KR20160098408A - Generating dental panoramic images - Google Patents

Abstract

The present invention relates generally to generating a digital tooth panorama image from multiple frame images acquired during a tooth panorama imaging scan centered on a patient's head. This generation includes using the information of the position and orientation of the x-ray beam and the x-ray detector at the time of taking the frame in the procedure of summing the information of the frame.

Description

Generation of Dental Panoramic Images {GENERATING DENTAL PANORAMIC IMAGES}

The present invention relates generally to tooth panorama imaging, and more particularly, to generating a digital tooth panorama image from multiple frame images acquired during a tooth panorama imaging scan centered on a patient's head.

The traditional working principle of a panoramic X-ray device is that the film is moved about the X-ray beam so that the dental arch can be imaged as a flat photograph on the film, And driving.

This basic operation of traditional tooth panoramic imaging involves creating a mutual movement between the X-ray source, the image information receiver and the patient, respectively. While there are many possibilities to create this movement, the most common arrangement is to attach the X-ray source and the image information receiver to the support arm at a distance from each other, and the arm then moves in a certain way do. In such a situation, in order to obtain a clear image of the desired layer in the object, i. E. The layer of the dental arch in the head of the patient, the speed of movement of the film should be specifically related to the sweep speed of the X-ray beam along the desired layer to be imaged. With this arrangement, unwanted structures in front of and behind the desired layer in the patient ' s head are blurred so that they are invisible.

In traditional panoramic imaging, the thickness of the layer that can be clearly photographed is directly proportional to the distance from the film level to the instantaneous center of rotation of the support arm and is inversely proportional to the width and magnification of the beam.

Panoramic imaging This basic equation can be expressed as:

v1 / v0 = L1 / L0

v0 = ωr

here:

L0 = distance from the X-ray tube focus F to a point of the object to be imaged at a predetermined moment;

L1 = distance from X-ray tube focus (F) to X-ray film (or detector) plane;

ω = angular velocity of rotation about the instantaneous center of rotation;

r = distance of the point of the object to be imaged from the instantaneous center of rotation; And

v1 = velocity of the image point on the film (detector) plane.

The velocity v1 is thus related to the rate at which the film travels during the panoramic imaging scan with respect to the x-ray beam hitting the film. With respect to digital imaging, when the so-called TDI imaging technique (Time Delayed Integration) is used, the moving speed of the pixel charge across the detector is made to correspond to the speed of film movement. Thus, the image data read from the sensor may correspond to the panoramic film image in that already the blurring of the layer outside the desired layer is performed when the scan process and charge transfer are performed to follow this imaging equation. In this situation, as long as it is relevant to select the tomographic layer to be displayed, post-exposure image processing is not required and is not possible since the data read from the sensor already represents the velocity v1 of the layer to which it corresponds to be.

Prior art digital panoramic imaging also includes so-called Frame Transfer (FT) technology. In the case of using FT or any other technique in which a plurality of individual superimposed frames are photographed during an imaging scan, if a typical technician wishes to observe the same layer that is obtained when following a conventional panorama imaging equation provided above, The overlapping degree of the frame at the time of constructing the layer so as to correspond to the speed v1.

One advantage of the frame technique is that by varying the degree of overlapping, the tomographic layer after exposure can be adjusted to a predetermined extent It is possible to change it. The range in which the layer can be changed depends on how the frame data is acquired and the means by which the frame data is acquired. Typically, however, only a marginal variation of the position of the layer is possible.

In addition, while the prior art frame panorama system includes the possibility of slightly changing the clear layer, the overlap used in the image composition is based on some predetermined system. This scheme typically involves using a standard overlay of frames and the actual output of the panoramic image does not include any parameters that can be associated with the actual imaging geometry of the imaging system at the exposure position of the frame.

In addition, the viewing direction of the anatomical structure may be determined by the imaging geometry used to acquire the frame data, i. E., By the geometry in which the imaging means (x-ray source and image information receiver) Since it is primarily determined, the prior art system is fixed in the viewing direction because it lacks means for changing the viewing direction in which the panoramic image or its section is shown.

In addition, when using more conventional continuous scanning techniques, frame imaging techniques can use a wider detector area than is practically possible, but not only do not have a major change in magnification ratio within a single frame, There is a criterion such as that relating to the need to be able to read, which also sets a practical limit on the width of the detector that can be used by a typical technologist in prior art tooth panorama frame imaging.

The main object of the present invention and its preferred embodiments is that the frame image data acquired in a single panoramic imaging scan is associated with each exposure position and is used in an imaging procedure to provide a new possibility of generating a tooth panorama image from frame data after exposure And to provide a system that can be used with respect to the recognition of the true imaging geometry used. A secondary objective of the present invention is to not only create more than one tomographic layer from frame image data acquired in a single panoramic imaging scan, but also to construct and display an image or partial image of the dental arch when viewed from different directions .

These and other objects of the invention to be described below can be attained by the embodiments of the present invention as defined in the appended claims. The essence of the present invention is that the information of the focus of the detector and of the x-ray tube, and hence of the geometry of the imaging, which is the position and orientation of the x-ray beam, is known at these exposure positions, It is to implement a panoramic scan to be used for calculation.

An advantage of various embodiments of the present invention includes the possibility of generating a tooth panorama image from a single set of frame data when viewed from more than one direction. If it is possible to virtually change the angle of view, the features of the anatomical structure that can not be observed from certain other viewing directions can be made observable. Thus, for example, a re-exposure of the patient to x-radiation due to the need for re-imaging of the image can be avoided. In addition, the embodiments described below offer the possibility of using a wider detector than typically used in tooth frame panoramic imaging.

The invention and some preferred embodiments thereof will also be described below with reference to the accompanying drawings.
Figure 1 shows an example of a panoramic imaging device.
Figure 2 illustrates some of the basic components of a system that implements the embodiments described below.
FIG. 3A shows a tooth panoramic image and FIG. 3B shows an individual frame image other than the number in which a tooth panoramic image can be generated.
Figure 4 shows a separate superposition frame with lines representing vertical sections of the anatomical structure projected at different locations of the frame when the imaging detector is moved to a new exposure position.
Figure 5 shows a schematic diagram of the principle of panoramic imaging processing according to an embodiment of the present invention.
Figure 6 illustrates steps of a method in which the principles of the present invention are applied.
Figure 7 shows a schematic diagram illustrating the hardware configuration of an information processing / computer system that may be used in implementing the invention.

The embodiments and various features and advantageous details disclosed herein are more fully described with reference to the non-limiting embodiments illustrated in the accompanying drawings and described in detail in the following description. The detailed description of well known components and processing techniques is omitted herein to avoid unnecessarily obscuring the embodiments. The examples used herein are intended only to facilitate understanding of the manner in which the embodiments herein may be practiced, as well as to enable those of ordinary skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

It should also be understood that the embodiments are illustrative. For example, wherever the specification refers to a "singular," "one," or "some" embodiment (s), it should be understood that each such reference is the same embodiment (s) But is not meant to be limited to a single embodiment. The single features of the different embodiments may be combined to provide alternative embodiments, even if explicitly disclosed in the context.

Embodiments of the invention disclosed herein use position and orientation information of the x-ray beam and x-ray detector when taking a superposition frame along the dental arch to produce a tooth panoramic image. For example, the embodiments described below allow the user to observe a particular point of interest of the dental arch from an angular region, i.e., from more than one observation direction. Thus, the embodiments described herein may allow a user to observe certain features between the user's teeth in a tooth panoramic radiograph, for example, It may be impossible to observe within the panoramic radiograph.

In the accompanying drawings, Fig. 1 provides the structure of an exemplary panoramic X-ray imaging device. The apparatus includes a base portion 27 and a column-shaped frame portion 12 secured to the base portion 27 by a lower end thereof. The support arm 13 (shown without the cover of the support arm) is rotatably mounted on the upper end of the frame portion 12. Correspondingly, another intermediate support arm 14 is rotatably mounted on the outer end of the support arm 13, and on the outer end of the intermediate support arm is an imaging arm 15, or a so-called C- Is rotatably mounted. The C-arm 15 supports the imaging means, i. E. The x-ray source 26 and the image detector 16. In addition, the positioning support portion 25 is attached to the column-shaped frame portion 12 to help position the person to be imaged. Instead of the column-shaped frame portion 12, the rotatable support arm 13 can also be mounted on the wall or ceiling structure.

The structure shown in Figure 1 has been simplified for clarity. For example, the force receiving means functioning as the transfer means of the arm structures 13 to 15 is not shown in the drawings. Similarly, the stepping motor 1 for rotating the arm structures 13 to 15 is shown in a simplified form.

The apparatus as shown in Figure 1 and its control system (not shown in Figure 1) provides an example of a structure that moves the center of rotation of the C-arm 15, and the C- The imaging means is basically used to perform a panoramic imaging scan around the patient ' s head. The structural part of the tooth panoramic imaging device is varied, and most simply, the imaging device can enable only one fixed imaging geometry.

2, the basic components of the system embodying the invention include a control system (CS) of an imaging device, the control system comprising a motor 1 for driving arms or arms 13-15, Or it is in operative connection with the motor and includes or is in connection with the working electronics of the detector 16. The system includes, among other things, a memory M for recording frame image information and information relating to the associated imaging geometry, a processing means (IP) for generating a panoramic image, a screen S showing an image, ).

FIG. 3A shows a typical tooth panorama image 200. FIG. Since digital panoramic image 200 is constructed from frame image data acquired during a panoramic imaging scan, FIG. 3B can be considered to represent one of hundreds or even thousands of partially superimposed frame images 300 taken during a scan. And Figure 4 illustrates the principle of how the overlapping individual frames 310, 315, 320 acquired during a panoramic imaging scan may be used in constructing the digital panoramic image 200. Line 210, which spans frames 310, 315 and 320 vertically, represents the position of a pixel column of each frame, and the frame contains image information of the same thin vertical section of the anatomical structure to be imaged. The image information that these columns contain is used to construct a pixel column C of the final digital panoramic image 200 to be generated, as will be described in more detail below. Frames taken before and after frame 310, which do not intersect line 210 and thus do not include information regarding a particular section of the anatomical structure represented by line 210, (C) < / RTI > of < / RTI >

Fig. 5 shows a schematic diagram illustrating the principle of the panoramic imaging process of the present invention. This process uses what can be referred to herein as the virtual panoramic curve 400, and uses the location and orientation data of the imaging means in the coordinate system of this curve together during exposure. That is, for this and as will be described in greater detail below, the process includes placing a virtual panoramic curve 400, wherein the virtual panoramic curve is used to shoot the location and shape of the tomographic layer to be generated, In the coordinate system of the imaging geometry used in the process.

In Fig. 5, a plurality of points P1, P2, P3, P4 are shown on the virtual panoramic curve 400, each of which can be considered corresponding to the position of the section of the anatomical structure to be displayed in the panoramic image. That is, each point (P1, P2, etc.) represents the position of the vertical layer of the dental arch to be displayed as an individual pixel column in the generated digital panoramic image.

Figure 5 additionally shows two exposure positions, i.e. the positions (E ', E ") of the x-ray source and detector upon exposure, so that the x-ray beam penetrates the anatomical structure to be imaged and strikes the detector . If an imaging geometry is known, a typical technician will be able to determine the position of the projection portion P 'of each point P on the detector at each of the exposure positions where the projection P' is on the detector . These projection points P 'determine the pixel columns on the detector that are used to construct the column C of the panoramic image representing the predetermined point (PN) of the anatomical structure, and the projection (P? P' Can be considered to form the projection direction of the point P with respect to the projection system 300.

As shown in Figure 5, at the first exposure position E ', the projection portion P'2 of the point P2 as seen from the focus of the radiation source is located at a position far from the center of the detector, , While in the second position E ", the projection portion P " 2 is essentially in the center of the detector. This is an event that the prior art image composition process may miss when summing the columns of the nested frame by some standard predetermined procedure, and the embodiment described herein may be configured to construct a panoramic image based on the actual perception of the imaging geometry It is possible to select the column to be used when That is, instead of merely adding column information of a superposition frame in accordance with some standard summation protocols, a typical descriptor may be used to define a certain point (P1, P2) when viewed from the instantaneous position of the focus of the X- , Etc.) determines that particular column of each placed frame image and uses these columns, particularly in calculating the column (C) of the resulting panoramic image.

When recognizing the imaging geometry, which is the location and orientation of the X-ray source and detector during an imaging scan, constructing and displaying an object layer viewed from different directions as well as yielding different layers of the anatomical structure may be performed using a panoramic curve 400 ), Or by altering both of them. This aspect of the present invention can be understood by considering that the panoramic curve 400 of FIG. 5 can be rotated slightly counterclockwise about the point P4. Considering the imaging positions (E ', E "), this allows the projection portions P'2, P " 2 to be further on the detector (on the frame as viewed from the direction of the focus of the x- So that different pixel column information can be selected to be used in constructing the panoramic image. These different columns may represent different angles of view as well as different layers of objects than those according to Fig.

In principle, a typical descriptor may use a virtual panoramic curve 400 that is arbitrary in shape and arranged in any orientation within the coordinate system of the imaging geometry. This allows for the construction of a tomographic layer having a shape that can not be produced with each other merely by mechanical movement of the arm configuration of the device even with the very versatile device of Fig.

In a further embodiment, an individual local observation vector D for any number of points P1, P2 may be determined. In addition to what has been described above with reference to Figure 5, vector D is included in the figure to indicate the desired local viewing direction of point P2. This vector D can be used to determine the weighting factor for the pixel value of the column of the frame representing the particular point P1, P2 of the anatomical structure. 5, the angle between the vector D and the projection direction is smaller than the second exposure position E '' in the first exposure position E 'of FIG. 5, for example, And the projection direction is formed by the line starting from the focus of the radiation source and terminating at the projected point P '. If this type of embodiment is applied, the relatively low weight in the image configuration is less than the value of the projected point (P'2) of the first exposure, the pixel value of the column of the projected point (P " As shown in FIG. When this principle is applied to the projection part P 'of the point P, that is, when more weights are given to pixel values in a given projection direction than in other directions, the characteristics of the anatomical structure Additional emphasis can be given.

The flowchart shown in Figure 6 illustrates one preferred method of implementing the principles of the present invention. In the first step 500 of FIG. 7, during the performed panoramic imaging scan, the respective exposure positions of the frame and frame are read. Then, at step 510, a virtual panorama curve desired to be used by an ordinary technician in the image configuration is obtained, which is then divided into a plurality of points P at step 520, A plurality of points P are preferably selected equidistantly from the curves to form points of the dissection structure corresponding to the column C of FIG. An individual viewing direction D for point P may be determined at step 530. [

Indeed, in view of the imaging geometry used in a panoramic imaging scan, virtual panorama curves or curves 400 that are intended to be used in an image configuration such that an imaging geometry can reasonably produce such a desired layer (s) It would be desirable for the technician to recognize it.

Now that all the data is available, the creation of the column C of the panoramic image 200 to be configured may begin (step 540). First, a locus P corresponding to column C of the panoramic image, and the associated local observational direction D, when determined for locus P, are obtained at step 550. Processing can then be performed for each frame (step 560), since the panoramic curve 400 and the respective position and orientation are known at the time of exposure of each frame and radiation source, and at step 570 First, a point P is projected onto a frame along a line derived from the focus of the radiation source. In practice, for most frames, the projected point P 'will not be present since the line that originates from the focus of the x-ray source and passes through point P on the panoramic curve does not intersect most of the frame, However, for the remaining few frames, the projected point P 'on the frame will form a pixel column of the particular frame used to construct the column C of the panoramic image represented by that point P (steps 580 and 580) 610).

If a local viewing direction D for a given point P is determined, then the process includes determining in step 590 an angle between the local viewing direction D and the line from the focus of the x-ray source, and And crossing the corresponding point (P). This angle is more or less dependent on the projection direction of the point P (or, in other words, the vector of P to P ', referring to Figure 5) from the desired local viewing direction D, May be used as a weighting factor in step 600 to provide a small weight in the image configuration (e.g., for the pixel value of point P ') (step 610). After completion of this process (step 620), the pixel values of each column (C) of the final panoramic image are normalized by dividing the value of a given column by the total sum of the weighting factors of that column.

The above-described procedure comprises using a plurality of separate superimposed frames 300 taken along the dental arches by a tooth panorama x-ray imaging device in a more general aspect, the device producing an x- Ray source and an image detector having a pixel column, the frame 300 being taken by moving the x-ray source and the image detector around the head of the patient, and by summing the information of the frame 300, Generating the panoramic image 200 by summing the information of the frame 300 with information of the position and orientation of the x-ray beam and the x-ray detector at the time of taking the frame, May be provided. And summing the information includes determining the position of the desired point or points (P) relative to the information of the position and orientation of the x-ray beam and x-ray detector at the time of taking the frame, 200 includes summing columns or columns (C) of the panoramic image (200) with respect to the point or points (P). On the other hand, at least two panoramic images 200 when viewed from different directions can be generated, and at least two images representing a field of view from different directions are provided on the display as a combined image or simultaneously as a moving image .

The embodiment also includes generating a virtual panoramic curve 400 representing the tomographic layer to be displayed by the panoramic image 200, the curve 400 and the position and orientation of the x-ray beam and x- Placing the information in the same set of coordinates, and generating a panoramic image (200) representing the tomographic layer according to the position of the curve (400) in the set's coordinates.

Another embodiment includes generating a virtual panoramic curve 400 for information of the position and orientation of the x-ray beam and the x-ray detector, wherein the panoramic curve includes a desired single layer to be displayed by the generated panoramic image 200 Determining a desired point P on the curve 400 for the column C of the panoramic image 200 and determining a point P as viewed from the focal point of the radiation source, Generating a column C of the panoramic image 200 by summing up these columns of the individual frames 300 projected thereon, wherein the projections P? P ' Thereby forming the projection direction of the point P.

With respect to the weighting factor, the associated process may be provided to include determining the desired viewing direction D for at least one point P, whereby the line from the focus of the radiation source to the point P A weighting factor is calculated for the column on the individual frame 300 based on the angle between the direction formed by the frame 300 and the viewing direction D and the weighting factor is set to the desired viewing direction when summing the information of the frame 300 The larger the angle between the direction vector D representing the radiation source and the direction formed by the line from the focal point of the radiation source to the point P, is used to provide a lesser weight to the column of the frame.

The virtual panoramic curve used in the above-described embodiment can be considered to be a tool capable of changing the tomographic layer in a controlled manner with respect to the imaging geometry used in frame data acquisition, and it can also be considered that the anatomical structure, Lt; / RTI > By varying the shape or orientation of the virtual panoramic curve, or both, and also by applying the above-described local viewing direction vector, different images of the dental arch may be obtained from one and the same set of original x-rays acquired in a single panoramic imaging scan And may be configured based on frame image data.

The virtual panoramic curve 400 used to generate the panoramic image may be formed in a number of different ways. One preferred method is to first create a curve that satisfies the curve that fulfills the basic panorama equation described above for the movement of the imaging means. When the movement of the imaging means is fixed frequently in certain types of panoramic imaging devices, or when the same few number of standard movements are typically used, a panoramic curve 400 corresponding to a particular imaging procedure can be created and saved for later use . In addition, previously used or stored panoramic curves, or just used virtual panoramic curves, can be modified, for example, by means including a linear transformation of all points P and associated viewing directions. The linear transformation may include rotational and translational portions. The modification may also include using a non-linear mapping function, such as a two-dimensional spline surface, and this function may be used to transform the panoramic curve.

Embodiments of the present invention include novel ways of generating tooth panorama images as well as showing them on the display, as disclosed. For example, when information about the position and orientation of the x-ray beam and the x-ray detector is available when taking a frame, two or more panoramic images when viewed from different directions may be viewed as x-ray beams and x- Position and orientation information, which can eventually be displayed on the display as a combined image or a moving image, for example, at the same time in succession, when viewed from different directions.

For example, first and second virtual panoramic curves can be generated for information of the position and orientation of the x-ray beam and x-ray detector, both curves representing the desired layer to be displayed by the panoramic image, The two curves can be generated from the first curve by changing the orientation of the first curve and the two panoramic images can be calculated by summing the information of the frames acquired in the panoramic imaging process for the different curves. Of course, more than two curves may be used, for example, illusion of rotating the dental arch may be generated by plotting on a continuous panoramic image that changes the viewing direction. That is, embodiments of this type may include continuously providing an image on the display in order of their viewing direction to provide an impression of the rotating dental arch on the display.

A further embodiment includes generating multiple panoramic images when viewed from different directions, generating multiple images representing different vivid layers for each of these viewing directions, and with respect to this viewing direction, different sharp layers Can be selected to represent the viewing direction, so that the selected image can be provided on the display-as a combination image, as a combined image, or as a moving image, for example, simultaneously and continuously.

The use of the weighting factors described above can improve the effect of different viewing angles by further emphasizing the column with the main x-ray running path in the line having the viewing angle of the panoramic curve at the predetermined point P

The use of weighting factors also contributes to the possibility of using a wider detector surface than is commonly used in teeth frame panorama applications. In the prior art, if the summation of frame data is based on some standard overlapping procedure, the columns that are summed together become farther away from the center of the detector as they do not provide the same section of the anatomical structure. This is due to the exact change in the overall imaging geometry during the exposure process, i.e., the summation protocol which does not recognize the desired layer and the mutual position of the imaging means and the changes present in the orientation. Using the principles described herein can be avoided even if there is blurring of the panoramic image due to adding information to the column C of the panoramic image 200 indicating the change in the location of the anatomical structure. The weighting factor may also be used to compensate for the change magnification.

For an embodiment of the present invention, one possibility of creating illusions that rotate the picked anatomical structure is to use a variety of panoramas based on this by systematically changing the orientation of the local viewing direction vector D of the point P described above It uses only one virtual panorama curve to generate the image. Overall, the scope of the present invention in terms of displaying the anatomical structural features imaged based on the frame data acquired in a single panoramic imaging scan may be such that different layers of the anatomical structure are displayed and either from different viewing angles, , But includes any combination of modifying the orientation of the local direction vector D of the point P and the virtual panorama curve 400, including modifying only the selected number of vectors (D) .

The embodiments described herein may use tooth frame panoramic imaging to realize a tooth panoramic imaging device embodiment, wherein the dental panoramic imaging device includes an x-ray source with focus and an image detector having a plurality of pixel columns, an x- And a control system with means for controlling the device to take several separate superimposed frames along the dental arch, wherein the x-ray source and the image detector are arranged in relation to the device Are arranged at a first distance from each other. The detector may be implemented as a second distance or wider, and the control system is arranged to control the apparatus such that its width is equal to the second distance, and the second distance is about 2 to 10% of the first distance . In an embodiment, the distance between the x-ray source and the image detector may preferably be about 500 to 550 mm.

As described, the embodiments described herein can also make it possible for an ordinary technician to indicate a dissecting structure that can not be observed unless the patient is exposed to additional panoramic radiation treatment. When the normal descriptor can change the viewing angle, the details of the captured anatomical structure that can not be observed can be made observable. For example, a tooth filler may interfere with teeth on other side of the observable dental arch, but a change in the viewing direction may eventually cause such a tooth to be observed.

Fig. 7 is a schematic diagram showing the hardware configuration of an information processing / computer system in which an embodiment of the present invention can be realized. System 1000 of FIG. 7 includes at least one processor or central processing unit (CPU) 1010. CPU 1010 may be coupled to system bus 1012 via various devices such as random access memory (RAM) 1014, read only memory (ROM) 1016, and input / output (I / O) Gt; 1018 < / RTI > The I / O adapter 1018 may be connected to a peripheral device such as a disk unit 1011 and a tape device 1013, or other program storage device readable by the system 1000. The system 1000 may follow these instructions to read the creative instructions on the program storage and perform the methodology of the embodiments herein. The system further includes another user interface device, such as a keyboard 1015, a mouse 1017, a speaker 1024, a microphone 1022, and / or a touch screen device (not shown) (Not shown). In addition, the communication adapter 1020 connects the bus 1012 to the data processing network 1025 and the display adapter 1021 can be embodied as an output device such as a monitor, printer, transmitter, etc., To the display device 1023.

Thus, a further embodiment includes an image detector having a focal x-ray source and a plurality of pixel columns, drive means for moving the x-ray source and detector around the head of the patient, A control system including a control system including means for controlling the control system to take control of the x-ray source and a user interface for sending control commands to the control system, Means for calculating the panoramic image by summing the information recorded about the position and orientation of the detector and the information of the frame for said information to produce a panoramic image when viewed from at least two different directions, Ray source and the image detector are arranged at a distance from each other with respect to the apparatus, The user interface comprises at least one means for providing a command directed to showing the at least two of the panoramic image when viewed from at least two directions.

A tooth panorama imaging device with the structural features of the paragraphs above may also be used as including image processing or other features and / or control systems for acquiring and configuring an image in accordance with any of the embodiments described herein .

The previous detailed description of certain embodiments is provided to enable all of the general characteristics of the embodiments herein to be fully represented by applying the present knowledge, insofar as they may be readily modified and / or configured for various applications, specific embodiments thereof, And accordingly, such configurations and modifications are intended and should be construed to be understood within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Accordingly, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that modifications may be practiced within the spirit and scope of the appended claims.

Claims (23)

A method for generating a digital tooth panoramic image,
- using a plurality of individual superimposed frames (300) taken along the dental arch by a tooth panoramic x-ray imaging device,
The device
an x-ray source that produces an x-ray beam and has a focus, and
- an image detector having a pixel column,
The frame 300 is taken by moving the x-ray source and image detector around the head of the patient,
Step, and
- calculating the panoramic image (200) by summing the information of the frame (300)
- the panoramic image (200) is generated by summing the information of the frame (300) with information of the position and orientation of the x-ray beam and the x-ray detector then taking the frame. The method according to claim 1,
The position of the desired point or points P is determined with respect to the information of the position and orientation of the x-ray beam and x-ray detector at the time of taking the frame, and the sum of the information of the frame 200 is determined at the point And summing the columns or columns (C) of the panoramic image (200) with respect to the points (P). 3. The method according to claim 1 or 2,
A virtual panoramic curve 400 is generated and the virtual panoramic curve represents the tomographic layer to be displayed by the panoramic image 200 and the curve 400 and the position and orientation of the x- Is arranged in the same set of coordinates,
- the panoramic image (200) is generated, the panoramic image representing a tomographic layer according to the position of the curve (400) in the set of coordinates. 4. The method according to any one of claims 1 to 3,
a hypothetical panoramic curve 400 for the information of the position and orientation of the x-ray beam and x-ray detector is generated, the hypothetical panoramic curve represents the desired tomographic layer to be displayed by the panoramic image 200,
The desired point P of the curve 400 is determined for the column C of the generated panoramic image 200,
The column C of the panoramic image 200 is formed by summing the columns of the individual frame 300 onto which the point P when viewed from the focal point of the radiation source is projected, To form a projection direction of a point (P) with respect to a particular discrete frame (300). 5. The method according to any one of claims 2 to 4,
The desired viewing direction D is determined for at least one point P and the weighting factor is determined by the angle between the direction formed by the line from the focus of the radiation source to said point P and the viewing direction D, Is calculated for a column on an individual frame (300)
- the weighting factor is calculated by summing the information in the frame 300 between the direction formed by the line from the focus of the radiation source to the point P and the direction vector D representing the desired viewing direction Wherein a larger angle is used to provide less weight to the column of the frame. 6. The method of claim 5,
Wherein the pixel value of the column (C) of the final panoramic image (200) is normalized by dividing the pixel value of the predetermined column (C) by the total sum of the weighting factors of the corresponding column. A method for generating and providing a digital tooth panoramic image,
- using a plurality of separate superimposed frames (300) taken along the dental arch by a tooth panoramic x-ray imaging device, the device comprising:
- an x-ray source that produces an x-ray beam and has a focus,
An image detector having a pixel column, and
- a display in functional connection with the device,
The frame (300) is taken by moving an x-ray source and an image detector around the head of the patient,
step,
- calculating the panoramic image (200) by summing the information of the frame (300), and
- providing a panoramic image (200) of the resulting tomographic layer on a display,
- at least two panoramic images (200) when viewed from different directions are generated,
The at least two images representing observations from different directions are presented simultaneously on the display as a combined image or as a moving image. 8. The method of claim 7,
The generation of the at least two panoramic images 200 may include summing the information of the frame 300 by at least two different ways for the information of the position and orientation of the x-ray beam and the x- Lt; / RTI > 9. The method according to claim 7 or 8,
Wherein the at least two panoramic images (200) are provided on the display successively in order of their viewing directions to provide an impression of a rotating arch of the arch on the display. 10. The method of claim 9,
A plurality of panoramic images 200 are generated when viewed from different directions,
For each such viewing direction, several images representing different tomographic layers are generated,
- for each such viewing direction, one of the plurality of images representing a different tomographic layer is selected to represent the viewing direction,
Whereby the selected image is provided on the display. 11. The method according to any one of claims 8 to 10,
The position of the desired point or points P is determined relative to said information of the position and orientation of the x-ray beam and x-ray detector at the time of taking the frame, and the summation of the information of the frame (200) And summing the columns or columns (C) of the panoramic image (200) with respect to the points (P). 12. The method according to any one of claims 7 to 11,
A virtual panoramic curve 400 is generated and the virtual panoramic curve represents the tomographic layer to be displayed in the panoramic image 200 and the curve 400 and the position and orientation of the x- The information is placed in the same set of coordinates,
Said at least two panoramic images (200) when viewed from different directions are arranged in said curve (400) such that curves (400) are arranged in at least first and second orientations with respect to the respective set of coordinates For example, by summing the information of the frame (300)
For a column C of the resulting panoramic image 200, a point P on the curve 400 is determined,
The column C of the panoramic image 200 is formed by summing the columns of the individual frame 300 onto which the point P when viewed from the focal point of the radiation source is projected, To form a projection direction of the point (P) with respect to a particular discrete frame (300). A tooth panoramic imaging device,
An x-ray source (26) having a focus and an image detector (16) having a plurality of pixel columns,
- said x-ray source (26) and said image detector (16) are arranged at a distance from one another with respect to the apparatus, an x-ray source and an image detector,
- drive means (1) for moving the x-ray source (26) and the detector (16)
- a control system (CS) comprising means for controlling the device to take a plurality of separate superimposed frames (300) along the dental arch, and
- a user interface (UI) for sending control commands to said control system,
The control system CS is adapted to determine the position and orientation of the x-ray source 26 and x-ray detector 16 at that time taking the frame 300, (IP) of the panoramic image (200) by summing the information of the frame (300) for the position and orientation information to produce a panoramic image (200)
Wherein the user interface (UI) comprises means for providing at least one control command as to at least two panoramic images (200) when viewed from at least two different directions. 14. The method of claim 13,
Wherein the control system (CS) includes means for simultaneously and continuously displaying the at least two images (200) representing observations from different directions as a combined image or as a moving image. The method according to claim 13 or 14,
Wherein the control system (CS) comprises means for providing the image (200) successively along an order of their viewing directions to provide an impression of a rotating dental arch. 16. The method according to any one of claims 13 to 15,
The control system CS is adapted to detect the position and orientation of the x-ray source 26 and x-ray detector 16 at the time of taking the frame 300 by at least two different methods And means (IP) for generating said at least two panoramic images (200) by summing up the information. 16. The method according to any one of claims 13 to 15,
The means (IP) for calculating the panoramic image (200) comprises means for summing information of the frame (300) for information of the position and orientation of the x-ray beam and x- Dental panoramic imaging device. 18. The method of claim 17,
The means (IP) for calculating the panoramic image (200)
A virtual panoramic curve 400 representing the tomographic layer to be displayed by the panoramic image 200 is generated and the information of the position and orientation of the curve 400 and the x-ray beam and x- Coordinates,
To generate a panoramic image (200) representing a tomographic layer according to the position of the curve (400) in the set of coordinates
Means for acquiring an image of the tooth; The method according to claim 17 or 18,
The calculating means (IP)
For this information of the position and orientation of the x-ray beam and x-ray detector, a virtual panoramic curve 400 representing the desired tomographic layer to be displayed by the panoramic image 200 is generated,
Determining a desired point P on the curve 400 with respect to column C of the generated panoramic image 200,
(C) of the panoramic image 200 by summing the columns of the individual frame 300 onto which the point P as viewed from the focal point of the radiation source is projected
Means,
(P? P ') forms the projection direction of the point (P) with respect to a particular discrete frame (300). A tooth panoramic imaging device,
An x-ray source (26) having a focus and an image detector (16) having a plurality of pixel columns,
- the x-ray source (26) and the image detector (16) are arranged at a first distance from one another with respect to the apparatus, the x-ray source and the image detector,
- drive means (1) for moving the x-ray source (26) and the detector (16)
- a control system (CS) comprising means for controlling the device to take several separate superimposed frames (300) along the dental arch,
The control system CS is arranged to determine the position and orientation of the x-ray source 26 and x-ray detector 16 at that time taking the frame 300 and the information of the position of the frame 300 And means (IP) for calculating the panoramic image (200) by summing the information,
The detector 16 is configured to be wider than the second distance or wider than the second distance,
The control system is arranged such that the imaging device controls its width to take the same frame 300 as the second distance, and the second distance is about 2 to 10% of the first distance. 21. The method of claim 20,
Wherein the first distance is about 500 to 550 mm. 23. The method of claim 21 or 22,
The means (IP) for calculating the panoramic image (200)
A virtual panoramic curve 400 representing the tomographic layer to be displayed by the panoramic image 200 is generated and the curve 400 and the information of the position and orientation of the x-ray beam and x- Coordinates,
To generate a panoramic image (200) representing a tomographic layer according to the position of the curve (400) in the set of coordinates
Means for acquiring an image of the tooth; 23. The method of claim 22,
The calculating means (IP)
For this information of the position and orientation of the x-ray beam and x-ray detector, a virtual panoramic curve 400 representing the desired tomographic layer to be displayed by the panoramic image 200 is generated,
Determining a desired point P on the curve 400 with respect to column C of the generated panoramic image 200,
(C) of the panoramic image 200 by summing the columns of the individual frame 300 onto which the point P as viewed from the focal point of the radiation source is projected
Wherein the projection (P - > P ') forms the projection direction of the point (P) with respect to a particular discrete frame (300).

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