X-ray imaging method and system for reducing adjacent tooth overlap in panoramic images

Abstract

The present invention relates to a computer-implemented X-ray imaging method for generating a panoramic image (1) with reduced overlap (8) of adjacent teeth, the method comprising the steps of acquiring a plurality of 2D X-ray images (2) in a plurality of different X-ray imaging directions (3) by rotating an X-ray source (4) and an X-ray detector (5) around a patient's jaw (6), respectively, and further comprising the steps of identifying, from among the corresponding X-ray imaging directions (3), one or more regions (7) each including at least one pair of overlapping adjacent teeth (8) in the 2D X-ray images (2) and / or in a temporary panoramic image reconstructed from the 2D X-ray images (2), from which an optimal X-ray imaging direction (3') for reducing the overlap in the reconstructed panoramic image (1) can be determined, and determining, from among the corresponding X-ray imaging directions (3) of the 2D X-ray images identified in the step of identifying one or more regions (7) each including at least one pair of overlapping adjacent teeth (8), one or more optimal X-ray imaging directions (3') for reducing the overlap in the reconstructed panoramic image (1), respectively.

Description

[Technical Field]

[0001] The present invention relates to an X-ray imaging method for producing panoramic images with reduced overlap of adjacent teeth, and also to an X-ray imaging system for producing panoramic images with reduced overlap of adjacent teeth. [Background technology]

[0002] X-ray imaging systems for generating panoramic images of a patient's teeth are generally known in the art. Such X-ray imaging systems generally include an X-ray source for emitting X-rays towards the patient, an X-ray detector for detecting the X-rays that have passed through the patient's jaw, an acquisition means adapted to acquire a plurality of 2D X-ray images in a plurality of different X-ray imaging directions by rotating the X-ray source and the X-ray detector around at least the patient's jaw, and an image processing means adapted to reconstruct a panoramic image based on the 2D X-ray images and the X-ray imaging directions.

[0003] A commonly known problem with such panoramic images is that they typically contain areas where adjacent teeth overlap, as shown in Figure 1. As such, panoramic images with overlapping teeth typically complicate or prevent successful diagnosis. Summary of the Invention

[0004] The object of the present invention is to overcome the above-mentioned disadvantages of the prior art. This object is achieved by an X-ray imaging method according to claim 1 and an X-ray imaging system according to claim 13. The subject matter of the dependent claims relates to further developments and preferred embodiments.

[0005] The present invention provides a computer-implemented X-ray imaging method for generating a panoramic image with reduced overlap of adjacent teeth. The method includes the steps of: acquiring a plurality of 2D X-ray images at a plurality of different X-ray imaging directions by rotating an X-ray source and an X-ray detector around a patient's jaw; identifying, from among the corresponding X-ray imaging directions, one or more regions each including at least one pair of overlapping adjacent teeth in the 2D X-ray images and / or in a temporary panoramic image reconstructed from the 2D X-ray images, from which an optimal X-ray imaging direction that reduces overlap in the reconstructed panoramic image can be determined; and determining, from among the corresponding X-ray imaging directions of the 2D X-ray images identified in the step of identifying one or more regions each including at least one pair of overlapping adjacent teeth, one or more optimal X-ray imaging directions for reducing overlap in the reconstructed panoramic image. In this specification, the overlapping adjacent teeth are a pair of teeth, and each tooth of the pair may be in the upper jaw, or each tooth of the pair may be in the lower jaw, or one tooth of the pair may be in the upper jaw and the other tooth may be in the lower jaw.

[0006] The main advantage of the present invention is that it allows for improved diagnosis through the reduction of overlap areas.

[0007] Once the optimal radiographic orientation is determined, a panoramic image can be reconstructed and displayed according to a variety of different alternative embodiments.

[0008] According to an alternative embodiment, at least a partial panoramic image is reconstructed based on the 2D X-ray image in which an optimal X-ray orientation for the identified region or regions has been determined. Optionally, some additional information about the panoramic image can be provided to indicate the reduced overlap in the identified region, so as to inform the dentist of the fact that the X-ray orientation has been optimized. The additional information can be an icon, text, an outline, etc.

[0009] According to a further alternative embodiment, the at least partial panoramic image is reconstructed based on the 2D X-ray image and the X-ray shooting direction for one or more regions, as in the prior art, but additional information is provided for the identified regions, further comprising an inset showing the at least partial panoramic image reconstructed based on the 2D X-ray image for which the optimal X-ray shooting direction for the identified one or more regions has been determined. Through the inset, the dentist can preview the identified region with overlap reduction and thereby know that the X-ray shooting direction has been optimized. The inset can preferably be selected / deselected for preview by the user through the use of input means such as a keyboard cursor, mouse, etc.

[0010] According to a further alternative embodiment, the at least partial panoramic image without overlap reduction is displayed together with the at least partial panoramic image with overlap reduction in a toggle mode that can be switched by the user through input means such as, for example, a keyboard, a mouse, etc. This may enable the dentist to appreciate the effect of the optimal X-ray orientation.

[0011] According to a further alternative embodiment, at least a partial panoramic image is reconstructed based on 2D-X-ray images corresponding to interpolated X-ray imaging directions obtained through spatial interpolation between the determined optimal X-ray imaging directions of the corresponding identified one or more regions.

[0012] According to the present invention, an artificial intelligence (AI) algorithm can be used to identify regions in 2D-X-ray images and / or in a temporary reconstructed panoramic image, each containing at least one pair of overlapping adjacent teeth. According to the present invention, AI techniques can also be used in determining optimal radiographic orientations that reduce overlap in the reconstructed panoramic image. The trained artificial intelligence algorithm can be trained with inputs of previously acquired 2D-X-ray images and / or previously reconstructed panoramic images, each with manual annotations indicating overlap. Furthermore, the trained artificial intelligence algorithm can be trained with inputs of previously acquired 2D-X-ray images or previously reconstructed panoramic images, each with manual annotations indicating optimal radiographic orientations that reduce overlap in the reconstructed panoramic image.

[0013] The present invention also provides a computer-implemented X-ray imaging system for generating a panoramic image with reduced overlap of adjacent teeth. The computer-implemented X-ray imaging system includes an X-ray source for emitting X-rays toward a patient, an X-ray detector for detecting the X-rays transmitted through the patient's jaw, an acquisition means adapted to acquire a plurality of 2D X-ray images in a plurality of different X-ray imaging directions by rotating the X-ray source and the X-ray detector around at least the patient's jaw, and an image processing means for executing a computer program that causes the computer-implemented X-ray imaging system to perform the X-ray imaging method of the present invention. The system is not provided as a single device per se. For example, the image processing means may be located in the cloud or on a computer in a radiologist's office.

[0014] In the following description, the invention is explained in more detail by using illustrative embodiments and by making reference to the drawings. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a partial schematic diagram of an X-ray imaging system, according to an embodiment. [Figure 2] FIG. 10 is a schematic diagram of a panoramic image without overlap reduction in identified areas with overlapping adjacent teeth. [Figure 3] FIG. 1 is a schematic diagram of a panoramic image with overlap reduction, according to an embodiment. [Figure 4] 1 is a schematic diagram of a panoramic image with selectable / non-selectable insets with overlap reduction, according to an embodiment.

[0016] The reference numbers shown in the drawings indicate elements listed below and will be referenced in the subsequent description of the illustrative embodiments. 1. Panoramic image (with overlap reduction) 1a. Inset 1'. Panoramic image (without overlap reduction) 2.2DX ray image 3. X-ray direction 3. Optimal X-ray orientation 4.X-ray source 5. X-ray detector 6. Jaw 7.Area 8. Overlapping adjacent teeth 9. X-ray Imaging System DETAILED DESCRIPTION OF THE INVENTION

[0017] 1 shows a schematic partial view of a computer-implemented X-ray imaging system (9) for generating a panoramic image (1) with reduced overlap (8) of adjacent teeth. The computer-implemented X-ray imaging system (9) comprises an X-ray source (4) for emitting X-rays toward a patient, an X-ray detector (5) for detecting the X-rays transmitted through the patient's jaw (6), acquisition means adapted to acquire a plurality of 2D X-ray images (2) in a plurality of different X-ray imaging directions (3) by rotating the X-ray source (4) and the X-ray detector (5) around at least the patient's jaw (6), and image processing means adapted to execute a computer program according to the present invention. Further details of the X-ray imaging system (9), which are commonly known to those skilled in the art, are omitted to avoid unnecessary prolongation of the description.

[0018] The computer program comprises computer-executable code for causing the computer-implemented X-ray imaging system (9) to perform the method steps of the present invention, which are described in more detail later in this specification. The computer program can be stored in a computer-readable storage means connected to the computer-implemented X-ray imaging system (9). The connection can be external, such as the storage means being in the cloud, a remote location, or at a dentist's office.

[0019] The computer-implemented X-ray imaging method of the present invention is suitable for generating panoramic images (1) with reduced overlap (8) of adjacent teeth. The method includes the steps of acquiring a plurality of 2D X-ray images (2) in a plurality of different X-ray imaging directions (3) by rotating an X-ray source (4) and an X-ray detector (5) around a patient's jaw (6); identifying, from among the corresponding X-ray imaging directions (3), one or more regions (7) (see, for example, FIG. 2 ) in the 2D X-ray images (2) and / or in a temporary panoramic image reconstructed from the 2D X-ray images (2) for which an optimal X-ray imaging direction (3') (see FIG. 2 ) that reduces overlap in a reconstructed panoramic image (1) can be determined; and determining, from among the corresponding X-ray imaging directions (3) of the 2D X-ray images identified in the step of identifying one or more regions (7) that each include at least one pair of overlapping adjacent teeth (8) for reducing overlap in the reconstructed panoramic image (1), one or more optimal X-ray imaging directions (3').

[0020] The following description describes two different alternative embodiments for reconstructing a panoramic image (1). A first alternative embodiment is provided in FIG. 3, which shows a schematic diagram of a panoramic image (1) with overlap reduction. The panoramic image (1) with overlap reduction can be displayed on a display of a computer-implemented X-ray imaging system (9). In the first alternative embodiment, the method comprises the steps of reconstructing at least a partial panoramic image (1) based on a 2D X-ray image (2) in which an optimal X-ray shooting direction (3′) for one or more identified regions (7) has been determined, and an optional step of displaying additional information (A) on the reconstructed panoramic image (1) to inform the user of the reduced overlap. As shown in FIG. 3, the additional information (A) can inform the dentist of the fact that the optimal X-ray shooting direction (3′) was used for the reconstruction. The additional information can be an icon, text, an outline, or the like that informs the user of the presence of the reduced overlap. Alternatively, the display of the additional information (A) can be omitted. For comparison, FIG. 2 shows a schematic diagram of a panoramic image (1′) without overlap reduction. The panoramic image (1′) without overlap reduction can be optionally displayed on the display of the X-ray imaging system (9) together with the panoramic image (1) with overlap reduction, for example in a toggle mode. This can allow the dentist to appreciate the effect of the optimal X-ray shooting direction (3′). A second alternative embodiment is provided in FIG. 4, which shows a schematic diagram of a panoramic image (1′) without overlap reduction but with additional information (A) with an inset (1a) showing at least a partial panoramic image (1) with overlap reduction. In a second alternative embodiment, the method comprises the steps of reconstructing at least a partial panoramic image (1') based on a 2D-X-ray image (2) and an X-ray imaging direction (3) for one or more regions (7), and representing on the reconstructed panoramic image (1') additional information (A) comprising the identified one or more regions (7) in an inset (1a) showing the at least partial panoramic image (1) reconstructed based on the 2D-X-ray image (2) in which an optimal X-ray imaging direction (3') for the identified one or more regions (7) has been determined.As shown in FIG. 4, through the additional information (A) including the inset (1a), the dentist can preview the identified region (7) with reduced overlap while being informed of the optimal radiographic direction (3'). The inset (1a) can preferably be selected for preview by the user through the use of an input means such as a keyboard, cursor, mouse, etc. The inset (1a) may pop up with a preset magnification or no magnification and may disappear when not selected. Alternatively, the inset (1a) may be fixed. The size of the inset (1a) may have the size of the identified region (7). In a second alternative embodiment, the additional information (A) may be an icon, text, an outline, etc., that notifies the user of the presence of a preview with reduced overlap.

[0021] According to a further alternative embodiment (not illustrated), radiographic directions (3) in the vicinity of the optimal radiographic direction (3') can be interpolated. In an alternative embodiment, the method comprises a step of reconstructing an at least partial panoramic image (1) based on 2D-X-ray images (2) corresponding to interpolated radiographic directions obtained through spatial interpolation between the determined optimal radiographic directions (3') of the identified one or more regions (7) whose image points correspond to the interpolated radiographic directions.

[0022] In the following description, we briefly discuss the use of deep learning techniques: trained artificial intelligence algorithms can be used in the identification and / or decision steps.

[0023] According to a further embodiment, in the identifying step, a trained artificial intelligence algorithm is used to identify one or more regions (7) each containing at least one pair of overlapping adjacent teeth (8) in the 2D-X-ray image (2) and / or in a temporary panoramic image reconstructed from the 2D-X-ray image (2). The trained artificial intelligence algorithm can be trained with input of previously acquired 2D-X-ray images and / or previously reconstructed panoramic images each with manual annotations indicating overlaps. The use of artificial intelligence is highly effective given the speed and reliability of the identification step. Alternatively, image processing techniques not based on deep learning can be used.

[0024] According to a further embodiment, in the determining step, a trained artificial intelligence algorithm is used to determine one or more optimal radiographic directions (3') from among the corresponding radiographic directions (3) of the 2D-X-ray images (2) in which one or more regions (7) each including at least one pair of overlapping adjacent teeth (8) are identified, in order to reduce overlap in the reconstructed panoramic image (1). In a first alternative form of this embodiment, in the determining step, a plurality of at least partial temporary panoramic images (1') are reconstructed based on the 2D-X-ray images (2), each having a different radiographic direction (3) for at least one or more regions (7) each including at least one overlapping adjacent tooth (8), and a trained artificial intelligence algorithm is used to determine, from among the different radiographic directions (3), an optimal radiographic direction (3') that reduces overlap in the reconstructed panoramic image (1) by comparing the plurality of at least partial temporary panoramic images (1') reconstructed for the identified one or more regions (7). In a second alternative to this embodiment, in the determining step, a trained artificial intelligence algorithm is used to determine an optimal radiographic orientation (3') that reduces overlap in the reconstructed panoramic image (1) by comparing a set of initially acquired 2D-X-ray images (2), in which one or more regions (7) each containing at least one overlapping adjacent tooth (8) are identified, with the corresponding radiographic orientations (3). The trained artificial intelligence algorithm can be trained with input from previously acquired 2D-X-ray images or previously reconstructed panoramic images (1) each with manual annotations indicating the optimal radiographic orientation that reduces overlap in the reconstructed panoramic image. The use of artificial intelligence is again highly effective given the speed and reliability of the determining step. As indicated above, image processing techniques not based on deep learning can alternatively be used. The inventions described in the original claims of this application are set forth below. [1] A computer-implemented x-ray imaging method for generating a panoramic image (1) with reduced overlap (8) of adjacent teeth, comprising: acquiring a plurality of 2D-X-ray images (2) in a plurality of different X-ray imaging directions (3) by rotating the X-ray source (4) and the X-ray detector (5) around the patient's jaw (6); A method comprising: identifying one or more regions (7) in the 2D-X-ray image (2) and / or in a temporary panoramic image reconstructed from the 2D-X-ray image (2) each containing at least one pair of overlapping adjacent teeth (8), from among the corresponding X-ray directions (3), from which an optimal X-ray direction (3') can be determined that reduces the overlap in the reconstructed panoramic image (1); determining one or more optimal X-ray imaging directions (3') from among the X-ray imaging directions (3) corresponding to the 2D-X-ray images identified in the step of identifying one or more regions (7) each including at least one pair of overlapping adjacent teeth (8) in order to reduce the overlap in the reconstructed panoramic image (1); The method further comprising: [2] In the identifying step, a trained artificial intelligence algorithm is used to identify one or more regions (7) each containing at least one pair of overlapping adjacent teeth (8) in the 2D-X-ray image (2) and / or in a temporary panoramic image reconstructed from the 2D-X-ray image (2). The method according to [1], [3] The method described in [2], characterized in that the trained artificial intelligence algorithm is trained on input of previously acquired 2D-X-ray images and / or previously reconstructed panoramic images, each with manual annotations indicating the overlap. [4] The method according to any one of [1] to [3], characterized in that in the determining step, a trained artificial intelligence algorithm is used to determine one or more optimal X-ray imaging directions (3') from among the corresponding X-ray imaging directions (3) of the 2D-X-ray image (2) in which one or more regions (7) each containing at least one pair of overlapping adjacent teeth (8) are identified in order to reduce the overlap in the reconstructed panoramic image (1). [5] The method according to [4], characterized in that in the determining step, a plurality of at least partial temporary panoramic images (1') are reconstructed based on 2D-X-ray images (2) each having a different X-ray shooting direction (3) for at least one or more regions (7) each including at least one overlapping adjacent tooth (8), and the trained artificial intelligence algorithm is used to determine the optimal X-ray shooting direction (3') that reduces the overlap in the reconstructed panoramic image (1) from among the different X-ray shooting directions (3) by comparing the plurality of at least partial temporary panoramic images (1') reconstructed for the identified one or more regions (7). [6] In the determining step, the trained artificial intelligence algorithm is used to determine the optimal radiographic orientation (3') that reduces the overlap in the reconstructed panoramic image (1) by comparing a set of originally acquired 2D-X-ray images (2) in which one or more regions (7) each containing at least one overlapping adjacent tooth (8) are identified with the corresponding radiographic orientations (3). The method according to [4], [7] The method according to any one of [4] to [6], characterized in that the trained artificial intelligence algorithm is trained with input of previously acquired 2D-X-ray images and / or previously reconstructed panoramic images, each of which has manual annotations indicating the optimal X-ray shooting direction that reduces the overlap in the reconstructed panoramic image (1). [8] Reconstructing at least a partial panoramic image (1) based on the 2D-X-ray image (2) in which an optimal X-ray direction (3') for one or more identified regions (7) has been determined; presenting additional information (A) indicating the reduced overlap to a user on the reconstructed panoramic image (1); The method according to any one of [1] to [7], further comprising: [9] Reconstructing at least a partial panoramic image (1') based on the 2D-X-ray image (2) and the X-ray imaging directions (3) for one or more regions (7); and displaying on the reconstructed panoramic image (1') an inset (1a) showing at least a partial panoramic image (1) reconstructed based on the 2D-X-ray image (2) in which an optimal X-ray shooting direction (3') for the identified one or more regions (7) has been determined, additional information (A) provided for the identified one or more regions (7); The method according to any one of [1] to [7], further comprising:

[10] Reconstructing at least a partial panoramic image (1) based on the 2D-X-ray images (2) whose image points correspond to interpolated X-ray imaging directions obtained through spatial interpolation between the determined optimal X-ray imaging directions (3') of the one or more identified regions (7). The method according to any one of [1] to [9], further comprising:

[11] A computer program comprising computer-executable code for causing a computer-implemented X-ray imaging system (9) to perform the steps of the method according to any one of [1] to

[10] .

[12] A computer-readable storage means comprising the computer program according to

[11] .

[13] An X-ray imaging system (9) for generating a panoramic image (1) with reduced overlap of adjacent teeth (8), comprising: an X-ray source (4) for emitting X-rays towards the patient; an X-ray detector (5) for detecting the X-rays that have passed through the jaw (6) of the patient; acquisition means adapted to acquire a plurality of 2D-X-ray images (2) in a plurality of different X-ray imaging directions (3) by rotating the X-ray source (4) and the X-ray detector (5) around at least the jaw (6) of the patient; In a system comprising: A system further comprising image processing means adapted to execute the computer program according to

[11] .

Claims

1. 1. A computer-implemented x-ray imaging method for generating a panoramic image (1) with reduced overlap of adjacent teeth (8), comprising: Acquiring a plurality of 2D-X-ray images (2) in a plurality of different X-ray imaging directions (3) by rotating the X-ray source (4) and the X-ray detector (5) around the patient's jaw (6). A method comprising: identifying one or more regions (7) in the 2D-X-ray image (2) and / or in a temporary panoramic image reconstructed from the 2D-X-ray image (2) each containing at least one pair of overlapping adjacent teeth (8), from among the corresponding X-ray directions (3), from which an optimal X-ray direction (3') that reduces the overlap in the reconstructed panoramic image (1) can be determined; determining one or more optimal X-ray imaging directions (3') from among the X-ray imaging directions (3) corresponding to the 2D-X-ray images identified in the identifying step, in order to reduce the overlap in the reconstructed panoramic image (1), each of which includes at least one pair of overlapping adjacent teeth (8); Further provided with In the determining step, a trained artificial intelligence algorithm is used to determine one or more optimal X-ray imaging directions (3') from among the corresponding X-ray imaging directions (3) of the 2D-X-ray images (2) in which one or more regions (7) each containing at least one pair of overlapping adjacent teeth (8) are identified in order to reduce the overlap in the reconstructed panoramic image (1).

2. In the identifying step, a trained artificial intelligence algorithm is used to identify one or more regions (7) each containing at least one pair of overlapping adjacent teeth (8) in the 2D-X-ray image (2) and / or in a temporary panoramic image reconstructed from the 2D-X-ray image (2).

2. The method of claim 1.

3. 3. The method of claim 2, wherein the trained artificial intelligence algorithm is trained with input of previously acquired 2D X-ray images and / or previously reconstructed panoramic images, each with manual annotations indicating the overlap.

4. 4. The method according to claim 1, wherein in the determining step, a plurality of at least partial temporary panoramic images (1') are reconstructed based on 2D-X-ray images (2) each having a different X-ray imaging direction (3) for at least one or more regions (7) each including at least one overlapping adjacent tooth (8), and the trained artificial intelligence algorithm is used to determine the optimal X-ray imaging direction (3') that reduces the overlap in the reconstructed panoramic image (1) from among the different X-ray imaging directions (3) by comparing the plurality of at least partial temporary panoramic images (1') reconstructed for the identified one or more regions (7).

5. In the determining step, the trained artificial intelligence algorithm is used to determine the optimal radiographic orientation (3') that reduces the overlap in the reconstructed panoramic image (1) by comparing a set of originally acquired 2D-X-ray images (2) in which one or more regions (7) each containing at least one overlapping adjacent tooth (8) are identified with the corresponding radiographic orientations (3). The method according to any one of claims 1 to 3, characterized in that

6. 6. The method according to claim 1, wherein the trained artificial intelligence algorithm is trained with input of previously acquired 2D-X-ray images and / or previously reconstructed panoramic images, each with manual annotations indicating the optimal X-ray shooting directions that reduce the overlap in the reconstructed panoramic image (1).

7. reconstructing at least a partial panoramic image (1) based on the 2D-X-ray image (2) in which an optimal X-ray direction (3') for one or more identified regions (7) has been determined; presenting additional information (A) indicating the reduced overlap to a user on the reconstructed panoramic image (1); The method according to any one of claims 1 to 6, further comprising:

8. reconstructing at least a partial panoramic image (1') based on the 2D-X-ray image (2) and the X-ray imaging directions (3) for one or more regions (7); a step of displaying on the reconstructed panoramic image (1') an inset (1a) showing an at least partial panoramic image (1) reconstructed based on the 2D-X-ray image (2) in which an optimal X-ray shooting direction (3') for the identified one or more regions (7) has been determined, and additional information (A) provided for the identified one or more regions (7); The method according to any one of claims 1 to 6, further comprising:

9. Reconstructing at least a partial panoramic image (1) based on the 2D-X-ray images (2) corresponding to interpolated X-ray imaging directions obtained through spatial interpolation between the determined optimal X-ray imaging directions (3') of the corresponding identified one or more regions (7). The method according to any one of claims 1 to 8, further comprising:

10. A computer program comprising computer executable code for causing a computer-implemented X-ray imaging system (9) to carry out the steps of the method according to any one of claims 1 to 9.

11. A computer readable storage means comprising the computer program of claim 10.

12. 1. An X-ray imaging system (9) for generating a panoramic image (1) with reduced overlap of adjacent teeth (8), comprising: an X-ray source (4) for emitting X-rays towards the patient; an X-ray detector (5) for detecting the X-rays transmitted through the jaw (6) of the patient; acquisition means adapted to acquire a plurality of 2D-X-ray images (2) in a plurality of different X-ray imaging directions (3) by rotating the X-ray source (4) and the X-ray detector (5) around at least the jaw (6) of the patient; In a system comprising: A system further comprising image processing means adapted to execute the computer program of claim 10.

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