Solution for dental x-ray imaging of a patient

Abstract

To provide a dental X-ray imaging system for dental X-ray imaging of a patient.SOLUTION: The system comprises a dental x-ray imaging unit comprising an x-ray source portion, an x-ray imaging detector portion comprising an x-ray detector, and a gantry portion comprising the x-ray source portion and the x-ray imaging detector portion, and a control system. The control system controls the part of the dental x-ray imaging unit to acquire an x-ray scout image by using a first part of the active area of the x-ray detector, and controls the part of the dental x-ray imaging unit to acquire panoramic dental x-ray image data by using a second part of the active area of the x-ray detector corresponding to panoramic imaging. The first portion of the active area is larger than the second portion. The invention also relates to a panoramic dental X-ray imaging method, a computer program and a computer-readable medium.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates generally to the technical field of dental x-ray imaging. In particular, the present invention relates to panoramic dental x-ray imaging. [Background technology]

[0002] Typically, correct patient positioning can be one of the most time-consuming tasks of a user, e.g., an operator, of a dental x-ray imaging unit in a dental x-ray imaging process, but it can also be one of the most important tasks. Particularly in panoramic imaging, correct patient positioning is important with respect to the quality of the resulting dental x-ray images. Incorrect patient positioning can result in suboptimal image quality and / or additional x-ray imaging of the patient.

[0003] Traditionally, patients can be positioned relative to a dental X-ray imaging unit using various support methods that are intended to keep the patient's head as still as possible. Traditional support means can be chin rests, static bite sticks, and head supports, in which the forehead, temples, and / or back of the skull are supported. In addition, different types of straps can be used to make the patient's positioning as rigid as possible. In addition, some dental X-ray imaging units have such bite sticks attached to the dental X-ray imaging unit such that the attachment means allows movement of the bite stick in several directions.

[0004] One approach that can also be considered conventional is the use of scout images, which are low-dose projection images that can be used as a targeting aid for panoramic images.

[0005] Furthermore, in panoramic imaging, the patient's anatomy is typically unknown before taking the panoramic image. The quality of the panoramic image is heavily influenced by how well the predefined imaging layers correspond to the patient's actual anatomy, such as the dental arch. Typically, an average shape is used for all patients, which can lead to suboptimal image quality. Summary of the Invention [Problem to be solved by the invention]

[0006] The following presents a simplified summary in order to provide a basic understanding of some aspects of various invention embodiments. This summary is not an extensive overview of the invention. It is not intended to identify key or critical elements of the invention or to delineate the scope of the invention. The following summary merely presents some concepts of the invention in a simplified form as a prelude to a more detailed description of example embodiments of the invention.

[0007] It is an object of the present invention to provide a dental x-ray imaging system, method, computer program, and computer readable medium for dental x-ray imaging 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 that improves the quality of panoramic dental x-ray images.

[0008] The object of the invention is 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. [Means for solving the problem]

[0009] According to a first aspect, there is provided a dental X-ray imaging system for dental X-ray imaging of a patient, the system comprising: a dental X-ray imaging unit comprising: an X-ray source portion that emits an X-ray beam; an X-ray imaging detector portion that has one X-ray detector for receiving the X-ray beam from the X-ray source portion; and a gantry portion that has the X-ray source portion and the X-ray imaging detector portion; and a control system configured to control the portion of the dental X-ray imaging unit to acquire an X-ray scout image of the patient by using a first portion of an active area of ​​the X-ray detector, and to control the portion of the dental X-ray imaging unit to acquire panoramic dental X-ray image data of the patient by using a second portion of the active area of ​​the X-ray detector that corresponds to panoramic imaging, wherein the first portion of the active area is larger than the second portion of the active area.

[0010] The first portion of the active area of ​​the X-ray detector may include the entire active area of ​​the X-ray detector.

[0011] Controlling the portion of the dental x-ray imaging unit to obtain the x-ray scout image may include controlling a collimator of the x-ray source portion to collimate the x-ray beam into a cone beam.

[0012] Alternatively or additionally, controlling a portion of the dental X-ray imaging unit to acquire the panoramic dental X-ray image data may include controlling a collimator of the X-ray source portion to collimate the X-ray beam into a narrow beam.

[0013] The control system may be configured to determine the patient's dental arch data based on the x-ray scout image.

[0014] The control system may be further configured to control parts of the dental x-ray imaging unit to acquire panoramic dental x-ray image data of the patient according to the determined dental arch data.

[0015] Determining the dental arch data may include the control system being configured to detect a plurality of anatomical structures of the patient from the X-ray scout image, determine positions of the plurality of anatomical structures of the patient, and determine the dental arch data of the patient based on the determined positions of the detected plurality of anatomical structures of the patient.

[0016] The control system may be configured to apply the at least one trained detection model to detect a plurality of anatomical structures of the patient from the X-ray scout image.

[0017] The at least one trained detection model may be a machine learning (ML) model or an artificial intelligence (AI) model.

[0018] The control system may be configured to determine the positions of multiple anatomical structures of the patient by utilizing the atlas data.

[0019] The control system may be further configured to detect at least one patient position error based on a plurality of anatomical structures of the patient and determine patient position correction data for correcting the at least one patient position error.

[0020] The control system may be configured to perform at least one of the following: use the patient position correction data when controlling portions of the dental X-ray imaging unit to acquire panoramic dental X-ray image data of the patient; generate guidance to the patient and / or an operator of the dental X-ray imaging system based on the patient position correction data; use the patient position correction data to minimize the effect of at least one patient position error.

[0021] According to a second aspect, there is provided a method for panoramic dental X-ray imaging of a patient, the method being implemented by the X-ray dental imaging system described above, the method including: controlling a portion of the dental X-ray imaging unit to acquire an X-ray scout image of the patient by using a first portion of an active area of ​​the X-ray detector; and controlling a portion of the dental X-ray imaging unit to acquire panoramic dental X-ray image data of the patient by using a second portion of the active area of ​​the X-ray detector corresponding to the panoramic imaging, wherein the first portion of the active area is larger than the second portion of the active area.

[0022] According to a third aspect, there is provided a computer program comprising instructions which, when the program is executed by an X-ray dental imaging system as above, cause the X-ray dental imaging system to perform a method as above.

[0023] According to a fourth aspect, there is provided a tangible, non-volatile computer readable medium comprising instructions that, when executed by an X-ray dental imaging system as described above, cause the X-ray dental imaging system to perform a method as described above.

[0024] Various exemplary and non-limiting embodiments of the present invention, both as to structure and method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific exemplary and non-limiting embodiments when read in connection with the accompanying drawings.

[0025] The verbs "comprise" and "include" are used herein as open qualifiers that do not exclude or require the presence of unrecited features. Features recited in dependent claims are mutually freely combinable unless otherwise stated. Furthermore, throughout this specification, the use of "a" or "an", i.e., the singular, is to be understood as not excluding the plural. [Brief explanation of the drawings]

[0026] Embodiments of the present invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings.

[0027] [Figure 1] 1 schematically illustrates an example of a dental x-ray imaging system for dental x-ray imaging of a patient. [Figure 2] 1 illustrates generally one example of a method for dental x-ray imaging of a patient. [Figure 3A] 1 schematically illustrates an example of lateral orientation (LAT) imaging of a patient to obtain an X-ray scout image of the patient. [Figure 3B] 1 schematically illustrates an example of a LAT X-ray scout image of a patient. [Figure 3C] 1 schematically illustrates a non-limiting example of a first portion of an active area of ​​an X-ray detector used to acquire an X-ray scout image. [Figure 3D] 10 schematically illustrates a non-limiting example of a second portion of an active area of ​​an X-ray detector used to acquire panoramic dental X-ray image data. [Figure 4] 10A and 10B illustrate generally an example of method steps for determining dental arch data. [Figure 5] 10A and 10B schematically illustrate one example of a non-limiting example of landmarks intended to detect anatomical structures of a patient from an X-ray scout image. [Figure 6] 10 illustrates generally one example of method steps for correcting at least one patient position error. [Figure 7] 1 illustrates schematically an example of a control system for a dental x-ray imaging system. DETAILED DESCRIPTION OF THE INVENTION

[0028] In this specification, the following vocabulary is used for the different stages of the dental X-ray imaging process: The term radiation simply refers to the stage involving irradiation, i.e., the stage in which an X-ray source provides an X-ray beam that passes through the object to an X-ray imaging detector. The object can be expected to remain as stationary as possible, i.e., immobile, during radiation. One or more parts of the dental X-ray imaging unit may move during radiation. The term scanning, in turn, refers to the stage involving radiation 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 location to provide an X-ray image. The term imaging refers to the entire process, including radiation, scanning, and positioning.

[0029] FIG. 1 illustrates an example of a dental X-ray imaging system 100 for dental X-ray imaging of an object (for clarity, the object is not shown in FIG. 1 ). The imaging system 100 includes a dental X-ray imaging unit 102 for acquiring X-ray image data from an object, such as a patient 300 or a calibration target, during dental X-ray imaging, e.g., 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 may be electrically and / or communicatively coupled to the dental X-ray imaging unit 102. The control system 106 may be implemented as a standalone unit or as a distributed control environment among multiple standalone units providing distributed control resources. Preferably, the control system 106 may be an embedded computer. The control system 106 may comprise, for example, a control unit of the dental X-ray imaging unit 102. The control system 106 may further comprise a computing unit (e.g., a cloud 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 proximate to the dental X-ray imaging unit 102, or the control unit of the dental X-ray imaging unit 102 may be embedded within the dental X-ray imaging unit 102. The X-ray imaging unit 102 may further comprise one or more user interfaces 130, for example, display(s), screen(s), and / or touchscreen(s).

[0030] The dental x-ray imaging unit 102 may be configured to perform different types of imaging procedures (i.e., imaging modes), including, but not limited to, computed tomography (CT) imaging and / or panoramic imaging. The CT imaging may be cone-beam CT (CBCT) imaging or any other type of CT imaging. The CT imaging provides (i.e., generates) x-ray image data for the reconstruction (i.e., formation) of a 3D volume from at least a portion of an imaged object. The panoramic imaging may be, for example, standard panoramic imaging, pediatric panoramic imaging, orthozonal panoramic imaging, wide-arch panoramic imaging, orthogonal panoramic imaging, etc. The panoramic imaging provides x-ray image data for the reconstruction of a panoramic 2D image. Alternatively or additionally, the dental x-ray imaging unit 102 may be configured to perform cephalometric imaging if the dental x-ray imaging unit 102 is equipped with the necessary components for cephalometric imaging. The cephalometric imaging may be, for example, pediatric lateral cephalometric projection, lateral cephalometric projection, anterior-posterior cephalometric projection, etc. The cephalometric imaging provides x-ray image data for the formation of a cephalometric 2D image. FIG. 1 illustrates only one example of a dental x-ray imaging unit 102 for use with the concepts of the present disclosure.

[0031] The dental X-ray imaging unit 102 includes a carriage portion 101 that can be movably supported on a support column 103. The carriage portion 101 can be moved up and down in a height, i.e., vertical direction (V), by a guide motor (not shown in FIG. 1 ) configured to move the carriage portion 101 up and down in the height direction along the support column 103. The upper shelf 110 is configured to support a gantry portion, i.e., a rotating portion 112, that can rotate in a horizontal plane relative to the upper shelf 110. The upper shelf 110 and / or the gantry portion 112 can include a rotation motor (not shown in FIG. 1 ) configured to rotate the gantry portion 112. Alternatively or additionally, the upper shelf 110 can include a pivot motor (not shown in FIG. 1 ) configured to pivot the upper shelf 110 about the support column 103. Alternatively or additionally, the upper shelf 110 and / or the gantry portion 112 may comprise at least one linear motor (not shown in FIG. 1) configured to provide linear movement(s). Alternatively or additionally, the dental x-ray imaging unit 102 may be mounted to a support structure (not shown in FIG. 1), illustratively a wall, so as to be supported by support columns 103.

[0032] The dental X-ray imaging unit 102 further includes an X-ray source portion 114 and an X-ray imaging detector portion 116 used in acquiring X-ray image data. The gantry portion 112 embodies and supports the source portion 114 and the imaging detector portion 116. The gantry portion 112 may have substantially the shape of the letter C, as shown in FIG. 1 , in which case the source portion 114 may be attached to one end of the gantry portion 112 and the imaging detector portion 116 may be attached to the other end of the gantry portion 112, such that the source portion 114 and the imaging detector portion 116 face each other. The X-ray source portion 114 includes an X-ray source that emits X-rays (i.e., generates an X-ray beam) through an object being imaged, e.g., the head of a patient 300, to the X-ray imaging detector portion 116, which includes an 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 being X-rayed, i.e., imaged.

[0033] The dental X-ray imaging unit 102 also includes a collimator (not shown in FIG. 1 ) for the X-ray source portion 114 to limit and / or shape the X-ray beam. The X-rays pass through a portion of the object, such as a patient's anatomical structure, e.g., 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 produce digitized output, i.e., X-ray image data, representing the X-rays not absorbed in at least one X-ray detector. The collection of digitized outputs from the X-ray imaging detector portion 116 corresponding to a single emission of the beam of X-rays from the X-ray source portion 114 may be referred to as a projection image of the object being imaged, e.g., the patient's head.

[0034] Furthermore, the dental X-ray imaging unit 102 may include patient support portions 124, 126 (presented in FIG. 1 , but not necessarily so) that can be used to support the patient 300 during CT or panoramic imaging. The patient support portions 124, 126 may include a chin support portion 124 and / or a head support portion 126. The chin support portion 124 may support the tip of the patient's chin, and the head support portion 126 may support the patient's forehead or temples. The dental X-ray imaging unit 102 may include a lower shelf 122 extending from the carriage portion 101. The lower shelf 122 may include the chin support portion 124, as in the exemplary dental X-ray imaging unit 102 of FIG. 1 . The head support portion 126 may extend from the upper shelf 110 through the gantry portion 112, as in the exemplary dental X-ray imaging unit 102 of FIG. 1 . Alternatively, the lower shelf 122 may also include the head support portion 126. The patient support portions, i.e., the chin support portion 124 and / or the head support portion 126, may be optional, and positioning of the patient 300 may be performed in other manners. The dental X-ray imaging unit 102 may further include a handle 128 for the patient to grasp. The dental X-ray imaging unit 102 may further include, for example, a bite block, e.g., a bite stick (not shown in FIG. 1 ), disposed on the chin support portion 124.

[0035] The gantry portion 112 may be rotated by, for example, a rotational motor. 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 a rotation axis along a motion path. As the X-ray source portion 114 and the X-ray imaging detector portion 116 rotate around the object, for example, the head of the patient 300, the X-ray imaging device 102 operates to acquire multiple projection images of the object taken at incremental rotation angles. A dental X-ray image may be formed from the multiple projection images by reconstructing the X-ray image data into a dental X-ray image.

[0036] At least some exemplary embodiments of a method for panoramic dental x-ray imaging of an object, e.g., a patient 300, will now be defined with reference to Figure 2, which illustrates the method as a flow chart. The method is performed by the dental x-ray system 100 discussed above.

[0037] In step 210, the control system 106 controls the dental X-ray imaging unit 102 to acquire an X-ray scout image 302 of the patient 300 by using a first portion 320 of the X-ray detector active area 310 of the X-ray imaging detector portion 116. Typically, the X-ray detector active area 310 has a square or rectangular shape. The first portion 320 of the X-ray detector active area 310 may include the entire X-ray detector active area 310. This allows for as large a size of the X-ray scout image 302 as possible. Alternatively, the first portion 320 of the active area 310 may include only a portion of the X-ray detector active area 310. The size of the first portion 320 of the active area 310 used to acquire the X-ray scout image 302 may vary depending on the desired size of the X-ray scout image 302. The larger the size of the X-ray scout image 302, the larger the area in which the anatomical structures of the patient 300 can be detected from the X-ray scout image 302. Controlling the portions of the dental X-ray imaging unit 102 by the control system 106 to acquire the X-ray scout image 302 may include controlling a collimator of the X-ray source portion 114 to collimate (i.e., limit and / or shape) the X-ray beam into a cone beam. In other words, controlling the portions of the dental X-ray imaging unit 102 by the control system 106 to acquire the X-ray scout image 302 may include controlling the collimator of the X-ray source portion 114 such that the cone beam is collimated on the first portion 320 of the X-ray detector active area 310 of the X-ray imaging detector portion 116. The cone beam may have, for example, a cone shape or a pyramid shape. The X-ray scout image 302 is a two-dimensional (2D) X-ray projection image. Preferably, the X-ray scout image 302 may be a lateral axial (LAT) X-ray scout image, i.e., a lateral viewing angle X-ray scout image of the patient. Figure 3A schematically illustrates an example of lateral imaging of the patient 300 to obtain the X-ray scout image 302 of the patient 300. Figure 3B schematically illustrates an example of the X-ray scout image 302 of the patient 300 obtained by lateral imaging. The exemplary X-ray scout image 302 of Figure 3B is a LAT X-ray scout image.3C schematically illustrates a non-limiting example of a first portion 320 of the X-ray detector active area 310 used to acquire the X-ray scout image 302. In the example of FIG. 3C, the first portion 320 of the active area 310 includes a portion of the X-ray detector active area 310. However, the first portion 320 of the active area 310 may include the entire X-ray detector active area 310, as discussed above.

[0038] In step 220, the control system 106 controls the portion of the dental X-ray imaging unit 102 to acquire panoramic dental X-ray image data of the patient 300 by using a second portion 330 of the X-ray detector active area 310 of the X-ray imaging detector portion 116 corresponding to panoramic imaging. In other words, the control system 106 controls the portion of the dental X-ray imaging unit 102 to acquire panoramic dental X-ray image data by using the same X-ray detector of the X-ray imaging detector portion 116 used to acquire the X-ray scout image 302 in step 210. The first portion 320 of the X-ray detector active area 310 is larger than the second portion 330 of the X-ray detector active area 310. In other words, the X-ray detector active area used to acquire the X-ray scout image 302 (i.e., the first portion 320 of the active area 310) is larger than the X-ray detector active area used to acquire the panoramic dental X-ray image data (i.e., the second portion 330 of the active area 310). Because the second portion 330 of the X-ray detector active area 310 corresponds to panoramic imaging, the second portion 330 of the X-ray detector active area 310 includes a narrow linear region. The narrow linear region is preferably a narrow vertical linear region. In other words, the horizontal dimension of the second portion 330 of the active area 310 is substantially smaller than the vertical dimension of the second portion 330 of the active area 310. Controlling the portion of the dental X-ray imaging unit 102 to acquire the panoramic dental X-ray image data may include controlling the collimator of the X-ray source portion 114 to collimate (i.e., limit and / or shape) the X-ray beam into a narrow beam. The narrow beam is preferably a narrow vertical beam. In other words, controlling the portion of the dental X-ray imaging unit 102 to acquire the panoramic dental X-ray image data may include controlling the collimator of the X-ray source portion 114 so that the narrow beam is collimated on the second portion 330 of the X-ray detector active area 310 of the X-ray imaging detector portion 116. FIG. 3D schematically illustrates a non-limiting example of a second portion 330 of an active area 310 of an X-ray detector used to acquire panoramic dental X-ray image data.

[0039] Using a first portion 320 of the X-ray detector active area 310 (larger than the X-ray detector active area used to acquire the panoramic dental X-ray image data) for acquisition of the X-ray scout image 302 enables acquisition of a single large X-ray scout image 302 for use in panoramic dental X-ray imaging. In particular, if the first portion 320 of the active area 310 includes the entire X-ray detector active area 310, the size of the X-ray scout image 302 can be maximized. Typically, in panoramic dental X-ray imaging, multiple X-ray scout images are acquired by using the X-ray detector active area for panoramic imaging or by using a separate panoramic X-ray detector that is a narrow linear detector with a narrow linear active area.

[0040] The control system 106 may determine dental arch data for the patient 300 based on the x-ray scout image acquired in step 210. Figure 4 illustrates generally one example of method steps for determining dental arch data based on an x-ray scout image 302.

[0041] In step 410, the control system 106 may detect multiple anatomical structures of the patient 300 from the X-ray scout image 302. The control system 106 may detect multiple anatomical structures of the patient from the X-ray scout image 302 by using automatic detection. The automatic detection includes applying at least one trained detection model 716 to the X-ray scout image 302. In other words, the control system 106 may detect multiple anatomical structures of the patient from the X-ray scout image 302 by applying the at least one trained detection model 716. The X-ray scout image 302 is used as input data for the at least one trained detection model 716, and the multiple anatomical structures of the patient are obtained as output data of the at least one trained detection model 716. Detecting multiple anatomical structures of the patient 300 means that the multiple anatomical structures are located, i.e., their spatial locations within the X-ray scout image 302 are defined, and their identification information (e.g., label names) is defined.

[0042] At least one trained detection model 716 may be formed by using training data. Training the at least one detection model 716 may preferably be supervised training, i.e., supervised learning, although other training paradigms, such as unsupervised learning, reinforcement learning, or a hybrid paradigm including two or more training paradigms, may be used. In supervised training, the training data includes input training data and output training data. The input training data may include, for example, a plurality of X-ray scout images. The plurality of X-ray scout images included in the input training data may include, for example, previously acquired X-ray scout images. The previously acquired X-ray scout images may preferably include X-ray scout images of a patient. Alternatively or in addition, the previously acquired X-ray scout images may include X-ray scout images of a phantom (e.g., a dry skull). Alternatively or in addition, the plurality of X-ray scout images included in the input training data may include simulated and / or artificial X-ray scout images. Data augmentation may also be used to generate additional input training data. The output training data may include, for example, annotations of anatomical structures, e.g., annotation data representing the location and identity of anatomical structures. The output training data may be generated in a manual process, e.g., by a human expert, in a semi-automated process, or in a fully automated process. The at least one trained detection model 716 may be based on one or more machine learning (ML) methods or one or more artificial intelligence (AI) methods. In other words, the at least one trained detection model 716 may be an ML model or an AI model. For example, the at least one trained detection model 716 may be based on a tree-based machine learning (ML) method, e.g., a decision tree, particularly a regression tree. Preferably, the at least one trained detection model 716 may be based on an ensemble ML method of regression trees. Alternatively, the at least one trained detection model 716 may be based on a convolutional neural network (CNN). The at least one trained detection model 716 may be stored in a memory portion of the control system 106.

[0043] Detecting the anatomical structures of the patient 300 from the X-ray scout image 302 may be based on, for example, landmark-based detection. In landmark-based detection, landmarks are detected from the X-ray scout image 302 by using automatic detection, i.e., by applying at least one trained detection model 716. In other words, the X-ray scout image 302 may be used as input data for the at least one trained detection model 716, and the landmarks may be obtained as output data of the at least one trained detection model 716. The landmarks represent the anatomical structures of the patient 300. Because the X-ray scout image 302 is a 2D X-ray image, the detected landmarks are 2D landmarks. The landmarks may include any relevant anatomical structures from the head-neck region of the patient 300. Some non-limiting examples of the plurality of landmarks may include teeth (e.g., mandibular teeth and / or maxillary teeth), temporomandibular joint(s) (TMJ(s)), one or more mandibular structures (e.g., uncinate process(es), condyle(s), ridge(s), and / or any other mandibular structures), one or more orbital structures (e.g., inferior orbit(s) and / or any other orbital structures), auditory canal(s), one or more nasal and / or skull structures (e.g., anterior nasal spine (ANS), posterior nasal spine (PNS) and / or any other nasal and / or skull structures), one or more neck structures (e.g., upper cervical spine and / or any other neck structure), and / or any other anatomically relevant structure. Similarly, the detected plurality of anatomical structures of the patient 300 may include any relevant anatomical structures from the head-neck region of the patient 300. Thus, the above list of non-limiting examples of plurality of landmarks also applies to the plurality of anatomical structures of the patient 300. The anatomical structures of the patient 300 to be detected from the X-ray scout image 302 may be selected depending on which portion(s) of the head-neck region of the patient 300 are relevant to the imaging process. For example, to determine dental arch data of the patient 300, at least a plurality of dental arch-related anatomical structures may be detected from the X-ray scout image 302.5 schematically illustrates a non-limiting example of landmarks 502 for the purpose of detecting anatomical structures of a patient 300 from an X-ray scout image 302. In the example of FIG. 5, small circles inside dashed ellipses represent the landmarks 502.

[0044] The control system 106 may further detect one or more other structures from the X-ray scout image 302 in step 410. The one or more other structures may include, for example, one or more foreign body structures and / or one or more soft tissue structures. A foreign body structure is a non-anatomical object originating from the external environment. Typically, foreign body structures made from metals and other radiopaque materials may cause larger artifacts in X-ray images than foreign bodies made from more radiolucent materials. In addition to the material, the size and location of the foreign body structure may also affect how serious the induced artifact is from a clinical standpoint. One particularly harmful example of a foreign body structure is the collar of an X-ray protective apron. If the collar of an X-ray protective apron is positioned too high, the collar can cast a large artifact (referred to as a shark fin artifact) that may, for example, shadow the teeth of the lower jaw and even structures of the upper jaw. Other common examples of foreign body structures in the head-neck region of the patient 300 may include jewelry (e.g., necklaces, earrings, metal piercings, etc.), hair accessories (e.g., clips, hairpins, etc.), and / or eyeglasses. Soft tissue structures may also cause artifacts in X-ray images. For example, the patient's 300 head, neck, and jaw may be in the correct position, but the patient's 300 soft tissue may still be erroneously deformed. One common and damaging example of an artifact caused by a soft tissue structure is a mispositioned tongue, where the tongue is not pressed against the roof of the mouth and there is an air cap in the oral cavity above the tongue. Other examples of soft tissue structures that may cause artifacts in X-ray images may include an open mouth and / or lips.

[0045] The control system 106 may detect one or more other structures from the X-ray scout image 302 by using automatic detection as described above, where automatic detection includes applying at least one trained detection model 716 to the X-ray scout image 302. In other words, the control system 106 may detect one or more other structures from the X-ray scout image 302 by applying at least one trained detection model 716. The same at least one trained detection model 716 applied to detect the multiple anatomical structures of the patient 300 may also be applied to detect the one or more other structures from the scout image 302. Also, the landmark-based detection used to detect the multiple anatomical structures from the X-ray scout image 302 may be used to detect the one or more other structures from the X-ray scout image 302. Alternatively, a particular at least one trained detection model may be applied to the X-ray scout image 302 to detect the one or more other structures. Detecting one or more other structures from the X-ray scout image 302 by applying the particular at least one trained detection model may also include determining the location of the detected one or more other structures. Detecting one or more other structures by applying the particular at least one trained detection model may include, for example, at least one of the following tasks: a classification task, a detection task, or a segmentation task. In a classification task, the particular at least one trained detection model is trained to classify which other structures, if any, the scout image 302 contains. In a detection task, the particular at least one trained detection model is trained to locate one or more other structures in the scout image 302 (e.g., by using bounding boxes). In segmentation, the particular at least one trained detection model is trained to divide the scout image 302 into segments and identify which type of structure(s) is associated with the segment. The formulation may be a binary, multi-class, or multi-label formulation. The particular at least one trained detection model may be based, for example, on one or more machine learning (ML) methods or one or more artificial intelligence (AI) methods.In other words, the particular at least one trained detection model may be an ML model or an AI model. For example, the particular at least one trained detection model 716 may be based on a neural network, a deep neural network, a convolutional neural network, a recurrent neural network, a (mask) region-based convolutional neural network, Fast / Super Fast R-CNN, a residual neural network, ResNet, You Only Look Once (YOLO), a single-shot detector, a U-Net, a transformer, a vision transformer, a histogram of oriented gradients (HoG), a support vector machine, a bag of features, a decision tree, a bagged decision tree, and / or a random forest, etc. Similarly, similar to the at least one trained detection model 716 described above, the particular at least one trained detection model may be formed by using training data. The particular at least one trained detection model may be stored in a memory portion of the control system 106.

[0046] Alternatively, the automatic detection may include applying image analysis and processing methods to detect one or more other structures from the X-ray scout image 302. The most significant structures are presented as either high intensity / high density (e.g., a shark fin) or low opacity / low density (e.g., an air cap due to a tongue depression). The location of the one or more other structures may also be defined by applying image analysis and processing methods. The high intensity region associated with the shark fin should be located at the lower border of the X-ray scout image 302 and behind the neck of the patient 300, while the low intensity region associated with the air cap should be located in the upper part of the oral cavity of the patient 300. Therefore, detecting and / or segmenting these one or more other structures is possible using image processing methods alone. Furthermore, different hybrid combinations may also be applied to detect one or more other structures. For example, landmark information from landmark-based detection may be used to extract relevant regions of interest before applying image analysis methods and / or before using at least one trained detection model 716 to fine-tune the results of the image analysis.

[0047] In step 420, the control system 106 may determine the positions of the patient's anatomical structures detected in step 410. The control system 106 may determine the positions of the patient's anatomical structures by using the atlas data 718. Once the patient's anatomical structures detected in step 410 are presented in 2D image coordinates, the detected anatomical structures may be transformed into 3D imaging device coordinates (i.e., coordinates of the dental x-ray imaging unit 102). In other words, the control system 106 may determine the positions of the patient's anatomical structures in the 3D imaging device coordinates by using the atlas data 718.

[0048] The positions of the patient's anatomical structures in 3D imaging device coordinates can be used, for example, to correct positional errors of the patient 300. The goal is to align the atlas data 718 with the patient 300. If the atlas data 718 is aligned sufficiently closely with the patient 300, the positions of the patient's anatomical structures in 3D imaging device coordinates can be defined directly from the aligned atlas data. Because direct alignment between the patient 300 and the atlas data 718 is not possible, the problem turns to aligning the actual 2D scout image-extracted anatomical data of the patient 300 with a virtual projection of the same anatomical data in the atlas data 718 using the same imaging geometry used during acquisition of the scout image 302. In other words, alignment of the atlas data 718 with the patient 300 can be performed by using imaging geometry data representing the imaging geometry of the dental x-ray imaging unit 102 relative to the x-ray scout image 302. The control system 106 may, for example, acquire the imaging geometry data at the time, i.e., in conjunction with, the acquisition of the X-ray scout image 302 in step 210. The goal of this process is to geometrically transform the atlas data 718 until its virtually projected anatomical data and the scout-extracted anatomical data are as similar as possible. The output is aligned atlas data.

[0049] The main operations during alignment may include, for example, transformation, virtual projection, cost function, minimization, and final alignment. Transformation modifies the geometric information of the atlas data 718. It may modify the position of the geometric information (such as the location of anatomical structures) included in the atlas data 718. These main operations during alignment are discussed further below.

[0050] The transformation may modify the position of the anatomical structures and may be, for example, a rigid (6D) transformation. The transformation may also be, for example, a similarity (7D) transformation, which changes both the position and scale of the geometric information contained in the atlas data 718. The transformation may also include, for example, rigid transformations and anisotropic scaling (9D), thus allowing for modification of the position, scale, and shape of the geometric information contained in the atlas data 718. The transformation may be, for example, affine (12D), which is more flexible than a 9D model. The above transformations are only a few non-limiting examples of linear transformations that may be used in the transformation. Alternatively to or in addition to linear transformations, the transformation may be a nonlinear transformation. Nonlinear transformations typically have a much larger number of free parameters and therefore allow for very flexible shape deformations in addition to position changes. In some cases, the transformation may be parameterized as part of the atlas data 718 (e.g., a statistical model / atlas may include shape modes). Transformations are well known, and there are many other transformations that may be used.

[0051] Because the imaging geometry and X-ray detector characteristics used in acquiring the scout image 302 are known, the transformed atlas data 718 (e.g., anatomical structure locations) can be virtually projected onto the same imaging plane as the X-ray scout image 302. In a simple example, a line can be formed through the X-ray source (location known from the imaging geometry data) and the transformed anatomical structure locations (known from the transformed atlas data). Similarly, a virtual imaging plane representing the X-ray detector can be formed using the imaging geometry data and the X-ray detector characteristics. The intersection of the line and the plane at the plane is a virtual projection of the anatomical structure in the virtual scout image plane. By repeating the process for all anatomical structures used in the registration process, two pieces of data in the same scout image coordinate system can be defined: target data representing the location of the anatomical structure extracted from the actual X-ray scout image 302, and floating data representing a virtually projected version of the same structure. At each iteration of the registration process, the virtually projected data may change as the transformation applied to the atlas data 718 changes, but the target data remains fixed during the entire alignment registration process.

[0052] The cost function determines the goodness of the registration. The smaller the cost, the better the registration. According to a simple example, anatomical data may be encoded as points, in which case, after virtual projection, there are two anatomical point sets, both defined in imaging device coordinates. The cost function may, for example, be a distance-based cost function. In a simple case, the cost function may, for example, be the average of all point pairs relating to the same anatomical structure. Alternatively or in addition to the arithmetic mean, the cost function may also be a weighted average, in which different structures are weighted differently. The cost function may also be any other cost function. In some cases, constraints may be imposed on the geometric transformation to prevent some (typically unphysical) transformations. Therefore, in addition to the data-dependent term, the cost function may also include a penalty term to regularize the transformation.

[0053] Registration is a minimization problem. Once a cost function is minimized with respect to the transformation parameters, the datasets are geometrically aligned. Typically, gradient-based minimization algorithms are used in minimization for simpler (linear) transformations, although non-gradient-based (Powell, Simplex, etc.) minimization methods can also be used. The minimization terminates when at least one stopping criterion is met. The stopping criterion can be related, for example, to the cost function value (i.e., the value falls below a stopping limit), or the rate of change (the change in the cost function and / or transformation parameters between iterations is less than a set threshold), or something as simple as the number of iterations exceeding a maximum number of iterations. Minimization and stopping criteria are well known in optimization, and although only a few non-limiting, simple examples are given above, there are many other possibilities that can be used.

[0054] The ultimate goal of the alignment, as discussed above, is to align the atlas data 718 with the patient 300. Here, the 2D alignment of the scout-extracted anatomical data and the virtually projected anatomical data from the atlas data 718 is used as a proxy for the actual target. When the minimization converges and stops at a global minimum, the patient's anatomical structures and the anatomical structures of the atlas data 718 are aligned in imaging device coordinates. In other words, the positions of the patient's 300's anatomical structures are defined in 3D imaging device coordinates by using the atlas data 718. Therefore, the optimal transformation (the final result of the minimization) is used to transform the atlas data 718. It should be noted that the atlas data 718 may also contain other geometric information besides the anatomical information used for registration. Once the atlas data 718 is aligned with the patient 300, all geometric instances (anatomical data, imaging-related data, etc.) are all transformed with the same optimal transformation. As a result, any geometric information contained in the atlas data 718 is aligned with the patient 300 in imaging device coordinates.

[0055] Atlas data 718 may include atlas anatomical data. The atlas anatomical data of atlas data 718 may include, for example, atlas anatomical structure data, i.e., information about at least one anatomical structure on the head-neck region. The atlas anatomical structure data may include, for example, at least one location of one or more anatomical structures. The atlas anatomical data may also include other information related to one or more anatomical structures, for example, labels or identification information for the anatomical structure(s). The atlas anatomical data may include any relevant anatomical structures from the head-neck region. For example, the atlas anatomical data may comprise, but is not limited to, one or more of the following anatomical structures: teeth (e.g., maxillary and / or mandibular teeth), TMJ(s), one or more mandibular locations (e.g., uncinate process(es), condyle(s), ridge(s), and / or any other mandibular locations), one or more orbital locations (e.g., inferior orbit(s) and / or any other orbital locations), auditory canal(s), one or more nasal and / or skull locations (e.g., ANS, PNS, and / or any other nasal and / or skull locations), one or more neck structures (e.g., upper cervical spine and / or any other neck structures), and / or any other anatomically related structures. The atlas anatomical data may typically be extracted from radiological or dental images, such as CT images (e.g., CBCT images), medical CT images, magnetic resonance images (MRI), and / or other radiological or dental images. Typically, these CT images are 3D images, although the CT images may be 2D or 4D images. Atlas anatomical data may be extracted from a single subject or multiple subjects. Thus, the atlas anatomical data may present a single subject's anatomy or an average anatomy of multiple subjects, and / or may include information about intra-subject anatomical variation (e.g., statistical atlas, probabilistic atlas, etc.). The image or volume from which the atlas anatomical data is extracted may be part of atlas data 718. If multiple images are used, an average image / volume may be generated and included in atlas data 718. Alternatively, atlas anatomical data may be created without actual images.Therefore, the atlas anatomical data can be synthetic or generic.

[0056] There are many ways to represent atlas anatomical data. Anatomical structures in the atlas data 718 may be represented, for example, as landmarks (e.g., 3D points), surfaces, pixels, voxels, or any known shape (e.g., lines, planes, curves, etc.). For simplicity of presentation, the representation of anatomical data will now be limited to landmarks. However, it should be noted that this is merely for the sake of simplicity of disclosure and the present invention is not limited in this respect.

[0057] In addition to the atlas anatomical data and possible image data, the atlas dental data may further include other geometric information related to x-ray dental imaging, such as information related to the scan trajectory, the start position of the scan trajectory, the end position of the scan trajectory, any other position of the scan trajectory, the complete motion path, the dental arch, the sharpening layer, information about exposure values ​​along the scan trajectory, and / or any other similar information.

[0058] The atlas data 718 may be generated from data obtained from one or more atlas databases. The term "atlas" may be referred to as a model, mold, generic, prosthetic, template, arch, prototype, sample, framework, and any other similar term. It may also be combined with terms such as teeth, head, neck, skull, maxillofacial, jaw, maxilla, mandible, head and neck, and / or any other similar term. The atlas data 718 may be stored in the memory portion 708 of the control system 106.

[0059] In step 430, the control system 106 may determine dental arch data for the patient based on the positions of the detected anatomical structures determined in step 420. To determine the dental arch data for the patient 300, the detected anatomical structures may include at least a plurality of dental arch-related anatomical structures (e.g., a plurality of mandibular teeth, a plurality of maxillary teeth, and / or any other dental arch-related anatomical structures). However, the detected anatomical structures may further include any other one or more anatomical structures. The dental arch data represents an estimate of the position of the dental arch of the patient 300. Because the positions of the detected anatomical structures are known (i.e., determined), the dental arch data for the patient 300 representing an estimate of the position of the dental arch of the patient 300 may be determined substantially accurately.

[0060] In step 220, the control system 106 may, for example, control the dental X-ray imaging unit 102 to acquire panoramic dental X-ray image data of the patient 300 according to the determined dental arch data. The control system 106 may, for example, control the gantry portion 112 of the dental X-ray imaging unit 102 to scan the patient 300 according to a scan trajectory defined based on the determined dental arch data. The scan trajectory includes a starting position of the panoramic scan and a motion path of the panoramic scan. The scan trajectory of the panoramic scan may be defined based on the dental arch data so that an imaging layer (i.e., a focal trough) corresponds to the dental arch of the patient 300. The imaging layer is a 3D curved zone, and the patient's anatomical structures within this layer are sharp in the panoramic dental X-ray image, while other parts of the patient's anatomical structures are blurred in the panoramic dental X-ray image. This sharp layer is narrowest in the anterior region (i.e., the anterior tooth region). Therefore, the scan trajectory of the panoramic scan may be defined so that at least the anterior region falls within the sharp layer, i.e., the imaging layer. According to one example, a patient-specific scan trajectory may be defined based on the determined dental arch data. The patient-specific scan trajectory allows substantially the entire dental arch of the patient 300 to be exposed to the sharp layer. In some cases, the dental X-ray imaging unit 102 may not be able to implement the patient-specific scan trajectory and / or may not be able to define the patient-specific scan trajectory. The scan trajectory may then be defined by selecting the most appropriate scan trajectory from among multiple predefined scan trajectories that best correspond to the determined dental arch data. Each predefined scan trajectory includes a starting position and a motion path for the predefined scan trajectory. For example, the control system 106 may compare the determined dental arch data with the dental arches corresponding to the multiple predefined scan trajectories and select the scan trajectory for each dental arch that best corresponds to the determined dental arch data (e.g., the shape and / or size of the dental arch). Controlling the portions of the dental x-ray imaging unit 102 may include controlling the gantry portion 112 to rotate according to a panoramic scanning motion path about an axis of rotation to acquire panoramic dental x-ray image data of the patient 300. The motion path may be, for example, a substantially arcuate path about the axis of rotation.The rotation axis may be the mechanical rotation axis of the gantry portion 112 or may be a virtual rotation axis of the gantry portion 112. Controlling the portions of the dental X-ray imaging unit 102 may also include controlling the gantry portion 112 of the dental X-ray imaging unit 102 to move to the start position of the panoramic scan if the gantry portion 112 is not already at the start position of the panoramic scan. For example, for acquisition of the X-ray scout image 302, the gantry portion 112 may be controlled to move to the start position of the panoramic scan or at least very close to the start position of the panoramic scan. Thus, if the gantry portion 112 has already been controlled to move to the start position of the panoramic scan for acquisition of the X-ray scout image 302, there is no need to control the gantry portion 112 to move to the start position of the panoramic scan for acquisition of the panoramic dental X-ray image data. To move the gantry portion 112 to the start position of the panoramic scan, the rotation axis of the gantry portion 112 may be positioned, for example, at the start position of the panoramic scan. Other techniques or alignments for the rotation axis may also be used, as will be recognized by those skilled in the art.

[0061] According to one example, multiple anatomical structures detected from the X-ray scout image 302 may be used to correct at least one patient position error. Depending on the patient position error, one or more other structures detected from the X-ray scout image 302 may alternatively or additionally be used to correct the patient position error in question. Figure 6 schematically illustrates one example of method steps for correcting at least one patient position error. This allows different types of patient position errors to be detected and corrected or at least minimized, which improves the quality of the resulting panoramic dental X-ray image.

[0062] In step 610, the control system 106 detects at least one patient position error based on a plurality of anatomical structures detected from the X-ray scout image 302. The control system 106 may further use the determined positions of the plurality of anatomical structures in detecting the at least one patient position error. The at least one patient position error that may be detected based on the plurality of anatomical structures may include, for example, at least one of a left-right head tilt, a linear anterior-posterior (AP) movement, a linear left-right (LR) movement, an incorrect Frankfort horizontal (FH) line, a slump neck, and an uneven occlusion. Alternatively or additionally, the control system 106 may detect the at least one patient position error based on one or more other structures detected from the X-ray scout image 302. The control system 106 may further use the determined positions of the one or more other structures in detecting the at least one patient position error. The at least one patient position error that may be detected based on the one or more other structures may include, for example, at least one of a shark fin artifact and a misplaced tongue. The detection of shark fin artifacts and misplaced tongues from X-ray scout images 302 is discussed above.

[0063] The control system 106 may detect a non-uniform occlusion, for example, by detecting misalignment of the mandibular and maxillary anterior teeth based on multiple anatomical structures detected from the X-ray scout image 302. The control system 106 may detect a slumped neck, for example, by fitting a line through the upper cervical vertebrae and comparing that line to another line parallel to the main beam from the X-ray source to the X-ray detector when it is directed just behind the neck. In the optimal case (i.e., without a slumped neck), these lines intersect at a 90-degree angle. The smaller this angle, the more slumped the neck is, i.e., the greater the error caused by a slumped neck. The control system 106 can detect out-of-plane rotation of the patient's 300 head (e.g., head tilt, linear AP translation, linear LR translation, erroneous FH line) by, for example, fitting lines and / or planes to the anatomical structure and defining angles between the lines and / or planes and the respective reference lines and / or planes. There are several options for the anatomical structure used, regarding which shape (e.g., line, plane, etc.) is fitted to the anatomical structure and / or how the reference is determined. Some non-limiting examples are now disclosed. Head nods (false FH lines) can be detected, for example, based on a line passing through the cranial opening of the ear canal and the inferior orbit of the eye. If the FH line is correct, the angle between the line and the horizontal plane should be zero. If the angle is non-zero, the angle indicates a necessary correction of the erroneous FH line. Head twists (i.e., linear LR translation) can be detected, for example, based on the LR symmetry line. For example, the nasal bridge point, ANS, and mandibular ridge can be used to determine the LR line of symmetry. Further structures for determining the LR line of symmetry can be defined by averaging symmetrical structures, such as any opposing teeth on the right and left sides, any orbital structures on the right and left sides, TMJs, etc. The LR line of symmetry structures can be projected onto the same coronal plane, and a 2D line can be fitted to the LR line of symmetry. In the optimal case (i.e., when the head is straight), the angle between the 2D line and the vertical line in the imaging device coordinate system is zero. If the angle is non-zero, it indicates the necessary correction of the linear LR movement.

[0064] When the selected scan trajectory is used instead of the patient-specific scan trajectory, the at least one patient position error may include at least one scan trajectory deviation. The selected scan trajectory and the dental arch corresponding to the selected scan trajectory deviate from the determined dental arch data. The at least one scan trajectory deviation may include, for example, at least one of a linear deviation in the horizontal plane and a rotational angle deviation in the horizontal plane. In a linear deviation in the horizontal plane, the selected scan trajectory and the dental arch for the selected scan trajectory deviate from the determined dental arch data of the patient 300 in the horizontal plane. The control system 106 may, for example, determine the linear deviation between the location of the dental arch for the selected scan trajectory and the determined dental arch data of the patient 300. Because the shapes and sizes of the dental arches are offset from each other, the dental arch may only be partially accurately matched. Because the sharpening layer is narrowest in the anterior region (i.e., the anterior tooth region) as discussed above, the matching of the dental arch for the selected scan trajectory to the determined dental arch data of the patient 300 may preferably be performed in this region, for example, based on the location of the anterior teeth. For example, the control system 106 may determine the position vectors of the anterior teeth (e.g., the center points of the anterior teeth) in the horizontal plane for the anterior teeth of the dental arch data of the patient 300 and for the dental arch relative to the selected scanning trajectory. The difference in the position vectors indicates a linear deviation between the dental arch data of the patient 300 and the dental arch data of the dental arch relative to the selected scanning trajectory. The deviation in the rotation angle in the horizontal plane is caused by the rotation of the patient's head in the horizontal plane (i.e., the yaw rotation of the patient's 300 head). The control system 106 may determine the deviation in the rotation angle in the horizontal plane, for example, by utilizing the PA axis. A line parallel to the PA axis of the patient 300 may be determined, for example, based on the LR line of symmetry. For example, the nasal bridge point, the ANS, and the mandibular ridge may be used to determine the LR line of symmetry. Further structures for determining the LR line of symmetry may be defined by averaging symmetrical structures, such as any opposing teeth on the right and left sides, any orbital structures on the right and left sides, the TMJ, etc. By projecting the LR symmetry line structures onto the horizontal plane, a line can be fitted to these LR symmetry line structures, which defines a line parallel to the PA axis of the patient 300.The line parallel to the PA axis of the selected scan trajectory is known or can be determined similarly to the line parallel to the PA axis of the patient 300 described above. The control system 106 can then determine the angle between the line parallel to the PA axis of the patient 300 and the line parallel to the PA axis of the selected scan trajectory, which corresponds to the angle of rotation in the horizontal plane.

[0065] In step 620, the control system 106 determines patient position correction data for correcting the at least one patient position error. The patient position correction data represents a correction required to correct the at least one patient position error. The patient position correction data may be determined, for example, substantially in accordance with detecting the at least one patient position error.

[0066] In response to the detected at least one patient position error, the control system 106 may perform one or more different types of patient position error correction actions 630-650 based on the determined patient position correction data.

[0067] The control system 106 may use the patient position correction data in controlling portions of the dental X-ray imaging unit 102 to acquire panoramic dental X-ray image data of the patient 300 (630). According to one example, if the detected at least one patient position error includes linear AP movement, the control system 106 may move the gantry portion 112 in the AP direction until the linear AP movement is compensated in accordance with the determined patient position correction data. To move the gantry portion 112, the control system may control at least one linear motor to move the gantry portion 112 in the AP direction. According to another example, if the detected at least one patient position error includes linear LR movement, the control system 106 may move the gantry portion 112 by pivoting until the linear LR movement is compensated in accordance with the determined patient position correction data. To pivot the gantry portion 112, the control system 106 may control a pivot motor to pivot the upper shelf about the support column 103. According to yet another example, if the at least one detected patient position error includes an erroneous Frankfort horizon, the control system 106 may adjust the height of the portion of the dental X-ray imaging unit 102 until the erroneous Frankfort horizon is compensated for in accordance with the determined patient position correction data. To adjust the height of the portion of the dental X-ray imaging unit 102, the control system 106 may control the guide motor to move the carriage portion 101 up and down in the height direction Z along the support column 103. According to yet another example, if the at least one detected patient position error includes a slumped neck, the control system 106 may adjust the height of the portion of the dental X-ray imaging unit 102 until the slumped neck is compensated for in accordance with the determined patient position correction data (i.e., the slumped neck is outside the image). According to yet another example, if the at least one detected patient position error includes a left-right head tilt, the control system 106 may adjust the head support portion 126 until the head tilt is compensated for in accordance with the determined patient position correction data.According to yet another example, if the detected at least one patient position error includes a shark fin artifact, the control system 106 may adjust the height of the dental x-ray imaging unit 102 until the shark fin artifact is compensated in accordance with the determined patient position correction data (i.e., the shark fin artifact is outside the panoramic FOV). According to yet another example, if the detected at least one patient position error includes at least one scan trajectory deviation (which is a linear deviation in the horizontal plane and / or a rotational angle deviation in the horizontal plane), the control system 106 may adjust the head support portion 126 until the scan trajectory deviation is compensated in accordance with the determined patient position correction data. If the detected at least one patient position error includes at least one scan trajectory deviation that is a linear deviation in the horizontal plane, the control system 106 may further adjust the starting position of the panoramic scan until the scan trajectory deviation is compensated in accordance with the determined patient position correction data. If the detected at least one patient position error includes at least one scan trajectory deviation, which is a deviation in the rotation angle in the horizontal plane, the control system 106 may further adjust the angle of the starting position of the panoramic scan and / or rotate an axis of the X-ray imaging unit 102 (e.g., the PA axis of the X-ray imaging unit 102) until the scan trajectory deviation is compensated according to the determined patient position correction data.

[0068] Alternatively or additionally, the control system 106 may generate guidance to the patient 300 and / or an operator of the dental x-ray imaging system 100 based on the patient position correction data (640). For example, the guidance may be provided via one or more user interface devices, such as via a display device and / or a loudspeaker device. The one or more user interface devices may comprise the user interface device 130 and / or one or more other user interface devices. The guidance is implemented during the imaging process. Depending on the type of the at least one patient position error, action to compensate for the at least one patient position error in response to the guidance may be implemented during the imaging process, or the imaging process may be interrupted to implement action to compensate for the at least one patient position error. According to one example, if the detected at least one patient position error includes a slumped neck, the control system 106 may generate guidance that includes instructing the patient 300 to move forward to compensate for the slumped neck. According to another example, if the at least one detected patient position error includes a shark fin artifact, the control system 106 may generate guidance including instructions to remove any foreign object (e.g., accessories of the patient 300) and / or adjust protective equipment(s) (e.g., an apron) to compensate for (e.g., remove) the shark fin artifact. According to yet another example, if the at least one detected patient position error includes a misplaced tongue, the control system 106 may generate guidance including instructing the patient 300 to correct the location of the tongue to compensate for the misplaced tongue, for example, during the imaging process. Correcting the location of the tongue to compensate for the misplaced tongue may be performed, for example, during the imaging process. According to yet another example, if the at least one detected patient position error includes an uneven bite, the control system 106 may generate guidance including instructions for the patient 300 to correct their bite on a bite stick to compensate for the uneven bite. Correction of the on-stick bite to compensate for uneven bite is performed, for example, during the imaging process.According to yet another example, if the detected at least one patient position error includes at least one scan trajectory deviation (which is a linear deviation in the horizontal plane and / or a rotational angular deviation in the horizontal plane), the control system 106 may generate guidance including instructions for the patient 300 to correct head posture to compensate for the scan trajectory deviation.

[0069] Alternatively or additionally, the control system 106 may use the patient position correction data to minimize the effect of at least one patient position error (650). Minimizing the effect of the at least one patient position error may include, for example, at least one of adjusting exposure parameters for a panoramic scan, post-processing projection images from which dental x-ray images are formed by reconstructing x-ray image data, post-processing reconstruction parameters, and post-processing dental x-ray images reconstructed from the acquired x-ray image data. According to one example, if the detected at least one patient position error includes a slumped neck, the control system 106 may adjust the exposure (i.e., radiation) parameters to minimize the effect of the slumped neck in accordance with the determined patient position correction data. For example, the exposure parameters may be adjusted to increase exposure in a direction in which the patient 300 is exposed through the slumped neck. According to another example, if the detected at least one patient position error includes a misplaced tongue, the control system 106 may adjust the exposure (i.e., radiation) parameters to minimize the effect of the misplaced tongue in accordance with the determined patient position correction data. A misplaced tongue (e.g., when the tongue is not on the roof of the mouth) can, for example, cause an air cap in the oral cavity above the tongue, which in turn can result in overexposure to the X-ray detector. In this case, the exposure parameters can be adjusted to reduce exposure. One or more other exposure parameters (e.g., the size of the collimation area and / or the size of the second portion of the active area of ​​the X-ray detector) can alternatively or additionally be adjusted to minimize the effect of at least one patient position error according to the determined patient position correction data. According to yet another example, if the detected at least one patient position error includes a slump neck, the control system 106 can post-process the projection images by, for example, increasing noise suppression in projection images being acquired at the back of the neck so that the effect of the slump neck is minimized according to the determined patient position correction data.According to yet another example, if the at least one detected patient position error includes a non-uniform occlusion, the control system 106 may post-process the reconstruction parameters to minimize the effect of the non-uniform occlusion according to the determined patient position correction data. According to yet another example, if the at least one detected patient position error includes a left-right head tilt, the control system 106 may post-process the dental x-ray images reconstructed from the acquired x-ray image data to minimize the effect of the left-right head tilt according to the determined patient position correction data.

[0070] FIG. 7 illustrates a schematic example of the control system 106 of the dental x-ray imaging system 100. The control system 106 may include a processor portion 702, a data transfer portion 704, a user interface portion 706, and a memory portion 708. The processor portion 702 is configured to execute instructions and process data initiated by a user and / or a computer program (software). The processor portion 702 may include at least one processor. The memory portion 708 is configured to store and maintain data. The data may include instructions, computer programs, at least one trained detection model 716, and any data files. The memory portion 708 may include at least one memory. The memory portion 708 may further include at least a data transfer application 710 for controlling the data transfer portion 704, a user interface application 712 for controlling the UI portion 706, and a computer program (code) 714 for controlling the operation of the control system 106. The memory portion 708 and the computer programs 714, together with the processor portion 702, may cause the control system 106 to at least implement one or more method steps and / or operations of the control system 106, as described above. The data transfer portion 704 may be configured to send control commands to other units, such as the dental X-ray imaging unit 102. Additionally, the data transfer portion 704 may receive data from other units, such as the dental X-ray imaging unit 102, database(s), and / or any other external unit. The user interface (UI) portion 706 may be configured to input control commands, receive information and / or instructions, and display information. The UI portion 706 may comprise one or more user interface devices 130, such as a display, a screen, a touchscreen, at least one function key, a keyboard, a wired or wireless remote controller, and / or any other user input and / or output device.The computer program 714 may be a computer program product, which may be contained on a tangible, non-volatile (non-transitory) computer-readable medium having computer program code 714 embodied therein for use in a computer, for example, the control system 106.

[0071] The specific examples provided in the above specification should not be deemed to limit the applicability and / or interpretation of the appended claims. The lists and groupings of examples provided in the above specification are not exhaustive unless expressly stated otherwise.

Claims

1. A dental x-ray imaging system (100) for dental x-ray imaging of a patient (300), said system (100) comprising: A dental x-ray imaging unit (102), comprising: an X-ray source portion (114) for emitting an X-ray beam; an X-ray imaging detector portion (116) comprising an X-ray detector for receiving the X-ray beam from the X-ray source portion (114); a gantry portion (112) including the X-ray source portion (114) and the X-ray imaging detector portion (116); A control system (106) comprising: controlling the portion of the dental x-ray imaging unit (102) to acquire an x-ray scout image (302) of the patient (300) by using a first portion of an active area of ​​the x-ray detector; a control system (106) configured to control the portion of the dental X-ray imaging unit (102) to acquire panoramic dental X-ray image data of the patient (300) by using a second portion of the active area of ​​the X-ray detector corresponding to panoramic imaging; A dental x-ray imaging system (100), wherein the first portion of the active area is larger than the second portion of the active area.

2. The dental x-ray imaging system of claim 1 , wherein the first portion of the active area of ​​the x-ray detector includes the entire active area of ​​the x-ray detector.

3. 10. A dental X-ray imaging system (100) according to any one of the preceding claims, wherein the controlling of the portion of the dental X-ray imaging unit (100) to acquire the X-ray scout image (302) includes controlling a collimator of the X-ray source portion (114) to collimate the X-ray beam into a cone beam.

4. 10. The dental X-ray imaging system (100) of claim 1, wherein the controlling of the portion of the dental X-ray imaging unit (102) to acquire the panoramic dental X-ray image data includes controlling the collimator of the X-ray source portion (114) to collimate the X-ray beam into a narrow beam.

5. 10. The dental x-ray imaging system (100) of any one of the preceding claims, wherein the control system (106) is configured to determine dental arch data of the patient based on the x-ray scout image (302).

6. 6. The dental X-ray imaging system (100) of claim 5, wherein the control system (106) is further configured to control the portion of the dental X-ray imaging unit (102) to acquire the panoramic dental X-ray image data of the patient according to the determined dental arch data.

7. The determining of the dental arch data includes the control system (106): detecting a plurality of anatomical structures of the patient (300) from the x-ray scout image (302); determining the locations of the plurality of anatomical structures of the patient (300); 7. The dental x-ray imaging system (100) of claim 5 or 6, further comprising: configured to determine dental arch data of the patient (300) based on the determined positions of the detected anatomical structures of the patient (300).

8. 8. The dental X-ray imaging system of claim 7, wherein the control system is configured to apply at least one trained detection model to detect the plurality of anatomical structures of the patient from the X-ray scout image.

9. The dental x-ray imaging system (100) of claim 8, wherein the at least one trained detection model (716) is a machine learning (ML) model or an artificial intelligence (AI) model.

10. 10. The dental x-ray imaging system (100) of claim 7, wherein the control system (106) is configured to determine the positions of the plurality of anatomical structures of the patient (300) by utilizing atlas data (718).

11. The control system (106) Detecting at least one patient position error based on the plurality of anatomical structures of the patient (300); The dental x-ray imaging system (100) of any one of claims 7 to 10, configured to determine patient position correction data for correcting said at least one patient position error.

12. The control system (106) using the patient position correction data in controlling the portion of the dental x-ray imaging unit (102) to acquire the panoramic dental x-ray image data of the patient (300); generating guidance to the patient (300) and / or an operator of the dental x-ray imaging system (100) based on the patient position correction data; and using the patient position correction data to minimize the effect of at least one patient position error.

13. 1. A method for panoramic dental X-ray imaging of a patient (300), said method being implemented by an X-ray dental imaging system (100) according to any one of the preceding claims, said method comprising the steps of: controlling (210) the portion of the dental x-ray imaging unit (102) to acquire an x-ray scout image (302) of the patient (300) by using a first portion of an active area of ​​the x-ray detector; and controlling (220) the portion of the dental x-ray imaging unit (102) to acquire panoramic dental x-ray image data of the patient (300) by using a second portion of the active area of ​​the x-ray detector corresponding to panoramic imaging; The method, wherein the first portion of the active area is larger than the second portion of the active area.

14. 14. A computer program (714) comprising instructions, which when executed by an X-ray dental imaging system (100) according to any one of claims 1 to 12, cause the X-ray dental imaging system (100) to perform the method according to claim 13.

15. 14. A tangible, non-volatile computer readable medium containing instructions that, when executed by an X-ray dental imaging system (100) according to any one of claims 1 to 12, cause the X-ray dental imaging system (100) to perform the method of claim 13.

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