Controller, dental imaging system and method for dental imaging of an object

Abstract

The invention relates to a controller (106) for dental imaging of a subject. The controller comprises at least one processor (802) and at least one memory (808) including computer program code (814). The at least one memory (808) and the computer program code (814) are configured to, with the at least one processor (802), cause the controller (106) at least to obtain first image data from an optical scanner unit (104), obtain second image data from a dental X-ray imaging unit (102), generate a first surface model (202) from the obtained first image data, wherein the first surface model (202) represents an optical three-dimensional shape of a surface of a first portion of the subject, and process the obtained second image data using the first surface model (202). The invention also relates to an imaging system (100), a method, a computer program (814) and a computer readable medium for dental imaging of a subject.

Description

Technical Field

[0001] This invention relates generally to the technical field of dental imaging. Background Technology

[0002] Proper patient positioning is often one of the most time-consuming tasks for the user of the X-ray imaging unit during X-ray imaging. Traditionally, various support methods are used to position the patient in the X-ray imaging unit, assuming that the patient's head is kept as still as possible.

[0003] Traditional support devices can be chin rests, static bite bars, and head supports, in which the forehead, temples, and / or the back of the skull are supported. Additionally, various types of straps can be used to position the patient as securely as possible. Furthermore, some X-ray imaging units have such bite bars that attach to the unit, allowing the bite bar to move in certain directions.

[0004] Another approach, which can also be considered traditional, is to use reconnaissance images. These are small panoramic images or a set of two projected images taken at a 90-degree angle, which can be used as alignment aids for three-dimensional (3D) images.

[0005] For this method, strict setup is crucial. Once patient positioning (alignment) is complete, the patient should remain stable throughout the imaging process. If the patient and / or X-ray imaging unit moves between the alignment and X-ray scanning phases—that is, the patient's position changes relative to the X-ray imaging unit—the resulting X-ray images may be diagnostically useless. Movement of the patient and / or X-ray imaging unit during the scanning phase can cause significant artifacts in the resulting X-ray images, and these motion-induced artifacts need to be reduced (if possible) during the reconstruction of dental X-ray images from the image data acquired during the scanning phase. Alternatively, these artifacts can be reduced by using software-based corrections, i.e., computer programs. Motion-induced artifacts can significantly affect the quality of dental X-ray images. The result may be, for example, a blurred or distorted image.

[0006] Furthermore, in panoramic imaging, the anatomical shape of the patient's mandible is unknown before the panoramic image is captured. The quality of the panoramic image is severely affected by the degree to which a predefined imaging layer corresponds to the patient's actual anatomical shape (e.g., dental arch). Typically, an average shape is used for all patients, which may result in unoptimized image quality. Summary of the Invention

[0007] The following is a simplified overview to provide a basic understanding of some aspects of various embodiments of the invention. This overview is not a comprehensive summary of the invention. It is not intended to identify important or critical elements of the invention, nor is it intended to depict the scope of the invention. The following overview presents only some concepts of the invention in a simplified form as a prelude to a more detailed description of exemplary embodiments of the invention.

[0008] One object of the present invention is to provide a controller, imaging system, method, computer program, and tangible non-volatile computer-readable medium for dental imaging of a subject, as well as a method for using optical image data in dental X-ray imaging of a subject. Another object of the present invention is to improve the quality of dental X-ray images through the controller, imaging system, method, computer program, and tangible non-volatile computer-readable medium for dental imaging of a subject, and the method for using optical image data in dental X-ray imaging of a subject.

[0009] The object of the present invention is achieved by the defined controller, imaging system, method, computer program, and tangible non-volatile computer-readable medium.

[0010] According to a first aspect, a controller for dental imaging of an object is provided, wherein the controller includes: at least one processor; and at least one memory containing computer program code, wherein the at least one memory and the computer program code are configured to utilize the at least one processor to cause the controller to at least: acquire first image data from an optical scanner unit; acquire second image data from a dental X-ray imaging unit; generate a first surface model based on the acquired first image data, wherein the first surface model represents the optical three-dimensional shape of a surface of a first portion of the object; and process the acquired second image data using the first surface model.

[0011] The optical scanner unit can be an intraoral scanner unit.

[0012] The first image data obtained may include the first image data previously obtained from the optical scanner unit.

[0013] The controller can be configured to: detect motion of an object that occurs during the acquisition of second image data based on a first surface model, and reduce motion-induced artifacts in two-dimensional or three-dimensional dental X-ray images reconstructed from the acquired second image data based on the first surface model.

[0014] Motion detection may include: generating a second surface model based on acquired second image data, wherein the second surface model represents the X-ray 3D shape of a surface of a second part of an object, and wherein the second part of the object at least partially overlaps with a first part of the object; comparing the similarity between the second surface model and a first surface model; and performing motion detection if the second surface model is different from the first surface model.

[0015] The generation of the second surface model may include: reconstructing the obtained second image data into a three-dimensional dental X-ray image; and extracting the second surface model from the three-dimensional dental X-ray image by using segmentation.

[0016] Alternatively or additionally, motion detection may further include registration of the first and second surface models prior to comparison.

[0017] Alternatively, the controller can be configured to: determine the anatomical shape of the object based on a first surface model, and adjust the reconstructed dental X-ray image based on the obtained second image data such that the focused layer in the dental X-ray image corresponds to the anatomical shape of the object determined based on the first surface model.

[0018] According to a second aspect, an imaging system for dental imaging of an object is provided, wherein the imaging system includes: a dental X-ray imaging unit for providing second image data, wherein the dental X-ray imaging unit includes a gantry portion, an X-ray source portion for emitting X-rays, and an X-ray imaging detector portion for receiving X-rays from the source portion, wherein the gantry portion includes the source portion and the detector portion; an optical scanner unit for providing first image data; and a controller as described above, wherein the controller is configured to: acquire the first image data from the optical scanner unit; acquire the second image data from the dental X-ray imaging unit; generate a first surface model based on the acquired first image data, wherein the first surface model represents the optical three-dimensional shape of a surface of a first portion of the object; and process the acquired second image data using the first surface model.

[0019] According to a third aspect, a method for dental imaging of an object is provided, the method being executed by a controller as defined above, wherein the method includes: acquiring first image data from an optical scanner unit; acquiring second image data from a dental X-ray imaging unit; generating a first surface model based on the acquired first image data, wherein the first surface model represents the optical three-dimensional shape of a surface of a first portion of the object; and processing the acquired second image data using the first surface model.

[0020] According to a fourth aspect, a computer program is provided, wherein the computer program includes instructions that, when executed by a controller as described above, cause the controller to perform the methods as described above.

[0021] According to a fifth aspect, a tangible non-volatile computer-readable medium is provided, wherein the tangible non-volatile computer-readable medium contains instructions that, when executed by a controller as described above, cause the controller to perform the methods as described above.

[0022] According to a sixth aspect, a method for using optical image data in dental X-ray imaging of an object is provided, wherein the method includes: obtaining optical image data of the object from an optical scanner unit; and using the obtained optical image data in dental X-ray imaging of the object.

[0023] The use of the acquired optical image data may include: detecting motion of the object that occurs during the acquisition of X-ray image data of the object based on the optical image data; and reducing motion-induced artifacts in two-dimensional or three-dimensional dental X-ray images reconstructed from the X-ray image data of the object based on the optical image data.

[0024] Alternatively, the use of the acquired optical image data may include: adjusting the reconstruction of a dental X-ray image based on the X-ray image data of the object so that the focal layer in the dental X-ray image corresponds to the anatomical shape of the object determined based on the optical image data.

[0025] Alternatively, the use of the acquired optical image data may include: defining the imaging geometry of a dental X-ray imaging unit based on the optical image data for the acquisition of X-ray image data of an object.

[0026] When read in conjunction with the accompanying drawings, the various exemplary and non-limiting embodiments of the invention with respect to its structure and operation, as well as its additional objects and advantages, will be best understood from the following description of specific exemplary and non-limiting embodiments.

[0027] The verbs “comprising” and “including” are used herein as open-ended restrictions, neither excluding nor requiring the presence of any unlisted features. Unless otherwise expressly stated, the features described in the dependent claims may be freely combined with each other. Furthermore, it should be understood that the use of “a” or “one” (i.e., the singular form) throughout this document does not exclude the plural. Attached Figure Description

[0028] In the accompanying drawings, some embodiments of the invention are shown by way of example rather than limitation.

[0029] Figure 1An example of an imaging system according to the present invention is illustrated schematically.

[0030] Figure 2 An example of a first surface model generated from optical image data is shown.

[0031] Figure 3 An example of a second surface model generated from dental X-ray image data is shown.

[0032] Figure 4 An example of the method according to the present invention is illustrated schematically.

[0033] Figure 5 Another example of the method according to the invention is illustrated schematically.

[0034] Figure 6 Another example of the method according to the invention is illustrated schematically.

[0035] Figure 7 Another example of the method according to the invention is illustrated schematically.

[0036] Figure 8 An example of a controller according to the present invention is shown schematically. Detailed Implementation

[0037] In this description, we use the following terms to describe the different stages of the dental X-ray imaging process. The term "irradiation" refers only to the stage of exposure, i.e., 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 will remain as stationary as possible during irradiation. During irradiation, one or more parts of the dental X-ray imaging unit may move. The term "scanning" further refers to the stage involving 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 location for providing an X-ray image. The term "imaging" refers to the entire process including irradiation, scanning, and positioning.

[0038] Figure 1 An example of an imaging system 100 according to the present invention is shown. The imaging system 100 includes a dental X-ray imaging unit 102 for providing dental X-ray image data (i.e., second image data) of a subject, an optical scanner unit 104 for providing optical image data (i.e., first image data) of a subject, and a controller 106.

[0039] The dental X-ray imaging unit 102 can be configured for imaging, for example, the dentofacial complex of the human skull. The dental X-ray imaging unit 102 can be configured to provide different types of imaging procedures, including but not limited to computed tomography (CT) imaging, panoramic imaging (standard, pediatric, anteroposterior, wide arch, orthogonal, etc.), and / or cephalometric imaging (pediatric lateral cephalometric projection, lateral cephalometric projection, posterior-anterior cephalometric projection, etc.). The CT imaging can be cone-beam CT (CBCT) imaging, where the beam is a cone beam, or alternative CT imaging, where the beam is a pyramidal beam, a crescent-shaped cone beam, or any other beam shape. Figure 1 Only one example of a dental X-ray imaging unit 102 used with the concepts in this disclosure is shown.

[0040] The dental X-ray imaging unit 102 includes a housing 101 movably supported on a support column 103. The housing 101 can be guided by a motor ( Figure 1 (Not shown in the image) moves vertically up and down, and the guide motor is configured to move the housing 101 vertically up and down along the support column 103. The support section (i.e., the upper shelf) 110 is configured to support a frame portion (i.e., the rotating portion) 112 that can rotate relative to the support section 110 in a horizontal plane. The support section 110 and / or the frame portion 112 may include a rotary motor configured to rotate the frame portion 112. Figure 1 (Not shown in the image). Alternatively or additionally, the support section 110 may include a pivot motor configured to pivot the frame section 112 about the column 103. Figure 1 (Not shown in the image). Alternatively or additionally, the dental X-ray imaging unit 102 can be mounted to a support structure (…). Figure 1 (Not shown in the image), the supporting structure is exemplarily a wall supported by column 103.

[0041] The dental X-ray imaging unit 102 further includes an X-ray source housing 114 and an X-ray imaging detector housing 116, which are arranged opposite to each other and extend generally vertically from the frame portion 112. The source housing 114 includes an X-ray source 118. The X-ray source 118 is positioned to emit X-rays that pass through the object being imaged (e.g., a patient's head) to the X-ray imaging detector 120 located in the X-ray imaging detector housing 116.

[0042] In addition, the dental X-ray imaging unit 102 may include a lower shelf 122 extending from the housing 101. (As in...) Figure 1 In the example dental X-ray imaging unit 102, the lower shelf 122 may include a chin support 124 for holding an object, such as a patient's head ( Figure 1(Not shown in the image) Positioned between the opposing X-ray source 118 and X-ray imaging detector 120. Alternatively or additionally, such as in... Figure 1 In the example dental X-ray imaging unit 102, the dental X-ray imaging unit 102 may include a head support 126 extending from the horizontal support section 110 through the rotating section 112. Alternatively, the lower shelf 122 may include the head support 126. The patient support sections (i.e., the chin support 124 and the head support 126) may be optional, and patient positioning may be performed in other ways.

[0043] X-ray source 118 is configured to project an X-ray beam toward X-ray imaging detector 120. Figure 1 (Not depicted in the text). X-ray source 118 may include a collimator ( Figure 1 (Not shown) to limit and / or shape the X-ray beam. The X-rays pass through a portion of an object, such as the anatomical structure of a patient, for example, the patient's head. The anatomical structure through which the X-rays pass may absorb varying amounts of X-ray energy. After passing through the object, the attenuated X-rays are received by an X-ray imaging detector 120. The X-ray imaging detector 120 is configured to convert the magnitude of the received X-ray energy and produce a digital output representing the X-rays that were not absorbed at the X-ray imaging detector 120, i.e., X-ray image data. The collection of digital outputs from the X-ray imaging detector 120 corresponding to a single emission of the X-ray beam from the X-ray source 118 can be referred to as a projected image of the object being imaged (e.g., the patient's head).

[0044] The gantry portion 112 can be rotated, for example, by a rotary motor. Rotation of the gantry portion 112 causes the X-ray source 118 and the X-ray imaging detector 120 to rotate about the object to be imaged (e.g., about an axis of rotation). The axis of rotation can be a mechanical axis of rotation or a virtual axis of rotation. The mechanical axis of rotation of the gantry portion 112 can be oriented, i.e., aligned, with the center of the object to be imaged or with a specific anatomical feature of interest within the object to be imaged (e.g., a patient's head). A virtual axis of rotation can be obtained, for example, by moving the mechanical axis of rotation along a circular path, thereby forming a virtual axis of rotation at the center of said circular path. Non-circular rotation can be generated, for example, by moving the X-ray source 108 and the X-ray imaging detector 120 along a path deviating from the circular path (e.g., an elliptical path). Other techniques or alignments for the axis of rotation can also be used, as will be appreciated by those skilled in the art or of ordinary skill. As the X-ray source 118 and the X-ray imaging detector 120 rotate about the object (e.g., a patient's head), the X-ray imaging apparatus 102 operates to acquire multiple projected images of the object taken at incremental rotation angles. As a non-limiting example, such as in CT imaging, a projected image rotated approximately 180° or 360° can be acquired. According to another non-limiting example, such as in panoramic imaging, a projected image rotated approximately 220° can be acquired. Furthermore, in imaging operations, the X-ray imaging unit 102 can capture, for example, between 250 and 1600 projected images. However, this is not intended to limit the present disclosure. Such increments can represent fractions of rotation degrees. Within the scope of this disclosure, other angular increments and other total rotation angles are considered. By reconstructing X-ray image data into a dental X-ray image, a dental X-ray image can be formed from multiple projected images.

[0045] like Figure 1 As shown in the example, the optical scanner unit 104 may be an intraoral scanner (IOS) unit. An intraoral scanner is a device used in dentistry to capture direct optical impressions. Using the IOS unit 104, optical image data of the object can be provided directly inside the patient's mouth or based on a stone model or dental impression generated from the object. Alternatively, the optical scanner unit 104 may be a benchtop optical scanner unit. Using the benchtop optical scanner unit 104, optical image data of the object can be provided based on a stone model or dental impression generated from the object. Figure 1 Only one example of an optical scanner unit 104 used with the concepts in this disclosure is shown.

[0046] Controller 106 is configured to acquire first image data of an object (e.g., a patient's anatomy, such as the patient's dental arch) from optical scanner unit 104. This first image data may be optical image data provided (i.e., acquired) by, for example, optical scanner unit 104 as described above. Furthermore, controller 106 is configured to acquire second image data of the same object, at least partially, from dental X-ray imaging unit 102. This second image data may be X-ray image data provided (i.e., acquired) by, for example, dental X-ray imaging unit 102 as described above. The field of view (FOV) of optical scanner unit 104 when the first image data of the object is provided and the 3D FOV of dental X-ray imaging unit 102 when the second image data of the same object is provided may at least partially overlap. Controller 106 may acquire the first image data directly from optical scanner unit 104 or from database 108 (to which the first image data previously acquired from optical scanner unit 104 may be stored), i.e., the acquired first image data includes the first image data previously acquired from optical scanner unit 104. For example, the previously acquired first image data may have been acquired and stored in database 108 minutes or even years before image processing was performed using controller 106. Alternatively or additionally, controller 106 may acquire the second image data directly from dental X-ray imaging unit 102 or from database 108 (where previously acquired second image data from dental X-ray imaging unit 102 may be stored). For example, the previously acquired second image data may have been acquired and stored in database 108 minutes or even years before image processing was performed using controller 106. The previously acquired first image data and the previously acquired second image data may be stored in separate databases or in the same database 108, such as... Figure 1 As shown in the example.

[0047] According to an example of the invention, in response to obtaining second image data from the dental X-ray imaging unit 102, the controller 106 can be configured to check whether previously obtained first image data of the same object has been stored in the database 108. If the controller 106 detects that previously obtained first image data of the same object has been stored in the database 108, the controller 106 is configured to obtain the first image data from the database 108.

[0048] The controller 106 may be further configured to generate a first surface model 202 based on the acquired first image data. The first surface model represents the optical three-dimensional (3D) shape of the surface of a first portion of the object. Figure 2A non-limiting example of a first surface model 202 generated from the first image data is shown. The controller 106 may be further configured to use the first surface model 202 to process the acquired second image data. The use of the first surface model 202 by the controller 106 to process the acquired second image data may depend on the type of imaging process, such as CT imaging or panoramic imaging, i.e., panoramic modality.

[0049] The following discussion presents an example of how controller 106 uses the first surface model 202 to process the acquired second image data, wherein the imaging process used by the dental X-ray imaging unit 102 can be, for example, CT imaging, such as CBCT imaging. Controller 106 can be configured to detect motion of an object occurring during the acquisition of the second image data (i.e., during the scanning process in which the second image data is provided), and is configured to reduce motion-induced artifacts in the reconstructed two-dimensional (2D) or three-dimensional (3D) dental X-ray images based on the first surface model 202. The 2D or 3D dental X-ray images can be, for example, CT images.

[0050] The controller 106 can be configured to generate a second surface model 302 based on the acquired second image data. The second surface model 302 represents the X-ray 3D shape of the surface of a second portion of the object. Figure 3 A non-limiting example of a second surface model 302 generated from second image data is shown. The second portion of the object at least partially overlaps with the first portion of the object, such that the first surface model 202 and the second surface model 302 at least partially originate from the same portion of the same object. For example, the first portion of the object's provided first surface model 202 may include a patient's upper and / or lower complete dental arch, a portion of the patient's upper and / or lower dental arch, or a single tooth of the patient. Alternatively or additionally, the second portion of the object's provided second surface model 302 may include a patient's upper and / or lower complete dental arch, a portion of the patient's upper and / or lower dental arch, or a single tooth of the patient, provided that the second portion of the object at least partially overlaps with the first portion of the object. The generation of the second surface model 302 may include reconstructing the obtained second image data into a 3D dental X-ray image, and extracting the second surface model 302 from the 3D dental X-ray image using segmentation.

[0051] To detect object motion occurring during the acquisition of the second image data, the controller 106 can be configured to: compare the similarity between the second surface model 302 and the first surface model 202, and detect motion if the second surface model 302 differs from the first surface model 202. According to an example, before comparing the similarity of surface models 202 and 302, the controller 106 can be configured to register, i.e., align, the first surface model 202 and the second surface model 302. Registration may include: determining at least one reference structure from the second surface model 302; finding a corresponding at least one reference structure from the first surface model 202; and registering the first surface model 202 and the second surface model 302 based on the at least one reference structure. Alternatively, registration may include: determining at least one reference structure from the first surface model 202; finding a corresponding at least one reference structure from the second surface model 302; and registering the first surface model 202 and the second surface model 302 based on the at least one reference structure. For example, the at least one reference structure may be, but is not limited to, a specific tooth.

[0052] As discussed above, dental X-ray images can be formed from multiple projection images. Each projection image has a precisely defined and known imaging geometry. If the object does not remain stationary or the movement of the dental X-ray imaging unit 102 does not follow the defined imaging geometry, the reconstruction result (i.e., the reconstructed dental X-ray image) will be distorted due to motion-induced artifacts. If the controller 106 detects that the second surface model 302 differs from the first surface model 202, the controller 106 detects motion, i.e., infers that the object has moved during the acquisition of the second image data. In response to detecting motion, the controller 106 can be further configured to reduce motion-induced artifacts in the dental X-ray image reconstructed from the acquired second image data. Alternatively, if the controller 106 detects that there is no substantial difference between the second surface model 302 and the first surface model 202, the controller 106 detects no motion, i.e., infers that the object did not move during the acquisition of the second image data, which results in no need to perform any corrections to the X-ray image, such as artifact reduction.

[0053] According to the example, reducing motion-induced artifacts may include iteratively adapting the mutual imaging geometry of multiple projected images forming a dental X-ray image reconstructed from the obtained second image data to provide minimum differences between the first surface model 202 and the second surface model 302, i.e., finding the best match between the first surface model and the second surface model such that the second surface model 302 becomes as similar as possible to the first surface model 202.

[0054] The following discussion presents another example of how controller 106 uses the first surface model 202 to process the acquired second image data, where the imaging process used by dental X-ray imaging unit 102 can be, for example, panoramic imaging. Controller 106 can be configured to determine the anatomical shape of the object (e.g., the patient's dental arch or jawbone shape) based on the first surface model 202 and adjust the reconstruction of the dental X-ray image based on the acquired second image data such that the focused layer in the dental X-ray image corresponds to the anatomical shape of the object determined based on the first surface model 202. The dental X-ray image can be a 2D dental X-ray image, such as a 2D panoramic image or a bite wing image. The portions of the patient's anatomy that touch the sharp layers are clear in the dental X-ray image, while other portions of the patient's anatomy are blurred.

[0055] According to an exemplary embodiment of the invention, where the imaging process used by the dental X-ray imaging unit 102 can be, for example, panoramic imaging, the controller 106 can be configured to use first image data, such as optical image data, obtained from the optical scanner 104 in acquiring second image data using the dental X-ray imaging unit 102. In this exemplary embodiment, the use of the first image data can include: the controller 106 can be configured to use the first image data to define the imaging geometry of the X-ray imaging unit 102 for the acquisition of second image data, i.e., for use in a scanning process in which the second image data can be provided. As discussed above, the controller 106 can be configured to obtain first image data of an object (e.g., the anatomy of a patient) from the optical scanner unit 104. Also as discussed above, the controller 106 can obtain the first image data directly from the optical scanner unit 104 or from a database 108 (to which the first image data previously obtained from the optical scanner unit 104 can be stored), i.e., the obtained first image data includes the first image data previously obtained from the optical scanner unit 104.

[0056] The controller 106 may be further configured to generate a first surface model 202 based on the acquired first image data. As discussed above, the first surface model 202 represents the optical 3D shape of a first portion of the surface of the object. The first portion of the object, which may provide the first surface model 202, may include the patient's upper and / or lower complete dental arch. As discussed above, the controller 106 may be further configured to determine the anatomical shape of the object, such as the patient's dental arch or jawbone shape, based on the first surface model 202.

[0057] As discussed above, controller 106 can be configured to define the imaging geometry of dental X-ray imaging unit 102 based on first surface model 202 for the acquisition of second image data. The imaging geometry of dental X-ray imaging unit 102 can be defined by controller 106 based on the anatomical shape of the object determined based on first surface model 202, such that the focal layer in the dental X-ray image reconstructed from the second image data (acquired using the defined imaging geometry) corresponds to the anatomical shape of the object determined based on first surface model 202. In other words, in this example embodiment, the first surface model 202 is formed and the anatomical shape of the object is determined based on the first surface model 202 before dental X-ray imaging unit 102 acquires the second image data, i.e., before the scanning process in which the second image data is provided. Controller 106 can be further configured to define the imaging geometry of dental X-ray imaging unit 102 using information representing the object's location, such that the focal layer in the dental X-ray image reconstructed from the second image data (acquired using the defined imaging geometry of X-ray imaging unit 102) corresponds to the anatomical shape of the object determined based on first surface model 202. Information representing the object's location may include, for example, the location where the object is supported using one or more of the patient support portions and / or the center of the object. Information representing the object's location can be defined using any known technique. According to a non-limiting example, the location where the object is supported may be defined based, for example, on an occlusal block (e.g., an occlusal bar) arranged to the chin support 124. The controller 106 may be configured to provide the defined imaging geometry of the dental X-ray imaging unit 102, which can therefore be configured to acquire, i.e., provide, second image data of the same object using the defined imaging geometry.

[0058] The controller 106 may be further configured to obtain second image data from the dental X-ray imaging unit 102 by using the imaging geometry defined by the dental X-ray unit 102, and to reconstruct the obtained second image data into a dental X-ray image, such as a 2D panoramic image or a bite flap image, wherein the focal layer in the dental X-ray image reconstructed from the obtained second image data corresponds to the anatomical shape of the object determined based on the first surface model 202.

[0059] The invention has been described above with reference to controller 106. The invention also relates to a method for dental imaging of an object. First image data (e.g., optical image data) can be used for dental X-ray imaging of the object. The first image data can be used to process acquired second image data, such as X-ray image data. Alternatively, the first image data can be used to acquire second image data using a dental X-ray imaging unit 102. For example, in panoramic imaging, the use of the acquired first image data in acquiring the second image data can include defining the imaging geometry of the dental X-ray imaging unit 102 based on the first image data for the acquisition of the second image data. For example, in CT imaging, using the first image data to process the acquired second image data can include: detecting motion of the object occurring during the acquisition of the second image data based on the first image data; and reducing motion-induced artifacts in a two-dimensional or three-dimensional dental X-ray image reconstructed based on the second image data based on the first image data. Alternatively, for example in panoramic imaging, using the first image data to process the acquired second image data can include: adjusting the reconstruction of the dental X-ray image based on the second image data such that the focal layer in the dental X-ray image corresponds to the anatomical shape of the object determined based on the first image data.

[0060] Next, refer to Figure 4 Examples of methods according to the present invention are described. Figure 4 The invention is illustrated schematically in the form of a flowchart. It should be understood that embodiments of the method may be performed without each of the steps disclosed herein or in combination with additional steps.

[0061] At step 402, the controller 106 obtains first image data of an object (e.g., the anatomical structure of a patient) from the optical scanner unit 104. The first image data may be, for example, optical image data. As discussed above, the controller 106 may obtain the first image data directly from the optical scanner unit 104 or from a database 108 (to which the first image data previously obtained from the optical scanner unit 104 may be stored), i.e., the obtained first image data includes the first image data previously obtained from the optical scanner unit 104.

[0062] At step 404, controller 106 obtains second image data of the same object from, for example, dental X-ray imaging unit 102. The second image data may be, for example, X-ray image data. According to an example, in response to obtaining the second image data from dental X-ray imaging unit 102, controller 106 checks whether previously obtained first image data of the same object has been stored in database 108. If controller 106 detects that previously obtained first image data of the same object has been stored in database 108, then at step 402, controller 106 is configured to obtain the first image data from database 108.

[0063] At step 406, the controller 106 generates a first surface model 202 based on the acquired first image data. As discussed above, the first surface model 202 represents the optical 3D shape of the surface of a first portion of the object.

[0064] At step 408, controller 106 uses the first surface model 202 to process the acquired second image data. The use of the first surface model 202 by controller 106 to process the acquired second image data at step 408 can depend on the type of imaging process, such as CT imaging or panoramic imaging, i.e., panoramic modality. (See reference...) Figure 5 and Figure 6 Let’s discuss step 408 in more detail. Figure 5 An example embodiment of the method according to the invention is shown, wherein the imaging process used by the dental X-ray imaging unit 102 may be, for example, CT imaging, such as CBCT imaging. Figure 6 Another example embodiment of the method according to the invention is shown, wherein the imaging process used by the dental X-ray imaging unit 102 may be, for example, panoramic imaging. Figure 5 and Figure 6 Steps 402 to 408 of the example method correspond to Figure 4 Steps 402 to 408 of the example method, but refer to Figure 5 and Figure 6 Step 408, which involves processing the obtained second image data using the first surface model 202, will be discussed in more detail.

[0065] Next reference Figure 5 An example is discussed whereby the controller 106 uses the first surface model 202 to process the acquired second image data at step 408, wherein the imaging process used by the dental X-ray imaging unit may be, for example, CT imaging, such as CBCT imaging.

[0066] At step 501, controller 106 generates a second surface model 302 based on the acquired second image data. The second surface model 302 represents the 3D X-ray shape of the surface of a second portion of the object. As discussed above, the second portion of the object at least partially overlaps with the first portion of the object, such that the first surface model 202 and the second surface model 302 are at least partially derived from the same portion of the object.

[0067] exist Figure 5 At step 408, the controller 106 can detect motion of the object occurring during the acquisition of the second image data (i.e., the scanning process in which the second image data is provided), and reduce motion-induced artifacts in the 2D or 3D dental X-ray image reconstructed from the acquired second image data based on a first surface model. This will refer to Figure 5Steps 502-510 will be discussed in more detail. 2D or 3D dental X-ray images can be, for example, CT images.

[0068] At step 502, controller 106 compares the similarity between the second surface model 302 and the first surface model 202 to detect whether the object has moved during the acquisition of the second image data (i.e., during the scanning process). According to an example, before comparing the surface models, controller 106 may register, or align, the first surface model 202 and the second surface model 302. Registration may include: determining at least one reference structure from the second surface model 302; finding a corresponding at least one reference structure from the first surface model 202; and registering the first surface model 202 and the second surface model 302 based on the at least one reference structure. Alternatively, registration may include: determining at least one reference structure from the first surface model 202; finding a corresponding at least one reference structure from the second surface model 302; and registering the first surface model 202 and the second surface model 302 based on the at least one reference structure. For example, the at least one reference structure may be, but is not limited to, a specific tooth.

[0069] If at step 504 the controller 106 detects that the second surface model 302 is different from the first surface model 202 based on the comparison at step 502, then at step 506 the controller 106 detects motion, i.e., infers that the object has moved during the acquisition of the second image data. In response to the motion detection at step 506, at step 510 the controller reduces motion-induced artifacts in the dental X-ray image reconstructed from the acquired second image data caused by motion. Alternatively, if at step 504 the controller 106 detects that there is no substantial difference between the second surface model 302 and the first surface model 202 based on the comparison at step 502, then at step 508 the controller 106 detects no motion, i.e., infers that the object has not moved during the acquisition of the second image data, making it unnecessary to perform any corrections to the dental X-ray image, such as artifact reduction.

[0070] According to the example, reducing motion-induced artifacts at step 510 may include iteratively adapting the mutual imaging geometry of multiple projected images forming a dental X-ray image reconstructed from the obtained second image data to provide the minimum difference or maximum similarity between the first surface model 202 and the second surface model 302, i.e., finding the best match between the first surface model 202 and the second surface model 302 such that the second surface model 302 becomes as similar as possible to the first surface model 202.

[0071] Next reference Figure 6An example is discussed whereby the controller 106 uses the first surface model 202 to process the acquired second image data at step 408, wherein the imaging process used by the dental X-ray imaging unit may be, for example, panoramic imaging.

[0072] At step 602, the controller 106 determines the anatomical shape of the object, such as the patient's dental arch or jawbone shape, based on the first surface model 202.

[0073] At step 604, the controller 106 may further adjust the reconstruction of the dental X-ray image based on the acquired second image data, such that the focused layer in the dental X-ray image corresponds to the anatomical shape of the object determined based on the first surface model 202. The portions of the patient's anatomy that touch the sharp layers are clear in the dental X-ray image, while other portions of the patient's anatomy are blurred. The dental X-ray image may be a 2D dental X-ray image, such as a 2D panoramic image.

[0074] Figure 7 Another example embodiment of the method according to the invention is illustrated schematically, wherein in acquiring second image data using the dental X-ray imaging unit 102, i.e., during a scan in which the second image data can be provided, the controller 106 can use first image data, such as optical image data, obtained from the optical scanner 104. For example, in Figure 7 In the example method, the imaging process used by the dental X-ray imaging unit 102 can be panoramic imaging.

[0075] As discussed above with reference to step 402, at step 702, controller 106 obtains first image data of an object (e.g., the anatomical structure of a patient) from optical scanner unit 104. The first image data may be, for example, optical image data. Also as discussed above, controller 106 may obtain the first image data directly from optical scanner unit 104 or from database 108 (where the first image data previously obtained from optical scanner unit 104 can be stored), i.e., the obtained first image data includes the first image data previously obtained from optical scanner unit 104.

[0076] At step 704, controller 106 generates a first surface model 202 based on the acquired first image data. As discussed above with reference to step 406, the first surface model 202 represents the optical 3D shape of a first portion of the surface of the object. The first portion of the object, which may provide the first surface model 202, may include the patient's upper and / or lower complete dental arch.

[0077] As discussed above with reference to step 602, at step 706, the controller 106 determines the anatomical shape of the object, such as the patient's dental arch or jawbone shape, based on the first surface model 202.

[0078] At step 708, in the acquisition of the second image data, the controller 106 uses the first image data. Using the first image data in the acquisition of the second image data may include: the controller 106 defining an imaging geometry of the X-ray imaging unit 102 based on the first surface model 202 for the acquisition of the second image data. The imaging geometry of the dental X-ray imaging unit 102 may be defined by the controller 106 based on the anatomical shape of the object determined based on the first surface model 202, such that the focused layer in the dental X-ray image reconstructed according to the second image data (acquired using the defined imaging geometry of the X-ray imaging unit 102) corresponds to the anatomical shape of the object determined based on the first surface model 202. In other words, in this example embodiment, the first surface model 202 is formed and the anatomical shape of the object is determined based on the first surface model 202 before the dental X-ray imaging unit 102 acquires the second image data, i.e., before the scanning process in which the second image data is provided. The controller 106 may further use information representing the object's location to define the imaging geometry of the dental X-ray imaging unit 102, such that the focused layer in the dental X-ray image reconstructed based on the second image data (acquired using the defined imaging geometry of the X-ray imaging unit 102) corresponds to the anatomical shape of the object determined based on the first surface model 202. The information representing the object's location may include, for example, the location of the object being supported using one or more of the patient support portions and / or the center of the object. The information representing the object's location can be defined using any known technique. According to a non-limiting example, the location of the object being supported may be defined based, for example, on an occlusal block (e.g., an occlusal bar) arranged to the chin support 124. The controller 106 may provide the defined imaging geometry of the dental X-ray imaging unit 102, which can then acquire, i.e., provide, the second image data of the same object using the defined imaging geometry.

[0079] At step 710, the controller 106 may further obtain second image data from the dental X-ray imaging unit 102, acquired by using the defined imaging geometry of the dental X-ray unit 102.

[0080] At step 712, the controller 106 may further reconstruct the acquired second image data into a dental X-ray image, such as a 2D panoramic image or bite flap, wherein the focal layer in the dental X-ray image reconstructed from the acquired second image data corresponds to the anatomical shape of the object determined based on the first surface model 202.

[0081] Figure 8A schematic example of a controller 106 according to the present invention is shown. The controller 106 may include a processor portion 802, a data transmission portion 804, a user interface portion 806, and a memory portion 808. The processor portion 802 is configured to execute instructions initiated by a user and / or a computer program (software) and to process data. The processor portion 802 may include at least one processor. The memory portion 808 is configured to store and maintain data. The data may be instructions, computer programs, and any data files. The memory portion 808 may include at least one memory. The memory portion 808 may further include at least: a data transmission application 810 for controlling the data transmission portion 804; a user interface application 812 for controlling the UI portion 806; and a computer program (code) 814 for controlling the operation of the controller 106. The memory portion 800 and the computer program 814, together with the processor portion 802, enable the controller 106 to at least implement one or more method steps and / or operations of the controller 106 as described above.

[0082] The data transmission section 804 can be configured to send control commands to external units (such as the dental X-ray imaging unit 102). Furthermore, the data transmission section 804 can receive data from external units (such as the dental X-ray imaging unit 102, the optical scanner unit 104, a database, and / or any other external unit).

[0083] The user interface (UI) portion 806 can be configured to input control commands, receive information and / or instructions, and display information. The UI portion 806 may include at least a display, screen, touchscreen, at least one function key, keyboard, wired or wireless remote control, or any other user input and / or output device.

[0084] Computer program 814 may be a computer program product, which may be included in a tangible, non-volatile (non-transitory) computer-readable medium carrying computer program code 814 contained therein for use with a computer (i.e., controller 106).

[0085] Some non-limiting examples of controller 106 may be, for example, a server, cloud server, personal computer, laptop computer, computing circuitry, or a network of computing devices. The location of controller 106 is not limited, and controller 106 can be located anywhere. For example, controller 106 may be implemented as part of dental X-ray imaging unit 102. Alternatively, controller 106 may be implemented as an external part of dental X-ray imaging 102, i.e., an external unit.

[0086] The above-described embodiments of the present invention enable a simple method for reducing artifacts caused by the motion of an object in 2D or 3D dental X-ray images (e.g., 3D CBCT images) by using optical image data. The above-described embodiments of the present invention improve the quality of dental X-ray images (e.g., 3D CBCT images and / or 2D panoramic images) by using optical image data.

[0087] The specific examples provided in the description above should not be construed as limiting the applicability and / or interpretation of the appended claims. Unless otherwise expressly stated, the list and groups of examples provided in the description above are not exhaustive.

[0088] The following numbered clauses describe some aspects of the invention.

[0089] Clause 1. A controller 106 for dental imaging of an object, the controller 106 comprising: At least one processor 802; and At least one memory 808 contains computer program code 814. The at least one memory 808 and computer program code 814 are configured, together with the at least one processor 802, to cause the controller 106 to at least: First image data is obtained from the optical scanner unit 104. A first surface model 202 is generated based on the obtained first image data, wherein the first surface model 202 represents the optical three-dimensional shape of the surface of a first portion of the object, and The first surface model 202 is used in the acquisition of the second image data of the object.

[0090] Clause 2. The controller 106 as described in Clause 1, wherein the optical scanner unit 104 is an intraoral scanner unit.

[0091] Clause 3. The controller 106 according to any one of the preceding clauses, wherein the acquired first image data includes the first image data previously acquired from the optical scanner unit 104.

[0092] Clause 4. The controller 106 according to any one of the preceding clauses, wherein the controller 106 is configured to: define the imaging geometry of the dental X-ray imaging unit 102 based on the first surface model 202 for the acquisition of second image data of the object.

[0093] Clause 5. The controller 106 as described in Clause 4, wherein the controller 106 is further configured to: Second image data of the object obtained from the dental X-ray imaging unit 102 using the imaging geometry defined by the dental X-ray imaging unit 102, and The obtained second image data was reconstructed into a dental X-ray image.

[0094] Clause 6. An imaging system 100 for dental imaging of an object, the imaging system 100 comprising: Dental X-ray imaging unit 102, for providing second image data, wherein dental X-ray imaging unit 102 includes: Rack section 112, X-ray source section 118, used to emit X-rays, and X-ray imaging detector section 120 is used to receive X-rays from source section 118. The rack section 112 includes a source section 118 and a detector section 120. Optical scanner unit 104, for providing first image data, and The controller 106 according to any one of the foregoing clauses, wherein the controller 106 is configured to: First image data is obtained from the optical scanner unit 104. A first surface model 202 is generated based on the obtained first image data, wherein the first surface model 202 represents the optical three-dimensional shape of the surface of a first portion of the object, and The first surface model 202 is used in the acquisition of the second image data of the object.

[0095] Clause 7. A method for dental imaging of an object, the method being performed by a controller 106 according to any one of Clauses 1 to 5, wherein the method comprises: First image data is obtained from the optical scanner unit 104. A first surface model 202 is generated based on the obtained first image data, wherein the first surface model 202 represents the optical three-dimensional shape of the surface of a first portion of the object, and The first surface model 202 is used in the acquisition of the second image data of the object.

[0096] Clause 8. A computer program 814 comprising instructions that, when executed by a controller 106 pursuant to any one of Clauses 1 to 5, cause the controller 106 to perform the method pursuant to Clause 7.

[0097] Clause 9. A tangible, non-volatile, computer-readable medium comprising instructions that, when executed by a controller 106 according to any one of Clauses 1 to 5, cause the controller 106 to perform the method according to Clause 7.

Claims

1. A controller (106) for dental imaging of an object, the controller comprising: At least one processor (802); as well as At least one memory (808) contains a computer program (814). The at least one memory (808) and the computer program (814) are configured, together with the at least one processor (802), to cause the controller (106) to at least: First image data is obtained from the optical scanner unit (104). Second image data is obtained from the dental X-ray imaging unit (102). A first surface model (202) is generated based on the obtained first image data, wherein the first surface model (202) represents the optical three-dimensional shape of the surface of a first portion of the object. The first surface model (202) is used to process the obtained second image data. Based on the first surface model (202), the motion of the object occurring during the acquisition of the second image data is detected, and Based on the first surface model (202), reduce artifacts caused by the motion in two-dimensional or three-dimensional dental X-ray images reconstructed from the obtained second image data; The detection of the motion includes: A second surface model (302) is generated based on the obtained second image data, wherein the second surface model (302) represents the X-ray 3D shape of the surface of a second part of the object, and wherein the second part of the object at least partially overlaps with the first part of the object; Compare the similarity between the second surface model (302) and the first surface model (202); and If the second surface model (302) is different from the first surface model (202), then the motion is detected.

2. The controller (106) according to claim 1, wherein, The optical scanner unit (104) is an intraoral scanner unit.

3. The controller (106) according to claim 1, wherein, The first image data obtained includes the first image data previously obtained from the optical scanner unit (104).

4. The controller (106) according to claim 1, wherein, The generation of the second surface model (302) includes: The obtained second image data is reconstructed into a three-dimensional dental X-ray image, and The second surface model (302) is extracted from the three-dimensional dental X-ray image by segmentation.

5. The controller (106) according to any one of claims 1 to 4, wherein, The detection of the motion further includes registering the first surface model (202) and the second surface model (302) prior to the comparison.

6. An imaging system (100) for dental imaging of an object, the imaging system (100) comprising: A dental X-ray imaging unit (102) for providing second image data, wherein the dental X-ray imaging unit (102) includes: Rack section (112). The X-ray source section (118) is used to emit X-rays, and X-ray imaging detector section (120) is used to receive the X-rays from the source section (118). The rack portion (112) includes the source portion (118) and the detector portion (120). An optical scanner unit (104) is used to provide first image data, and The controller (106) according to any one of claims 1 to 5, wherein the controller (106) is configured to: The first image data is obtained from the optical scanner unit (104). The second image data is obtained from the dental X-ray imaging unit (102). A first surface model (202) is generated based on the obtained first image data, wherein the first surface model (202) represents the optical three-dimensional shape of the surface of a first portion of the object. The first surface model (202) is used to process the obtained second image data. Based on the first surface model (202), the motion of the object occurring during the acquisition of the second image data is detected, and Based on the first surface model (202), reduce artifacts caused by the motion in two-dimensional or three-dimensional dental X-ray images reconstructed from the obtained second image data; The detection of the motion includes: A second surface model (302) is generated based on the obtained second image data, wherein the second surface model (302) represents the X-ray 3D shape of the surface of a second part of the object, and wherein the second part of the object at least partially overlaps with the first part of the object; Compare the similarity between the second surface model (302) and the first surface model (202); and If the second surface model (302) is different from the first surface model (202), then the motion is detected.

7. A method for dental imaging of an object, said method being performed by a controller (106) according to any one of claims 1 to 5, said method comprising: First image data is obtained from the optical scanner unit (104). Second image data is obtained from the dental X-ray imaging unit (102). A first surface model (202) is generated based on the obtained first image data, wherein the first surface model (202) represents the optical three-dimensional shape of the surface of a first portion of the object. The first surface model (202) is used to process the obtained second image data. Based on the first surface model (202), the motion of the object occurring during the acquisition of the second image data is detected, and Based on the first surface model (202), reduce artifacts caused by the motion in two-dimensional or three-dimensional dental X-ray images reconstructed from the obtained second image data; The detection of the motion includes: A second surface model (302) is generated based on the obtained second image data, wherein the second surface model (302) represents the X-ray 3D shape of the surface of a second part of the object, and wherein the second part of the object at least partially overlaps with the first part of the object; Compare the similarity between the second surface model (302) and the first surface model (202); and If the second surface model (302) is different from the first surface model (202), then the motion is detected.

8. A computer program (814) comprising instructions that, when the program is executed by a controller (106) according to any one of claims 1 to 5, cause the controller (106) to perform the method according to claim 7.

9. A tangible, non-volatile, computer-readable medium comprising instructions that, when executed by a controller (106) according to any one of claims 1 to 5, cause the controller (106) to perform the method according to claim 7.

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