconstructed image. The narrower the beam profile, the greater the resulting focal layer thickness. Therefore, the slice thickness of the spatial panoramic image resulting from the reconstruction may be increased using either the method in Figure 5 or Figure 6, and thus the amount of information provided to the computed CEPH image created from the reconstructed panoramic image may be increased.

[0046] Figure 7 shows the mapping between three-dimensional space and the reconstructed panoramic image. This figure shows how the 3D mesh 710 represents, or corresponds to, the shape of the focal curves in 3D space (e.g., focal curve 340, focal curve 430). The 3D mesh 710 also defines a set of points (voxels) in 3D space that map to individual points (pixels) of the 2D panoramic image 720. The reconstructed 2D panoramic image 720 represents the information presented when the 3D mesh 710 is shown as a 2D layer. Therefore, when the representation of the reconstructed 2D panoramic image 720 is placed in 3D space (e.g., in operation 205), the shape of the resulting 3D object resembles that of the 3D mesh 710.

[0047] Figure 8 shows the creation of a virtual CEPH projection image based on simulated X-rays in a defined three-dimensional space. Specifically, a 3D panoramic image 830 showing the patient's jawbone 840 is represented in this 3D space. The 3D panoramic image 830 is oriented and shaped based on a 3D mesh (e.g., 3D mesh 710) used for panoramic image reconstruction. Specifically, this 3D mesh represents the focal curve of the two-dimensional panoramic image in the geometric shape of the panoramic scan. The right side of this figure shows the virtual focal layer 850 for the CEPH projection image. The left side of this depiction shows the resulting virtual CEPH projection image in the CEPH layer 810, and the distance between these two layers is based on the geometric shape of the CEPH view.

[0048] Figure 8 also shows how multiple virtual X-ray beams from simulated X-ray sources in this 3D space intersect with a 3D panoramic image 830 formed based on a 3D mesh. Information from the virtual X-ray beams is accumulated, weighted, and stored at the corresponding pixel locations (e.g., pixel location 812) of the generated CEPH layer 810. The distances in 3D space between the generated CEPH layer 810, the virtual focus layer 850, and the 3D panoramic image 830 are selected based on the geometric relationships used to capture conventional CEPH scans.

[0049] This method for calculating CEPH views based on panoramic images can also be optionally extended to calculate CEPH views from different spatial directions (e.g., directions other than the conventional lateral direction). Furthermore, this method for calculating CEPH views may be retrospectively applicable to FFPAN image data without requiring new raw data to be incorporated for the CEPH view, based on an analysis of existing projection image data.

[0050] Because FFPAN projection images have height limitations, the resulting calculated CEPH image may be shorter than a conventional CEPH view. If necessary, this limitation can be addressed by one of the following techniques to create a two-dimensional panoramic image with an enlarged image height. The first technique may involve combining two height-shifted projection images (e.g., acquired from a dedicated FFPAN sensor) using a technique to combine image data in a geometrically correct manner (e.g., with / without markers for alignment of FFPAN image data). The second technique may involve modifying the readout range used by the X-ray sensor, such as by extending the height of the vertical dimension of the sensor's active area to acquire additional information used for the CEPH view. Other techniques, such as the use of trained artificial intelligence models and algorithms, may also be applied.

[0051] Figure 9 is a flowchart of an exemplary method for generating a calculated cephalometric image. This method may be carried out by a machine-readable medium (e.g., a computer-readable medium) containing instructions that cause a processing circuit to perform the following operations. In another example, this method may be carried out by an X-ray system comprising an X-ray source and X-ray detector for acquiring panoramic image data and a computing unit for performing the following operations. In yet another example, this method may be carried out by a computer system comprising a memory for storing panoramic image data and at least one processor configured to perform the following operations.

[0052] Operation 901 includes the step of acquiring panoramic image data generated from a panoramic X-ray scan. This may correspond to an embodiment of operation 201 described above, including the use of the X-ray system 100 described above. In a particular example, the panoramic image data includes a two-dimensional panoramic image, and the method also includes the step of reconstructing a two-dimensional panoramic image from multiple X-ray projection images, as in operation 203 described above. For example, the multiple X-ray projection images may be acquired by the extraoral X-ray system 100 using a full-frame panoramic (FFPAN) scan. The method may also include the step of performing at least one image correction technique on the multiple X-ray projection images, as in operation 202 described above, or the step of performing at least one image correction technique on the reconstruction of the two-dimensional panoramic image.

[0053] In a further example, as in operation 203 described above, the reconstruction of a two-dimensional panoramic image from multiple X-ray projection images includes extending the thickness of the focal layer (for example, as described with reference to Figure 4). The step of establishing this extended focal layer thickness may include at least one of the following: omitting each frame of the multiple X-ray projection images for use in the reconstruction of the two-dimensional panoramic image (for example, as described with reference to Figure 5), or using the weighted collimator beam profile of at least one projection image from the multiple X-ray projection images used in the reconstruction of the two-dimensional panoramic image (for example, as described with reference to Figure 6). In yet another example, the step of reconstructing a two-dimensional panoramic image includes combining two (or more) height-shifted projection images to create a two-dimensional panoramic image with an enlarged image height.

[0054] Operation 902 includes the step of generating a representation of panoramic image data in a defined three-dimensional space. This operation may correspond to an aspect of operation 205 described above and may include the step of mapping pixel data of the two-dimensional panoramic image to voxels of a three-dimensional mesh in the defined three-dimensional space, as described with reference to Figure 7. This three-dimensional mesh may correspond to the focal curve of the two-dimensional panoramic image in the geometric shape of the panoramic X-ray scan.

[0055] Operation 903 includes the step of determining the geometric shape of the cephalometric view in the defined three-dimensional space. This operation may correspond to an aspect of operation 206 as described above, and may include the step of determining the dimensions and resolution of the CEPH image in 3D space for the representation of the panoramic image data and the generated CEPH layer, as described with reference to Figure 8. The change in the geometric shape of the cephalometric view may be based on the known temporal acquisition geometric shape of the source panoramic imaging data and the change in the acquisition geometric shape of the desired cephalometric view.

[0056] Operation 904 includes the step of modeling simulated X-rays in the geometric shape of the cephalometric view in order to identify the portion of panoramic image data to be used in the calculated cephalometric image. This operation may correspond to the embodiments of operations 206 and 207 described above. Modeling the simulated X-rays may include the use of alternative methods. A first method for modeling includes the step of creating virtual cephalometric projection images and then reconstructing these projection images into a cephalometric image. A second method for modeling includes the step of modeling one X-ray beam per pixel of the cephalometric image. In the second method, the creation and reconstruction of virtual cephalometric projection images are not required.

[0057] In relation to the first method, the step of modeling simulated X-rays may include intersecting simulated X-rays in a three-dimensional space defined via voxels of a three-dimensional mesh, and the method also includes the steps of creating multiple virtual cephalometric projection images from voxels of a three-dimensional mesh and reconstructing a cephalometric image calculated from the multiple virtual cephalometric projection images. Furthermore, weighting may be performed on image information of overlapping points in the multiple virtual cephalometric projection images so as to correspond to the aspects of operation 208 described above. In relation to the second method, the step of modeling simulated X-rays may include intersecting simulated X-rays in a defined three-dimensional space via voxels of a three-dimensional mesh into a virtual cephalometric image, and the method also includes the steps of modeling one X-ray beam for each pixel of the virtual cephalometric image and creating a cephalometric image calculated from the pixels of the virtual cephalometric image. Furthermore, weighting may be performed on image information of overlapping points along the same X-ray beam corresponding to pixels in the virtual cephalometric image.

[0058] As illustrated with reference to Figure 8, the simulated X-rays may correspond to at least one virtual focal point originating from a virtual focal layer, the virtual focal layer corresponding to a simulated X-ray source in the geometric shape of the cephalometric view. In a further example, the simulated X-rays extend in defined three-dimensional space from the virtual focal layer to a virtual projection image or virtual cephalometric image constructed with the generated layers via a three-dimensional model of panoramic image data. Furthermore, the respective distances in defined three-dimensional space between the virtual focal layer, the three-dimensional model of panoramic image data, and the generated layers may be established based on the geometric relationships used for cephalography.

[0059] Operation 905 includes outputting the calculated cephalometric image. This operation may correspond to an embodiment of operation 210 described above. In some examples, image post-processing and correction / adjustment techniques may be performed on the calculated cephalometric image before or after outputting.

[0060] The techniques discussed herein can generate computed CEPH images to support dental treatments such as restorative treatment, endodontic treatment, periodontal treatment, implant treatment, mouthpiece treatment, and orthodontic treatment. Such computed CEPH images may be used to provide therapeutic and diagnostic information regarding teeth, roots, nerve canals, temporomandibular joints, jawbones, and the like. Furthermore, the exemplary embodiments described herein are not limited to FFPAN panoramic imaging and acquisition techniques, but may also be applied to panoramic images generated by other modalities and techniques.

[0061] To be understood, the exemplary embodiments described herein can be implemented using a single computer or using a computer system comprising multiple computers, each programmed with control logic to perform various functions described above. Embodiments may be implemented in hardware (e.g., circuitry), firmware, software, or any combination thereof. Embodiments may also be implemented as instructions stored in a machine-readable medium that can be read and executed by one or more processors (e.g., in the form of a processor circuitry implementation).

[0062] Figure 10 shows a block diagram of an example computing system 1000 (or appropriate device, apparatus, system, or machine) on which one or more of the techniques (e.g., methods) described herein may be performed. In alternative embodiments, system 1000 may operate as a standalone device or may be connected to other machines (e.g., networked). In a networked deployment, system 1000 may operate as a server machine, a client machine, or both in a server-client network environment. System 1000 may be a personal computer (PC), a tablet PC, a server computer, a mobile phone, a web appliance, a network device, or any machine capable of executing instructions (sequential or otherwise) that specify the actions to be performed by that machine. Furthermore, although only a single machine is shown, the term “machine” should also be interpreted to include any set of machines that individually or collectively execute a set of instructions (or sets of instructions) to perform any one or more of the methods described herein, such as cloud computing, software as a service (SaaS), or other computer cluster configurations.

[0063] System 1000 may receive user commands by any of the following: input device 1012, UI navigation device 1014, display device 1010, or signals from a remote system (e.g., received via network 1026). System 1000 may output an indication that an operation has been performed by either the display device 1010 or the signal generator 1018. System 1000 may also provide an output of a computed cephalometric image to a machine-readable medium 1022 based on techniques for generating the computed cephalometric image, as described herein. System 1000 may be used to perform operations performed by methods for generating the computed cephalometric image (e.g., as described with reference to Figure 9), as well as related data processing operations involving the processing, reconstruction, modeling, representation, and visualization of related data.

[0064] System 1000 (e.g., a computer system) may include processing circuits such as a hardware processor 1002 (e.g., a central processing unit (CPU), a graphics processing unit (GPU), a hardware processor core, a field-programmable gate array (FPGA), or any combination thereof), main memory 1004, and static memory 1006, some or all of which may communicate with each other via an interlink (e.g., a bus) 1008. System 1000 may further include a display device 1010, an input device 1012 (e.g., a keyboard or other alphanumeric input device), and a user interface UI navigation device 1014 (e.g., a mouse). In one example, the display device 1010, the input device 1012, and the UI navigation device 1014 may be integrated into a touchscreen display. System 1000 may further include a mass storage device 1016 (e.g., a drive unit or other similar storage device or unit), a signal generating device 1018 (e.g., a speaker), a network interface device 1020 connected to a network 1026, and one or more sensors 1030. System 1000 may also include a serial output controller 1028 (e.g., Universal Serial Bus (USB), parallel, or other wired or wireless connection such as infrared (IR), near-field communication (NFC), etc.) for communicating with or controlling one or more peripheral devices (e.g., a printer, a card reader, etc.).

[0065] The mass storage device 1016 may include a machine-readable medium 1022 in which one or more sets of data structures or instructions 1024 (e.g., software) that embody or use any one or more of the technologies or functions described herein are stored. The instructions 1024 may also reside, all or at least partially, in the main memory 1004, static memory 1006, or hardware processor 1002 during their execution by the system 1000. In one example, one or any combination of the hardware processor 1002, main memory 1004, static memory 1006, or mass storage device 1016 may constitute the machine-readable medium.

[0066] Although machine-readable medium 1022 is shown as a single medium, the term “machine-readable medium” may also include a single or multiple mediums configured to store one or more instructions 1024 (e.g., a centralized or distributed database, and / or associated caches and servers). The term “machine-readable medium” may also include any medium capable of storing, encoding, or carrying instructions for execution by system 1000, causing system 1000 to execute one or more of the technologies of this disclosure, or storing, encoding, or carrying data structures used by or associated with such instructions. Examples of non-limiting machine-readable mediums may include solid-state memory, as well as optical and magnetic media. Specific examples of machine-readable media (e.g., one or more non-temporary storage media) may include non-volatile memory such as read-only memory (ROM), random-access memory (RAM), semiconductor memory devices (e.g., electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM)), and flash memory devices, magnetic disks such as internal hard disks and removable disks, magneto-optical disks, and CD-ROM and DVD-ROM disks.

[0067] The examples described herein may include logic or several components, or mechanisms, including within a circuit, or may operate by them. A circuit includes a collection of circuits implemented on a tangible entity including hardware (e.g., simple circuits, gates, logic, etc.). The elements constituting a circuit may change flexibly over time or in response to changes in the underlying hardware. A circuit includes components that can perform specified operations, either individually or in combination, when in operation. In one example, the hardware of a circuit may be designed immutably to perform or execute a particular operation (e.g., hardwired). In one example, the hardware of a circuit may include variable-connected physical components (e.g., execution units, transistors, simple circuits, etc.) including a computer-readable medium that is physically modified to encode instructions for a particular operation (e.g., magnetic, electrical, movable arrangement of invariant mass particles). The instructions enable embedded hardware (e.g., execution units or loading mechanisms) to create components of the circuit within the hardware via variable connections to perform or execute a portion of a particular operation when in operation. Thus, the computer-readable medium is communicatively coupled to other components of the circuit when the device is in operation. In one example, any of the physical components may be used by two or more members of two or more circuit units. For example, during operation, an execution unit may be used at one point in a first circuit of a first circuit unit, then reused by a second circuit of the first circuit unit, or at a different point in time by a third circuit of a second circuit unit.

[0068] Therefore, embodiments can be implemented in hardware (e.g., circuitry), firmware, software, or any combination thereof. Embodiments may also be implemented as instructions stored in a machine-readable medium that can be read and executed by one or more processors. Furthermore, firmware, software, routines, and instructions can be described herein as performing specific operations. However, such descriptions are merely for convenience, and it should be understood that such operations actually originate from computing devices, processors, controllers, or other devices that perform firmware, software, routines, instructions, etc. Furthermore, any variation of the implementation may be performed by a general-purpose computer.

[0069] The various components described herein may be referred to as “modules,” “units,” “devices,” “functions,” or similar terms. Such components may be implemented through any suitable combination of hardware and / or software components that are applicable and / or known to achieve their respective intended functions. This may include, in addition to or instead of, mechanical and / or electrical components, processors, processing circuits, or other suitable hardware components. Such components may be configured to operate independently or to execute instructions or computer programs stored on a suitable computer-readable medium. Regardless of the particular embodiment, such components may be referred to herein by alternative terms such as “circuits,” “controllers,” “processors,” or “processing circuits,” or by other alternative terms as described herein, where applicable and relevant.

[0070] Further aspects and features of this disclosure are described in the numbered examples below.

[0071] Example 1 is a method for generating a computed cephalometric image, comprising the steps of: obtaining panoramic image data generated from a panoramic X-ray scan; generating a representation of the panoramic image data in defined three-dimensional space; determining the geometric shape of the cephalometric view in defined three-dimensional space; modeling simulated X-rays in the geometric shape of the cephalometric view to identify the portion of the panoramic image data to be used in the computed cephalometric image; and outputting the computed cephalometric image.

[0072] In Example 2, the subject of Example 1 optionally includes a subject in which panoramic image data includes a two-dimensional panoramic image, and the method further includes the step of reconstructing a two-dimensional panoramic image from multiple X-ray projection images.

[0073] In Example 3, the subject of Example 2 optionally includes a subject in which multiple X-ray projection images are acquired in an extraoral X-ray system using a full-frame panoramic (FFPAN) scan, and the method further includes the step of performing at least one image correction technique on the multiple X-ray projection images or two-dimensional panoramic images.

[0074] In Example 4, one or more of the themes from Examples 2 to 3 may optionally include a theme in which the step of reconstructing a two-dimensional panoramic image from multiple X-ray projection images includes a step of expanding the thickness of the focal layer, wherein the step of expanding the thickness of the focal layer includes at least one of the following: a step of omitting each frame of the multiple X-ray projection images for use when reconstructing the two-dimensional panoramic image, or a step of using a weighted collimator beam profile of at least one of the multiple X-ray projection images used when reconstructing the two-dimensional panoramic image.

[0075] In Example 5, one or more themes from Examples 2 to 4 optionally include a theme in which the step of reconstructing a two-dimensional panoramic image includes the step of combining two height-shifted projection images to create a two-dimensional panoramic image having an enlarged image height.

[0076] In Example 6, one or more themes from Examples 1 to 5 optionally include a theme in which the step of generating a representation of panoramic image data in a defined three-dimensional space includes the step of mapping the pixel data of a two-dimensional panoramic image to voxels of a three-dimensional mesh in a defined three-dimensional space, wherein the three-dimensional mesh corresponds to the focal curve of the two-dimensional panoramic image in the geometric shape of the panoramic X-ray scan.

[0077] In Example 7, the subject of Example 6 optionally includes a subject in which the step of modeling simulated X-rays includes a step of intersecting simulated X-rays in a defined three-dimensional space through voxels of a three-dimensional mesh, and the method further includes a step of creating a plurality of virtual cephalometric projection images from the voxels of the three-dimensional mesh, and a step of reconstructing a cephalometric image calculated from the plurality of virtual cephalometric projection images.

[0078] In Example 8, the subject of Example 7 optionally includes the step of weighting image information of overlapping points in multiple virtual cephalometric projection images.

[0079] In Example 9, one or more of the themes from Examples 6 to 8 optionally include a theme in which the step of modeling simulated X-rays includes a step of intersecting simulated X-rays in a defined three-dimensional space through voxels of a three-dimensional mesh into a virtual cephalometric image, and the method further includes a step of modeling one X-ray beam for each pixel of the virtual cephalometric image, and a step of creating a cephalometric image calculated from the pixels of the virtual cephalometric image.

[0080] In Example 10, the subject of Example 9 optionally includes the step of weighting image information of overlapping points along the same X-ray beam corresponding to pixels in a virtual cephalometric image.

[0081] In Example 11, one or more themes from Examples 1 to 10 are selected at will. The subject includes a simulated X-ray source in the geometric shape of a cephalometric view, where the simulated X-ray corresponds to at least one virtual focal point position originating from a virtual focal layer, and the virtual focal layer corresponds to a simulated X-ray source in the geometric shape of the cephalometric view.

[0082] In Example 12, the subject of Example 11 optionally includes a subject in which simulated X-rays extend in a defined three-dimensional space from a virtual focal layer to a virtual projection image or virtual cephalometric image constructed with the generated layers via a three-dimensional modeling of panoramic image data.

[0083] In Example 13, the subject of Example 12 optionally includes a subject based on the geometric relationships used in cephalometric imaging, where the virtual focus layer, the three-dimensional modeling of panoramic image data, and the respective distances in the defined three-dimensional space between the generated layers are determined.

[0084] In Example 14, one or more of the themes from Examples 1 to 13 are selected at will. The process includes the step of performing image post-processing on the calculated cephalometric image.

[0085] Example 15 is at least one machine-readable medium that, when executed by a processing circuit, causes the processing circuit to perform one of the methods of Examples 1 to 14 to generate a cephalometric image calculated from panoramic image data.

[0086] Example 16 is an X-ray system comprising an X-ray source, an X-ray detector for acquiring panoramic image data, and a computing unit for generating a cephalometric image calculated from the panoramic image data by performing one of the methods in Examples 1 to 14.

[0087] Example 17 is a computer system comprising a memory for storing panoramic image data and at least one processor configured to perform one of the methods of Examples 1 to 14 to generate a cephalometric image calculated from the panoramic image data.

[0088] Example 18 is at least one non-temporary machine-readable medium containing instructions, An instruction that causes a computing system to generate a cephalometric image calculated from panoramic image data, by performing an operation that includes the step of acquiring panoramic image data generated from a panoramic X-ray scan, includes the steps of generating a representation of the panoramic image data in defined three-dimensional space, determining the geometric shape of the cephalometric view in defined three-dimensional space, modeling simulated X-rays in the geometric shape of the cephalometric view in order to identify the portion of the panoramic image data to be used in the calculated cephalometric image, and outputting the calculated cephalometric image.

[0089] In Example 19, the subject of Example 18 optionally includes a subject in which panoramic image data includes a two-dimensional panoramic image, and the operation further includes the step of reconstructing a two-dimensional panoramic image from multiple X-ray projection images.

[0090] In Example 20, the subject of Example 19 optionally includes a subject in which multiple X-ray projection images are acquired in an extraoral X-ray system using a full-frame panoramic (FFPAN) scan, and the operation further includes the step of performing at least one image correction technique on the multiple X-ray projection images or two-dimensional panoramic images.

[0091] In Example 21, one or more of the themes from Examples 19 to 20 optionally include a theme in which the step of reconstructing a two-dimensional panoramic image from a plurality of X-ray projection images includes a step of expanding the thickness of the focal layer, wherein the step of expanding the thickness of the focal layer includes at least one of the following: a step of omitting each frame of the plurality of X-ray projection images for use when reconstructing the two-dimensional panoramic image, or a step of using a weighted collimator beam profile of at least one of the plurality of X-ray projection images used when reconstructing the two-dimensional panoramic image.

[0092] In Example 22, one or more themes from Examples 19 to 21 optionally include a theme in which the step of reconstructing a two-dimensional panoramic image includes the step of combining two height-shifted projection images to create a two-dimensional panoramic image having an enlarged image height.

[0093] In Example 23, one or more subjects from Examples 18 to 22 optionally include the step of generating a representation of panoramic image data in a defined three-dimensional space. The process includes the step of mapping the pixel data of a two-dimensional panoramic image to voxels of a three-dimensional mesh in a defined three-dimensional space, wherein the three-dimensional mesh contains a subject that corresponds to the focal curve of the two-dimensional panoramic image in the geometric shape of the panoramic X-ray scan.

[0094] In Example 24, the subject of Example 23 optionally includes a subject in which the steps of modeling simulated X-rays include intersecting simulated X-rays in a defined three-dimensional space through voxels of a three-dimensional mesh, and the operation further includes creating multiple virtual cephalometric projection images from the voxels of the three-dimensional mesh, and reconstructing a cephalometric image calculated from the multiple virtual cephalometric projection images.

[0095] In Example 25, the subject of Example 24 optionally includes a subject in which the operation further includes the step of weighting image information of overlapping points in multiple virtual cephalometric projection images.

[0096] In Example 26, one or more subjects from Examples 23 to 25 optionally include a subject in which the step of modeling simulated X-rays includes the step of intersecting simulated X-rays in a defined three-dimensional space through voxels of a three-dimensional mesh into a virtual cephalometric image, and the operation further includes the steps of modeling one X-ray beam for each pixel of the virtual cephalometric image and creating a cephalometric image calculated from the pixels of the virtual cephalometric image.

[0097] In Example 27, the subject of Example 26 optionally includes a subject in which the operation further includes the step of weighting image information of overlapping points along the same X-ray beam corresponding to pixels in a virtual cephalometric image.

[0098] In Example 28, one or more subjects from Examples 18 to 27 optionally include a subject in which the simulated X-rays correspond to at least one virtual focal point position originating from a virtual focal layer, and the virtual focal layer corresponds to a simulated X-ray source in the geometric shape of the cephalometric view.

[0099] In Example 29, the subject of Example 28 optionally includes a subject in which simulated X-rays extend in a defined three-dimensional space from a virtual focal layer to a virtual projection image or virtual cephalometric image constructed with the generated layers via a three-dimensional modeling of panoramic image data.

[0100] In Example 30, the subject of Example 29 optionally includes a subject in which the virtual focus layer, the three-dimensional modeling of panoramic image data, and the respective distances in defined three-dimensional space between the generated layers are based on the geometric relationships used in cephalometric imaging.

[0101] In Example 31, one or more subjects from Examples 18 to 30 optionally include a subject whose operation further includes the step of performing image post-processing on the computed cephalometric image.

[0102] Example 32 is a computer system comprising a processing circuit and a memory device containing instructions embodied thereon, wherein the instructions configure the processing circuit to generate a calculated cephalometric image from panoramic image data in the following actions when executed by the processing circuit: acquiring panoramic image data generated from a panoramic X-ray scan; generating a representation of the panoramic image data in a defined three-dimensional space; determining the geometric shape of a cephalometric view in a defined three-dimensional space; modeling simulated X-rays in the geometric shape of a cephalometric view to identify the portion of the panoramic image data to be used in the calculated cephalometric image; and outputting the calculated cephalometric image.

[0103] In Example 33, the subject of Example 32 optionally includes a subject in which panoramic image data includes a two-dimensional panoramic image, and the operation further includes reconstructing a two-dimensional panoramic image from multiple X-ray projection images.

[0104] In Example 34, the subject of Example 33 optionally includes a subject in which multiple X-ray projection images are acquired in an extraoral X-ray system using a full-frame panoramic (FFPAN) scan, and the operation further includes performing at least one image correction technique on the multiple X-ray projection images or two-dimensional panoramic images.

[0105] In Example 35, one or more of the themes from Examples 33 to 34 optionally include a theme in which reconstructing a two-dimensional panoramic image from multiple X-ray projection images includes an operation to expand the thickness of the focal layer, and expanding the thickness of the focal layer includes at least one of the steps of omitting each frame of the multiple X-ray projection images for use when reconstructing the two-dimensional panoramic image, or using a weighted collimator beam profile of at least one of the multiple X-ray projection images used when reconstructing the two-dimensional panoramic image.

[0106] In Example 36, one or more subjects from Examples 33 to 35 optionally include a subject in which reconstructing a two-dimensional panoramic image involves combining two height-shifted projection images to create a two-dimensional panoramic image having an enlarged image height.

[0107] In Example 37, one or more themes from Examples 32 to 36 optionally include a theme in which generating a representation of panoramic image data in a defined three-dimensional space involves mapping the pixel data of a two-dimensional panoramic image to voxels of a three-dimensional mesh in a defined three-dimensional space, where the three-dimensional mesh corresponds to the focal curve of the two-dimensional panoramic image within the geometric shape of the panoramic X-ray scan.

[0108] In Example 38, the subject of Example 37 optionally includes a subject in which modeling simulated X-rays involves an operation to intersect simulated X-rays in a defined three-dimensional space through voxels of a three-dimensional mesh, the operation further comprising creating multiple virtual cephalometric projection images from the voxels of the three-dimensional mesh, and reconstructing a calculated cephalometric image from the multiple virtual cephalometric projection images.

[0109] In Example 39, the subject of Example 38 optionally includes a subject in which the operation further includes weighting image information of overlapping points in multiple virtual cephalometric projections.

[0110] In Example 40, one or more of the themes from Examples 37 to 39 optionally include a theme in which modeling simulated X-rays involves intersecting simulated X-rays in a three-dimensional space defined via voxels of a three-dimensional mesh into a virtual cephalometric image, the operation further comprising modeling one X-ray beam per pixel of the virtual cephalometric image and creating a cephalometric image calculated from the pixels of the virtual cephalometric image.

[0111] In Example 41, the subject of Example 40 further includes the step of optionally weighting image information of overlapping points along the same X-ray beam corresponding to pixels in a virtual cephalometric image.

[0112] In Example 42, one or more subjects from Examples 32 to 41 optionally include a subject in which the simulated X-rays correspond to at least one virtual focal point position originating from a virtual focal layer, and the virtual focal layer corresponds to a simulated X-ray source in the geometric shape of the cephalometric view.

[0113] In Example 43, the subject of Example 42 optionally includes a subject in which simulated X-rays extend in a defined three-dimensional space from a virtual focal layer to a virtual projection image or virtual cephalometric image constructed with the generated layers via a three-dimensional modeling of panoramic image data.

[0114] In Example 44, the subject of Example 43 optionally includes a subject based on the geometric relationships used in cephalometric imaging, where the virtual focus layer, the three-dimensional modeling of panoramic image data, and the defined distances in three-dimensional space between the generated layers are determined.

[0115] In Example 45, one or more subjects from Examples 32 to 44 optionally include a subject whose operation further comprises performing image post-processing on a computed cephalometric image.

[0116] The various embodiments described above are presented as examples, not as limitations. Those skilled in the art will see that various modifications of form and detail (e.g., different hardware, communication protocols, etc.) can be made without departing from the scope of these embodiments. Furthermore, it should be understood that the accompanying drawings, which highlight the features described herein, are presented as illustrative examples. The architecture of this embodiment is sufficiently flexible and configurable and can be utilized and navigated in ways other than those shown in the drawings.

Claims

1. A method for generating a calculated cephalometric image, The steps include obtaining panoramic image data generated from a panoramic X-ray scan, A step of generating a representation of the panoramic image data in a defined three-dimensional space, The steps include determining the geometric shape of the cephalometric view in the defined three-dimensional space, The steps include: modeling simulated X-rays in the geometric shape of the cephalometric view in order to identify the portion of the panoramic image data to be used in the calculated cephalometric image; The steps include outputting the calculated cephalometric image, A method for generating a computed cephalometric image, including [specific data / features].

2. The method according to claim 1, wherein the panoramic image data includes a two-dimensional panoramic image, and the method further includes the step of reconstructing the two-dimensional panoramic image from a plurality of X-ray projection images.

3. The method according to claim 2, wherein the plurality of X-ray projection images are acquired in an extraoral X-ray system using a full-frame panoramic (FFPAN) scan, and the method further comprises the step of performing at least one image correction technique on the plurality of X-ray projection images or the two-dimensional panoramic image.

4. The step of reconstructing the two-dimensional panoramic image from the plurality of X-ray projection images is: The process includes a step of expanding the thickness of the focal layer, and the step of expanding the thickness of the focal layer is A step of omitting each frame of the plurality of X-ray projection images for use when reconstructing the two-dimensional panoramic image, or A step of using a weighted collimator beam profile of at least one projection image from among the plurality of X-ray projection images used to reconstruct the two-dimensional panoramic image, The method according to claim 2, comprising at least one of the following.

5. The method according to claim 2, wherein the step of reconstructing the two-dimensional panoramic image includes the step of combining two height-shifted projection images to create the two-dimensional panoramic image having an enlarged image height.

6. The method according to claim 1, wherein the step of generating the representation of the panoramic image data in the defined three-dimensional space includes the step of mapping the pixel data of the two-dimensional panoramic image to voxels of a three-dimensional mesh in the defined three-dimensional space, wherein the three-dimensional mesh corresponds to the focal curve of the two-dimensional panoramic image in the geometric shape of the panoramic X-ray scan.

7. The step of modeling the simulated X-rays includes the step of intersecting the simulated X-rays in the defined three-dimensional space through the voxels of the three-dimensional mesh, and the method is The steps include creating a plurality of virtual cephalometric projection images from the voxels of the three-dimensional mesh, The steps include: reconstructing the calculated cephalometric image from the plurality of virtual cephalometric projection images; The method according to claim 6, further comprising:

8. The step of weighting the image information of overlapping points in the plurality of virtual cephalometric projection images is performed as follows: The method according to claim 7, further comprising:

9. The step of modeling the simulated X-rays includes intersecting the simulated X-rays in the defined three-dimensional space through the voxels of the three-dimensional mesh with a virtual cephalometric image, and the method is The steps include: modeling one X-ray beam for each pixel of the virtual cephalometric image; The steps include creating the calculated cephalometric image from the pixels of the virtual cephalometric image, The method according to claim 6, further comprising:

10. A step of weighting image information of overlapping points along the same X-ray beam corresponding to pixels in the virtual cephalometric image, The method according to claim 9, further comprising:

11. The method according to claim 1, wherein the simulated X-rays correspond to at least one virtual focal position originating from a virtual focal layer, and the virtual focal layer corresponds to a simulated X-ray source in the geometric shape of the cephalometric view.

12. The method according to claim 11, wherein the simulated X-rays are extended in the defined three-dimensional space from the virtual focal layer to a virtual projection image or virtual cephalometric image constructed from the generated layers through the three-dimensional modeling of the panoramic image data.

13. The method according to claim 12, wherein the distances in the defined three-dimensional space between the virtual focus layer, the three-dimensional model of the panoramic image data, and the generated layer are based on the geometric relationships used for cephalometric imaging.

14. The step of performing image post-processing on the calculated cephalometric image is as follows: The method according to claim 1, further comprising:

15. A machine-readable medium comprising, when executed by a processing circuit, an instruction causing the processing circuit to perform the method according to any one of claims 1 to 14 in order to generate a cephalometric image calculated from panoramic image data.

16. An X-ray source and X-ray detector for acquiring panoramic image data, A computing unit for performing any method according to any one of claims 1 to 14 in order to generate a cephalometric image calculated from the panoramic image data, X-ray systems, including...

17. Memory for storing panoramic image data, To generate a cephalometric image calculated from the panoramic image data, at least one processor configured to perform any method according to any one of claims 1 to 14, A computer system, including a computer system.

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