Dental x-ray imaging system and method for dental x-ray imaging of a patient

Abstract

The invention relates to a dental X-ray imaging system (100) for dental X-ray imaging of a patient (600). The system (100) comprises a dental X-ray imaging unit (102) and a control system (106). The dental X-ray imaging unit (102) comprises an X-ray source portion (114), an X-ray imaging detector portion (116), and a gantry portion (112) comprising the source portion (114) and the imaging detector portion (116). The control system (106) is configured to: obtain at least one optical image (105) of the patient (600); receiving a scan request including region of interest (ROI) data; and defining an ROI position based on the ROI data, the at least one optical image (105), dental map data (1116), and at least one image analysis model (1118) formed based on previously collected reference image data. The invention also relates to a method, a computer program and a tangible non-volatile computer readable medium for dental X-ray imaging of a patient (600).

Description

Technical Field

[0001] The present invention relates generally to the technical field of dental X-ray imaging. Background Art

[0002] Typically, during dental X-ray imaging, correct positioning of a patient can be one of the most time-consuming tasks for a user (e.g., an operator) of a dental X-ray imaging unit, but also one of the most important tasks. Traditionally, various support methods that assume that the patient's head is kept as still as possible can be used to position the patient in a dental X-ray imaging unit.

[0003] Conventional support means may be chin rests, static bite bars and head supports, where the forehead, temples and / or the back of the skull are supported. Additionally, different kinds of straps may be used to position the patient as securely as possible. Additionally, some dental X-ray imaging units have such a bite bar attached to the dental X-ray imaging unit, such that the attachment means allow the bite bar to be moved in certain directions.

[0004] An approach that can also be considered traditional is to use a scout image. This is a low-dose panoramic image or a set of two projection images taken at 90 degrees, which can be used as an alignment aid for the three-dimensional (3D) image.

[0005] For this approach, a strict setup is very important. After completing the patient positioning (alignment), the patient should remain stable throughout the imaging process. If the patient and / or the X-ray imaging unit moves between the positioning and X-ray scanning phases, i.e. the position of the patient relative to the X-ray imaging unit changes, the resulting X-ray image may be diagnostically useless. The movement of the patient and / or the X-ray imaging unit during the scanning phase may cause severe artifacts in the resulting X-ray image, and during the reconstruction of the image data obtained during the scanning phase into the dental X-ray image, these artifacts caused by the movement need to be corrected (if possible), or an attempt can be made to reduce these artifacts by using software-based, i.e. computer program-based corrections. Artifacts caused by movement may significantly affect the quality of dental X-ray images. The result may be, for example, a blurred image or a distorted image.

[0006] Furthermore, typically in panoramic imaging, the anatomical shape of the patient is unknown before the panoramic image is taken. The panoramic image quality is severely affected based on how well the predefined imaging layers correspond to the patient's actual anatomical shape (e.g. dental arch). Typically, an average shape is used for all patients, which can result in suboptimal image quality. Furthermore, correct positioning of the patient is important, especially in panoramic imaging. Incorrect patient positioning may result in additional X-ray imaging of the patient.

[0007] Typically, the imaging workflow is manually controlled by an operator. Therefore, the quality of the resulting dental X-ray images and the duration of imaging may depend on the operator's actions. Summary of the invention

[0008] A simplified overview is presented below to provide a basic understanding of some aspects of various invention embodiments. This overview is not an extensive review of the present invention. This overview is neither intended to identify important or critical elements of the present invention nor to describe the scope of the present invention. The following overview only presents some concepts of the present invention in a simplified form as a prelude to a more detailed description of exemplary embodiments of the present invention.

[0009] An object of the present invention is to provide a dental X-ray imaging system, method, computer program and computer readable medium for dental X-ray imaging of a patient, as well as a method, computer program and computer readable medium for determining aligned dental atlas data of a patient. Another object of the present invention is to provide a dental X-ray imaging system, method, computer program and computer readable medium for dental X-ray imaging of a patient, as well as a method, computer program and computer readable medium for determining aligned dental atlas data of a patient to improve the quality of dental X-ray images.

[0010] The objects of the invention are achieved by a dental X-ray imaging system, a method, a computer program and a computer readable medium as defined by the respective independent claims.

[0011] According to a first aspect, a dental X-ray imaging system for dental X-ray imaging of a patient is provided, wherein the system comprises: a dental X-ray imaging unit, the dental X-ray imaging unit comprising: an X-ray source portion for emitting X-rays, an X-ray imaging detector portion for receiving the X-rays from the source portion, and a gantry portion comprising the source portion and the imaging detector portion; and a control system, the control system being configured to: obtain at least one optical image of the patient (600); receive a scan request comprising region of interest (ROI) data; and define a ROI position based on the ROI data, the at least one optical image, dental atlas data, and at least one image analysis model formed based on previously collected reference image data.

[0012] The at least one optical image of the patient may include at least one optical image in which the patient's dentition is at least partially visible, wherein the control system may be configured to: determine a plurality of head landmark points of the patient based on the at least one optical image of the patient and the at least one image analysis model, select a plurality of atlas landmark points corresponding to the plurality of head landmark points of the patient based on the dental atlas data, and align the plurality of atlas landmark points with the plurality of head landmark points of the patient to determine aligned dental atlas data of the patient.

[0013] The control system may be configured to define the ROI location based on the ROI data and the determined aligned dental atlas data of the patient.

[0014] Alternatively or additionally, the control system may be further configured to determine exposure parameters for the scan of the patient based on imaging modality data further included in the scan request, the at least one optical image of the patient and the at least one image analysis model.

[0015] The control system can be configured to: determine multiple head landmarks of the patient based on the at least one optical image of the patient and the at least one image analysis model, determine head size data of the patient based on the multiple head landmarks of the patient, and use the head size data to determine the exposure parameters.

[0016] The control system may be further configured to determine classification data of the patient based on the at least one optical image of the patient and the at least one image analysis model, and to use the classification data in determining the exposure parameter.

[0017] Alternatively or additionally, the control system can be further configured to: determine at least one head landmark point of the patient based on the at least one optical image of the patient and the at least one image analysis model, determine height data of the patient based on the at least one head landmark point of the patient, and use the determined height data to adjust the height of a portion of the dental X-ray imaging unit.

[0018] Alternatively or additionally, the control system may be further configured to: determine a plurality of body landmarks of the patient based on the at least one optical image of the patient and the at least one image analysis model, determine width data of the patient based on the plurality of body landmarks of the patient, and use the determined width data to reduce a risk of collision between the patient and the gantry portion of the dental X-ray imaging unit.

[0019] The dental X-ray imaging system may include at least one optical imaging device configured to capture the at least one optical image of the patient (600).

[0020] The ROI data may include an indication of at least one of: a single tooth, a group of teeth, a dental arch, two dental arches, a temporomandibular joint (TMJ), the entire dentition, and bilateral TMJs.

[0021] Alternatively or additionally, the control system may be further configured to generate patient position correction data for patient positioning based on the at least one optical image of the patient and the at least one image analysis model.

[0022] According to a second aspect, a method for dental imaging is provided, wherein the method is performed by the X-ray dental imaging system discussed above, wherein the method comprises: obtaining at least one optical image of the patient; receiving a scan request including region of interest (ROI) data; and defining the ROI position based on the ROI data, the at least one optical image, dental atlas data, and at least one image analysis model formed based on previously collected reference image data.

[0023] According to a third aspect, there is provided a computer program, wherein the computer program comprises instructions which, when the program is executed by a computer, cause the computer to perform the method discussed above.

[0024] According to a fourth aspect, there is provided a tangible non-transitory computer readable medium, wherein the computer readable medium comprises instructions which, when executed by a computer, cause the computer to perform the method discussed above.

[0025] According to a fifth aspect, a method for determining aligned dental atlas data for a patient is provided, wherein the method comprises: obtaining at least one optical image of the patient, wherein the patient's dentition is at least partially visible; determining a plurality of head landmark points of the patient based on the at least one optical image of the patient and at least one image analysis model formed based on previously collected reference image data; selecting a plurality of atlas landmark points corresponding to the plurality of head landmark points of the patient based on the dental atlas data; and aligning the plurality of atlas landmark points and the plurality of head landmark points of the patient to determine the aligned dental atlas data of the patient.

[0026] According to a fifth aspect, there is provided a computer program, wherein the computer program comprises instructions which, when the program is executed by a computer, cause the computer to perform the method discussed above.

[0027] According to a sixth aspect, there is provided a tangible non-transitory computer readable medium, wherein the computer readable medium comprises instructions which, when executed by a computer, cause the computer to perform the method discussed above.

[0028] Various illustrative and non-limiting embodiments of the invention, both as to constructions and methods of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific illustrative and non-limiting embodiments when read in connection with the accompanying drawings.

[0029] The verbs "comprise" and "include" are used in this document as open limitations, neither excluding nor requiring the presence of unrecited features. Unless explicitly stated otherwise, the features recited in the dependent claims are mutually freely combinable. Furthermore, it should be understood that the use of "a" or "an" (i.e. the singular) throughout this document does not exclude a plurality. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In the figures of the accompanying drawings, there are shown some embodiments of the invention by way of example and not by way of limitation.

[0031] Figure 1 An example of an example of a dental X-ray imaging system is schematically shown.

[0032] Figure 2 An example of a method for dental imaging of a patient is schematically shown.

[0033] Figure 3 Examples of reference imaging positions for providing at least a portion of reference image data are schematically illustrated.

[0034] Figure 4 An example of a method for determining aligned dental atlas data for a patient is schematically illustrated.

[0035] Figure 5A and Figure 5B An example of multiple head landmarks of a patient is schematically shown.

[0036] Fig. 6A An example of a method for defining coordinate transformation data is schematically shown.

[0037] Figure 6B An example of extracting device orientation data is schematically shown.

[0038] Figure 6C Another example of extracting device orientation data is schematically illustrated.

[0039] 7A to 7D An example of the gantry section moving to the starting position of the scanning trajectory is shown.

[0040] Fig. 8A An example of a method for determining exposure parameters for a scan of a patient is schematically shown.

[0041] Figure 8B Yet another example of multiple head landmarks of a patient is schematically shown.

[0042] Fig.9A An example of a method for adjusting the height of a portion of a dental X-ray imaging unit is schematically shown.

[0043] Fig. 9BExamples of height offset values ​​are schematically shown.

[0044] Fig. 10A An example of a method for reducing the risk of collision between a patient and a gantry part of a dental X-ray imaging unit is schematically illustrated.

[0045] Fig. 10B Examples of multiple body landmarks of a patient are schematically shown.

[0046] Fig.11 An example of a control system for a dental X-ray imaging system is schematically shown.

[0047] Fig.12 An example of a method for detecting a patient readiness state is schematically shown.

[0048] Fig.13 An example of a method for detecting a device ready state is schematically shown. DETAILED DESCRIPTION

[0049] In this description, we use the following vocabulary regarding the different stages of the dental X-ray imaging process. The term irradiation refers to the stage that includes only the irradiation, i.e. the stage when the X-ray source provides an X-ray beam that travels through the object to the X-ray imaging detector. It is expected that the object remains as still as possible during the irradiation, i.e. does not move. During the irradiation, one or more parts of the dental X-ray imaging unit may move. The term scanning, in turn, refers to the stage that includes both irradiation and movement of one or more parts of the dental X-ray imaging unit. Scanning does not include positioning one or more parts of the X-ray imaging unit in the correct position for providing an X-ray image. The term imaging refers to the entire process including irradiation, scanning and positioning.

[0050] Figure 1 Shown for patient 600 (patient 600 is not shown in Figure 1An example of a dental X-ray imaging system 100 for dental X-ray imaging of a dental object (shown in ). The imaging system 100 includes a dental X-ray imaging unit 102, which is used to acquire X-ray image data from an object (e.g., a patient or a calibration target) in dental X-ray imaging (e.g., in extraoral dental X-ray imaging). The acquired X-ray image data is used to form a two-dimensional (2D) X-ray image or to reconstruct a three-dimensional (3D) X-ray volume from at least a portion of the imaged object. The dental X-ray imaging system 100 further includes a control system 106. The control system 106 can be electrically and / or communicatively connected to the dental X-ray imaging unit 102. The implementation of the control system 106 can be accomplished as a stand-alone unit or as a distributed control environment between multiple stand-alone units providing distributed control resources. Preferably, the computing unit 106 can be an embedded computer. The control system 106 can, for example, include a control unit of the dental X-ray imaging unit 102. The control system 106 may further include a computing unit of at least one imaging device 104a, 104b of the dental X-ray imaging system 100 and / or a computing unit external to the dental X-ray imaging unit 102. The control unit of the dental X-ray imaging unit 102 is configured to at least partially control the operation of the dental X-ray imaging unit 102. The control unit of the dental X-ray imaging unit 102 may be located near the dental X-ray imaging unit 102, or the control unit of the dental X-ray imaging unit 102 may be embedded in the dental X-ray imaging unit 102.

[0051] The dental X-ray imaging unit 102 can be configured to perform different types of imaging processes (i.e., imaging modes), including but not limited to computed tomography (CT) imaging and / or panoramic imaging. CT imaging can be cone beam CT (CBCT) imaging, in which the beam is a cone beam, or, for example, other types of CT imaging, in which the beam is a pyramidal beam, a half-moon cone beam, or any other shaped beam. CT imaging generates (i.e., produces) X-ray image data for reconstructing a 3D volume from at least a portion of the imaged object. Panoramic imaging can be, for example, standard panoramic imaging, pediatric panoramic imaging, orthodontic area panoramic imaging, wide-bow panoramic imaging, orthogonal panoramic imaging, etc. Panoramic imaging generates X-ray image data for forming a panoramic 2D image. Alternatively or additionally, if the dental X-ray imaging unit 102 is equipped with the parts necessary for cephalometric imaging, the dental X-ray imaging unit 102 can be configured to perform cephalometric imaging. Cephalometric imaging can be, for example, a lateral projection of a child's cephalometric projection, a lateral projection of a cephalometric projection, a posterior-anterior projection of a cephalometric projection, etc. Cephalometric imaging generates X-ray image data that is used to form cephalometric 2D images. Figure 1 Only one example of a dental X-ray imaging unit 102 for use with the concepts of the present disclosure is shown.

[0052] The dental X-ray imaging unit 102 includes a carriage portion 101 movably supported on a support column 103. The carriage portion 101 can be moved by means of a guide motor ( Figure 1 The guide motor is configured to move the carriage 101 up and down in the height direction (Z) (i.e., the vertical direction) along the support column 103 in the height direction. The upper shelf 110 is configured to support a frame portion (i.e., a rotating portion) 112 that can rotate relative to the upper shelf 110 in a horizontal plane. The upper shelf 110 and / or the frame portion 112 may include a rotating motor ( Figure 1 Alternatively or additionally, the upper shelf 110 may include a pivot motor ( Figure 1 Alternatively or additionally, the dental X-ray imaging unit 102 may be mounted to a support structure ( Figure 1 ), the support structure is illustratively a wall supported by columns 103.

[0053] The dental X-ray imaging unit 102 further includes an X-ray source portion 114 for acquiring X-ray image data and an X-ray imaging detector portion 116. The gantry portion 112 includes and supports the source portion 114 and the imaging detector portion 116. The gantry portion 112 may substantially have the form of a letter C, such as Figure 1 As shown, the source portion 114 can be attached to one end of the gantry portion 112, and the imaging detector portion 116 can be attached to the other end of the gantry portion 112, so that the source portion 114 and the imaging detector portion 116 are opposite to each other. The X-ray source portion 114 includes an X-ray source that transmits X-rays (i.e., generates an X-ray beam) through an object being imaged (e.g., the head of the patient 600) to the X-ray imaging detector portion 116, which includes at least one X-ray detector that receives the X-rays emitted from the source portion 114. The X-ray imaging detector portion 116 further generates X-ray image data from the object exposed to (i.e., imaged by) the X-rays.

[0054] The X-ray imaging unit further comprises a collimator ( Figure 1600). The X-rays pass through a portion of an object, such as an anatomical structure of a patient, such as the patient's head. The anatomical structure through which the X-rays pass may absorb different amounts of X-ray energy. After passing through the object, the attenuated X-rays are received by the X-ray imaging detector portion 116. The X-ray imaging detector portion 116 is configured to convert the magnitude of the received X-ray energy and generate a digitized output representing unabsorbed X-rays at at least one X-ray detector, i.e., X-ray image data. A collection of digitized outputs from the X-ray imaging detector portion 116 corresponding to a single emission of an X-ray beam from the X-ray source portion 114 can be referred to as a projection image of the object being imaged (e.g., the head of the patient 600).

[0055] In addition, the dental X-ray imaging unit 102 may include patient support components 124, 126 (eg, Figure 1 The patient support member 124, 126 may include a chin support member 124 and / or a head support member 126. The chin support member 124 may support the tip of the chin of the patient 600, and the head support member 126 may support the forehead or temple of the patient 600. The dental X-ray imaging unit 102 may include a lower shelf 122 extending from the carriage 101. The lower shelf 122 may include a chin support member 124, as shown in FIG. Figure 1 As in the example dental X-ray imaging unit 102. The head support member 126 can extend from the upper shelf 110 through the rotating portion 112, as in Figure 1 As in the example dental X-ray imaging unit 102 of . Alternatively, the lower shelf 122 may also include a head support component 126. The patient support component (i.e., the chin support component 124 and / or the head support component 126) may be optional, and the positioning of the patient 600 may be performed in other ways. The dental X-ray imaging unit 102 may further include a handle 128 for the patient 600 to grasp.

[0056] The gantry portion 112 can be rotated by, for example, a rotary motor. The rotation of the gantry portion 112 causes the X-ray source portion 114 and the X-ray imaging detector portion 116 to rotate around the object to be imaged, for example, around the rotation axis along a scanning trajectory. When the X-ray source portion 114 and the X-ray imaging detector portion 116 rotate around the object (e.g., the head of the patient 600), the X-ray imaging device 102 operates to acquire a plurality of projection images of the object taken at incremental rotation angles. By reconstructing the X-ray image data into a dental X-ray image, a dental X-ray image can be formed based on the plurality of projection images.

[0057] The dental X-ray imaging system 100 may further include at least one optical imaging device 104a, 104b. The at least one optical imaging device 104a, 104b may include at least one external imaging device 104a and / or at least one internal imaging device 104b. The at least one external imaging device 104a is located outside the dental X-ray imaging unit 102. In other words, the at least one external imaging device 104a may be a device that is not part of the dental X-ray imaging unit 102. Using the at least one external imaging device 104a may achieve a better lighting environment for collecting optical image data compared to the at least one internal imaging device 104b, because at least some parts of the dental X-ray imaging unit 102 (e.g., the patient support components 124, 126, the X-ray source portion 114 and / or the X-ray imaging detector portion 116) may interfere with the lighting environment for capturing optical images by using the at least one internal imaging device 104b. Alternatively or additionally, it is easy and simple to capture optical images by using the at least one external imaging device 104a. The at least one internal imaging device 104b may be disposed in connection with the dental X-ray imaging unit 102, such as embedded within the dental X-ray imaging unit 102. For example, the at least one internal imaging device 104b may be mounted (eg, fixed) to the dental X-ray imaging unit 102. Figure 1Only one non-limiting implementation example of at least one internal imaging device 104b is shown, and any other number of internal imaging devices 104b can be used and positioned at any other position on the dental X-ray imaging unit 102. At least one imaging device 104a, 104b can be a 2D imaging device and / or a 3D imaging device. Preferably, at least one imaging device 104a, 104b is a 3D imaging device, i.e., a range-finding imaging device. The 3D imaging device can be based on any 3D imaging technology, such as stereo triangulation, light sheet triangulation, structured light, light time, interferometry, coded aperture and / or any other 3D imaging technology. The 3D imaging device can be an independent unit that includes all hardware and software related to 3D imaging, and an internal computing unit may also be provided in the same module. Alternatively, the 3D imaging device can be a collection of separate components arranged in a 3D imaging configuration, wherein, for example, two optical cameras (e.g., a camera pair) are arranged in a stereoscopic vision configuration, and the 3D calculation is completed at an external computing unit (e.g., a control unit or the like). The 2D imaging device may be, for example, an optical camera and / or any other 2D imaging device. According to non-limiting examples, the at least one external imaging device 104a may be, but is not limited to, an optical camera, a mobile device (e.g., a mobile phone, a tablet) including at least one optical camera, and / or an independent 3D facial scanner system. The at least one internal optical imaging device 104b may be a multifunctional optical imaging device. In other words, the at least one internal optical imaging device 104b may also be used for one or more other operations or functions, such as, but not limited to, patient positioning, motion detection, and / or motion correction, etc.

[0058] Next, refer to Figure 2 At least some example aspects of a method for dental imaging of a patient 600 are defined. Figure 2 The method is shown in a flow chart. The method is performed by the dental X-ray system 100 discussed above.

[0059] At step 210, the control system 106 obtains at least one optical image 105 of the patient 600. The at least one optical image 105 of the patient 600 may be captured by using at least one optical imaging device 104a, 104b (e.g., at least one external imaging device 104a and / or at least one internal imaging device 104b) of the dental X-ray system 102. The control system 106 may obtain the at least one optical image 105 of the patient 600 from the at least one optical imaging device 104a, 104b (e.g., from at least one external imaging device 104a and / or from at least one internal imaging device 104b). Alternatively, the control system 106 may obtain the at least one optical image 105 of the patient 600 from a database, in which the at least one optical image 105 captured by using the at least one optical imaging device 104a, 104b may be stored. Figure 1 In the example of FIG. 1 , a non-limiting example is shown, in which the at least one optical image 105 obtained is captured by at least one external optical imaging device 104a, but alternatively or additionally, the at least one optical image 105 obtained may be captured by at least one internal optical imaging device 104b. According to a non-limiting example, when the patient 600 enters the room where the dental X-ray imaging unit 102 is located, the at least one optical image 105 of the patient 600 belonging to the at least one optical image 105 of the patient 600 may be captured. According to another non-limiting example, the at least one optical image 105 of the patient 600 may have been captured before the patient 600 enters the room where the dental X-ray imaging unit 102 is located, as long as the at least one optical image of the patient 600 is substantially recently captured. The at least one optical image 105 may be a still image and / or a video image. The at least one optical image 105 of the patient 600 may include at least one facial image of the patient 600, at least one upper torso image of the patient 600, and / or at least one full body image of the patient 600.

[0060] At step 220, the control system 106 receives a scan request. The scan request may be received locally or remotely via the user interface portion 140a, 140b. The user interface portion 140a, 140b may, for example, be located at the same location as the X-ray imaging unit 102, i.e., the scan request may be received locally. For example, the X-ray imaging unit 102 may include a user interface portion 140a, such as a touch screen, as in Figure 1As in the example of a dental X-ray imaging unit 102. An operator of the X-ray imaging unit 102 can input a scan request via the user interface portion 140a. Alternatively or additionally, the user interface portion 140b can be, for example, located at another location other than the location where the X-ray imaging unit 102 is located, that is, the user interface portion 140b can be located at a location away from the X-ray imaging unit 102 and communicatively connected to the control system 106. In this case, the scan request can be received remotely. The scan request includes region of interest (ROI) data. The scan request can further include imaging mode data. The image mode data can, for example, include an indication of an imaging mode (i.e., an imaging modality) for scanning, such as CT imaging and possibly also including the type of CT imaging, panoramic imaging and possibly also including the type of panoramic imaging, or cephalometric imaging and possibly also including the type of cephalometric imaging. The ROI data can include an indication of one or more regions of the patient to be included in the scan (e.g., one or more target anatomical structures), i.e., a target ROI. For example, the ROI data may include, but is not limited to, an indication of at least one of: a single tooth, a group of teeth, a dental arch (maxillary or mandibular), two dental arches (maxillary and mandibular), a temporomandibular joint (TMJ), bilateral TMJ, full dentition, and bilateral TMJ. The scan request may further include patient identification data (e.g., patient name, patient identification number, photograph, fingerprint, retinal scan, facial recognition and / or other biometric data, etc.) and / or resolution data, the resolution data including an indication of a resolution to be used in the scan. Figure 2 In the embodiment, step 210 is presented before step 220, but step 220 may also be performed before step 210 or simultaneously with step 210.

[0061] At step 230, the control system 106 defines a ROI position on the patient 600 based on the ROI data, at least one optical image 105, the dental atlas data 1116, and at least one image analysis model 1118. The ROI position on the patient 600 to be defined may depend on the imaging mode. For example, in the case of CT imaging, the ROI position to be defined may be the position of the field of view (FOV). For example, in the case of panoramic imaging, the ROI position to be defined may be the position of the imaging layer.

[0062] The dental atlas data 1116 may include atlas anatomical data. The anatomical data of the dental atlas data 1116 may, for example, include atlas anatomical structure data. The atlas anatomical structure data may, for example, include the location of one or more anatomical structures, such as teeth, dental arches (maxillary and / or mandibular), (bilateral) TMJ, (bilateral) mandibular head, submental point, mental notch, nasal spine, (bilateral) tragus, (bilateral) external auditory canal, (multiple) sinuses, (two) orbits (e.g., inferior orbital rims), and / or any other anatomically relevant structures. The atlas anatomical data may further include atlas landmark data. The atlas landmark data may include the location of multiple atlas landmarks (e.g., multiple mandibular atlas landmarks, multiple maxillary atlas landmarks, and / or one or more other landmarks). A plurality of atlas landmarks may, for example, include but are not limited to a predetermined number of maxillary anterior teeth (e.g., the 3 most central teeth on both sides, i.e., the teeth from the canine to the right canine, including both canines) landmarks, a predetermined number of mandibular anterior teeth (e.g., the 3 most central teeth on both sides) landmarks, (multiple) mandibular head landmarks, submental landmarks, mental notch landmarks, nasal spines (i.e., nasal chiasm) landmarks, (multiple) tragus landmarks, (multiple) external auditory canal landmarks, (multiple) sinus landmarks, (multiple) TMJ landmarks, (multiple) orbital landmarks (e.g., orbital inferior rim landmarks), and / or any other anatomically relevant structure landmarks. The atlas landmark data may further include labels for the plurality of atlas landmarks, such as identifiers (IDs). The atlas anatomical data may typically be extracted from CT images (e.g., CBCT images, medical CT images, or other radiological images). Typically, these CT images are 3D images, but the CT images may also be 2D or 4D images. The atlas anatomical data may be extracted from a single subject or from multiple subjects. Alternatively, the atlas anatomical data can also be created without a CT image. Therefore, the atlas anatomical data can also be artificially generated or universal. In addition to the atlas anatomical data, the dental atlas data 1116 can further include atlas imaging data. The atlas imaging data can, for example, include atlas ROI data. The atlas ROI data can include the location of one or more possible ROI positions. For example, in the case of CT imaging, the location of one or more possible ROI positions can include one or more single teeth, a group of teeth, a dental arch (maxillary and / or mandibular), (bilateral) TMJ, the entire dentition and bilateral TMJ and / or the location of any other specific ROI position. For example, in the case of panoramic imaging, the location of one or more possible ROI positions can include the location of one or more imaging layers. Preferably, the atlas ROI data can include the location of all possible ROI positions. The location of each possible ROI position can, for example, include the center of the possible ROI. The atlas ROI data can further include labels for one or more possible ROI positions.The atlas imaging data may further include atlas scanning trajectory data and / or any other imaging data that depends on the geometry. The atlas scanning trajectory data may, for example, include rotation axis data, rotation angle data, exposure parameter data, sharp layer data (in the case of panoramic imaging) and / or timing diagram data. The rotation axis data may include the position of the mechanical (i.e., physical) rotation axis (i.e., mechanical rotation center) of the gantry portion 112 during scanning, such as the start position of the scan (i.e., the scan start control position), the intermediate control point of the scan and / or the scan end position (i.e., the scan start control position). Alternatively or additionally, the rotation axis data may, for example, include the position of the virtual rotation axis (i.e., virtual rotation center) of the gantry portion 112 during scanning, such as the start position of the scan, the intermediate control point of the scan and / or the scan end position. The rotation angle data may, for example, include the rotation angle of the gantry portion 112 during scanning, such as the scan start angle, the intermediate angle and / or the scan end angle. The exposure parameter data may, for example, include information about the exposure parameters during the scanning trajectory and / or for each ROI position. The sharp layer data may, for example, include the size, shape and position of the sharp layer. The portion of the patient's anatomical structure that touches the sharp layer is clear in the dental X-ray image, while other portions of the patient's anatomical structure are blurred. The timing diagram data may, for example, include a timing diagram indicating when the emission of the X-ray beam is turned on / off for each specific ROI position. The dental atlas data 1116 may be generated based on data acquired from one or more dental atlas databases. The term "dental atlas" may also be referred to as a dental model, a dental template, a dental mold, a dental sample, a dental framework, a dental artifact, a dental prototype, and / or any other similar term. The dental atlas data 1116 may cover not only information from the dentition, but also information about the mandible, maxilla, and / or skull or portions thereof. Therefore, the dental prefix in the term "dental atlas data" may have at least the following synonyms: jaw, dental arch, mandible, maxilla, and / or maxillofacial, etc. The dental atlas data 1116 may be stored in the memory portion 1108 of the control system 106.

[0063] At least one image analysis model 1118 may be formed based on previously collected reference image data. For example, at least one image analysis model 1118 may be trained using previously collected reference image data. At least one image analysis model 1118 may include at least one machine learning (ML)-based model and / or at least one artificial intelligence (AI)-based model. At least one image analysis model 1118 may further include at least one conventional image analysis model. At least one ML-based model may be formed by applying one or more known ML techniques. According to a non-limiting example, at least one ML-based model may be, for example, based on a regression tree ensemble ML method and / or a directional gradient histogram (HoG) ML method. At least one AI-based model may be formed by applying one or more known AI techniques. According to a non-limiting example, at least one AI-based model may be, for example, based on a deep neural network, a deep convolutional neural network, a traditional neural network, a region-based convolutional network, and / or a region-based fully convolutional network, etc. Prior to implementing the at least one image analysis model 1118 by the control system 106 (e.g., in the definition of an ROI location), previously collected reference image data for the at least one image analysis model can be collected, and the at least one image analysis model 1118 can be formed based on the previously collected reference image data. The at least one imaging model 1118 can be stored in the memory portion 1108 of the control system 106.

[0064] The previously collected reference image data may include image data of a large number of people. According to a non-limiting example, the large number of people may include approximately more than 1000 people. Preferably, the large number of people may include approximately 2000 to 3000 people or even more. The reference image data may include at least one optical reference image belonging to each of the plurality of large numbers of people. Preferably, the reference image data may include multiple optical images belonging to each of the plurality of large numbers of people. The multiple optical images of each person may include optical images from multiple different positions and / or perspectives of the person. For example, the multiple optical images of each person may include at least one optical image from the front of the person, from each side of the person, a head-down position, a head-up position, and / or a facial expression with a grimace (i.e., a facial expression in which the teeth of the person are at least partially visible, preferably fully visible). The reference optical image of the reference image data may be a still image and / or a video image. The reference image data may be captured by using at least one reference imaging device 302. Preferably, the reference image data may be captured by using multiple reference imaging devices 302. This enables substantially simultaneous capture of multiple optical images from different perspectives. The at least one reference imaging device 302 may be a 2D imaging device and / or a 3D imaging device. Preferably, the at least one reference imaging device 302 is a 3D imaging device. The descriptions related to 3D imaging devices and 2D imaging devices described above with reference to the at least one imaging device 104a, 104b also apply to the at least one reference imaging device 302.

[0065] According to a non-limiting example, reference image data may be provided from one or more reference imaging locations, such as from one or more photo booths 300. Each reference image location 300 may include a plurality of reference imaging devices 302 configured to provide at least a portion of the reference image data. Figure 3 A non-limiting example of a reference imaging location (e.g., a photo booth) 300 is shown that includes a plurality of reference imaging devices 302 configured to provide at least a portion of reference image data. Figure 3 In the example of , a plurality of reference imaging devices 302 are arranged in a stereoscopic configuration. Therefore, reference numeral 302 refers to a pair of reference imaging devices. Figure 3 In the example of FIG. 3 , a person 304 is being photographed within the photo booth 300 , and the plurality of reference imaging devices 302 are configured to capture reference optical images of the person 304 , wherein the captured reference optical images of the person 304 may be included in the reference image data.

[0066] According to an example, the at least one image analysis model 1118 may be further retrained using further reference image data collected later, for example during use of the method by the dental X-ray imaging system 100. For example, the optical images 105 of the (multiple) patient 600 captured by the at least one optical imaging device 104a, 104b may be used as further reference image data to further retrain the at least one image analysis model. Alternatively or additionally, the further reference image data may be collected, for example, at one or more photo booths 300 using at least one reference imaging device 302. The retrained at least one image analysis model 1118 may be stored in the memory portion 1108 of the control system 106 and replace the previously stored at least one image analysis model 1118.

[0067] As discussed above, the control system 106 defines the ROI location at step 230 based on the ROI data, the at least one optical image 105, the dental atlas data 1116, and the at least one image analysis model 1118. To define the ROI location, the control system 106 may first determine aligned dental atlas data of the patient 600 based on the at least one optical image 105, the dental atlas data 1116, and the at least one image analysis model 1118 of the patient 600. The aligned dental atlas data may include the dental atlas data 1116 aligned with the patient 600, for example, the atlas anatomical data aligned with the patient 600, and may also include at least a portion of the atlas imaging data aligned with the patient 600. When the dental atlas data 1116 is aligned with the patient 600, the atlas anatomical data and possibly at least a portion of the atlas imaging data may be transferred to the exact location and anatomical structure of the patient 600. After determining the aligned dental atlas data of the patient 600 , the control system 106 is configured to define the ROI location based on the ROI data and the determined aligned dental atlas data of the patient 600 . Figure 4An example of a method for determining aligned dental atlas data of a patient 600 based on at least one optical image 105 of the patient 600, dental atlas data 1116, and at least one image analysis model 1118 is schematically shown. At step 230, the determined aligned dental atlas data of the patient 600 may be used for the definition of the ROI position. Alternatively or additionally, the determined aligned dental atlas data of the patient 600 may be used in one or more other applications, for example, in the definition of exposure parameters for scanning as will be described later in this application. In order to determine the aligned dental atlas data of the patient 600, at least one optical image 105 of the patient 600 is required in which the dentition of the patient 600 is at least partially visible. In other words, the at least one optical image 105 of the patient 600 used in determining the aligned dental atlas data includes at least one optical image in which the dentition of the patient 600 is at least partially visible. Preferably, at least two optical images 105 of the patient 600 captured from different viewing angles may be used in which the dentition of the patient 600 is at least partially visible. This allows the head of the patient 600 to be better covered in the optical image(s) 105 .

[0068] At step 410, the control system 106 may determine (e.g., extract) a plurality of head landmarks 502, 504, 506, 508, 510, 512 of the patient 600 based on at least one optical image 105 of the patient 600 and at least one image analysis model 1118. For example, at least one image analysis model 1118 (e.g., at least one ML-based model) may be used to detect the plurality of head landmarks 502, 504, 506, 508, 510, 512 from at least one optical image 105 of the patient 600. In other words, the at least one optical image 105 of the patient 600 may be used as input data of the at least one image analysis model 1118, and the plurality of head landmarks 502, 504, 506, 508, 510, 512 of the patient 600 may be obtained as output data of the at least one image analysis model 1118. The determined multiple head landmarks 502, 504, 506, 508, 510, 512 can be presented as 3D coordinates. The determined multiple head landmarks 502, 504, 506, 508, 510, 512 can, for example, include but are not limited to a predetermined number of maxillary anterior teeth (e.g., the 3 most central teeth on both sides, i.e., the teeth from the canine to the right canine, including both canines) landmarks 502, a predetermined number of mandibular anterior teeth (e.g., the 3 most central teeth on both sides) landmarks 512, a mandibular head landmark 504, a submental landmark 506, a mental notch landmark 508, and / or a nasal spine (i.e., nasal chiasm) landmark 510. Another non-limiting example of head landmarks may include, but is not limited to: (multiple) tragus landmarks, (multiple) external auditory canal landmarks, (multiple) sinus landmarks, (multiple) TMJ landmarks, (multiple) orbital landmarks (e.g., orbital rim landmarks), and / or landmarks of any other anatomically relevant structures. A predetermined number of maxillary anterior teeth landmarks 502 are located directly on the maxilla. Similarly, a predetermined number of mandibular anterior teeth landmarks 512 are located directly on the mandible. Other landmarks of the patient 600 (e.g., mandibular head landmarks 504, chin vertex landmarks 506, chin notch landmarks 508, and / or nasal spine landmarks 510) may be detected on the skin surface and may be projected onto the bone by projecting them through the average skin-subcutaneous fat thickness, i.e., by moving them inward by the amount of the average skin-subcutaneous fat thickness. Alternatively or additionally, both the maxillary anterior teeth landmarks 502 and the mandibular anterior teeth landmarks 512 need not be determined. For example, if the maxillary anterior landmark 502 is determined, the mandibular anterior landmark 512 may be determined by projecting the maxillary anterior landmark 502 downward onto the bone by a known amount of tooth length.

[0069] Figure 5A and Figure 5BA non-limiting example of multiple head landmarks 502, 504, 506, 508, 510, 512 of a patient 600 determined based on at least one optical image 105 of the patient 600 and at least one image analysis model 1118 is schematically shown. In this example, the multiple head landmarks 502, 504, 506, 508, 510, 512 of the patient 600 include three maxillary anterior teeth landmarks on both sides 502, a mandibular head landmark 504, a submental landmark 506, a mental notch landmark 508, and a nasal spine landmark 510. Figure 5A A non-limiting example maxillary bone model 520 is shown onto which the maxillary landmarks of the determined head landmarks 502, 504, 506, 508, 510, 512 of the patient 600 are projected. In this example, the maxillary landmarks include three maxillary anterior teeth landmarks 502 on both sides and a nasal spine landmark 510. The projection of the nasal spine landmark 510 onto the bone is Figure 5A The nasal spine point is shown by an arrow in the figure, and the nasal spine point landmark point detected on the skin surface is shown by reference numeral 510'. Figure 5B A non-limiting example mandibular bone model 530 is shown on which the mandibular landmarks of a plurality of head landmarks 504, 506, 508, 510, 512 of the patient 600 are projected. In this example, the mandibular landmarks include three mandibular anterior teeth landmarks 512 on both sides, the mandibular head landmark 504, the submental point landmark 506, and the mental notch landmark 508. The projections of the mandibular head landmark 504, the submental point landmark 506, and the mental notch landmark 508 on the bone are shown in FIG. Figure 5B , and the mandibular head landmark, submental point landmark, and mental notch landmark detected on the skin surface are represented by reference numerals 504', 506', and 508', respectively. In addition, the projection of the maxillary anterior teeth landmark 502 on the bone is Figure 5B The mandibular anterior teeth landmark point 512 is indicated by an arrow.

[0070] According to an example, the control system 106 may further estimate the confidence of the plurality of landmark points of the patient 600 extracted at step 410 and / or at any other step described later in this application. Figure 4In the example of , an estimate of the confidence of multiple landmarks of patient 600 is shown in optional step 412. The confidence estimate can be, for example, binary and / or weighted. In a binary confidence estimate, multiple landmarks can be divided into two groups: 1) valid landmarks (used for registration in step 430), and 2) invalid landmarks (not used for registration in step 430). The registration of step 430 will be described later in this application. In a weighted confidence estimate, each landmark is given a weight that reflects the estimated confidence. High confidence results in a large weight, and low confidence results in a small weight. The weighted confidence estimate can assume that the registration process at step 430 can handle the weights. Alternatively, binary labeling can be used and invalid landmarks can be removed. Typically, at least one image analysis model 1118 can output all landmark points, even in the presence of occlusion (e.g., lips obstruct visibility of a particular tooth (e.g., canine)) and / or in the absence of a target structure (e.g., patient 600 does not have a particular tooth (e.g., canine)), and / or in the presence of a displaced landmark point (e.g., a detected canine landmark point corresponds to the location of a premolar). These landmark points are invalid and should not be used in the registration process of step 430. Similarly, in the weighted confidence estimate, these invalid landmark points should be assigned a zero weight or at least a very small weight. The control system 106 can perform the confidence estimate, for example, using spatial analysis. The relative distance between any two landmark points (the distance that takes into account scaling differences between different heads) is approximately known in advance. Similarly, the relative angle between two lines is approximately known in advance. For example, it is known that a line connecting landmark points associated with the tragus and the inferior orbital rim and a line connecting landmark points associated with the tragus and the nasal spine 510 have a relative angle of approximately 10 degrees. A large deviation from the expected relative distance and / or relative angle indicates a low confidence. Alternatively or additionally, the control system 106 may, for example, use regional content analysis to make a confidence estimate. In regional content analysis, the control system 106 analyzes the content of at least one optical image 105 near the detected landmark point. Regional content analysis may, for example, be texture region analysis, color texture region analysis, and / or any other region analysis. Regional analysis may also be based on an AI model trained to make landmark confidence estimates. Alternatively or additionally, if at least one imaging device 104a, 104b captures optical images at different time points, the control system 106 may use time analysis to make a confidence estimate. If the patient 600 is supported by the patient support members 124, 126, it is assumed that the target anatomical structure has a substantially stable spatial position within a short time interval. If the position of the landmark point changes greatly within a short period of time, a low confidence may be assumed. Similarly, if the landmark point remains stable, a high confidence may be assumed.

[0071] According to another example, the control system 106 may alternatively or additionally combine landmarks of the patient 600 at the same anatomical location and / or combine spatial information, i.e., combine landmarks detected from optical images obtained from more than one imaging device 104a, 104b. Figure 4In the example of , the combination of the landmarks of the patient 600 is shown in optional step 414. According to the example, if multiple imaging devices 104a, 104b are used, there may be multiple detected landmarks for the same anatomical position observed from different imaging devices, and / or there may be multiple landmark detections that take slightly different times (multiple time positions). Therefore, there may be multiple landmarks to the same anatomical position. There may be many strategies for combining multiple instances of the same landmark into a single landmark, and any of them may be used here. For example, a weighted averaging scheme may be used. Some non-limiting exemplary averaging schemes may, for example, include fixed weighting (e.g., arithmetic mean), weighting according to time (e.g., more recent time points have greater weights than older samples, i.e., temporal average), and / or weighting according to confidence, etc. This landmark combination is only an optional process, and the need for combination may depend on the registration process at step 430. For example, if the registration process is capable of handling point sets of unequal sizes (e.g., iterative closest point (ICP) algorithm), more than one landmark for each single anatomical position may be maintained. According to another example, if more than one imaging device 104b is used, some marker points may be visible and detected in an optical image from one imaging device 104a, 104b, and other marker points may be visible and detected in another optical image of another imaging device 104a, 104b. The detected marker points may be presented in an internal imaging device coordinate system that is unique to each imaging device 104a, 104b. Combining spatial information means transforming marker points from different imaging device coordinate systems into a base coordinate system. One possibility is to designate one imaging device 104a, 104b as a master imaging device, to which marker points detected in optical images of (multiple) other (i.e., slave) imaging devices 104a, 104b may be transmitted. The transformation between imaging devices 104a, 104b may be known from a joint calibration of imaging devices 104a, 104b. Another option may be to agree on some other fixed coordinate system, such as the coordinate system of the dental X-ray imaging unit 102, as the base coordinate system and transform the landmarks determined from the optical image of each imaging device 104a, 104b into the coordinate system of the dental X-ray imaging unit 102. The conversion from the imaging device coordinates to the coordinates of the dental X-ray imaging unit 102 may be known based on calibration data formed by performing a calibration of the (multiple) imaging devices 104a, 104b to the dental X-ray imaging unit 102. The calibration may be performed, for example, during the setup of the dental X-ray imaging unit 102. The calibration may be further repeated after any period of time, for example during annual maintenance. In the calibration, a calibration target comprising at least three calibration marks visible in the optical image and the X-ray image may be used.

[0072] According to an example, if the control system 106 cannot determine one or more of the plurality of head landmarks 504, 506, 508, 510, 512 of the patient 600 based on the at least one optical image 105 of the patient 600 and the at least one image analysis model 1118, the control system 106 may generate an indication to an operator of the dental X-ray imaging unit 102 via one or more user interface devices (e.g., via the user interface device 140a). In response to generating the indication for the operator, the operator may manually input one or more missing head landmarks of the patient 600 (e.g., one or more of the plurality of head landmarks 502, 504, 506, 508, 510 of the patient 600 that 106 cannot determine) via one or more user interface devices (e.g., via the user interface device 140a). The minimum number of landmarks of the patient 600 used in the registration at step 430 may be, for example, three. Preferably, the landmarks of the patient 600 used in the registration at step 430 may be sampled from different parts of the patient 600, and not all landmarks are located in the same area. For example, three landmark points all located at the front teeth of the patient 600 may not be sufficient to provide accurate registration across the entire modeling region. For example, if after estimating the confidence of the determined landmark points of the patient 600 at optional step 412, fewer than three reliable landmark points are found and / or if there are no reliable landmark points outside the central tooth region, the control system 106 can generate an indication to the operator of the dental X-ray imaging unit 102 to manually input one or more missing head landmark points of the patient 600 via one or more user interface devices.

[0073] At step 420, the control system 106 may select a plurality of atlas landmarks included in the dental atlas data 1116. For example, the plurality of selected atlas landmarks may correspond to the plurality of head landmarks 502, 504, 506, 508, 510, 512 of the patient 600 determined at step 410 discussed above. In other words, the number of the plurality of head landmarks 502, 504, 506, 508, 510, 512 of the patient 600 is the same as the number of atlas landmarks. This enables point-based pairwise registration at step 430. In the pairwise registration for each head landmark 502, 504, 506, 508, 510, 512 of the patient 600, exactly one atlas landmark corresponds to the same anatomical location. As discussed above, at least some of the detected plurality of head landmarks 502, 504, 506, 508, 510, 512 of the patient 600 may be marked as invalid landmarks and removed. In this case, the control system 106 may select only their corresponding counterparts from the dental atlas data 1116 among the valid landmarks. Figure 4In the embodiment, step 410 is presented before step 420, but step 420 may also be performed before or at the same time as step 410. In other words, the control system 106 may first select a plurality of atlas landmarks included in the dental atlas data 1116. Then, the control system 106 may determine a plurality of head landmarks 502, 504, 506, 508, 510, 512 of the patient 600, wherein the plurality of head landmarks of the patient 600 correspond to the selected plurality of atlas landmarks.

[0074] At step 430, the control system 106 may register (i.e., align) a plurality of atlas landmarks and a plurality of head landmarks 502, 504, 506, 508, 510, 512 of the patient 600 to determine aligned dental atlas data of the patient 600, i.e., the atlas anatomical data of the dental atlas data 1116 is aligned with the patient 600. The control system 106 may, for example, perform a point-based pairwise registration transformation between the plurality of head landmarks 502, 504, 506, 508, 510, 512 of the patient 600 and a plurality of corresponding atlas landmarks. Alternatively, the point-based registration transformation may be performed without pairing. The aligned dental atlas data of the patient 600 may, for example, include a patient-specific anatomical model representing an estimate of the anatomical structure of the patient 600. As already discussed above, the aligned dental atlas data may include at least the atlas anatomical data aligned with the patient 600. For example, the aligned dental atlas data may include estimated locations of anatomical structures of the patient 600, such as one or more individual teeth, a group of teeth, dental arches (maxillary and / or mandibular), (bilateral) TMJ, (bilateral) mandibular head, submental point, mental notch, nasal spine, (bilateral) tragus, (bilateral) external auditory canal, (multiple) sinuses, (two) orbits, and / or any other anatomically relevant structures. The control system 106 may further align the atlas imaging data with the patient 600 at step 430. Thus, the aligned dental atlas data of the patient 600 may further include atlas imaging data aligned with the patient 600. For example, the control system 106 may further define one or more possible ROI locations in the anatomical model of the patient 600 based on the atlas ROI data included in the dental atlas data 116. Thus, the determined aligned dental atlas data may further include one or more possible ROI locations in the anatomical model of the patient 600. . Alternatively or additionally, in the case of panoramic imaging, at step 430, the control system 106 may further define initial scan trajectory data based on atlas scan trajectory data included in the dental atlas data 1116. Thus, the determined aligned dental atlas data of the patient 600 may further include the defined initial scan trajectory data.

[0075] The dental atlas data 1116 and the multiple head landmarks 502, 504, 506, 508, 510, 512 of the patient 600 can be presented in different coordinate systems. For example, the multiple atlas landmarks, atlas ROI data and / or atlas scanning trajectory data included in the dental atlas data 1116 can be presented in the atlas coordinate system. The multiple head landmarks of the patient 600 can be presented, for example, in an imaging device coordinate system (e.g., an imaging device coordinate system of a single imaging device, a base coordinate system (e.g., a main imaging device coordinate system or a coordinate system of the dental X-ray imaging unit 102 as discussed above), or any other known coordinate system). The atlas coordinates and the imaging device coordinates can be 2D coordinates, 3D coordinates and / or 4D coordinates. Preferably, the atlas coordinates and the imaging device coordinates are 3D coordinates. In other words, in step 430, the control system 106 can register the dental atlas data 1116 presented in the atlas coordinate system to the imaging device coordinate system by using a registration transformation. The registration transformation can be any type of transformation, such as but not limited to a rigid body transformation, a rigid body transformation with isotropic scaling, a rigid body transformation with anisotropic scaling, an affine transformation, a perspective transformation, or any other linear transformation, or any nonlinear or deformable transformation. Additionally, if necessary, a regularization term can be used in combination with some transformations to guide the transformation to be constrained by a physically more likely solution. In some special cases, there is indeed an analytical solution (e.g., a paired point-based registration with some transformations). Otherwise, iterative minimization can be used. In iterative minimization, any minimization algorithm can be used. Registration can be defined as a minimization problem in which a cost function is minimized. For example, in the case where the registration problem is expressed as similarity maximization, the similarity value can be negated (with a negative sign) to express it as a minimization problem. Preferably, a transformation that minimizes the residual registration error can be used. After registration, the residual registration error (e.g., the final distance between the registration points) can be known. The residual registration error indicates the accuracy of the registration. For an accurate registration, a small residual error can be expected, while a large total residual error or a large individual error at a single point can generally indicate an inaccurate registration result. Therefore, the accuracy of the registration can be evaluated based on the residual registration error. According to an example, if the residual registration error exceeds a threshold, it can be assumed that the registration is too inaccurate, and the control system 106 can generate an auxiliary request for manually entering one or more landmark points of the patient 600 to an operator of the dental X-ray imaging unit 102 via one or more user interface devices (e.g., via the user interface device 140a).For example, the control system 106 may define one or more possible ROI positions in the anatomical model included in the aligned dental atlas data by using a registration transformation at step 430, for example, the control system 106 may transform one or more possible ROI positions indicated in the atlas ROI data into imaging device coordinates to define one or more possible ROI positions in the anatomical model included in the aligned dental atlas data. After transforming the atlas ROI data (i.e., one or more possible ROI positions) into imaging device coordinates, the one or more possible ROI positions are known in the imaging device coordinates. Therefore, the one or more possible ROI positions in the anatomical model included in the aligned dental atlas data are also known. For example, in the case of CT imaging, the control system 106 may convert one or more possible FOV positions indicated in the atlas ROI data into imaging device coordinates to define one or more possible FOV positions in the anatomical model of the patient 600 included in the aligned dental atlas data. Alternatively or additionally, in the case of panoramic imaging, the control system 106 may further define initial scanning trajectory data based on the atlas scanning trajectory data by using a registration transformation at step 430, for example, the control system 106 may transform at least one scanning trajectory indicated in the atlas scanning trajectory data included in the dental atlas data 1116 into imaging device coordinates to define initial scanning trajectory data included in the aligned dental atlas data.

[0076] As discussed above, after determining the aligned dental atlas data of the patient 600, the control system 106 may define the ROI position at step 230 based on the ROI data and the aligned dental atlas data of the patient 600 determined more. The ROI data included in the scan request may indicate a target ROI. The target ROI corresponds to a possible ROI position in the aligned dental atlas data included in the aligned dental atlas data. Therefore, the control system 106 may define the ROI position to be the one possible ROI position corresponding to the target ROI. For example, if the target ROI is a single tooth, the control system 106 may define the ROI position to be the position of the single tooth in the anatomical model included in the aligned dental atlas data. Since the ROI position is defined in the dental arch model included in the aligned dental atlas data, the ROI position is presented in the imaging device coordinates. For example, in the case of CT imaging, the control system 106 may define the FOV position to be the FOV position in the anatomical model included in the aligned dental atlas data, which corresponds to the target FOV indicated in the ROI data. In the case of CT imaging, the definition of the ROI position may further include defining a center point of the defined ROI position, i.e., the ROI center, such as the FOV center. According to a non-limiting example, if the target ROI includes a single structure, such as a single tooth, the control system 106 may define the ROI center to be the center of the single structure. According to another non-limiting example, if the target ROI includes multiple structures, such as a group of teeth, the control system 106 may define the ROI center to be the center of multiple structures. Alternatively or additionally, in the case of CT imaging, the control system 106 may be further configured to adjust the size of the FOV based on the determined aligned dental atlas data of the patient 600. In CT imaging, the FOV may preferably have a cylindrical shape. Therefore, adjusting the size of the FOV based on the determined aligned dental atlas data of the patient 600 may include adjusting the height and / or radius of the cylindrical FOV. Since the determined aligned dental atlas data of the patient 600 enables reliable estimation of the anatomical structure of the patient 600 and determination of the FOV position, the size of the FOV may be reduced so that the target FOV indicated in the ROI data is still within the reduced FOV. A smaller FOV enables a smaller radiation dose to the patient 600 and a smaller amount of acquired X-ray image data, which in turn results in faster processing of the acquired X-ray image data. For example, in the case of panoramic imaging, the control system 106 can define the position of the imaging layer based on the ROI data and the determined aligned dental atlas data of the patient 600 so that it corresponds to the anatomical structure of the patient 600.

[0077] The use of the dental atlas data 1116 with the at least one optical image 105 and the at least one image analysis model 1118 enables determination of one or more dental structures of the patient 600 located inside the head of the patient 600, such as the aligned dental atlas data of the patient 600 discussed above. The use of the at least one optical image 105 and the at least one image analysis model 1118 (without the dental atlas data 1116) of the patient 600 enables determination of visible patient-related data including one or more visible structures of the patient 600. For example, the control system 106 can also determine the visible patient-related data based on the at least one optical image 105 and the at least one image analysis model 1118 of the patient 600. The visible patient-related data can, for example, include head size data of the patient 600, classification data of the patient 600, height data of the patient 600, and / or width data of the patient 600. Examples of the use of the visible patient-related data will be discussed later in this application.

[0078] After defining the ROI position at step 230 as described above, the control system 106 may further define a scanning trajectory of a portion of the dental X-ray imaging unit 102 at step 240 based on the defined ROI position, the imaging mode data, and the patient positioning data. According to an example, the defined ROI position may also include patient positioning data. Since the ROI position is defined at step 230 by using the aligned dental atlas, the defined ROI position is enabled to be substantially accurate, for example, compared to an estimate of the ROI position that is typically used in the definition of the scanning trajectory. Defining the scanning trajectory may include defining a starting position of the scanning trajectory (i.e., a starting position of the portion of the X-ray imaging unit 102 used for scanning) and / or a motion path of the scanning trajectory. The patient positioning data may include a position where the patient is positioned, such as a position where the patient 600 is supported. The patient positioning data may be defined, for example, based on the patient support components 124, 126 of the dental X-ray imaging unit 102. According to a non-limiting example, the position where the patient is positioned may be defined based on, for example, a bite block (e.g., a bite bar) arranged to the chin support component 124. Alternatively, the patient positioning data may be defined, for example, based on optical image data collected by at least one internal optical imaging device 104b of the dental X-ray imaging unit 102. The patient positioning data enables the control system 106 to know the position of the head of the patient 600, for example, the position in which the patient 600 is supported.

[0079] The motion path of the scanning trajectory may depend on the imaging mode indicated in the imaging mode data. In the case of CT imaging, the motion path of the scanning trajectory may be, for example, a circular path or a non-circular path, such as an elliptical path, around the rotation axis. The circular path or the non-circular path may be a complete rotation or a partial rotation around the rotation axis. The rotation axis may be a mechanical rotation axis or a virtual rotation axis of the gantry portion 112. The mechanical rotation axis of the gantry portion 112 may be oriented, i.e. aligned, with the defined ROI position, as will be discussed. The virtual rotation axis may be obtained, for example, by moving the mechanical rotation axis of the gantry portion 112 along a circular path, so that the virtual rotation axis may be formed in the center of the circular path. A non-circular rotation path may be generated, for example, by moving the gantry portion 112 along a motion path (e.g., an elliptical path) that deviates from the circular path. As will be appreciated by those skilled in the art or ordinary skilled in the art, other techniques or alignments for the rotation axis may also be used. In the case of panoramic imaging, the scanning trajectory may be, for example, a substantially arched path.

[0080] When the position of the head of the patient 600 is known based on the patient position data, the starting position of the scanning trajectory can be defined based on the defined ROI position. For example, in the case of symmetrical CT imaging, where the motion path of the scanning trajectory is a circular path, the starting position of the scanning trajectory can be the ROI center defined at step 230. According to another example, in the case of offset CT imaging, where the motion path of the scanning trajectory is a circular path, the starting position of the scanning trajectory can be offset by a known amount from the ROI center defined at step 230 in a known direction, that is, offset by a known offset vector. As discussed above, in the case of panoramic imaging, the aligned dental atlas data of the determined patient 600 may include initial scanning trajectory data. In the case of panoramic imaging, the scanning trajectory can be defined based on the initial scanning trajectory data. According to an example, a patient-specific scanning trajectory can be defined based on the initial scanning trajectory data. The patient-specific scanning trajectory may include the starting position of the patient-specific scanning trajectory and the motion path of the patient-specific scanning trajectory. In some cases, the patient-specific scanning trajectory may violate some basic conditions, such as the magnification is not constant over the entire dental arch because the registration transformation may not be rigid. Therefore, the defined patient-specific scan trajectory can be adjusted (i.e., changed) to ensure that the basic conditions are not violated. The patient-specific scan trajectory enables substantially the entire dental arch of the patient 600 to touch the sharp layer. According to an example, the predefined scan trajectory can be selected based on the initial scan trajectory data. The initial scan trajectory data can include a plurality of predefined scan trajectories, each predefined scan trajectory including a starting position of the predefined scan trajectory and a motion path of the predefined scan trajectory. The predefined scan trajectory that best fits the anatomical structure of the patient 600 can be selected from a plurality of predefined scan trajectories included in the initial scan trajectory data, for example, based on the minimum residual registration error in the registration transformation. The selected predefined scan trajectory is a good approximation of the patient 600, although not a perfect fit. Therefore, even if the starting position of the predefined scan trajectory is known, this may not be the best starting position. If it is not possible to achieve the best fit on the entire scan trajectory, the starting position of the predetermined scan trajectory can be preferably adjusted so that the best match can be made near the anterior teeth area, because the sharp layer is narrowest at this area. In other words, the starting position of the predefined scan trajectory can be preferably adjusted so that at least the anterior teeth area touches the sharp layer. Advantages of using the selected predefined scan trajectory may include at least that the scan trajectory and timing diagram etc. are known in advance and there are no technical or mechanical limitations to their application.

[0081] The ROI position may be presented in coordinates different from the device coordinates (i.e., in the coordinates of the dental X-ray imaging unit 102). Therefore, the control system 106 may define coordinate transformation data to determine the defined ROI position in the device coordinates, and therefore also determine the starting position of the scanning trajectory in the device coordinates. The coordinate transformation data may represent a transformation between coordinates presenting the ROI position in the device coordinates. For example, as discussed above, the ROI position defined at step 230 may be presented in the imaging device coordinates. The control system 106 may define coordinate transformation data representing the transformation between the imaging device coordinates and the device coordinates. The coordinate transformation data may, for example, include device axis orientation data in the imaging device coordinates. The device axis orientation data in the imaging device coordinates may, for example, include the Z-axis (e.g., lower-upper (IS) axis) orientation, the Y-axis (e.g., posterior-anterior (PA) axis) orientation, and the X-axis (e.g., left-right (LR) axis) orientation of the dental X-ray imaging unit 102 in the imaging device coordinates. The coordinate transformation data may be defined as a device orientation encoding and / or a device position encoding.

[0082] Fig. 6A An example of a method for defining coordinate transformation data by using device orientation coding is shown. The method can be performed by the dental X-ray imaging system 100 as discussed above. At step 610, the control system 106 can obtain at least one optical image of the dental X-ray imaging unit 102. The at least one optical image of the dental X-ray imaging unit 102 can be captured, for example, by at least one internal imaging device 104b of the dental X-ray imaging unit 102. For example, if the at least one internal imaging device 104b from which the at least one optical image of the dental X-ray imaging unit 102 is obtained is arranged in the gantry portion 112 of the dental X-ray imaging unit 102, the device orientation coding can be used. Preferably, the control system 106 can obtain at least two optical images of the dental X-ray imaging unit 102 at step 610. The at least two optical images can be captured by at least two internal imaging devices 104b of the dental X-ray imaging unit 102. The control system 106 may, for example, obtain at least one optical image of the dental X-ray imaging unit 102 from at least one internal imaging device 104 b of the dental X-ray imaging unit 102. Alternatively, the control system 106 may obtain at least one optical image of the dental X-ray imaging unit 102 from a database, in which at least one optical image of the dental X-ray imaging unit 102 captured by using at least one internal optical imaging device 104 b may be stored.

[0083] At step 620, the control system 106 may determine (i.e., extract) device orientation data by detecting at least one device coding marker arranged to the dental X-ray imaging unit 102 from at least one optical image of the dental X-ray imaging unit 102. The device orientation data may be encoded in at least one device coding marker. The control system 106 may extract the device orientation data encoded in the detected at least one coding marker. The device orientation data may be encoded in at least one device coding marker, for example, by any geometric primitive, object, or pattern formed by, for example, but not limited to, circles, dots, crosses, lines, rectangles, and / or triangles. At least one device coding marker may have a dual purpose, or it may be hidden. For example, a chessboard, a QR code, a company name and / or logo, a brand name and / or logo, a device name and / or logo may also be used as a device coding marker. At least one device coding marker may be a 2D coding marker located on a 2D plane or a 2D surface. With one 2D encoding marker, two of the three axes of the dental X-ray imaging unit 102 can be explicitly encoded, and the third axis encoding is implicit, for example defined as the cross product of the two explicitly encoded axes. For explicit encoding with 2D encoding, at least two 2D encoding markers that are not located in the same plane are required. Alternatively, at least one device encoding marker can be a 3D encoding marker. With one 3D encoding marker, all three axes of the dental X-ray imaging unit 102 can be explicitly encoded. If only one optical image of the dental X-ray imaging unit 102 is obtained, the device encoding marker needs to be a 3D device encoding marker. This makes it possible to define the orientation of all three axes of the dental X-ray imaging unit 102 using only one optical image of the dental X-ray imaging unit 102. Alternatively, the device orientation data can be determined based on two 2D device encoding markers of different orientations. In addition, this makes it possible to define the orientation of all three axes of the dental X-ray imaging unit 102 using only one optical image of the dental X-ray imaging unit 102.

[0084] At step 630, the control system 106 may determine coordinate transformation data, i.e., an X-axis orientation, a Y-axis orientation, and a Z-axis orientation of the dental X-ray imaging unit 102, based on the device orientation data determined at step 620. According to an example, the Z-axis orientation may be explicitly encoded in at least one device encoding tag. According to another example, at least one internal imaging device 104b from which at least one optical image data of the dental X-ray imaging unit is obtained may be fixed to the dental X-ray imaging unit 102 so that one side of the imaging sensor of the internal imaging device 104b is completely vertical, and thus the Z-axis orientation of the dental X-ray imaging unit 102 is defined in the imaging device coordinates. According to yet another example, the X-axis orientation and the Y-axis orientation may be explicitly encoded in at least one device encoding tag, and then the Z-axis orientation may be implicitly determined as the cross product of the X-axis orientation and the Y-axis orientation. Alternatively, the Z-axis orientation and the X-axis orientation may be explicitly encoded in at least one device encoding tag, and then the Y-axis orientation may be implicitly determined as the cross product of the Z-axis orientation and the X-axis orientation. Alternatively, the Z-axis orientation and the Y-axis orientation may be explicitly encoded in at least one device encoding flag, and the X-axis orientation may then be implicitly determined as the cross product of the Z-axis orientation and the Y-axis orientation.

[0085] Figure 6B A non-limiting example of an optical image 601 of a dental X-ray imaging unit 102 is schematically shown for extracting device orientation data and determining coordinate transformation data of the dental X-ray imaging unit 102 by using device orientation encoding. Figure 6B In the example of , the internal imaging device 104b from which the optical image 601 of the dental X-ray imaging unit 102 is obtained is arranged to the dental X-ray imaging device 102 on the right side of the patient 600, but alternatively, the internal imaging device 104b from which the optical image 601 of the dental X-ray imaging unit 102 is obtained may also be arranged to the dental X-ray imaging device 102 on the left side of the patient 600. Figure 6B In the example of , a device coding mark is arranged to the dental X-ray imaging unit 102, which is located on the same side as the internal imaging device 104b, from which the optical image 601 of the dental X-ray imaging unit 102 is obtained. The device coding mark includes three points 602, 603, 604 arranged in the chin support part 126 of the lower shelf 122 of the dental X-ray imaging unit 102. Figure 6BIn the example of , the X-axis and the Y-axis are explicitly encoded into the device coding mark. However, this is only a non-limiting example of arranging the device coding mark to the dental X-ray imaging unit 102, and at least one device coding mark can also be arranged to any other part of the dental X-ray imaging unit 102 that is rigidly attached to the upper shelf 110 of the dental X-ray imaging unit 102. The upper shelf 110 determines the device axis orientation. For example, when the upper shelf 110 does not pivot, then at least one device coding mark can be arranged to the lower shelf 112 of the dental X-ray unit 102 (e.g., as Figure 6B 102 or 104) to the support column 103 or to the upper shelf 110. Alternatively, when the upper shelf 110 pivots, at least one device coding marker needs to be arranged on the upper shelf 110 or any structure attached to the upper shelf 110. The coding markers including these points can be detected from the optical image 601. A first unit vector 605 connecting points 602 and 603 of the coding markers can define the Y-axis orientation of the dental X-ray imaging unit 102 in the imaging device coordinates. A second unit vector 606 connecting points 603 and 604 of the coding markers can define the Z-axis orientation of the dental X-ray imaging unit 102 in the imaging device coordinates. The X-axis orientation can be determined, for example, as the cross product of the Z-axis and the Y-axis.

[0086] Figure 6C A non-limiting example of two optical images 601a, 601b of a dental X-ray imaging unit 102 is schematically shown for extracting device orientation data and determining coordinate transformation data of the dental X-ray imaging unit 102 by using device orientation encoding. Figure 6C In the example of , the first internal imaging device 104b from which the optical image 106a is obtained is arranged to the dental X-ray imaging device 102 on the right side of the patient 600, and the second internal imaging device 104b from which the optical image 601b is obtained is arranged to the dental X-ray imaging device 102 on the left side of the patient 600. Figure 6CIn the example of , two device coding markers are arranged to the dental X-ray imaging unit 102, so that one device coding marker is arranged on each side of the dental X-ray imaging unit 102. The device coding marker on the right side includes three points 602R, 603R, 604R arranged in the chin support part 126 of the lower shelf 122 of the dental X-ray imaging unit 102. The device coding marker on the left side includes three points 602L, 603L, 604L arranged in the chin support part 126 of the lower shelf 122 of the dental X-ray imaging unit 102. The coding marker including these points can be detected from the two optical images 601a, 601b. The first right unit vector 605R connecting the points 602R and 603R of the coding marker on the right side can define the Y-axis orientation of the dental X-ray imaging unit 102 in the imaging device coordinates. The second right unit vector 606R connecting the points 603R and 604R of the coding mark on the right side can define the Z-axis orientation of the dental X-ray imaging unit 102 in the imaging device coordinates. The first left unit vector 605L connecting the points 602L and 603L of the coding mark on the left side can define the Y-axis orientation of the dental X-ray imaging unit 102 in the imaging device coordinates. The second left unit vector 606L connecting the points 603L and 604L of the coding mark on the left side can define the Z-axis orientation of the dental X-ray imaging unit 102 in the imaging device coordinates. For example, the X-axis orientation can be determined by connecting the same points in the left and right sides to form a line parallel to the X-axis using combined information about the two coding marks. Using two optical images to extract device orientation data enables the maximum amount of data to be provided for extraction. In addition, using two optical images to extract device orientation data enables the orientation of all three axes (i.e., the X-axis, the Y-axis, and the Z-axis) to be explicitly defined.

[0087] In device position encoding, the control system 106 may obtain at least one optical image of the dental X-ray imaging unit 102. The at least one optical image of the dental X-ray imaging unit 102 may be captured, for example, by at least one internal imaging device 104b of the dental X-ray imaging unit 102. For example, if the at least one internal imaging device 104b that obtains the at least one optical image of the dental X-ray imaging unit 102 is arranged in any portion of the dental X-ray imaging unit 102 that is rigidly attached to the upper shelf 110 of the dental X-ray imaging unit 102, device position encoding may be used. In device position encoding, at least one device position and orientation encoding marker may be arranged in the gantry portion 112 of the dental X-ray imaging unit 102. The at least one device position encoding marker may encode at least one gantry point (here defined as the gantry origin) and at least one horizontal gantry axis (e.g., the X-axis of the gantry portion 112 or the Y-axis of the gantry portion 112). The above description of at least one device orientation encoding marker also applies to at least one device position encoding marker. The vertical gantry axis (e.g., the Z axis of the gantry portion 112) can be defined according to the imaging device orientation, or it can be encoded in the device position encoding mark. After defining the vertical axis and the horizontal axis, another horizontal axis can be defined as the cross product of the defined vertical axis and the defined horizontal axis. The defined axis of the gantry portion 112 can define a gantry-specific coordinate system. The rotation center position of the gantry portion 112 in the gantry coordinate system can be defined by calibration. Any movement of the dental X-ray imaging unit 102 does not change the rotation center position of the gantry portion 112 relative to the gantry coordinate system. If at least one internal imaging device 104b from which at least one optical image of the dental X-ray imaging unit 102 is obtained is arranged in any other part of the dental X-ray imaging unit 102 except the gantry portion 112 and in any part of the upper shelf 110 rigidly attached to the dental X-ray imaging unit 102 (e.g., in the support column 103), the combination of the device orientation encoding and the device position encoding can be used to define the coordinate transformation data. Alternatively or additionally, if at least one optical image of the dental X-ray imaging unit 102 is obtained from at least one external imaging device 104a, a combination of the device orientation code and the device position code may be used to define the coordinate transformation data.

[0088] After defining the scanning trajectory at step 240 as discussed above, the control system 106 may further control the portion of the dental X-ray imaging unit 102 to scan the patient 600 according to the defined scanning trajectory at step 250 so as to acquire dental X-ray image data of the patient 600. The control system 106 may define a current position of the rotation axis of the gantry portion 112 based on calibration data of at least one imaging device 104a, 104b to the dental X-ray imaging unit 102. In order to control the gantry portion 112 of the dental X-ray imaging unit 102 to move from the current position of the rotation axis of the gantry portion 112 to the starting position of the scanning trajectory, the control system 106 may define device transformation data. The device transformation data may indicate a transformation in device coordinates required to move the rotation axis of the gantry portion 112 from the current position to the starting position. The control system 106 may be configured to control the portion of the dental X-ray imaging unit 102 to move to the starting position of the scanning trajectory (i.e., the defined ROI position) based on the defined device transformation data. The movement of the components of the dental X-ray imaging unit 102 (e.g., the gantry portion 112) can be linear and / or rotational. Thus, the rotation axis of the gantry portion 112 moves to the defined starting position of the scanning trajectory. Next, the control system 106 can control the gantry portion 112 to rotate around the rotation axis of the gantry portion 112 according to the defined motion path of the scanning trajectory.

[0089] Fig. 7A and Figure 7B A non-limiting example of moving the gantry portion 112 from a current position of a rotation axis of the gantry portion 112 to a starting position of a scanning trajectory based on device transformation data in the case of CT imaging is shown. Fig. 7A The situation of the rotation axis of the gantry portion 112 in the current position (i.e., before the movement of the gantry portion 112 is controlled) is shown. The current position of the rotation axis of the gantry portion 112 is shown by reference numeral 702, and the starting position of the scanning trajectory is shown by reference numeral 704. In this example, the device transformation data includes an X-direction transformation shown by vector 706 and a Y-direction transformation shown by vector 708. Figure 7B FIG. 1 shows a situation after the control frame part 112 is moved from the current position 702 of the rotation axis of the frame part 112 to the starting position 704 of the scanning trajectory. In other words, Figure 7BIn the case of CT imaging with offset scanning, the rotation axis of the gantry portion 112 is placed at the starting position of the scanning trajectory 704. For example, in the case of CT imaging, where the motion path is a cylindrical path, the rotation axis of the gantry portion 112 is placed in the defined FOV, that is, the rotation axis of the gantry portion 112 is parallel to the center of the defined FOV. According to another example, in the case of CT imaging with offset scanning, the rotation axis of the gantry portion 112 may be slightly offset from the center of the defined FOV, and the gantry portion 112 moves through the FOV during scanning. Therefore, in the offset scanning, the starting position of the scanning trajectory 704 is offset from the center of the defined FOV.

[0090] Figure 7C and Fig.7D A non-limiting example of moving the gantry portion 112 from a current position of a rotation axis of the gantry portion 112 to a starting position of a scanning trajectory based on device transformation data in the case of panoramic imaging is shown. Figure 7C The situation of the rotation axis of the gantry portion 112 in the current position (i.e., before the movement of the gantry portion 112 is controlled) is shown. The current position of the rotation axis of the gantry portion 112 is shown by reference numeral 710, and the starting position of the scanning trajectory is shown by reference numeral 712. In this example, the device transformation data includes an X-direction transformation shown by vector 714 and a Y-direction transformation shown by vector 716. Fig.7D FIG. 1 shows a situation after the control frame part 112 is moved from the current position 710 of the rotation axis of the frame part 112 to the starting position 712 of the scanning trajectory. In other words, Fig.7D In this case, the rotation axis of the frame part 112 is placed at the starting position of the scanning trajectory 712. Fig.7D In the example of FIG. 1 , an example of a motion path of a scanning trajectory of a mechanical rotation axis (i.e., a mechanical rotation center) of the gantry portion 112 in panoramic imaging is further illustrated by reference numeral 718. The motion path 718 of the scanning trajectory begins from a starting position 712 of the scanning trajectory. The midpoint of the motion path 718 of the scanning trajectory is illustrated by point 720, and the end points of the motion path 718 of the scanning trajectory are illustrated by points 720 and 722. In addition, since the gantry portion 112 rotates around the mechanical rotation axis of the gantry portion 112 according to the defined motion path 718 of the scanning trajectory, a virtual rotation axis of the gantry portion 112 is also formed. Fig.7D In the example of FIG. 1 , the motion path of the virtual rotation axis of the gantry portion 112 is further shown at reference numeral 724. The starting position of the motion path 724 of the virtual rotation axis of the gantry portion 112 is shown at point 726. The midpoint of the motion path 724 of the virtual rotation axis of the gantry portion 112 is shown at point 728, and the end point of the motion 724 of the virtual rotation axis of the gantry portion 112 is shown at point 730.

[0091] According to an example, the control system 106 may alternatively or additionally determine exposure (i.e., radiation) parameters for scanning the patient 600 based on the imaging mode data, the at least one optical image 105 of the patient, and the at least one image analysis model 1118. The exposure parameters may include, but are not limited to, radiation power, radiation dose, and / or radiation time, etc. In order to determine the exposure parameters, the control system 106 may first determine the head size data of the patient 600 based on the at least one optical image 105 of the patient 600 and the at least one image analysis model 1118. Then, the control system 106 may use the determined head size data of the patient 600 and the imaging mode data in determining the exposure parameters. Fig. 8A An example of a method for determining exposure parameters for a scan of a patient 600 is schematically shown.

[0092] At step 810, the control system 106 may determine a plurality of head landmarks of the patient 600 based on at least one optical image of the patient 600 and at least one image analysis model. The plurality of head landmarks of the patient 600 may, for example, correspond at least in part to the head landmarks 502, 504, 506, 508, 510 of the patient 600 defined with reference to step 410 discussed above. Alternatively or additionally, the plurality of head landmarks of the patient 600 may include any other head landmarks 802 of the patient 600. Figure 8B Schematically illustrates an example of a plurality of head landmarks 802 of a patient 600 that may be determined to define head dimension data of the patient 600. Figure 8B , only one side of the head of the patient 600 is shown, and thus a plurality of head landmarks 802 of the patient 600 on one side of the head of the patient 600 are also shown, but corresponding head landmarks 802 of the patient 600 may also be determined on the other side of the head of the patient 600. For example, at least one image analysis model 1118 (e.g., at least one ML-based model) may be used to detect a plurality of head landmarks 802 of the patient 600 from at least one optical image 105 of the patient 600. In other words, at least one optical image 105 of the patient 600 may be used as input data of at least one image analysis model 1118, and a plurality of head landmarks 802 of the patient 600 may be obtained as output data of at least one image analysis model 1118.

[0093] At step 820, the control system 106 may determine head size data for the patient 600 based on the plurality of head landmarks 802 of the patient 600 determined at step 810. The head size data may, for example, include an estimate of the head size of the patient 600. The determination of the head size data for the patient 600 may further include the use of anthropometric measurements. Through anthropometric measurements, population statistics may be known, for example, a head size may be greater than 90% of individuals in the population (e.g., adult males). The plurality of head landmarks 802 of the patient 600 may further include points for anthropometric measurements (e.g., the root of the nose, the canthus, the tragus, the chin, and / or any point that may be used in anthropometric head measurements). The head size determines the amount of tissue. The more tissue there is, the higher the exposure required.

[0094] In step 830, the control system 106 may use the head size data of the patient 600 determined in step 820 to determine the exposure parameters. For example, the head size data of the patient 600 may be used to select the value of the exposure parameter. In addition to the head size, the value of the exposure parameter may also depend on the imaging mode. As discussed above, the imaging mode is indicated in the image mode data. The exposure parameters may be based on tabulated values, for example. These tabulated values ​​may include parameters tabulated based on the imaging mode and / or the head size. There may be a single population (i.e., only the head size plays a role). Additionally, there may be different tables for different populations divided by age and / or gender. In this case, the classification data may be used to select the correct population table. The determination of the classification data of the patient 600 will be described later in this application. In addition to the tabulated values, the exposure parameters may be determined by an equation based on the head size data and optionally the classification data. There may also be different equations for different populations, and the correct equation may be selected based on the patient classification data. After determining the exposure parameters, the control system 106 may provide the determined exposure parameters via one or more user interface devices (e.g., user interface device 140a) for operator review and approval.

[0095] According to an example, at step 830, the control system 106 may also determine classification data for the patient 600, and also use the classification data in determining exposure parameters. The control system 106 may determine the classification data for the patient 600 based on at least one optical image 105 of the patient 600 and at least one image analysis model 118. The classification data may, for example, include an estimate of the age of the patient 600 and / or an estimate of the gender of the patient 600. In other words, the control system 106 may estimate the age of the patient 600 and / or the gender of the patient 600 from at least one optical image 105 of the patient 600 by using at least one image analysis model 1118 (e.g., at least one AI-based model). The estimate of the age of the patient 600 may, for example, be an estimate of an age category (e.g., a child, a teenager, an adult, or an elderly person). This optional step of determining the classification data for the patient 600 is performed at Fig. 8A In the example of , it is shown as optional step 840. Fig. 8A In the embodiment, step 820 is presented before step 840, but optional step 840 may also be performed before step 820 or simultaneously with step 820.

[0096] According to another example, the control system 106 may alternatively or additionally use the aligned dental atlas data of the patient 600 in determining the exposure parameters. The aligned dental atlas data of the patient 600 may be, for example, as described above with reference to Figure 4 The method steps 410 to 430 are defined as discussed above. This optional step of determining the aligned dental atlas data of the patient 600 is described in detail below. Fig. 8A In the example of , it is shown as optional step 850. Fig. 8A In the embodiment, steps 820 and 830 are presented before step 850, but steps 820, 830 and 840 may also be performed in any other order or simultaneously.

[0097] According to yet another example, the control system 106 may alternatively or additionally adjust the height of the portion of the dental X-ray imaging unit 102 based on at least one optical image 105 of the patient 600 and at least one image analysis model 1118. The height of the portion of the dental X-ray imaging unit 102 may be adjusted by moving the slide 101 upward or downward in the height direction Z along the support column 103 by means of a guide motor. In order to adjust the height of the portion of the dental X-ray imaging unit 102, the control system 106 may first determine the height data of the patient 600 based on at least one optical image 105 of the patient 600 and at least one image analysis model 1118. Then, the control system 106 may adjust the height of the portion of the dental X-ray imaging unit 102 using the determined height data of the patient 600. Fig.9A An example of a method for adjusting the height of components of the dental X-ray imaging unit 102 is schematically illustrated.

[0098] At step 910, the control system 106 may determine at least one head landmark of the patient 600 based on at least one optical image of the patient 600 and at least one image analysis model. At least one of the head landmarks of the patient 600 may be one of the head landmarks 502, 504, 506, 508, 510, 512, 802 of the patient 600 as defined with reference to step 410 and / or step 810 discussed above. Alternatively or additionally, the at least one head landmark of the patient 600 may be any other at least one head landmark of the patient 600. For example, the at least one head landmark of the patient 600 may be the submental point 506 of the patient 600. For example, at least one image analysis model 1118 (e.g., at least one ML-based model) may be used to detect at least one head landmark of the patient 600 from the at least one optical image 105 of the patient 600. In other words, at least one optical image 105 of the patient 600 can be used as input data of at least one image analysis model 1118, and at least one head landmark point of the patient 600 (for example, the submental point 506 of the patient 600) can be obtained as output data of at least one image analysis model 1118.

[0099] At step 920, the control system 106 may determine height data of the patient 600 based on at least one of the head landmarks of the patient 600 determined at step 910. The height data may, for example, include a height offset value (h) between at least one head landmark of the patient 600 and at least one reference height point in the dental X-ray imaging unit 102. off ) and / or the absolute distance between at least one head landmark of the patient 600 and the floor. The at least one reference height point in the dental X-ray imaging unit 102 may, for example, include the top of the chin support component 124. For example, it may be necessary to know the position of the optical imaging device configured to capture at least one optical image 105 used in this example relative to the at least one reference height point in the dental X-ray imaging unit 102 to define a height offset value between the at least one head landmark of the patient 600 and the at least one reference height point in the dental X-ray imaging unit 102. Fig. 9B An example is schematically shown, which shows a height offset value (h ) between at least one head landmark point of the patient 600 (e.g., the submental point 506 of the patient 600 in this example) and at least one reference height point in the dental X-ray imaging unit 102 (e.g., the top of the chin support component 124 in this example). off ) instance.

[0100] At step 930, the control system 106 may adjust the height of portions of the dental X-ray imaging unit 102 based on the height data of the patient 600 determined at step 920. Fig. 9B In the example of FIG. 9 , possible adjustment directions (upward and downward) of the height of the components of the dental X-ray imaging unit 102 are shown by arrows 910 .

[0101] According to yet another example, the control system 106 may alternatively or additionally reduce the risk of collision between the patient 600 and the gantry portion 112 of the dental X-ray imaging unit 102 based on at least one optical image 105 of the patient 600 and at least one image analysis model 1118 (e.g., at least one ML-based model). To reduce the risk of collision, the control system 106 may first determine width data of the patient 600 based on at least one optical image 105 of the patient 600 and at least one image analysis model 1118. Then, the control system 106 may use the determined width data of the patient 600 in reducing the risk of collision. Fig. 10A An example of a method for reducing the risk of collision between a patient 600 and the gantry portion 112 of the dental X-ray imaging unit 102 is schematically illustrated.

[0102] In step 1010, the control system 106 may determine a plurality of body landmarks 1002 of the patient 600 based on at least one optical image 105 of the patient 600 and at least one image analysis model 1118. The plurality of body landmarks 1002 may, for example, include a shoulder of the patient 600. For example, at least one image analysis model 1118 (e.g., at least one ML-based model) may be used to detect the shoulder of the patient 600 from at least one optical image 105 of the patient 600. In other words, at least one optical image 105 of the patient 600 may be used as input data of at least one image analysis model 1118, and the plurality of body landmarks 1002 of the patient 600 (e.g., the shoulder of the patient 600) may be obtained as output data of the at least one image analysis model. Fig. 10B An example of a plurality of body landmark points 1002 of the patient 600 (e.g., shoulders of the patient 600) that may be determined for defining width data of the patient 600 is schematically shown. Alternatively, at step 1010, the control system 106 may determine an extreme point of the body of the patient 600 (e.g., shoulders of the patient 600) based on at least one optical image 105 of the patient 600.

[0103] At step 1020, the control system 106 may determine width data of the patient 600 based on the plurality of body landmarks 1002 of the patient 600 or the extreme points of the body of the patient 600 determined at step 1010. The width data may, for example, include the width of the patient 600, such as the distance between the body landmarks 1002 of the patient 600, such as the distance between the shoulders of the patient 600. Fig. 10B In the example of FIG. 6 , the distance (w) between the shoulders 1002 of the patient 600 is shown.

[0104] At step 1030, the control system 106 uses the width data of the patient determined at step 1020 to reduce the risk of collision between the patient 600 and the gantry portion 112 of the dental X-ray imaging unit 102. For example, the control system 106 can use the determined width data of the patient 600 in guiding the patient 600 and / or an operator of the dental X-ray imaging unit 102 during the patient 600 entering the dental imaging unit 102 via one or more user interface devices (e.g., via a display device and / or a speaker device). The one or more user interface devices may include the user interface device 140a and / or one or more other user interface devices. For example, the guidance may include guiding the patient 600 to take a suitable grip of the handle 128 of the dental X-ray imaging unit 102. The suitable grip can be selected by using the determined width data so that the risk of collision between the patient 600 and the gantry portion 112 of the dental X-ray imaging unit 102 can be reduced.

[0105] According to yet another example, the control system 106 may alternatively or additionally generate patient position correction data for patient positioning. The patient position correction data may be generated based on at least one optical image 105 of the patient 600 and at least one image analysis model 1118. In this example, at least one optical image 105 of the patient 600 may be captured by at least one internal imaging device 104b, for example, during patient positioning. For example, the patient 600 may be initially positioned, for example, with the aid of at least one of the patient support components 124, 126, and then at least one optical image 105 of the patient 600 may be captured to generate patient position correction data. Then, the control system 106 may define the patient position correction data based on at least one optical image 105 of the patient 600 and at least one image analysis model 1118. For example, the control system 106 may determine a plurality of head landmarks of the patient 600 based on at least one optical image 105 of the patient 600 and at least one image analysis model 1118. For example, at least one image analysis model 1118 (e.g., at least one ML-based model) can be used to detect a plurality of head landmarks from at least one optical image 105 of the patient 600. In other words, at least one optical image 105 of the patient 600 can be used as input data of at least one image analysis model 1118, and a plurality of head landmarks of the patient 600 can be obtained as output data of at least one image analysis model 1118. The determined plurality of head landmarks of the patient 600 can, for example, include the head landmarks of the patient 600 described above. Figure 4 Step 410 and / or reference Fig. 8AThe control system 106 may determine the patient position correction data based on the determined multiple head landmarks of the patient 600. The patient position correction data may include an indication of one or more position errors in the patient position and / or a corresponding correction for compensating for one or more position errors in the patient position. The one or more position errors in the patient position may include, but are not limited to, head shaking, head twisting, and / or head rotation, etc., as will be described later in this application. According to an example, the control system 106 may use the determined patient position correction data in the guidance of the patient 600 and / or the operator of the dental X-ray imaging unit 102 to compensate for one or more position errors in the patient position via one or more user interface devices (e.g., via a display device and / or a speaker device). The one or more user interface devices may include the user interface device 140a and / or one or more other user interface devices. Alternatively or additionally, the control system 106 may use the patient position correction data to control components of the dental X-ray imaging unit 102 to move according to the patient position correction data to compensate for one or more position errors in the patient position.Alternatively, at least one internal imaging device 104b may be used, for example, for motion correction.

[0106] The correction of head twist and / or head shaking can be considered as the correction of out-of-plane position error correction. Next, an example of generating patient position correction data to compensate (i.e., correct) head twist is described. Assuming that the Y axis comes out from behind the nose of the patient 600, the rotation around this Y axis is the head twist. For example, the head twist can be detected based on two head landmarks at the same level on both sides of the face of the patient 600. For example, the outer corners of both eyes as two head landmarks can be used to determine the head twist. Alternatively, other two head landmarks (such as bilateral tragus) can also be used as two head landmarks to determine the twist orientation. A line can be formed between the two head landmarks, and the angle between the formed line and the reference horizontal line indicates the amount of head twist and the direction of head twist. The generated patient position correction data may include the formed line between the two head landmarks and the formed line and the angle formed between the reference horizontal line. As discussed above, the head twist can be corrected, for example, by using the generated patient position correction data in the guidance of the patient 600 and / or the operator of the dental X-ray imaging unit 102. Guidance can be, for example, but not limited to visual guidance. For example, the head distortion may be corrected after obtaining at least one optical image at step 210 discussed above, but before using the dental atlas data at step 230 discussed above. Next, an example of generating patient position correction data to compensate for head shaking is described. Assuming that the X-axis passes through the ears of the patient 600, the rotation around the X-axis is the head shaking. For example, the head shaking may be detected based on two head landmarks of the patient 600, which may depend on the imaging mode. In CT imaging, the two head landmarks may be, for example, the nose and the tragus. In panoramic imaging, the two head landmarks may be, for example, the tragus and the eye socket (e.g., the lower edge of the eye socket). A line may be formed between the two head landmarks, and the angle between the formed line and the reference horizontal line indicates the amount of head shaking and the direction of head shaking. In CT imaging, the formed line may be, for example, referred to as the Camper line. In panoramic imaging, the formed line may be, for example, referred to as the Frankfurt horizontal line (FH line). The generated patient position correction data may include a line formed between two head landmarks and an angle formed between the formed line and a reference horizontal line. As discussed above, head shaking can be corrected, for example, by using the generated patient position correction data in the guidance of the patient 600 and / or the operator of the dental X-ray imaging unit 102. Guidance can be, for example, but not limited to visual guidance. Alternatively or additionally, head shaking can be corrected by controlling the patient support components 124, 126 to move upward (in the case of downward shaking) or downward (in the case of upward shaking) until the line formed between the two head landmarks is completely horizontal (i.e., parallel to the reference horizontal line) by utilizing the generated patient position correction data.For example, head pitch can be corrected after obtaining at least one optical image at step 210 discussed above and after receiving a scan request at step 220 discussed above, but before using the dental atlas data at step 230 discussed above. The out-of-plane position error correction allows the dental atlas data 1116 to be used to determine one or more dental structures of the patient 600 located inside the head of the patient 600, such as the aligned dental atlas data of the patient 600 discussed above.

[0107] The correction of head rotation can be considered as the correction of plane rotation. Next, an example of generating patient position correction data to compensate for head rotation is described. The head rotation correction can be performed after defining the ROI position at step 230 discussed above. After defining the ROI position, the imaging plane is straight. However, the imaging plane can be rotated relative to the dental X-ray imaging unit 102. It can be assumed that the front-to-back axis (PA axis) of the patient 600 should be aligned with the front-to-back axis (PA axis) of the dental X-ray imaging unit 102, which is the main axis of the upper shelf 110 of the rack portion 112. The offset of the PA axis of the patient 600 from the PA axis of the dental X-ray imaging unit 102 can be caused by the patient 600 turning his / her head horizontally to the left or right. Assuming that there is a Z axis passing through the center of the patient's 600 head from the foot of the patient 600, the rotation around this Z axis causes the head to rotate. For example, the head rotation can be detected based on two head landmarks at the same level on both sides of the patient's 600 face. For example, the tragus, which are two head landmarks, can be used to determine head rotation. A line can be formed between the two head landmarks to determine the LR axis (from the left tragus to the right tragus) of the patient 600. After correcting for planar motion, the IS axis of the dental X-ray imaging unit 102 can be a good estimate of the IS axis of the patient 600. The IS axis and the PA axis of the dental X-ray imaging unit 102 can be known or predefined. The PA axis is orthogonal to the LR axis and the IS axis, so the PA axis of the patient 600 can be defined as the cross product of the LR axis and the IS axis. The angle between the PA axis of the patient 600 and the PA axis of the dental X-ray imaging unit 102 indicates the amount of head rotation and the direction of head rotation. The generated patient position correction data may include the angle formed between the PA axis of the patient 600 and the PA axis of the dental X-ray imaging unit 102. For example, in the case of CT imaging, where the scanning trajectory does not generally move along the PA axis, but rotates around the ROI, the head rotation can be corrected by controlling the starting rotation angle of the gantry portion 112 to rotate in a direction opposite to and equal to the angle formed between the PA axis of the patient 600 and the PA axis of the dental X-ray imaging unit 102 included in the generated patient position correction data. In the case of panoramic imaging, the head rotation can be corrected, for example, by using the generated patient position correction data in the guidance of the patient 600 and / or the operator of the dental X-ray imaging unit 102, as discussed above. The guidance can be, for example, but not limited to, visual guidance. Alternatively or additionally, in the case of panoramic imaging, the head rotation can be corrected by controlling the rotation of the PA axis of the dental X-ray imaging unit 102 so that it is aligned with the PA axis of the patient 600, for example, by pivoting the upper shelf 110 according to the angle formed between the PA axis of the patient 600 and the PA axis of the dental X-ray imaging unit 102 included in the generated patient position correction data.If the pivot point of the upper shelf 110 is different from the center of head rotation, the pivoting may result in unwanted movements in the X-axis and / or Y-axis directions relative to the head of the patient 600. These unwanted movements in the X-axis and Y-axis directions can be compensated, for example, by equal-sized opposite movements in the X-axis and Y-axis directions. Alternatively or additionally, in the case of panoramic imaging, head rotation can be corrected by defining a patient-specific scan trajectory as discussed above, because the patient-specific scan trajectory naturally takes into account whether the patient's head rotates. Alternatively or additionally, in the case of panoramic imaging, head rotation can be corrected by minimizing the rotation error at the region of the defined ROI position, for example, by manipulating (i.e., optimizing) the starting position of the scan trajectory and / or the starting rotation angle of the gantry portion 112.

[0108] Fig.11 An illustrative example of a control system 106 of a dental X-ray imaging system 100 is shown. The control system 106 may include a processor portion 1102, a data transmission portion 1104, a user interface portion 1106, and a memory portion 1108. The processor portion 1102 is configured to execute instructions initiated by a user and / or a computer program (software) and process data. The processor portion 1102 may include at least one processor. The memory portion 1108 is configured to store and maintain data. The data may be instructions, computer programs, and any data files. The memory portion 1108 may include at least one memory. The memory portion 1108 may further include at least: a data transmission application 1110 to control the data transmission portion 1104; a user interface application 1112 to control the UI portion 1106; and a computer program (code) 1114 to control the operation of the control system 106. The memory portion 1108 and the computer program 1114 together with the processor portion 1102 may enable the control system 106 to at least implement one or more method steps and / or operations of the control system 106 as described above.

[0109] The data transmission portion 1104 may be configured to send control commands to other units, such as the dental X-ray imaging unit 1102. Additionally, the data transmission portion 1104 may receive data from other units, such as the dental X-ray imaging unit 102, at least one optical imaging device 104a, 104b, the user interface portion 140b, database(s), and / or any other external unit.

[0110] The user interface (UI) portion 1106 may be configured to input control commands, receive information and / or instructions, and display information. The UI portion 1106 may include at least a display, a screen, a touch screen, at least one function key, a keyboard, a wired or wireless remote control, or any other user input and / or output device.

[0111] The computer program 1114 may be a computer program product that may be included in a tangible, non-volatile (non-transitory), computer-readable medium carrying computer program code 1114 embodied therein for use with a computer (ie, the control system 106 ).

[0112] Fig.12 An example of a method for detecting a patient ready state is schematically shown. The method can be performed by the dental X-ray system 100 discussed above. Foreign matter in the head and neck region of the patient 600 may cause artifacts in the X-ray image. Typically, the foreign matter may be an object worn by the patient 600, such as glasses, earrings, nose rings, hair accessories, necklaces, and / or any similar object. Alternatively or additionally, the foreign matter may be an erroneous protective device given by an operator of the dental X-ray imaging unit 102. For example, a thyroid protective collar may destroy a panoramic X-ray image. At step 1210, the control system 106 may obtain at least one optical image 105 of the patient 600. The at least one optical image 105 of the patient 600 may be captured by using at least one optical imaging device 104a, 104b (e.g., at least one external imaging device 104a and / or at least one internal imaging device 104b) of the dental X-ray system 102, such as similar to step 210 discussed above. At step 1220, the control system 106 may detect one or more foreign bodies based on the obtained at least one optical image 105 of the patient 600 and at least one image analysis model 1118. In other words, the control system 106 may detect one or more foreign bodies from at least one optical image 105 of the patient 600 by using at least one image analysis model 1118 (e.g., at least one AI-based model). Classification of the detected one or more foreign bodies using at least one image analysis model 1118 may be further provided. At step 1230, in response to detecting one or more foreign bodies at step 1220, the control system 106 may guide the patient 600 and / or an operator of the dental X-ray imaging unit 102 to remove the detected one or more foreign bodies via one or more user interface devices (e.g., via a display device and / or a speaker device). The one or more user interface devices may include the user interface device 140a and / or one or more other user interface devices.

[0113] Fig.13An example of a method for detecting a device ready state is schematically shown. The method may be performed by the dental X-ray system 100 discussed above. In dental X-ray imaging using a dental X-ray imaging unit 102, different device accessories may be used. The required device accessories may depend on the imaging mode. At step 1310, the control system 106 may obtain at least one optical image of the dental X-ray imaging unit 102. The at least one optical image of the dental X-ray imaging unit 102 may be captured, for example, by at least one internal imaging device 104b of the dental X-ray imaging unit 102, similar to step 610 discussed above. At step 1320, the control system 106 may receive a scan request similar to that discussed above with reference to step 220, but the scan request may further include device accessory data indicating the required device accessories. At step 1330, the control system 106 may detect one or more device accessories based on the obtained at least one optical image 105 of the patient 600 and at least one image analysis model 118. In other words, the control system 106 can detect one or more device accessories from at least one optical image 105 of the patient 600 by using at least one image analysis model 1118 (e.g., at least one AI-based model). The detected one or more device accessories can be further classified by using at least one image analysis model 1118 to identify the detected one or more device accessories, that is, whether the one or more detected device accessories belong to the required device accessories indicated in the scan request, or whether the one or more detected device accessories belong to incorrect device accessories, which are not indicated as required device accessories in the scan request. At step 1230, in response to identifying one or more incorrect device accessories, the control system 106 can guide the operator of the dental X-ray imaging unit 102 to remove and / or replace the one or more incorrect device accessories via one or more user interface devices (e.g., via a display device and / or a speaker device). The one or more user interface devices may include the user interface device 140a and / or one or more other user interface devices.

[0114] At least some aspects of the present invention described above enable reduction of imaging time, at least partially eliminate the need for scout images in CT imaging, reduce patient dose, improve patient positioning, and / or minimize the need for additional imaging.

[0115] The specific examples provided in the description given above should not be construed as limiting the applicability and / or interpretation of the appended claims.The lists and groups of examples provided in the description given above are not exhaustive unless expressly stated otherwise.

Claims

1. A dental X-ray imaging system (100) for dental X-ray imaging of a patient (600), the system (100) comprising: A dental X-ray imaging unit (102) comprising: an X-ray source part (114) for emitting X-rays, an X-ray imaging detector section (116) for receiving the X-rays from the source section (114), and a gantry portion (112) including the source portion (114) and the imaging detector portion (116), and A control system (106) configured to: obtaining at least one optical image (105) of the patient (600); receiving a scan request including region of interest (ROI) data; and The ROI location is defined based on the ROI data, the at least one optical image (105), dental atlas data (1116), and at least one image analysis model (1118) formed based on previously collected reference image data.

2. The dental X-ray imaging system (100) of claim 1, wherein the at least one optical image (105) of the patient (600) comprises at least one optical image in which a dentition of the patient (600) is at least partially visible, and wherein the control system (106) is configured to: determining a plurality of head landmarks (502, 504, 506, 508, 510, 512) of the patient (600) based on the at least one optical image (105) of the patient (600) and the at least one image analysis model (1118), selecting a plurality of atlas landmark points corresponding to the plurality of head landmark points (502, 504, 506, 508, 510, 512) of the patient (600) based on the dental atlas data (1116), and The plurality of atlas landmarks and the plurality of head landmarks (502, 504, 506, 508, 510, 512) of the patient (600) are registered to determine aligned dental atlas data of the patient (600).

3. The dental X-ray imaging system (100) of claim 2, wherein the control system (106) is configured to define the ROI position based on the ROI data and the determined aligned dental atlas data of the patient (600).

4. A dental X-ray imaging system (100) according to any of the preceding claims, wherein the control system (106) is further configured to determine exposure parameters for scanning the patient (600) based on imaging mode data further included in the scan request, the at least one optical image (105) of the patient (600) and the at least one image analysis model (1118).

5. The dental X-ray imaging system of claim 4, wherein the control system (106) is configured to: determining a plurality of head landmarks (502, 504, 506, 508, 510, 512, 802) of the patient (600) based on the at least one optical image (105) of the patient (600) and the at least one image analysis model (1118), determining head size data of the patient (600) based on the plurality of head landmarks (502, 504, 506, 508, 510, 512, 802) of the patient (600), and The head dimension data is used in determining the exposure parameters.

6. The dental X-ray imaging system according to claim 5, wherein the control system (106) is further configured to: determining classification data of the patient (600) based on the at least one optical image (105) of the patient (600) and the at least one image analysis model (1118), and The classification data is used in determining the exposure parameters.

7. The dental X-ray imaging system (100) according to any one of the preceding claims, wherein the control system (106) is further configured to: determining at least one head landmark (502, 504, 506, 508, 510, 512, 802) of the patient (600) based on the at least one optical image (105) of the patient (600) and the at least one image analysis model (1118), determining height data of the patient (600) based on the at least one head landmark (502, 504, 506, 508, 510, 512, 802) of the patient (600), and The determined height data is used to adjust the height of a portion of the dental X-ray imaging unit (102).

8. The dental X-ray imaging system (100) according to any one of the preceding claims, wherein the control system (106) is further configured to: determining a plurality of body landmarks (1002) of the patient (600) based on the at least one optical image (105) of the patient (600) and the at least one image analysis model (1118), determining width data of the patient (600) based on the plurality of body landmarks (1102) of the patient (600), and The determined width data is used to reduce the risk of collision between the patient (600) and the gantry portion (112) of the dental X-ray imaging unit (102).

9. A dental X-ray imaging system (100) according to any one of the preceding claims, comprising at least one optical imaging device (104a, 104b), wherein the at least one optical imaging device is configured to capture the at least one optical image (105) of the patient (600).

10. The dental X-ray imaging system (100) of any one of the preceding claims, wherein the ROI data includes an indication of at least one of: a single tooth, a group of teeth, a dental arch, two dental arches, a temporomandibular joint (TMJ), the entire dentition, and bilateral TMJs.

11. A dental X-ray imaging system (100) according to any of the preceding claims, wherein the control system (100) is further configured to generate patient position correction data for patient positioning based on the at least one optical image (105) of the patient (600) and the at least one image analysis model (1118).

12. A method for dental imaging, the method being performed by the X-ray dental imaging system (100) according to any one of the preceding claims, wherein the method comprises: obtaining (210) at least one optical image (105) of the patient (600); receiving (220) a scan request including region of interest (ROI) data; as well as A ROI location is defined (230) based on the ROI data, the at least one optical image (105), dental atlas data (1116), and at least one image analysis model (1118) formed based on previously collected reference image data.

13. A computer program (1114) comprising instructions which, when said program (1114) is executed by a computer, cause said computer to perform the method according to claim 12.

14. A tangible non-transitory computer readable medium comprising instructions which, when executed by a computer, cause the computer to perform the method of claim 12.

15. A method for determining aligned dental atlas data of a patient (600), the method comprising: obtaining (210) at least one optical image (105) of the patient (600), wherein the dentition of the patient (600) is at least partially visible; determining (410) a plurality of head landmarks (502, 504, 506, 508, 510, 512) of the patient (600) based on the at least one optical image (105) of the patient (600) and at least one image analysis model (1118) formed based on previously collected reference image data; selecting (420) a plurality of atlas landmark points corresponding to the plurality of head landmark points (502, 504, 506, 508, 510, 512) of the patient (600) based on the dental atlas data (1116); as well as The plurality of atlas landmarks and the plurality of head landmarks (502, 504, 506, 508, 510, 512) of the patient (600) are registered (430) to determine the aligned dental atlas data of the patient (600).

16. A computer program (1114) comprising instructions which, when said program (1114) is executed by a computer, cause said computer to perform the method according to claim 15.

17. A tangible non-transitory computer readable medium comprising instructions which, when executed by a computer, cause the computer to perform the method of claim 15.

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