Controller, dental imaging system, and method for dental imaging of an object.
The controller and imaging system use optical scanner data to create surface models and adjust X-ray reconstructions, addressing positioning challenges and anatomical discrepancies, thereby improving dental X-ray image clarity and accuracy.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- PALODEX GROUP
- Filing Date
- 2021-10-20
- Publication Date
- 2026-05-20
AI Technical Summary
Conventional dental X-ray imaging techniques face challenges in maintaining patient positioning stability, leading to image artifacts and suboptimal image quality due to patient or imaging unit movement, and anatomical shape discrepancies affecting panoramic image quality.
A controller and imaging system that utilizes optical scanner data to create a surface model, detect movement, and adjust reconstruction to align with anatomical shape, reducing artifacts and improving image quality.
Enhances dental X-ray image quality by minimizing movement-induced artifacts and optimizing image alignment with patient anatomy, resulting in clearer and more accurate dental radiographs.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention generally relates to the technical field of dental imaging.
Background Art
[0002] Typically, proper positioning of a patient can be one of the most time-consuming tasks for a user of an X-ray imaging unit in X-ray imaging procedures. Conventionally, a patient can be positioned relative to an X-ray imaging unit using various support methods that will hold the patient's head as still as possible.
[0003] Conventional support means can be jaw stops, static bite sticks, and head supports, in which case the forehead, cheekbones, and / or the back of the skull are supported. Additionally, different types of straps can be used to make the patient's positioning as rigid as possible. Additionally, some X-ray imaging units have such bite sticks that are attached to the X-ray imaging unit, thereby enabling the attachment means to move the bite stick in several directions.
[0004] One approach that can be considered similarly conventional is to use scout images. These are low-dose panoramic images or a set of two projection images taken at a 90-degree angle and can be used as targeting aids for three-dimensional (3D) images.
[0005] In this approach, strict setup is crucial. Once patient positioning (targeting) is complete, the patient should remain stable throughout the entire imaging process. If the patient and / or the X-ray imaging unit moves, i.e., if the patient's position relative to the X-ray imaging unit changes between the targeting phase and the X-ray scanning phase, the resulting X-ray images may be diagnostically unhelpful. Movement of the patient and / or the X-ray imaging unit during the scanning phase can cause significant artifacts in the resulting X-ray images, and these artifacts caused by movement should, if possible, be reduced during the reconstruction of the acquired image data during the scanning phase into dental X-ray images, or attempts can be made to reduce them by using software-based, i.e., computer program-based correction. Artifacts caused by movement can significantly affect the image quality of dental X-rays. The result may be, for example, a blurred or distorted image.
[0006] Furthermore, in panoramic imaging, the anatomical shape of the patient's jaw is unknown before the image is taken. The quality of the panoramic image is largely influenced by how well the predefined imaging layers correspond to the patient's actual anatomical shape, such as the dental arch. Typically, an average shape is used for all patients, which can lead to unoptimized image quality. [Overview of the project] [Means for solving the problem]
[0007] The following is a simplified overview to provide a basic understanding of several aspects of various embodiments of the invention. This overview is not a comprehensive summary of the invention. It is not intended to identify any major or important elements of the invention or to describe its scope. The following overview merely presents some concepts of the invention in a simplified form as a prelude to a more detailed description of exemplary embodiments of the invention.
[0008] An 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 an object, as well as a method for using optical image data in dental X-ray imaging of an object. Another object of the present invention is that the controller, imaging system, method, computer program, and tangible non-volatile computer-readable medium for dental imaging of an object, as well as a method for using optical image data in dental X-ray imaging of an object, improve the quality of dental X-ray images.
[0009] The object of the present invention is achieved by controllers, imaging systems, methods, computer programs, and tangible non-volatile computer-readable media, as defined by the scope of each independent claim.
[0010] According to a first embodiment, a controller for dental imaging of an object is provided, the controller comprising at least one processor and at least one memory containing computer program code, the at least one memory and computer program code are configured to cause the controller to use at least one processor to perform at least: acquire first image data from an optical scanner unit; acquire second image data from a dental X-ray imaging unit; create a first surface model from the acquired first image data, wherein the first surface model represents the optical three-dimensional shape of the surface of a first part of the object; and use the first surface model to process the acquired second image data.
[0011] The optical scanner unit may be an intraoral scanner unit.
[0012] The first acquired image data may include the first image data previously acquired from the optical scanner unit.
[0013] The controller may be configured to detect the movement of an object that occurs while acquiring second image data, based on a first surface model, and to reduce artifacts caused by the movement in the two-dimensional or three-dimensional dental X-ray image reconstructed from the acquired second image data, based on the first surface model.
[0014] Motion detection may include: creating a second surface model from acquired second image data, wherein the second surface model represents the X-ray 3D shape of the surface of a second part of the object, and the second part of the object at least partially overlaps with the first part of the object; comparing the similarity between the second surface model and the first surface model; and detecting motion if the second surface model differs from the first surface model.
[0015] The preparation of the second surface model may include reconstructing the acquired 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 using segmentation.
[0016] Alternatively or additionally, motion detection may further include fitting together the first and second surface models prior to comparison.
[0017] Alternatively, the controller may be configured to determine the anatomical shape of the object based on a first surface model and to adjust the reconstruction of the dental X-ray image from the acquired second image data so that the focal trough of 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 embodiment, an imaging system for dental imaging of an object is provided, the imaging system comprising a dental X-ray imaging unit for providing a second image data, the dental X-ray imaging unit comprising a gantry section, an X-ray source section for emitting X-rays, and an X-ray imaging detector section for receiving X-rays from the source section, wherein the gantry section comprises the source section and the detector section, an optical scanner unit for providing a first image data, and the controller described above, wherein the controller is configured to acquire a first image data from the optical scanner unit, acquire a second image data from the dental X-ray imaging unit, create a first surface model from the acquired first image data, wherein the first surface model represents the optical three-dimensional shape of the surface of a first part of the object, and use the first surface model to process the acquired second image data.
[0019] According to a third aspect, a method for dental imaging of an object is provided, which is carried out by the controller defined above, the method comprising: acquiring first image data from an optical scanner unit; acquiring second image data from a dental X-ray imaging unit; fabricating a first surface model from the acquired first image data, wherein the first surface model represents the optical three-dimensional shape of the surface of a first part of the object; and using the first surface model to process the acquired second image data.
[0020] According to a fourth aspect, a computer program including instructions is provided, which cause the controller to perform the method described above when the program is executed by the controller described above.
[0021] According to a fifth aspect, a tangible, non-volatile, computer-readable medium containing instructions is provided, which, when executed by the controller described above, causes the controller to perform the method described above.
[0022] According to the sixth aspect, a method is provided for using optical image data in dental X-ray imaging of an object, the method comprising acquiring optical image data of an object from an optical scanner unit and using the acquired optical image data in dental X-ray imaging of the object.
[0023] Using acquired optical image data may include, based on the optical image data, detecting the movement of the object that occurs while the X-ray image data of the object is being obtained, and, based on the optical image data, reducing artifacts caused by movement in the two-dimensional or three-dimensional dental X-ray images reconstructed from the X-ray image data of the object.
[0024] Alternatively, using acquired optical image data may involve adjusting the reconstruction of the dental X-ray image from the object's X-ray image data so that the focal trough in the dental X-ray image corresponds to the anatomical shape of the object determined based on the optical image data.
[0025] Alternatively, using acquired optical image data may involve defining the imaging geometry of a dental X-ray imaging unit for acquiring X-ray image data of the object based on the optical image data.
[0026] Various exemplary and non-limiting embodiments of the present invention, along with additional objectives and advantages thereof, will be best understood from the following descriptions of specific exemplary and non-limiting embodiments when read in conjunction with the accompanying drawings, with respect to both structure and operation.
[0027] The verbs "to comprise" and "to include" are used herein as open limitations, neither excluding nor requiring the existence of features not enumerated. Features enumerated in the dependent claims may be freely combined with each other unless otherwise explicitly stated. Furthermore, it should be understood throughout this specification that the use of "a" or "an," i.e., the singular form, does not exclude the plural.
[0028] Embodiments of the present invention are illustrated by way of example and not limitation in the figures of the accompanying drawings.
Brief Description of the Drawings
[0029] [Figure 1] An example of an imaging system according to the present invention is schematically shown. [Figure 2] An example of a first surface model created from optical image data is shown. [Figure 3] An example of a second surface model created from dental X-ray image data is shown. [Figure 4] An example of a method according to the present invention is schematically shown. [Figure 5] Another example of a method according to the present invention is schematically shown. [Figure 6] Yet another example of a method according to the present invention is schematically shown. [Figure 7] Yet another example of a method according to the present invention is schematically shown. [Figure 8] An example of a controller according to the present invention is schematically shown.
Modes for Carrying Out the Invention
[0030] In this specification, the following vocabulary is used for different stages of dental X-ray imaging processing. The term "radiation" simply means the stage including irradiation, i.e., the stage where the X-ray source provides an X-ray beam passing through the object to the X-ray imaging detector. The object is expected to remain stationary as much as possible, i.e., immobile, during radiation. One or more parts of the dental X-ray imaging unit may move during radiation. Next, the term "scanning" means the stage including 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 place to provide an X-ray image. The term "imaging" means the entire process including radiation, scanning, and positioning.
[0031] Figure 1 shows an example of the imaging system 100 according to the present invention. The imaging system 100 comprises a dental X-ray imaging unit 102 for providing dental X-ray image data of an object, i.e., second image data; an optical scanner unit 104 for providing optical image data of an object, i.e., first image data; and a controller 106.
[0032] The dental radiography unit 102 may be configured, for example, for imaging the dentofacial complex of the human skull. The dental radiography unit 102 may be configured to provide different types of imaging, including but not limited to computed tomography (CT) imaging, panoramic imaging (standard, pediatric, orthozone, wide arch, orthogonal, etc.), and / or head matrix imaging (pediatric lateral projection, lateral projection, anterior-posterior projection, etc.). The CT imaging may be cone-beam CT (CBCT) imaging, where the beam is cone-shaped, or alternative CT imaging, where the beam is pyramidal, crescent-shaped cone, or any other shape. Figure 1 shows only an example of the dental radiography unit 102 for use with the concepts of this disclosure.
[0033] The dental X-ray imaging unit 102 comprises a housing 101 that is movably supported on a support column 103. The housing 101 can be moved vertically up and down by a guide motor (not shown in Figure 1) configured to move the housing 101 vertically up and down along the support column 103. A support section, i.e., an upper shelf 110, is configured to support a gantry section, i.e., a rotating section 112 that is rotatable in the horizontal plane relative to the support section 110. The support section 110 and / or the gantry section 112 may include a rotary motor (not shown in Figure 1) configured to rotate the gantry section 112. Alternatively or additionally, the support section 110 may include a pivot motor (not shown in Figure 1) configured to pivot the gantry section 112 around the column 103. Alternatively or additionally, the dental X-ray imaging unit 102 may be mounted on a support structure, exemplary a wall (not shown in Figure 1) supported by the column 103.
[0034] 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 positioned opposite each other and extend generally perpendicularly from the gantry section 112. The source housing 114 includes an X-ray source 118. The X-ray source 118 is positioned to emit X-rays from the X-ray source 118 through the object to be imaged, for example, the patient's head, to an X-ray imaging detector 120 located in the X-ray imaging detector housing 116.
[0035] Furthermore, the dental X-ray imaging unit 102 may include a lower shelf 122 extending from the housing 101. The lower shelf 122 may include a jaw support 124 for positioning an object, such as a patient's head (not shown in Figure 1), between the opposing X-ray source 118 and the X-ray imaging detector 120, as shown in the exemplary dental X-ray imaging unit 102 of Figure 1. Alternatively or additionally, 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, as shown in the exemplary dental X-ray imaging unit 102 of Figure 1. Alternatively, the lower shelf 122 may include the head support 126. The patient support section, i.e., the jaw support 124 and the head support 126, may be optional, and patient positioning may be performed by other means.
[0036] The X-ray source 118 is configured to project a beam of X-rays (not shown in Figure 1) toward the X-ray imaging detector 120. The X-ray source 118 may include a collimator (not shown in Figure 1) for limiting and / or shaping the X-ray beam. The X-rays pass through a portion of an object, such as a patient's biological structure, 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 the X-ray imaging detector 120. The X-ray imaging detector 120 is configured to convert the magnitude of the received X-ray energy and generate a digitized output, i.e., X-ray image data, representing the unabsorbed X-rays in the X-ray imaging detector 120. The collection of the digitized output from the X-ray imaging detector 120, corresponding to a single emission of the X-ray beam from the X-ray source 118, may refer to a projected image of the object being imaged, for example, the patient's head.
[0037] The gantry unit 112 may be rotated, for example, by a rotary motor. The rotation of the gantry unit 112 causes the X-ray source 118 and the X-ray imaging detector 120 to rotate around the object being imaged, for example, around a rotation axis. The rotation axis may be a mechanical rotation axis or a virtual rotation axis. The mechanical rotation axis of the gantry unit 112 may be oriented towards the center of the object being imaged, or towards, i.e., towards, a specific anatomical feature of interest within the object being imaged, such as a patient's head; i.e., it may be aligned with these features. A virtual rotation axis may be obtained, for example, by moving the mechanical rotation axis along a circular path, resulting in the virtual rotation axis being formed at the center of the circular path. Non-circular rotation may be created, for example, by moving the X-ray source 108 and the X-ray imaging detector 120 along a path that deviates from a circular path, such as an elliptical path. Other techniques or alignments for the rotation axis may also be used, as recognized by those skilled in the art. As the X-ray source 118 and X-ray imaging detector 120 rotate around an object, such as a patient's head, the X-ray imaging device 102 operates to acquire multiple projection images of the object taken at incremental rotation angles. In a non-limiting example, the projection images may be acquired at rotations of approximately 180° or 360°, for example in CT imaging. According to another non-limiting example, the projection images may be acquired at rotations of approximately 220°, for example in panoramic imaging. Furthermore, the X-ray imaging unit 102 may capture, for example, 250 to 1600 projection images during the imaging operation; however, this is not intended to limit the disclosure. Such increments may represent fractions of the degree of rotation. Other angular increments and other full rotation angles are contemplated within the scope of the disclosure. Dental X-ray images may be formed from multiple projection images by reconstructing X-ray image data into dental X-ray images.
[0038] The optical scanner unit 104 may be an intraoral scanner (IOS) unit, as shown in the example in Figure 1. An intraoral scanner is a device for directly capturing optical impressions in dentistry. Using the IOS unit 104, optical image data of an object may be provided directly in the patient's mouth, or from a dental model or dental impression made from the object. Alternatively, the optical scanner unit 104 may be a desktop optical scanner unit. Using the desktop optical scanner unit 104, optical image data of an object may be provided from a dental model or dental impression made from the object. Figure 1 shows only one example of an optical scanner unit 104 for use with the concepts of this disclosure.
[0039] The controller 106 is configured to acquire first image data of an object, such as a patient's biological structure, such as a patient's dental arch, from the optical scanner unit 104. The first image data may be, for example, optical image data provided, i.e., acquired, by the optical scanner unit 104 as described above. Furthermore, the controller 106 is configured to acquire second image data of the same object, at least partially, from the dental X-ray imaging unit 102. The second image data may be, for example, X-ray image data provided, i.e., acquired, by the dental X-ray imaging unit 102 as described above. The field of view (FOV) of the optical scanner unit 104 may at least partially overlap when providing the first image data of the object and the 3D FOV of the dental X-ray imaging unit 102, and when providing the second image data of the same object. The controller 106 may acquire the first image data directly from the optical scanner unit 104, or from a database 108 that can store the first image data previously acquired from the optical scanner unit 104; that is, the acquired first image data includes the first image data previously acquired from the optical scanner unit 104. For example, the previously acquired first image data may have been acquired several minutes or even several years prior to the image processing by the controller 106 and stored in the database 108. Alternatively or additionally, the controller 106 may acquire the second image data directly from the dental X-ray imaging unit 102, or from a database 108 that can store the second image data previously acquired from the dental X-ray imaging unit 102. For example, the previously acquired second image data may have been acquired several minutes or even several years prior to the image processing by the controller 106 and stored in the database 108. 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 as illustrated in the example in Figure 1.
[0040] According to one example of the present invention, in response to acquiring a second image data from the dental X-ray imaging unit 102, the controller 106 may be configured to check whether a first image data of the same object previously acquired is stored in the database 108. If the controller 106 detects that a first image data of the same object previously acquired is stored in the database 108, the controller 106 is configured to acquire the first image data from the database 108.
[0041] The controller 106 may be further configured to create a first surface model 202 from 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 2 shows a non-limiting example of a first surface model 202 created from the first image data. The controller 106 may be further configured to use the first surface model 202 to process the acquired second image data. Whether the controller 106 uses the first surface model 202 to process the acquired second image data may depend on the type of imaging method, such as CT imaging or panoramic imaging, i.e., panoramic modality.
[0042] Next, we consider an example in which the controller 106 uses the first surface model 202 to process the acquired second image data, where the imaging method used by the dental radiography unit 102 may be, for example, CT imaging, or CBCT imaging. The controller 106 may be configured to detect the movement of the object that occurs while acquiring the second image data, i.e., during the scanning process in which the second image data is provided, and to reduce artifacts caused by the movement in the two-dimensional (2D) or three-dimensional (3D) dental radiography reconstructed from the acquired second image data based on the first surface model 202. The 2D or 3D dental radiography may be, for example, CT imaging.
[0043] The controller 106 may be configured to fabricate a second surface model 302 from the acquired second image data. The second surface model 302 represents the X-ray 3D shape of the surface of the second part of the object. Figure 3 shows a non-limiting example of a second surface model 302 fabricated from the second image data. The second part of the object at least partially overlaps with the first part of the object such that the first surface model 202 and the second surface model 302 are at least partially from the same part of the object. For example, the first part of the object from which the first surface model 202 is provided may include the complete upper and / or lower dental arch of a patient, a portion of the upper and / or lower dental arch of a patient, or a single tooth of a patient. Alternatively or additionally, the second part of the object from which the second surface model 302 is provided may include the complete upper and / or lower dental arch of a patient, a portion of the upper and / or lower dental arch of a patient, or a single tooth of a patient, insofar as the second part of the object at least partially overlaps with the first part of the object. The fabrication of the second surface model 302 may include reconstructing the acquired 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.
[0044] To detect the movement of an object that occurs while obtaining the second image data, the controller 106 may be configured to compare the similarity between the second surface model 302 and the first surface model 202, and to detect the movement if the second surface model 302 differs from the first surface model 202. For example, before comparing the similarity between the surface models 202 and 203, the controller 106 may be configured to align, i.e., position, the first surface model 202 and the second surface model 302. Alignment may include determining at least one reference structure from the second surface model 302, finding at least one corresponding reference structure from the first surface model 202, and aligning the first surface model 202 and the second surface model 302 based on at least one reference structure. Alternatively, the fitting may include determining at least one reference structure from the first surface model 202, finding at least one corresponding reference structure from the second surface model 302, and fitting 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 could be, but is not limited to, a specific tooth.
[0045] As discussed above, dental radiographs can be formed from multiple projection images. Each projection image has a precisely defined, known imaging geometry. If the object is not stationary, or if the movement of the dental radiograph imaging unit 102 does not conform to the defined imaging geometry, the reconstruction result, i.e., the reconstructed dental radiograph, will be distorted by artifacts caused by the motion. If the controller 106 detects that the second surface model 302 is different from the first surface model 202, the controller 106 detects motion, i.e., infers that the object moved while the second image data was being obtained. In response to detecting motion, the controller 106 may be further configured to reduce artifacts caused by motion in the dental radiograph 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 infers that no motion was detected, i.e., that the object did not move while the second image data was being obtained, thereby eliminating the need to perform any corrections to the X-ray image, such as artifact reduction.
[0046] For example, reducing artifacts caused by motion may involve iterative fitting of the mutual imaging geometries of multiple projection images forming a dental radiographic image reconstructed from acquired second image data, in order to minimize the difference between the first surface model 202 and the second surface model 202, that is, to find the best match between the first and second surface models, so that the second surface model 302 becomes as similar as possible to the first surface model 202.
[0047] Next, we consider another example in which the controller 106 uses the first surface model 202 to process the acquired second image data, where the imaging method used by the dental radiography unit 102 may be, for example, panoramic imaging. The controller 106 may be configured to determine the anatomical shape of the object, for example, the patient's dental arch or jawbone shape, based on the first surface model 202, and to adjust the reconstruction of the dental radiography image from the acquired second image data so that the focal trough of the dental radiography image corresponds to the anatomical shape of the object determined based on the first surface model 202. The dental radiography image may be a 2D dental radiography image, for example, a 2D panoramic image or a bitewing image. Parts of the patient's biological structure that fall into sharp layers are sharp in the dental radiography image, while other parts of the patient's biological structure are blurred.
[0048] According to exemplary embodiments of the present invention, the imaging method used by the dental X-ray imaging unit 102 may be, for example, panoramic imaging, and the controller 106 may be configured to use first image data, such as optical image data, acquired from the optical scanner 104 in acquiring second image data using the dental X-ray imaging unit 102. The use of first image data in this exemplary embodiment may include the controller 106 being configured to use the first image data to define the imaging geometry of the X-ray imaging unit 102 for acquiring second image data, i.e., for the scanning process that provides the second image data. The controller 106 may be configured to acquire first image data of an object, such as a patient's biological structure, from the optical scanner unit 104, as discussed above. Also as discussed above, the controller 106 may acquire the first image data directly from the optical scanner unit 104, or from a database 108 that can store first image data previously acquired from the optical scanner unit 104, i.e., the acquired first image data includes first image data previously acquired from the optical scanner unit 104.
[0049] The controller 106 may be further configured to create a first surface model 202 from the acquired first image data. The first surface model 202 represents the optical 3D shape of the surface of a first part of the object, as discussed above. The first part of the object for which the first surface model 202 may be provided may include the complete upper and / or lower dental arch of a patient. The controller 106 may be further configured to determine the anatomical shape of the object, such as the dental arch or jawbone shape of a patient, based on the first surface model 202, as discussed above.
[0050] As discussed above, the controller 106 may be configured to define the imaging geometry of the dental radiography unit 102 for acquiring second image data based on the first surface model 202. The imaging geometry of the dental radiography 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 focal trough of the dental radiography image reconstructed from the second image data acquired using the defined imaging geometry corresponds to the anatomical shape of the object determined based on the first surface model 202. In other words, in this exemplary 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 acquisition of second image data by the dental radiography unit 102, i.e., before the scanning process that provides the second image data. The controller 106 may further be configured to define the imaging geometry of the dental radiography unit 102 using information representing the positioning of an object, such that the focal trough of the dental radiography image reconstructed from a second image data acquired using the defined imaging geometry of the radiography unit 102 corresponds to the anatomical shape of the object determined based on the first surface model 202. The information representing the positioning of an object may include, for example, the position where the object is supported by using one or more of the patient support parts, and / or the center of the object. The information representing the positioning of an object may be defined by using any known technique. In a non-limiting example, the position where the object is supported may be defined based on an occlusal block, such as an occlusal stick, placed on the jaw support 124. The controller 106 may also be configured to provide the dental radiography unit 102 with the defined imaging geometry, and then to acquire, i.e., provide, a second image data of the same object using the defined imaging geometry.
[0051] The controller 106 may be further configured to acquire second image data from the dental X-ray imaging unit 102 using the defined imaging geometry of the dental X-ray unit 102, and to reconstruct the acquired second image data into a dental X-ray image, such as a 2D panoramic image or a bitewing image, wherein the focal trough of 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.
[0052] The present invention is described above with reference to controller 106. The present invention also relates to a method for dental imaging of an object. A first image data, e.g., optical image data, may be used in dental radiography of the object. The first image data may be used to process acquired second image data, e.g., radiographic image data. Alternatively, the first image data may be used in acquiring second image data using dental radiography unit 102. Using acquired first image data to obtain second image data, for example in panoramic imaging, may include defining the imaging geometry of dental radiography unit 102 for acquiring second image data based on the first image data. Using the first image data to process the obtained second image data, for example in CT imaging, may include detecting object movement occurring while acquiring second image data based on the first image data, and reducing artifacts caused by movement in the two-dimensional or three-dimensional dental radiographic image reconstructed from the second image data based on the first image data. Alternatively, processing the obtained second image data may involve using the first image data, for example in a panoramic image, and adjusting the reconstruction of the dental X-ray image from the second image data so that the focal trough in the dental X-ray image corresponds to the anatomical shape of the object determined based on the first image data.
[0053] Next, an example of the method according to the present invention is described with reference to Figure 4. Figure 4 schematically illustrates the present invention as a flowchart. It should be recognized that embodiments of the method may be carried out without performing any of the steps disclosed herein, or in combination with additional steps.
[0054] In step 402, the controller 106 acquires first image data of an object, such as a patient's biological structure, from the optical scanner unit 104. The first image data may be, for example, optical image data. As discussed above, the controller 106 may acquire the first image data directly from the optical scanner unit 104, or it may acquire it from a database 108 that can store first image data previously acquired from the optical scanner unit 104, that is, the acquired first image data includes first image data previously acquired from the optical scanner unit 104.
[0055] In step 404, the controller 106 acquires, for example, a second image data of the same object from the dental X-ray imaging unit 102. The second image data may be, for example, X-ray image data. For example, in response to acquiring the second image data from the dental X-ray imaging unit 102, the controller 106 checks whether the first image data of the same object, which was acquired previously, is stored in the database 108. If the controller 106 detects that the first image data of the same object, which was acquired previously, is stored in the database 108, the controller 106 is configured to acquire the first image data from the database 108 in step 402.
[0056] In step 406, the controller 106 creates a first surface model 202 from the acquired first image data. The first surface model 202 represents the optical 3D shape of the surface of the first part of the object as discussed above.
[0057] In step 408, the controller 106 uses 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 in step 408 may depend on the type of imaging method, e.g., CT imaging or panoramic imaging, i.e., panoramic modality. Step 408 is discussed in more detail by referring to Figures 5 and 6. Figure 5 shows an exemplary embodiment of the method according to the present invention when the imaging method used by the dental radiography unit 102 may be, for example, CT imaging, e.g., CBCT imaging. Figure 6 shows another exemplary embodiment of the method according to the present invention when the imaging method used by the dental radiography unit 102 may be, for example, panoramic imaging. Steps 402-408 of the exemplary method in Figures 5 and 6 correspond to steps 402-408 of the exemplary method in Figure 4, but step 408, i.e., the step of using the first surface model 202 to process the acquired second image data, is disclosed in more detail by referring to Figures 5 and 6.
[0058] Next, we consider an example in step 408 in which the controller 106 uses the first surface model 202 to process the acquired second image data, with reference to Figure 5, where the imaging method used by the dental X-ray imaging unit 102 could be, for example, CT imaging, or for example, CBCT imaging.
[0059] In step 501, the controller 106 creates a second surface model 302 from the acquired second image data. The second surface model 302 represents the 3D X-ray shape of the surface of the second part of the object. The second part of the object at least partially overlaps with the first part of the object such that the first surface model 202 and the second surface model 302 are at least partially from the same part of the object considered above.
[0060] In step 408 of Figure 5, the controller 106 can detect the movement of the object occurring while acquiring the second image data, i.e., during the scanning process in which the second image data is provided, and reduce artifacts caused by the movement in the 2D or 3D dental radiography reconstructed from the acquired second image data based on the first surface model. This will be discussed in more detail by referring to steps 502-510 of Figure 5. The 2D or 3D dental radiography may be, for example, CT imaging.
[0061] In step 502, the controller 106 compares the similarity between the second surface model 302 and the first surface model 202 to detect whether the object moved while obtaining the second image data, i.e., during the scanning process. For example, before comparing the surface models, the controller 106 may align, i.e., position the first surface model 202 and the second surface model 302. Alignment may include determining at least one reference structure from the second surface model 203, finding at least one corresponding reference structure from the first surface model 202, and aligning the first surface model 202 and the second surface model 302 based on at least one reference structure. Alternatively, alignment may include determining at least one reference structure from the first surface model 202, finding at least one corresponding reference structure from the second surface model 302, and aligning the first surface model 202 and the second surface model 302 based on at least one reference structure. For example, the at least one reference structure could be, but is not limited to, a specific tooth.
[0062] If the controller 106 detects in step 504 that the second surface model 302 is different from the first surface model 202 based on the comparison in step 502, the controller 106 detects motion in step 506, i.e., it infers that the object moved during the acquisition of the second image data. In response to detecting motion in step 506, the controller reduces motion-induced artifacts in the dental radiograph reconstructed from the acquired second image data in step 510. Alternatively, if the controller 106 detects in step 504 that there is no substantial difference between the second surface model 302 and the first surface model 202 based on the comparison in step 502, the controller 106 does not detect motion in step 508, i.e., it infers that the object did not move while the second image data was being acquired, thereby eliminating the need to perform any corrections to the dental radiograph, such as artifact reduction.
[0063] For example, the reduction of motion-induced artifacts in step 510 may include iterative fitting of the mutual imaging geometries of multiple projection images forming a dental radiographic image reconstructed from the acquired second image data, in order to minimize the difference or maximize the similarity between the first surface model 202 and the second surface model 302, that is, to find the best match between the first surface model 202 and the second surface model 203, thereby making the second surface model 302 as similar as possible to the first surface model 202.
[0064] Next, we consider an example in step 408 in which the controller 106 uses the first surface model 202 to process the acquired second image data, with reference to Figure 6, where the imaging method used by the dental X-ray imaging unit 102 may be, for example, panoramic imaging.
[0065] In 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.
[0066] In step 604, the controller 106 may further adjust the reconstruction of the dental radiograph from the acquired second image data so that the focal trough of the dental radiograph corresponds to the anatomical shape of the object determined based on the first surface model 202. Parts of the patient's biological structure that fall into sharp layers are sharp in the dental radiograph, while other parts of the patient's biological structure are blurred. The dental radiograph may be a 2D dental radiograph, for example, a 2D panoramic image.
[0067] Figure 7 schematically illustrates another exemplary embodiment of the method according to the present invention, in which the controller 106 may use the dental X-ray imaging unit 102 to acquire a first image data, such as optical image data, obtained from the optical scanner 104, in the acquisition of a second image data, i.e., in the scanning process in which the second image data may be provided. For example, in the exemplary method of Figure 7, the imaging method used by the dental X-ray imaging unit 102 may be panoramic imaging.
[0068] In step 702, the controller 106 acquires first image data of an object, such as a patient's biological structure, from the optical scanner unit 104, as discussed above with reference to step 402. The first image data may be, for example, optical image data. As also discussed above, the controller 106 may acquire the first image data directly from the optical scanner unit 104, or it may acquire it from a database 108 that can store first image data previously acquired from the optical scanner unit 104, i.e., the acquired first image data includes first image data previously acquired from the optical scanner unit 104.
[0069] In step 704, the controller 106 fabricates a first surface model 202 from the acquired first image data. The first surface model 202 represents the optical 3D shape of the surface of a first portion of the object, as discussed above with reference to step 406. The first portion of the object for which the first surface model 202 may be provided may include the complete upper and / or lower dental arch of a patient.
[0070] In step 706, the controller 106 determines the anatomical shape of the object, for example, the shape of the patient's dental arch or jawbone, based on the first surface model 202, as discussed above with reference to step 602.
[0071] In step 708, the controller 106 uses the first image data in acquiring the second image data. Using the first image data in acquiring the second image data may include the controller 106 defining the imaging geometry of the X-ray imaging unit 102 for acquiring the second image data based on the first surface model 202. The imaging geometry of the dental X-ray imaging unit 102 may be defined by the controller 106 based on the determined anatomical shape of the object, determined based on the first surface model 202, such that the focal trough of the dental X-ray image reconstructed from the second image data acquired using the defined imaging geometry of the dental X-ray unit 102 corresponds to the anatomical shape of the object determined based on the first surface model 202. In other words, in this exemplary 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 acquisition of the second image data by the dental X-ray imaging unit 102, i.e., before the scanning process that provides the second image data. The controller 106 may further define the imaging geometry of the dental radiography unit 102 using information representing the positioning of the object, such that the focal trough of the dental radiography image reconstructed from second image data acquired using the defined imaging geometry of the radiography unit 102 corresponds to the anatomical shape of the object determined based on the first surface model 202. The information representing the positioning of the object may include, for example, the position where the object is supported by using one or more of the patient support parts, and / or the center of the object. The information representing the positioning of the object may be defined by using any known technique. In a non-limiting example, the position where the object is supported may be defined based on an occlusal block, such as an occlusal stick, placed on the jaw support 124. The controller 106 may provide the dental radiography unit 102 with the defined imaging geometry, and the dental radiography unit 102 may then acquire, i.e., provide, second image data of the same object by using the defined imaging geometry.
[0072] In step 710, the controller 106 may further acquire second image data from the dental X-ray imaging unit 102, which is obtained using the defined imaging geometry of the dental X-ray imaging unit 102.
[0073] In step 712, the controller 106 may further reconstruct the acquired second image data into a dental radiographic image, such as a 2D panoramic image or a bite wing, where the focal trough in the dental radiographic image reconstructed from the acquired second image data corresponds to the anatomical shape of the object determined based on the first surface model 202.
[0074] Figure 8 shows a schematic example of a controller 106 according to the present invention. The controller 106 may include a processor unit 802, a data transfer unit 804, a user interface unit 806, and a memory unit 808. The processor unit 802 is configured to execute instructions initiated by a user and / or a computer program (software) and to process data. The processor unit 802 may include at least one processor. The memory unit 808 is configured to store and maintain data. The data may be instructions, computer programs, and arbitrary data files. The memory unit 808 may include at least one memory. The memory unit 808 may further include at least a data transfer application 810 for controlling the data transfer unit 804, a user interface application 812 for controlling the UI unit 806, and a computer program (code) 814 for controlling the operation of the controller 106. The memory unit 880 and the computer program 814, together with the processor unit 802, can cause the controller 106 to implement at least one or more of the method steps and / or the operation of the controller 106 described above.
[0075] The data transfer unit 804 may be configured to transmit control commands to an external unit, such as the dental X-ray imaging unit 102. In addition, the data transfer unit 804 may 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 units.
[0076] The user interface (UI) unit 806 may be configured to input control commands, receive information and / or instructions, and display information. The UI unit 806 may include at least a display device, a screen, a touchscreen, at least one function key, a keyboard, a wired or wireless remote control, or any other user input and / or output device.
[0077] The computer program 814 may also be a computer program product, which may be contained in a tangible, non-volatile, computer-readable medium that carries the computer program code 814 embodied for use in a computer, i.e., the controller 106.
[0078] Some non-limiting examples of the controller 106 may be, for example, a server, a cloud server, a personal computer, a laptop computer, a computing circuit, or a network of computing devices. The location of the controller 106 is not limiting, and it may be located anywhere. For example, the controller 106 may be implemented as part of the dental X-ray imaging unit 102. Alternatively, the controller 106 may be implemented outside the dental X-ray imaging unit 102, i.e., as an external unit.
[0079] The above-described embodiments of the present invention enable a simple method for reducing artifacts caused by object movement from 2D or 3D dental X-ray images, such as 3D CBCT images, by using optical image data. The above-described embodiments of the present invention improve the quality of dental X-ray images, such as 3D CBCT images and / or 2D panoramic images, by using optical image data.
[0080] The specific embodiments provided in the above description should not be considered to limit the applicability and / or interpretation of the appended claims. The list and groups of embodiments provided in the above description are not exhaustive unless otherwise expressly stated.
[0081] The following numbered clauses describe some aspects of the present invention.
[0082] Clause 1. A controller 106 for dental imaging of an object, At least one processor 802, A device comprising at least one memory 808 containing computer program code 814, At least one memory 808 and computer program code 814 use at least one processor 802 to send at least, To acquire first image data from the optical scanner unit 104, The process involves creating a first surface model 202 from acquired first image data, wherein the first surface model 202 represents the optical three-dimensional shape of the surface of a first part of the object. A controller 106 is configured to use the first surface model 202 when acquiring second image data of the object.
[0083] Clause 2. The controller 106 described in Clause 1, wherein the optical scanner unit 104 is an intraoral scanner unit.
[0084] Clause 3. A controller 106 as described in any one of the preceding clauses, wherein the acquired first image data includes first image data previously acquired from the optical scanner unit 104.
[0085] 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 for acquiring a second image data of an object based on a first surface model 202.
[0086] Clause 5. Controller 106, Second image data of the object, acquired using the defined imaging geometry of the dental X-ray imaging unit 102, is obtained from the dental X-ray imaging unit 102. The controller 106 described in Clause 4 is further configured to reconstruct the acquired second image data into a dental X-ray image.
[0087] Article 6. An imaging system 100 for dental imaging of an object, wherein the imaging system 100 is A dental X-ray imaging unit 102 for providing a second image data, Gantry section 112 and, An X-ray source unit 118 for emitting X-rays, It includes an X-ray imaging detector unit 120 for receiving X-rays from the radiation source unit 118, The gantry section 112 includes a dental X-ray imaging unit 102, which includes a radiation source section 118 and a detector section 120. An optical scanner unit 104 for providing first image data, A controller 106 as described in any one of the preceding clauses, wherein the controller 106 is To acquire first image data from the optical scanner unit 104, The process involves creating a first surface model 202 from acquired first image data, wherein the first surface model 202 represents the optical three-dimensional shape of the surface of a first part of the object. The imaging system 100 is configured to use the first surface model 202 when acquiring second image data of the object.
[0088] Article 7. A method for dental imaging of an object, performed by the controller 106 described in any one of Articles 1 to 5, To acquire first image data from the optical scanner unit 104, The process involves creating a first surface model 202 from acquired first image data, wherein the first surface model 202 represents the optical three-dimensional shape of the surface of a first part of the object. A method comprising using a first surface model 202 when acquiring second image data of an object.
[0089] Article 8. Computer program 814 including instructions, wherein the instructions cause the controller 106 to perform the method described in Article 7 when the program is executed by the controller 106 described in any one of Articles 1 to 5.
[0090] Clause 9. A tangible non-volatile computer-readable medium containing instructions, wherein when such instructions are executed by the controller 106 described in any one of Clauses 1 to 5, the controller 106 causes the controller 106 to perform the method described in Clause 7.
Claims
1. A controller (106) for dental imaging of an object, At least one processor (802), It comprises at least one memory (808) containing computer program code (814), The at least one memory (808) and the computer program code (814) are transmitted to the controller (106) using the at least one processor (802), First image data is acquired from the optical scanner unit (104), A second image data is acquired from the dental X-ray imaging unit (102). A first surface model (202) is created from the acquired first image data, and the first surface model (202) represents the optical three-dimensional shape of the surface of the first part of the object. The acquired second image data is processed using the first surface model (202). Based on the first surface model (202), the movement of the object occurring while obtaining the second image data is detected. To reduce artifacts caused by motion in two-dimensional or three-dimensional dental X-ray images reconstructed from the second image data acquired based on the first surface model (202). It is configured to perform the following: The detection of the aforementioned motion Fabrication of a second surface model (302) from acquired second image data, wherein the second surface model (302) represents the X-ray 3D shape of the surface of the second part of the object, and the second part of the object at least partially overlaps with the first part of the object. A comparison of the similarity between the second surface model (302) and the first surface model (202), If the second surface model (302) is different from the first surface model (202), the motion detection and A controller (106) including the controller.
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 or 2, wherein the acquired first image data includes first image data previously acquired from the optical scanner unit (104).
4. The fabrication of the second surface model (302) is Reconstruction of the acquired second image data into a three-dimensional dental X-ray image, A controller (106) according to any one of claims 1 to 3, comprising extracting the second surface model (302) from the three-dimensional dental X-ray image using segmentation.
5. The controller (106) according to any one of claims 1 to 4, wherein the detection of the motion further includes fitting together the first surface model (202) and the second surface model (302) prior to the comparison.
6. A controller (106) for dental imaging of an object, At least one processor (802), It comprises at least one memory (808) containing computer program code (814), The at least one memory (808) and the computer program code (814) are transmitted to the controller (106) using the at least one processor (802), First image data is acquired from the optical scanner unit (104), A second image data is acquired from the dental X-ray imaging unit (102). A first surface model (202) is created from the acquired first image data, and the first surface model (202) represents the optical three-dimensional shape of the surface of the first part of the object. The acquired second image data is processed using the first surface model (202). Based on the first surface model (202), the anatomical shape of the object is determined. The system is configured to adjust the reconstruction of the dental X-ray image from the acquired second image data so that the focal trough of the dental X-ray image corresponds to the anatomical shape of the object determined based on the first surface model (202). Controller (106).
7. An imaging system (100) for dental imaging of an object, wherein the imaging system (100) A dental X-ray imaging unit (102) for providing a second image data, Gantry Unit (112), An X-ray source unit (118) for emitting X-rays, The X-ray imaging detector unit (120) includes an X-ray source unit (118) for receiving the X-rays, The gantry section (112) includes a dental X-ray imaging unit (102) which includes the X-ray source section (118) and the X-ray imaging detector section (120), An optical scanner unit (104) for providing first image data, A controller (106) according to any one of claims 1 to 5, wherein the controller (106) The first image data is acquired from the optical scanner unit (104). The second image data is acquired from the dental X-ray imaging unit (102). A first surface model (202) is created from the acquired first image data, and the first surface model (202) represents the optical three-dimensional shape of the surface of the first part of the object. To process the acquired second image data, the first surface model (202) is used, Based on the first surface model (202), the movement of the object occurring while obtaining the second image data is detected. To reduce artifacts caused by motion in two-dimensional or three-dimensional dental X-ray images reconstructed from the second image data acquired based on the first surface model (202). It is configured to do the following: The detection of the aforementioned motion Fabrication of a second surface model (302) from acquired second image data, wherein the second surface model (302) represents the X-ray 3D shape of the surface of the second part of the object, and the second part of the object at least partially overlaps with the first part of the object. A comparison of the similarity between the second surface model (302) and the first surface model (202), If the second surface model (302) is different from the first surface model (202), the motion detection and An imaging system (100) including the imaging system.
8. A method for dental imaging of an object, performed by a controller (106) according to any one of claims 1 to 5, First image data is acquired from the optical scanner unit (104), A second image data is acquired from the dental X-ray imaging unit (102). A first surface model (202) is created from the acquired first image data, and the first surface model (202) represents the optical three-dimensional shape of the surface of the first part of the object. To process the acquired second image data, the first surface model (202) is used, Based on the first surface model (202), the movement of the object occurring while obtaining the second image data is detected. To reduce artifacts caused by motion in two-dimensional or three-dimensional dental X-ray images reconstructed from the second image data acquired based on the first surface model (202). Includes, The detection of the aforementioned motion Fabrication of a second surface model (302) from acquired second image data, wherein the second surface model (302) represents the X-ray 3D shape of the surface of the second part of the object, and the second part of the object at least partially overlaps with the first part of the object. A comparison of the similarity between the second surface model (302) and the first surface model (202), If the second surface model (302) is different from the first surface model (202), the motion detection and Methods that include...
9. A computer program (814) including instructions, wherein the instructions cause the controller (106) to execute the method described in claim 8 when the computer program is executed by the controller (106) described in any one of claims 1 to 5.
10. A tangible non-volatile computer-readable medium containing an instruction, wherein when the instruction is executed by a controller (106) according to any one of claims 1 to 5, the controller (106) causes the controller (106) to execute the method according to claim 8.