Patent Application
20240354944
This patent application claims priority to European Patent Application No. 23169178.3, filed Apr. 21, 2023, which is incorporated herein by reference in its entirety.
The disclosure relates to a computer-implemented method and a system for providing merged image data of an object inside an oral cavity of a patient.
When applying magnetic resonance imaging in dentistry, hard structures of teeth (e.g. dentin, enamel) typically provide a poor signal for echo-time regimes that are most commonly available in clinical magnetic resonance devices. As a result, the geometry of the teeth cannot be reasonably well derived from magnetic resonance images. This constitutes a deficiency of magnetic resonance imaging in comparison to other imaging modalities, such as DVT (digital volume tomography) or X-Ray.
Specialized magnetic resonance scanners and sequences capable of imaging in ultra-short echo-time regimes have been used in scientific studies and the feasibility of imaging both enamel and dentin has been demonstrated. In alternative investigations, a dental impression material (e.g. a bite splint, toothpaste, or the like) inserted into the oral cavity of a patient has been used to indirectly depict surfaces of the teeth by visualizing the dental impression material.
However, due to various challenges such as high imaging effort, but also patient discomfort, none of the above-mentioned options is likely to be adopted for broader clinical practice in the near future.
The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate the embodiments of the present disclosure and, together with the description, further serve to explain the principles of the embodiments and to enable a person skilled in the pertinent art to make and use the embodiments.
The exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings. Elements, features and components that are identical, functionally identical and have the same effect are—insofar as is not stated otherwise—respectively provided with the same reference character.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the present disclosure. However, it will be apparent to those skilled in the art that the embodiments, including structures, systems, and methods, may be practiced without these specific details. The description and representation herein are the common means used by those experienced or skilled in the art to most effectively convey the substance of their work to others skilled in the art. In other instances, well-known methods, procedures, components, and circuitry have not been described in detail to avoid unnecessarily obscuring embodiments of the disclosure. The connections shown in the figures between functional units or other elements can also be implemented as indirect connections, wherein a connection can be wireless or wired. Functional units can be implemented as hardware, software or a combination of hardware and software.
It is therefore an objective of the disclosure to improve an efficiency of dental imaging applications based on magnetic resonance imaging.
This objective is achieved by a computer-implemented method and a medical imaging system according to the disclosure.
According to the inventive computer-implemented method, merged image data of an object inside an oral cavity of a patient is provided based on optical data of the oral cavity and magnetic resonance image data of a volume comprising the object.
The inventive computer-implemented method for providing merged image data of an object inside an oral cavity of a patient comprises a plurality of steps.
In one step of the inventive method, optical data of the oral cavity comprising surface information of the object is acquired.
In an exemplary embodiment, the optical data is acquired from an optical imaging device, such as a camera, a digital camera, an infrared camera, an optical profiler, a 3D scanner, or a combination of such optical imaging devices.
It is also conceivable that the optical data is acquired from a storage unit, such as a local data storage (i.e. a hard disk drive, a solid-state drive, a flash drive, etc.), a network storage device, a cloud storage, or the like.
In an exemplary embodiment, the acquired optical data of the oral cavity has a spatial resolution of at least 60 μm, at least 40 μm or at least 20 μm. In one embodiment, the spatial resolution of the optical data may correspond to a slice thickness of the magnetic resonance image data. In using optical data with a spatial resolution in the specified range, the spatial resolution may be on par or at least in a comparable range to the spatial resolution of the magnetic resonance image data. Thus, the merging of the optical data with the magnetic resonance image data may be facilitated and/or a quality of the merged image data may be improved.
Optionally, the inventive method may comprise the step of capturing the optical data of the oral cavity via an optical imaging device. However, the optical data may also be retrieved from a storage unit as described above.
The object comprises soft-tissue, such as blood vessels, nerves, a pulp, or the like. The object may also comprise hard-tissue, such as enamel and/or dentin. For example, the object may represent a tooth, a plurality of teeth, a dental arch or both dental arches of the patient.
According to an embodiment, the acquiring of optical data of the oral cavity comprises acquiring optical image data of an upper and/or a lower jaw of the patient.
In a further step of the inventive method, magnetic resonance image data of a volume of the oral cavity comprising the object is acquired. The acquired magnetic resonance image data contains soft-tissue information of the object.
In an exemplary embodiment, the inventive method comprises the step of capturing or recording the magnetic resonance image data via a magnetic resonance imaging device.
However, the magnetic resonance image data or a part of the magnetic resonance image data may also be retrieved from a storage unit as described above.
According to a further step of the inventive method, the optical data is merged with the magnetic resonance image data of the object to provide merged image data of the object.
The merging of the optical data with the magnetic resonance image data may comprise adapting, modifying, combining and/or superimposing image information contained within the optical data and the magnetic resonance image data. The image information may relate to color values, grey values and/or contrasts of individual pixels, but also groupings or arrays of pixels, which may indicate tissue structures, anatomies, or the like. However, an image information may also relate to an image parameter, such as an image resolution and/or an image scale. The optical data and the magnetic resonance image data may comprise any data type suitable for (digitally) storing and/or processing the image data. In one embodiment, the optical data and/or the magnetic resonance image data comprise raw or unprocessed image data. However, the optical data and/or the magnetic resonance image data may also comprise one or more (processed) digital images, such as an optical image and/or a magnetic resonance image.
In one embodiment, the merging of the optical data and the magnetic resonance image data comprises scaling the magnetic resonance image to the optical image. It is also conceivable that the merging of the optical data with the magnetic resonance data comprises assigning pixels of an optical image to a magnetic resonance image or vice versa.
In an exemplary embodiment, the merging of the optical data and the magnetic resonance image data comprises transforming the optical data and the magnetic resonance image data into one coordinate system. This process may also be understood as registering the optical data (or an optical image based on the optical data) and the magnetic resonance image data (or a magnetic resonance image based on the magnetic resonance image data).
In an exemplary embodiment, a processor configured to process image data is used to merge the optical data and the magnetic resonance image data. The processor may comprise a dedicated interface configured for receiving the optical data and/or the magnetic resonance image data.
The merged image data may comprise portions of the optical data and/or portions of the magnetic resonance image data.
In an exemplary embodiment, the optical data and the magnetic resonance image data comprise volumetric data, i.e. a 3D representation of the object within the oral cavity of the patient. However, the optical data may also comprise 2D data. In this case, merging the optical data and the magnetic resonance data may comprise mapping a 2D representation of the object onto a 3D magnetic resonance image or a 3D model of the object based on the magnetic resonance image data.
In a further step of the inventive method the merged image data is output. Outputting the merged image data may comprise storing the merged image in a storage unit according to an embodiment described above. However, outputting the merged image data may also comprise displaying a merged image based on the merged image data via a dedicated display unit, such as a screen or monitor, a display unit of a mobile device (i.e. tablet, smartphone, etc.), or the like. It is also conceivable that the merged image data is output to a further processing application, such as an image viewer or an image-processing application.
The inventive method favorably allows for a provision of diagnostic images of a part of the dentition of a patient based on magnetic resonance imaging while avoiding costly modifications to the magnetic resonance imaging device, such as dedicated radio-frequency coils for dental imaging or changes to a radio-frequency system.
Furthermore, the inventive method may favorably allow for reduced scan times in comparison to conventional magnetic resonance devices using imaging sequences adapted for imaging of hard-tissue (in addition to a disease specific imaging sequence), such as ultra-short echo-time (UTE) sequences. For example, the dedicated magnetic resonance imaging sequence may favorably be replaced by a fast optical scan of the oral cavity providing the optical data.
The inventive method may also allow for increased patient comfort in comparison to dental imaging applications which require the placement of a dental impression material within the oral cavity of the patient during the magnetic resonance measurement.
According to an embodiment of the inventive method, the merging of the optical data with the magnetic resonance image data comprises registering the optical data with the magnetic resonance image data.
In one example, the optical image is merged with the magnetic resonance image. The merging of the optical image with the magnetic resonance image may be carried out by means of any image registration method, such as an area-based method and/or a feature-based method.
It is conceivable, that the image registration method is based on a correlation function, a correspondence of control points, a global and/or local transformation, a pattern recognition, a radial basis function, a Fourier transform, or the like. The image registration method can be complemented using optical and/or magnetic markers, orientation points and/or a geometric equivalence of the positioning of the examination object relative to the magnetic resonance apparatus. Furthermore, registering the optical data with the magnetic resonance image data may comprise using a body model. For example, the body model may be configured to account for a relative movement between the lower jaw and the upper jaw during the acquisition of the magnetic resonance image data with the magnetic resonance imaging device. The registering of the optical data with the magnetic resonance image data may also be based on or carried out via an AI algorithm.
By registering the optical data with the magnetic resonance data, an increased spatial accuracy of the magnetic resonance image and/or an improved representation of a shape or outline of the object based on the magnetic resonance image data may favorably be provided.
According to a further embodiment of the inventive method, the optical data and the magnetic resonance image data comprise surface information of a section of a gingiva. The merging of the optical data with the magnetic resonance image data comprises matching the surface of the section of the gingiva in the magnetic resonance image data with the surface of the section of the gingiva in the optical data.
Due to its high color contrast with respect to enamel, but also its soft-tissue content, the gingiva may provide excellent contrasts and/or discernibility in the magnetic resonance image as well as the optical image. Thus, the gingiva may favorably be used in a feature-based image registration or an image registration method comprising pattern recognition.
In an exemplary embodiment, the optical data and the magnetic resonance image data comprise surface information of a section of a gum line. The surface information may comprise color values and/or grey values assigned to coordinates in a 3D space. Due to its excellent discernibility from enamel, a shape or contour of the gum line may be determined in both the optical image as well as the magnetic resonance image.
The merging of the optical data with the magnetic resonance image data comprises matching the section of the gum line in the magnetic resonance image data with the section of the gum line in the optical data. Matching the section of the gum line in the magnetic resonance image data with the section of the gum line in the optical data may comprise scaling the magnetic resonance image based on the optical image. However, it is also conceivable that the optical image is scaled in dependence of the magnetic resonance image.
In one embodiment, a cost function or minimizing function may be used for scaling of the magnetic resonance image based in the optical image (or vice versa). For example, the magnetic resonance image may be scaled in such a way that a deviation between one or more reference dimensions of the gum line in the magnetic resonance image and the gum line in the optical image is minimized or falls below a predetermined threshold.
In using a section of the gingiva and/or a section of the gum line for the merging of the optical data with the magnetic resonance image data, an accuracy of matching the optical image with the magnetic resonance image may favorably be increased.
According to a further embodiment of the inventive method, the object is a tooth. The acquiring of magnetic resonance image data of the oral cavity comprises acquiring magnetic resonance image data of a pulp of the tooth. As the pulp of the tooth comprises soft-tissue, it may provide for an excellent magnetic resonance contrast and discernibility from a surrounding dentin and/or enamel.
The merging of the optical data with the magnetic resonance image data comprises determining a shape of the tooth based on the magnetic resonance image data of the pulp in dependence of a biogeneric model and matching the surface of the tooth from the biogeneric model with a shape of the tooth in the optical data.
The pulp is contained within a pulp chamber typically mimicking an overall shape of the tooth. The natural similarity between the shape of the pulp chamber and the shape of the tooth may be used for determining the shape of the tooth based on the shape of the pulp chamber in the magnetic resonance image via the biogeneric model.
The shape of the tooth determined via the biogeneric model may be used for the merging of the optical data with the magnetic resonance image data, particularly for matching a feature in the optical image with the shape of the tooth provided via the biogeneric model.
In one embodiment, the magnetic resonance image may be positioned and/or scaled relative to the optical image based on a fit between the shape of the tooth in the optical image and the shape of the tooth determined via the biogeneric model. For example, a cost function or minimizing function may be used for positioning and/or scaling of the magnetic resonance image relative to the optical image.
By using a biogeneric model for determining the shape of a tooth or a plurality of teeth, additional imaging sequences for visualizing dentin and/or enamel may favorably be avoided. Furthermore, an accuracy of the merged image data may favorably be improved.
In one embodiment of the inventive method, the merging of the optical data with the magnetic resonance image data comprises a distortion correction of the magnetic resonance image data based on the optical data and/or a scaling of the magnetic resonance image data in dependence of the optical data.
The object depicted in the magnetic resonance image may be warped or deformed in comparison to the object in the optical image. Thus, the magnetic resonance image may be positioned, scaled and/or deformed in such a way that the shape of the object in the magnetic resonance image matches the shape of the object in the optical image. It is conceivable that distortion and/or scaling effects present in the magnetic resonance image data may be corrected or at least adjusted with respect to any distortion and/or scaling effects present in the optical image.
For example, by matching the optical image with the magnetic resonance image based on the surface information of a section of a gingiva, a section of the gum line and/or the shape of the tooth, an accurate fit between the optical image and the magnetic resonance image may be provided.
By adjusting or correcting the magnetic resonance image data in dependence of the optical data, diagnostically relevant regions contained in the magnetic resonance data may favorably be superimposed in and/or allocated to correct positions of the optical image when merging the optical data with the magnetic resonance image data. Thus, a risk of misplacing a diagnostically relevant region with respect to the optical image may favorably be reduced. Furthermore, an interpretation of the diagnostically relevant regions based on the merged image data may favorably be facilitated and/or a risk of misdiagnosis may favorably be reduced.
As a further advantage, distortion correction of the magnetic resonance image data according to the inventive method may allow for a provision of magnetic resonance images with increased spatial accuracy in comparison to conventional magnetic resonance images. Particularly, an increased geometrical accuracy across a magnetic resonance imaging volume may be obtained.
According to an embodiment, the inventive method comprises the further step of determining an information about a filling and/or a metal object inside the oral cavity based on the optical data and adapting an imaging protocol for acquiring of magnetic resonance image data of the oral cavity based on the information about the filling and/or the metal object.
For example, the information about the filling and/or metal object inside the oral cavity may comprise a shape, a dimension, a mass, a type, a location and/or a volume of the filling and/or metal object. The information about the filling and/or metal object may be acquired from the optical data, i.e. by processing the optical data via a pattern recognition algorithm and/or a dedicated image processing algorithm.
Adapting an imaging protocol for acquiring of the magnetic resonance image data may comprise adapting one or more imaging parameters. An imaging parameter may be any parameter effecting the acquisition of magnetic resonance image data. Examples of imaging parameters are a field of view, an echo-time, a repetition time, a shape and/or timing of a radio-frequency pulse and/or a sequence of radiofrequency pulses, but also a slice thickness, a slice increment, a gradient performance, and the like.
According to an embodiment, a deformation or deflection of a magnetic field in presence of a metal object is considered when adapting the imaging protocol for the acquiring of the magnetic resonance image data. In an exemplary embodiment, a later correction of the magnetic resonance image data based on the optical data is considered when adapting the imaging protocol. For example, a compatibility with the optical data (i.e. regarding resolution, field of view, slice orientation, or the like) may be considered when adapting the imaging protocol.
In adapting the imaging protocol used for acquiring the magnetic resonance image data, any requirements for correcting the magnetic resonance data based on the optical data and/or the merging of the optical data with the magnetic resonance image data may already be considered when acquiring the magnetic resonance image data. Particularly, detrimental effects of metal objects inside the oral cavity on a quality of the magnetic resonance image data and/or the merged image data may favorably be reduced. Thus, a high quality and/or high accuracy of the merged image data may be provided.
According to a further embodiment of the inventive method, the acquiring of optical data of the oral cavity comprises acquiring optical image data of an upper and/or a lower dental arch of the patient.
In an exemplary embodiment, the acquiring of optical data of the oral cavity comprises acquiring optical image data of both the upper dental arch and lower dental arch of the patient. Likewise, the magnetic resonance image data may be acquired from a volume comprising the upper dental arch and/or the lower dental arch of the patient. In merging the optical data with the magnetic resonance image data, merged data of the upper dental arch and lower dental arch, i.e. an entire dentition of the patient, may favorably be provided.
According to an embodiment, the acquiring of optical data and the acquiring of magnetic resonance image data is restricted to the upper dental arch, the lower dental arch, a section of the upper dental arch, or a section of the lower dental arch. In limiting the acquiring of optical data and/or the acquiring of magnetic resonance image data to a dental arch or a section of a dental arch (i.e. a set of teeth or a tooth), a time required for acquiring of the optical data and/or the magnetic resonance image data may favorably be reduced while still providing merged image data of a diagnostically relevant region.
According to a further embodiment of the inventive method, the merging of the optical data with the magnetic resonance image data comprises generating a contour information of a tooth and/or a periodontium based on the optical data and merging said contour information with soft-tissue information in the magnetic resonance image data.
The contour information may be understood as 3D surface information. For example, the contour information may comprise a 3D representation of a structure, such as a tooth, a set of teeth, a dental arch or both dental arches of a patient. Particularly, the contour information may comprise a 3D surface curve or contour plot comprising information on the shape of the tooth and/or periodontium.
Generating the contour information may comprise establishing a 3D contour plot or surface curve of the tooth, the set of teeth, the one or more dental arches and/or a section of the periodontium in a coordinate system. Thus, the contour information can be merged with the acquired magnetic resonance image data comprising soft-tissue information of said structures. For example, contour information can be converted into coordinates of the magnetic resonance image data by a coordinate transformation, i.e. using a transformation function or a transformation matrix.
Furthermore, generating the contour information may comprise using image processing algorithms, such as photogrammetry, but also additional sensors (i.e. infrared sensors, LIDAR sensors, or the like) providing depth information, when acquiring the optical data.
In one embodiment, one or more landmarks and/or anatomical structures in the magnetic resonance image data and the optical data are used to calculate a transformation matrix, which converts the coordinate system of the magnetic resonance image data and the coordinate system of the optical data into one another.
According to a further embodiment of the inventive method, the outputting of the merged image data comprises storing the merged image data in a storage unit and/or displaying the merged image data.
For example, the merged image data may be output to a local storage unit of the magnetic resonance imaging device, a network storage connected to the magnetic resonance device and/or a cloud storage. Thus, the merged image data may favorably be accessed by different terminal devices such as a display, a monitor, a medical device (i.e. a further magnetic resonance imaging device or a different medical device), a treatment planning system, but also a mobile device, such as a tablet, a smart phone, and the like.
In an exemplary embodiment, the outputting of the merged image data comprises integrally outputting the contour information and the soft-tissue information.
The merged image data may comprise soft tissue information from the magnetic resonance image data as well as contour information from the optical data, thus favorably compensating for a lack of hard-tissue information in the magnetic resonance image data, while allowing for reduced magnetic resonance measurement times in comparison to conventional magnetic resonance devices providing a contrast for hard tissues.
Furthermore, the merged image data may favorably provide for an integrated visualization of the contour information and the soft tissue information, thus facilitating diagnostic interpretation by trained personnel and/or reducing a risk of a misdiagnosis.
In a further embodiment of the inventive method, the merging of the optical data with the magnetic resonance image data comprises assigning image information of the magnetic resonance image data to sections of the optical data.
Merging the optical data with the magnetic resonance image data may comprise generating a data structure. The data structure may comprise a part of the optical data, a part of the magnetic resonance data as well as image information. The image information may comprise any information related to the optical image and/or the magnetic resonance image, particularly settings and/or parameters used to acquire the optical data and/or magnetic resonance image data.
In an exemplary embodiment, the image information comprises one or more slice positions of the magnetic resonance image data. Thus, the outputting of the merged image data may comprise outputting a slice position in dependence of a selection of a section of the optical data.
The image information may be assigned to one or more sections of the optical image, the magnetic resonance image and/or a merged image based on the merged image data. For example, one or more slice positions of the magnetic resonance measurement carried out to acquire the magnetic resonance image data are assigned to corresponding sections of the optical image. Thus, the merged image may favorably allow for navigating through a slice stack by selecting a desired section in the optical image and/or the merged image in a dedicated user interface.
In one embodiment, outputting the merged image data may comprise integrally outputting the merged image data and the image information. The merged image data and the image information may be included in a dedicated data structure. The merged image data and the image information may be output to an image viewer, a treatment planning system, a diagnosis system, or the like.
According to an embodiment, the merged image data and the image information is output to a user interface enabling the user to perform operations, such as sorting, filtering, selecting, and/or modifying the merged image, the optical image and/or the magnetic resonance image in dependence of the image information.
The inventive method may favorably enable a user to navigate the merged image data and/or modify the merged image in dependence of the image information.
The inventive magnetic resonance system comprises a magnetic resonance device, an optical imaging device, a controller and a processor. The controller is configured to control the magnetic resonance device to acquire magnetic resonance image data from an object inside an oral cavity of a patient and/or to control the optical imaging device to acquire optical data from the object inside the oral cavity of the patient. The processor is configured to merge the optical data with the magnetic resonance image data and to provide merged image data of the object.
The magnetic resonance system, particularly the controller and/or processor, may comprise one or more data interfaces configured for receiving or acquiring the optical data and the magnetic resonance image data. For example, the processor may be connected to the optical imaging device via a suitable signal connection (i.e. an electrical signal connection or a wireless connection).
The controller may represent a main controller of the magnetic resonance device or an independent controller. The controller may be connected to the optical imaging device via a suitable signal connection. In case the controller is an independent component, the controller may be connected to the main controller of the magnetic resonance device.
The processor may represent a main processor of the magnetic resonance device or an independent processor. The processor may be connected to the optical imaging device via a suitable signal connection. In case the processor is an independent component, the processor may be connected to the main controller of the magnetic resonance device via a suitable signal connection. It is conceivable that the processor is incorporated or integrated within the controller.
The processor and the controller are configured for coordinating and/or carrying out an inventive method according to an embodiment described above.
The processor and/or the control may comprise any graphics unit, storage unit and/or further component required for carrying out the inventive method according to an embodiment described above.
In one embodiment, the processor is configured to process the optical data, the magnetic resonance image data and/or the merged image data. The processor may implement an image processing algorithm, a pattern recognition algorithm, or the like for processing the optical data, the magnetic resonance image data, and/or the merged image data according to an embodiment described above.
The inventive magnetic resonance system shares the advantages of the inventive method. Furthermore, the inventive magnetic resonance system may favorably allow for carrying out an embodiment of the inventive method in a robust and/or reproduceable manner.
According to an embodiment, the magnetic resonance system according comprises an output unit configured for outputting merged image data to a user, and a user interface configured for adapting a magnetic resonance image and/or a merged image based on the magnetic resonance image data in dependence of an interaction with an optical image based on the optical data.
In an exemplary embodiment, the user interface is configured to allow for sorting, filtering, selecting, navigating and/or modifying the magnetic resonance image and/or the merged image in dependence of a user-selection of a section in the optical image. For example, the user interface may be configured to provide and/or output a section of the magnetic resonance image and/or an image information related to a section of the magnetic resonance image when a section in the optical image is selected via the user interface.
The inventive magnetic resonance system may favorably allow for synchronizing of operations performed on the optical image and the merged image and/or the magnetic resonance image. Furthermore, operations and/or selections regarding the optical image may favorably be applied to the magnetic resonance image and/or the merged image.
In an exemplary embodiment, the magnetic resonance system 10 may comprise a patient support 16 or patient table configured for transporting the patient 15 into the imaging region 14, particularly an isocenter (not shown) within the imaging region 14.
The magnetic resonance system 10 may comprise a gradient system 18 configured for providing magnetic gradient fields used for spatial encoding of magnetic resonance signals acquired during a magnetic resonance measurement. The gradient system 18 is activated or controlled by a gradient controller 19 via an appropriate current signal. It is conceivable that the gradient system 18 comprises one or more gradient coils for generating magnetic gradient fields in different, preferably orthogonally oriented, spatial directions.
The magnetic resonance system 10 may further comprise a high frequency system including a radiofrequency antenna 20 (body coil), which may be integrated into the magnetic resonance device. The radiofrequency antenna 20 is operated via a radiofrequency controller 21 that controls the radiofrequency antenna 20 to generate a high frequency magnetic field and emit radiofrequency excitation pulses into the imaging region 14.
The magnetic resonance system 10 may further comprise a local coil 26, which is positioned in proximity to a diagnostically relevant region (i.e. a head region or a jaw region) of the patient 15. The local coil 26 may be configured to emit radiofrequency excitation pulses into the patient 15 and/or receive magnetic resonance signals from the patient 15. It is conceivable, that the local coil 26 is controlled via the radiofrequency controller 21.
In the depicted embodiment, the local coil 26 is a dental coil, which is positioned in proximity to a jaw region 31 of the patient 15. In an exemplary embodiment, the dental coil comprises one or more antenna elements (not shown) configured to receive magnetic resonance signals from the jaw region 31 of patient 15 and transmit the detected magnetic resonance signals to the processing unit (processor) 28 and/or the control unit (controller) 22. In the illustrated example, the dental coil is connected to the radiofrequency unit 21 via a suitable signal connection 27. The dental coil 26 may be configured to emit radiofrequency signals into the jaw region 31 of patient 15 to excite nuclear spins. In an exemplary embodiment, the controller 22 includes processing circuitry that is configured to perform one or more operations/functions of the controller 22. Additionally, or alternatively, one or more components (e.g., processor 28) may include processing circuitry to perform its respective operation(s)/function(s).
According to an exemplary embodiment, the dental coil is a mask configured to be positioned on a skin surface of the jaw region 31 of patient 15. However, it is also conceivable that the dental coil 26 is mechanically connected to a mouthpiece which is positioned within the oral cavity of the patient 15.
The magnetic resonance system 10 may comprise a sensor, such as an optical imaging device 40 (e.g., a 2D camera, a 3D camera, an infrared camera, optical sensor, or the like). The optical imaging device 40 is designed to acquire optical data of the oral cavity of the patient 15. For acquiring of the optical data, the patient 15 may be positioned in front of the optical imaging device 40 before being positioned in the imaging region 14. However, it is also conceivable that the optical imaging device 40 is positioned within the imaging region 14 or adjacent to the imaging region 14. In one embodiment, the optical imaging device 40 is connected to the local coil 26.
The magnetic resonance system 10 may further comprise a controller 22 configured to control the magnetic resonance device. The controller 22 may include a processor 28 configured and/or adapted to process magnetic resonance image data and reconstruct magnetic resonance images. The processor 28 may also be configured to process input from a user of the magnetic resonance system 10 and/or provide an output to the user. For this purpose, the processor 28 and/or the controller 22 can be connected to an output unit 24 (e.g., display, speaker, etc.) and an input unit 25 (e.g., keyboard, mouse, microphone, touchscreen, etc.) via a suitable signal connection.
For a preparation of a magnetic resonance imaging measurement, preparatory information, such as imaging parameters or patient information, can be provided to the user via the output unit 24. In an exemplary embodiment, the output unit 24 is configured to output control information, such as imaging parameters of the magnetic resonance measurement. The output unit 24 may also be configured to output a magnetic resonance image, an optical image and/or a merged image of the oral cavity of the patient 15. The input unit 25 may be configured to receive information and/or imaging parameters from the user. However, the input unit 25 may also be configured to enable the user to select a section of the optical image, but also to navigate and/or modify the optical image, the merged image and/or the magnetic resonance image.
The magnetic resonance system 10 may comprise a user interface 23 comprising the output unit 24 and the input unit 25. The user interface 23 be configured to enable the user to control an acquisition of magnetic resonance image data via the magnetic resonance device and/or an acquisition of optical data via the optical imaging device 40. Furthermore, the user interface may enable the user to interact with the magnetic resonance image, the optical image and/or the merged image. In an exemplary embodiment, the user interface 23 is configured to allow for an interaction with a magnetic resonance image and/or a merged image in dependence of an interaction with an optical image. For example, the user interface may be configured to enable the user to navigate through a stack of slices of the magnetic resonance image data in dependence of a selection of a structure in the optical image. However, the user interface may be configured for allowing a user to interact with a merged image and/or a magnetic resonance image based on the magnetic resonance image data in dependence of an interaction with an optical image based on the optical data.
As illustrated in
It is conceivable that some processing tasks are outsourced to the server 30 (e.g. a cloud processor). For example, the server 30 may be configured to receive acquired optical data and magnetic resonance image data and merge the optical data with the magnetic resonance image data to provide merged image data of the object according to an embodiment described herein.
In a further example, the server 30 may be configured to determine a shape of a tooth based on the magnetic resonance image data of a pulp in dependence of a biogeneric model. The server 30 may also be configured to match a surface of the tooth from the biogeneric model with a shape of the tooth in the optical data.
In an exemplary embodiment, the server 30 may be configured to transmit a result of a processing task to the processor 28. The server 30 and the controller 22 may cooperatively perform one or more processing tasks in one or more aspects.
The magnetic resonance system 10 may of course comprise further components usually associated with magnetic resonance devices. It is conceivable that the field generation unit 11 of the magnetic resonance device has a conventional cylindrical design or a C-shaped design. However, the field generation unit 11 may also exhibit a triangular design, or an asymmetrical design. Particularly, the magnetic resonance system 10 may be configured to perform a magnetic resonance measurement of a standing or sitting patient 15.
The optical image 41 depicted in
The interaction menu 61 may also be configured to indicate imaging information, such as a slice position and/or an imaging parameter of the magnetic resonance measurement. In an exemplary embodiment, the interaction menu 61 is configured to allow the user to navigate through different slice positions, superimpose the magnetic resonance image, jump to a corresponding slice in the magnetic resonance image, change a transparency of the optical image and/or the magnetic resonance image, indicate an imaging parameter associated with the optical data and/or the magnetic resonance image data, and the like.
In step S1, optical data of the oral cavity comprising surface information of the object is acquired. In an exemplary embodiment, the optical data is acquired via a high-resolution 3D camera 40 providing a spatial resolution of at least 60 μm, at least 40 μm, or at least 20 μm. The camera 40 may be connected to the magnetic resonance system 10 as illustrated in
In an exemplary embodiment, the acquiring S1 of optical data of the oral cavity comprises acquiring optical image data of an upper dental arch 50a and/or a lower dental arch 50b of the patient 15 (see
In a step S2, magnetic resonance image data of a volume of the oral cavity comprising the object is acquired. The magnetic resonance image data contains soft-tissue information of the object. The magnetic resonance image data may be acquired using a magnetic resonance system 10 as depicted in
In one embodiment, the object is a tooth and the acquiring of magnetic resonance image data of the oral cavity comprises acquiring magnetic resonance image data of a pulp of the tooth.
In a further step S3, the optical data is merged with the magnetic resonance image data to provide merged image data of the object.
According to an embodiment, the merging of the optical data with the magnetic resonance image data comprises registering an optical image based on the optical data with a magnetic resonance image based on the magnetic resonance image data by means of an image registration method. The image registration method may be based on a correlation function, a correspondence of control points, a global and/or local transformation, a pattern recognition, a radial basis function, a Fourier transform, or the like.
According to a further embodiment, the optical data and the magnetic resonance image data comprise surface information of a section of a gingiva 51. In such a case, the merging of the optical data with the magnetic resonance image data may comprise matching the surface of the section of the gingiva 51 in the magnetic resonance image data with the surface of the section of the gingiva 51 in the optical data. In an exemplary embodiment, a feature-based image registration or an image registration method comprising pattern recognition is used to register the optical data with the magnetic resonance image data.
In one embodiment, the optical data and the magnetic resonance image data comprise surface information of a section of a gum line and the merging of the optical data with the magnetic resonance image data comprises scaling the magnetic resonance image based on a representation of the gum line in the optical image 41 and the magnetic resonance image.
According to a further embodiment, the step of merging the optical data with the magnetic resonance image data comprises determining a shape of the tooth based on the magnetic resonance image data of the pulp in dependence of a biogeneric model and matching the shape of the of the tooth from the biogeneric model with a shape of the tooth in the optical data. Determining the shape of the tooth in dependence of the biogeneric model as well as matching the shape of the of the tooth from the biogeneric model with a shape of the tooth in the optical data may be carried out via the processor 28 or a processor in the cloud 30.
In an exemplary embodiment, the step of merging the optical data with the magnetic resonance image data comprises correcting a distortion of the magnetic resonance image data based on the optical data and/or a scaling of the magnetic resonance image data in dependence of the optical data. For example, the representations of the gingiva 51 and/or the gum line in the optical image and the magnetic resonance image may be used for determining and/or correction distortions in the magnetic resonance image data.
The step merging the optical data with the magnetic resonance image data may further comprise generating a contour information of a tooth and/or a periodontium based on the optical data and merging said contour information with soft-tissue information in the magnetic resonance image data. The contour information of the tooth and/or periodontium may be generated via the processor 28 or a processor in the cloud 30. For example, the contour information may be generated via photogrammetry. However, it is also conceivable that depth information from an additional sensor, such as an infrared sensor or LIDAR sensor (not shown in
In each embodiment, the step of merging the optical data with the magnetic resonance image data may comprise assigning image information of the magnetic resonance image data to sections of the optical data.
According to an optional step S4, an information about a filling and/or a metal object inside the oral cavity is determined based on the optical data. The information about the filling and/or metal object may be acquired from the optical data, i.e. by processing the optical data via a pattern recognition algorithm and/or a dedicated image processing algorithm. The optical data may be processed via the processor 28 or a processor in the cloud 30, which may be configured to implement said pattern recognition algorithm and/or dedicated image processing algorithm. The information about the filling and/or metal object inside the oral cavity may comprise a shape, a dimension, a mass, a type, a location but also a volume of the filling and/or metal object.
In an optional step S5, an imaging protocol for acquiring of magnetic resonance image data of the oral cavity is adapted based on the information about the filling and/or the metal object. For example, adapting the imaging protocol may comprise adapting one or more imaging parameters to account for a deformation or deflection of a magnetic field in proximity to the metal object.
In a step S6, the merged image data is output. Outputting the merged image data may comprise storing the merged image in the storage unit 29 or the cloud storage 30. However, outputting the merged image data may also comprise displaying the merged image 60 based on the merged image data via the output unit 24. The merged image data may also be output to a further processing application, such as an image viewer or an image-processing application and/or a terminal device, such as a tablet or smartphone.
In an exemplary embodiment, outputting the merged image data comprises integrally outputting contour information based on the optical data and soft-tissue information based on the magnetic resonance image data. For example, outputting the merged image data may comprise outputting a merged image comprising a representation of the contour of teeth and/or the periodontium as well as a representation of a part of the pulp and/or a nerve. Integrally outputting contour information and soft-tissue information may also comprise superimposing the representation of the contour of teeth and/or the periodontium as well as the representation of the part of the pulp and/or nerve.
In a further example, outputting the merged image data comprises outputting a data structure comprising a part of the optical data, a part of the magnetic resonance data as well as image information.
The embodiments described above are to be recognized as examples. It is to be understood that individual embodiments may be extended by or combined with features of other embodiments if not stated otherwise. Particularly, the sequence of the steps of the inventive method is to be understood as an example. Individual steps may be carried out in a different order and/or overlap partially or completely in time.
To enable those skilled in the art to better understand the solution of the present disclosure, the technical solution in the embodiments of the present disclosure is described clearly and completely below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the embodiments described are only some, not all, of the embodiments of the present disclosure. All other embodiments obtained by those skilled in the art on the basis of the embodiments in the present disclosure without any creative effort should fall within the scope of protection of the present disclosure.
It should be noted that the terms “first”, “second”, etc. in the description, claims and abovementioned drawings of the present disclosure are used to distinguish between similar objects, but not necessarily used to describe a specific order or sequence. It should be understood that data used in this way can be interchanged as appropriate so that the embodiments of the present disclosure described here can be implemented in an order other than those shown or described here. In addition, the terms “comprise” and “have” and any variants thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or equipment comprising a series of steps or modules or units is not necessarily limited to those steps or modules or units which are clearly listed, but may comprise other steps or modules or units which are not clearly listed or are intrinsic to such processes, methods, products or equipment.
References in the specification to “one embodiment,” “an embodiment,” “an exemplary embodiment,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.
The exemplary embodiments described herein are provided for illustrative purposes, and are not limiting. Other exemplary embodiments are possible, and modifications may be made to the exemplary embodiments. Therefore, the specification is not meant to limit the disclosure. Rather, the scope of the disclosure is defined only in accordance with the following claims and their equivalents.
Embodiments may be implemented in hardware (e.g., circuits), firmware, software, or any combination thereof. Embodiments may also be implemented as instructions stored on a machine-readable medium, which may be read and executed by one or more processors. A machine-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer). For example, a machine-readable medium may include read only memory (ROM); random access memory (RAM); magnetic disk storage media; optical storage media; flash memory devices; electrical, optical, acoustical or other forms of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.), and others. Further, firmware, software, routines, instructions may be described herein as performing certain actions. However, it should be appreciated that such descriptions are merely for convenience and that such actions in fact results from computing devices, processors, controllers, or other devices executing the firmware, software, routines, instructions, etc. Further, any of the implementation variations may be carried out by a general-purpose computer.
The various components described herein may be referred to as “modules,” “units,” or “devices.” Such components may be implemented via any suitable combination of hardware and/or software components as applicable and/or known to achieve their intended respective functionality. This may include mechanical and/or electrical components, processors, processing circuitry, or other suitable hardware components, in addition to or instead of those discussed herein. Such components may be configured to operate independently, or configured to execute instructions or computer programs that are stored on a suitable computer-readable medium. Regardless of the particular implementation, such modules, units, or devices, as applicable and relevant, may alternatively be referred to herein as “circuitry,” “controllers,” “processors,” or “processing circuitry,” or alternatively as noted herein.
For the purposes of this discussion, the term “processing circuitry” shall be understood to be circuit(s) or processor(s), or a combination thereof. A circuit includes an analog circuit, a digital circuit, data processing circuit, other structural electronic hardware, or a combination thereof. A processor includes a microprocessor, a digital signal processor (DSP), central processor (CPU), application-specific instruction set processor (ASIP), graphics and/or image processor, multi-core processor, or other hardware processor. The processor may be “hard-coded” with instructions to perform corresponding function(s) according to aspects described herein. Alternatively, the processor may access an internal and/or external memory to retrieve instructions stored in the memory, which when executed by the processor, perform the corresponding function(s) associated with the processor, and/or one or more functions and/or operations related to the operation of a component having the processor included therein.
In one or more of the exemplary embodiments described herein, the memory is any well-known volatile and/or non-volatile memory, including, for example, read-only memory (ROM), random access memory (RAM), flash memory, a magnetic storage media, an optical disc, erasable programmable read only memory (EPROM), and programmable read only memory (PROM). The memory can be non-removable, removable, or a combination of both.
| Number | Date | Country | Kind |
|---|---|---|---|
| 23169178.3 | Apr 2023 | EP | regional |
