JP4806429B2 - Digital panorama photographing apparatus and panorama image processing program - Google Patents

Description

  The present invention relates to a digital panorama imaging apparatus and a panorama image processing program, and in particular, by superimposing a plurality of frame images stored by panoramic imaging of a general medical or dental object, an arbitrary tomographic image of the object is recorded. The present invention relates to a digital panorama photographing apparatus and a panorama image processing program for reconstructing an image.

  Conventionally, a panoramic imaging apparatus is known as a dental X-ray tomography apparatus (see, for example, Patent Documents 1 to 3). The devices disclosed in Patent Documents 1 to 3 acquire tomographic images in the vertical plane direction (Z direction) of the dentition at the position of the dentition aligned on the horizontal plane (XY plane), and to one dentition. On the other hand, a plurality of tomographic images (multi-tomographic images) can be displayed.

  For example, the dental panoramic X-ray imaging apparatus disclosed in Patent Document 1 uses a line sensor type digital sensor as an image receiving apparatus, and ends the first imaging when performing panoramic tomography. When the second shooting in the next range from the position is completed and the second shooting is completed, the operation of performing the third shooting in the next range from the end position is repeated. During this time, when the next shooting is started from the previous shooting end position, the swing arm automatically returns to the origin position by the swing angle, and then the shooting is started. For example, when a series of imaging by three operations is completed, each image data stored in the storage unit is displayed on the display device as one continuous image of the tomographic plane of the imaging target region. This dental panoramic X-ray imaging apparatus can perform multi-layer tomography together with the positions of two tomographic planes separated by several millimeters from the reference tomographic plane.

  However, the apparatus described in Patent Document 1 does not form a panoramic image of an arbitrary slice. On the other hand, the techniques disclosed in Patent Document 2 and Patent Document 3 perform a series of imaging corresponding to one tomography of the subject while turning the X-ray source and the X-ray imaging means around the subject. A plurality of frame images (frame data) are acquired by performing image processing for adding the respective frame images read from the storage means while shifting them by a predetermined distance, so that a panoramic image of an arbitrary tomographic image can be obtained regardless of the tomographic image. Form.

  Among these, in the panoramic image photographing device disclosed in Patent Document 2, when a plurality of sets of frame data are overlapped and added to each other as a parameter necessary for processing to reduce blur of the panoramic image, each set of frame data A “quantity indicating the degree of superposition (gain)” that indicates how much the positions are shifted and superimposed is introduced, and the relationship between the distance in the depth direction and the gain is quantitatively measured in advance using a phantom. Then, while observing the panoramic image, the user sets a region of interest (ROI) as a region of interest (ROI) on the image.

Further, in the digital panorama photographing apparatus disclosed in Patent Document 3, tomographic image construction processing by the frame skipping method is performed on a large number of frame images stored in the large-capacity frame image storage means acquired by photographing. Then, a desired value is obtained as a radius from the rotation center (rotation radius r) when the X-ray source and the X-ray imaging means are rotated, and then, a desired minute value is obtained from the rotation radius r by image construction by the frame minute movement method. A tomographic image on each radius having a constant interval is obtained.
JP 2006-320347 A (0030-0032, FIG. 4) JP 2007-136163 A (0032-0043, FIG. 3) JP 2006-180944 A

  However, in the technology described in Patent Document 2, in response to user operation information, the position specified on the front side or the back side from the cross section having the size of the region of interest on the panoramic image of the standard plane specified by the ROI. When examining a shifted section, the shifted position is defined in the structure of the phantom used for the preliminary measurement. Further, the panoramic image photographing apparatus described in Patent Document 2 reconstructs and displays the designated tomographic image when operation information such as 4 mm parallel movement is input on the back side. Therefore, it is difficult to compare a tomographic image whose position is shifted to the near side or the far side from the reference tomographic image with a reference tomographic image or another tomographic image. Even if the ROI is designated as a reference tomographic image and the images of each tomographic image are displayed continuously, the position of the ROI is unchanged, so that the tomographic image in the lingual side of the dentition has a narrower image width. The tomographic image in the buccal direction of the dentition becomes wider. Similarly, in the technique described in Patent Document 3, even if an image of a tomographic image whose position is shifted to the near side or the far side is specified by specifying a ROI with a reference tomographic image, the image width of each tomographic image is displayed. Are displayed differently.

  As described above, when the tomographic images whose positions are shifted to the front side or the back side by designating the ROI with the reference tomographic images are continuously displayed, However, when observing a tomographic image whose position is shifted to the near side or the far side from a lesioned part found in a reference tomographic image, there is a problem that it feels uncomfortable or it is difficult to visually recognize the lesioned part.

  Therefore, in the present invention, when the above-mentioned problem is solved and an image of a tomographic image whose position is shifted to the near side or the far side is specified by specifying the ROI as a reference tomographic image, the display is viewed. It is an object of the present invention to provide a technique capable of generating an image that is easy for a user to use.

In order to solve the above problem, a digital panoramic imaging apparatus according to claim 1 is an X-ray source that irradiates an object with X-rays, an X-ray imaging unit that receives X-rays transmitted through the object, and an X-ray source. A panoramic image of a tomographic image of the subject to be imaged, and a turning drive means for rotating an arm that holds the X-ray imaging means at a predetermined interval so that the subject can be accommodated at a predetermined interval. Frame image storage means for storing a plurality of frame images acquired by the X-ray imaging means, and when the stored plurality of frame images are preliminarily overlapped with a specified tomographic image of the subject A digital panoramic imaging apparatus for generating a reconstructed tomographic image relating to the designated tomographic image by adding and reconstructing while shifting by an overlap width indicating a shift width of On the panoramic tomographic image reconstructed with respect to the basic tomography, a two-dimensional coordinate value as a range of the region of interest and a tomography set in the depth direction indicating the inside and outside of the basic tomography corresponding to the region of interest An input unit that receives an input of the number and an interval in the depth direction between each set of tomographic frames, and all frames constituting the panoramic tomographic image based on a horizontal value of the input two-dimensional coordinate value A frame image constituting the region of interest is extracted from the image, and the size and position in the height direction of the extracted frame image are determined based on the vertical value of the two-dimensional coordinate value. performs processing for deleting unnecessary portions in the height direction of the size and position as equal as the extracted frame image, a tomographic your said number and spacing is set is input The, the plurality of post-process frame image processed is extracted corresponding to the region of interest of the panoramic tomographic image is formed when the reconstruction process in overlapping width corresponding to the position of the fault, the interest By dividing the value of the width of the region of interest of the panoramic tomographic image by the value of the width of the reconstructed tomographic image corresponding to the region, the image enlargement ratio corresponding to the position of the tomographic image is calculated, and for each set tomographic image Using the image enlargement ratio, the tomographic image after reconstruction processing corresponding to the region of interest does not change the center position of the image, and the width of the image becomes equal to the width of the region of interest of the panoramic tomographic image Panoramic image processing means for generating a normalized tomographic image by performing normalization processing, and output means for continuously outputting the normalized tomographic image for each set tomographic image And with The panoramic image processing means, as the normalization process, outputs the plurality of post-processed frame images extracted and processed corresponding to the region of interest of the panoramic tomographic image for each set tomogram in the width direction. Only by enlarging or reducing at the image enlargement ratio according to the position of the tomography, a normalized frame image having the same height as the post-processing frame image is generated, and at the same time according to the position of the tomography By multiplying the value of the overlap width by the image magnification corresponding to the position of the tomography, a second overlap width is calculated, and the generated normalized frame image is reconstructed with the second overlap width. A tomographic image normalized to the same shape as the height and width of the region of interest is generated .

  According to such a configuration, the digital panoramic imaging apparatus uses the input unit to input a two-dimensional coordinate value indicating the range of the region of interest on the panoramic tomographic image, the number of tomograms set in the depth direction of the region of interest, Accept input with interval. Then, the digital panorama imaging apparatus extracts the frame image constituting the region of interest by the panorama image processing means, and determines the height direction and size of the extracted frame image as the height and position of the region of interest. Processing to align. Then, the digital panoramic imaging apparatus divides the value of the width of the region of interest by the value of the width of the reconstructed tomographic image formed by normal processing for each tomography set by the panoramic image processing means, The image enlargement ratio corresponding to the position of the tomography is calculated, and the image enlargement ratio is used to make the tomographic image after reconstruction processing have the same width as the region of interest without changing the center position of the image. A normalization process is performed so that Therefore, since only a plurality of frame images extracted from the region of interest and processed are used to reconstruct them by superimposing them with the overlapping width (shifting width when overlapping) according to the set tomographic images, The time required for the creation process can be shortened. Then, the digital panoramic imaging apparatus continuously outputs normalized tomographic images for each tomography by the output means. Therefore, when the normalized tomographic image after the reconstruction process is continuously output, the displayed image becomes an image that is easy to use for the user who views the display.

  According to such a configuration, the digital panorama imaging apparatus enlarges or reduces the processed frame image used for the reconstruction process in advance using the image enlargement ratio for each tomography in the normalization process of the panorama image processing unit. In addition, a tomographic image reconstruction process is performed after multiplying the overlap width by the image magnification. Here, since the post-processed frame image is smaller in size than the reconstructed tomographic image formed by normal processing, the processing load related to image enlargement / reduction is larger than when the reconstructed tomographic image is enlarged / reduced. Can be reduced. The overlap width can be easily processed because it is a simple multiplication of scalar values. Therefore, the digital panoramic imaging apparatus can generate a normalized tomographic image while reducing the processing load related to the enlargement / reduction of the image.

The digital panoramic imaging device according to claim 2, in digital panoramic imaging apparatus of claim 1, wherein the panoramic image processing unit, continuously with the position of each fault is the set time elapses By switching to, the normalized tomographic images of the switched tomographic images are sequentially output to the output means, and the position of each tomographic image that is continuously switched as time elapses is followed. An animation screen that guides the position of the tomographic image displayed at that time in the tomographic image is output to the output unit, and the output unit sequentially outputs the normalized tomographic images to the monitor screen, thereby outputting the movie. In addition to displaying, the animation screen is simultaneously displayed on a monitor screen for displaying the movie.

  According to this configuration, the digital panorama imaging apparatus displays each normalized tomographic image as a movie, so that the user who observes the movie display can observe the region of interest without changing the viewpoint. In addition, the digital panorama imaging apparatus simultaneously displays on the monitor screen a normalized tomographic movie display and an animation screen that guides the position of the currently displayed tomographic image. The performance related to the used diagnosis can be improved.

Further, the digital panoramic imaging apparatus of claim 3, in digital panoramic imaging apparatus of claim 1 or claim 2, wherein the frame image storage means is spaced from the center of rotation by a distance r ₁ the N frame images obtained by photographing the first tomogram of the subject while shifting the length of one pixel of the X-ray imaging unit while being stored are stored, and the panoramic image processing unit stores the n pieces of panoramic images. Of the frame images, only (n / k) frames are sequentially read out every (k-1) frames in the shooting order, and the read frame images are overlapped with the length of one pixel of the X-ray imaging means as the overlap width. the reconstruction process using the frame interlace method, together with the distance from the rotation center to generate a second fault tomographic image of the subject is (r ₁ / k), the said object In order to perform reconstruction processing using (n / k) frame images read every (k−1) frames in a third tomography different from the second tomography, By multiplying the length of one pixel of the X-ray imaging means by the value of the ratio between the distance to the third slice and the distance from the rotation center to the second tomography, A frame small movement method of calculating a second overlap width as a new overlap width corresponding to the distance to the three faults and superimposing the (n / k) frame images with the calculated second overlap width. A tomographic image of the third tomographic image of the subject is generated by the used reconstruction process.

  According to such a configuration, the digital panorama photographing apparatus uses the frame skipping method and the frame minute movement method when the tomographic image reconstruction processing is performed by the panorama image processing means. According to the frame skipping method and the frame minute movement method, the third tomography of the subject can be set at the position of the end point of the vector obtained by scalar multiplication of the vector from the rotation center to the point on the second tomography. . Therefore, the digital panoramic imaging apparatus can easily set the third tomography of the subject at a minute fixed interval outside or inside the basic tomography using the second tomography of the subject as the basic tomography. Therefore, since the tomographic interval can be miniaturized, it is possible to improve the performance related to the diagnosis using the tomographic image. Furthermore, particularly in the movie display, the user who observes the movie display can observe the region of interest without changing the viewpoint without feeling uncomfortable.

Further, the panorama image processing program according to claim 4 , wherein a plurality of frame images obtained by panoramic photographing a tomographic image of a subject are overlapped in advance with respect to a designated tomographic image of the subject. Frame image storage means for storing the plurality of frame images in order to generate a reconstructed tomographic image relating to the specified tomographic image by adding and reconstructing while shifting by an overlapping width indicating a shift width when joining A two-dimensional coordinate value as a region of interest on a panoramic tomographic image reconstructed with respect to a predetermined basic fault, and a depth indicating the inside and outside of the basic fault corresponding to the region of interest An input information discrimination control unit that receives, as input information, the number of faults set in the direction and the interval in the depth direction between the set faults. Based on the input two-dimensional coordinate value in the horizontal direction, a frame image constituting the region of interest is extracted from all frame images constituting the panoramic tomographic image, and the vertical direction of the two-dimensional coordinate value is extracted. Based on the value of, an extra portion from the extracted frame image so that the size and position in the height direction of the extracted frame image are equal to the size and position in the height direction of the region of interest Frame image extraction processing means for performing processing for deleting the plurality of post-processing images that are extracted and processed corresponding to the region of interest of the panoramic tomographic image , for each set tomography in which the number and interval are input a frame image by reconstituted with overlapping width corresponding to the position of the tomographic image reconstruction means for generating a reconstructed tomographic image corresponding to the region of interest, each slice is the set, Serial value of the width of the region of interest of a panoramic tomographic image, by dividing by the value of the width of the reconstructed tomographic image corresponding to the region of interest, enlargement ratio calculating means for calculating an image enlargement ratio corresponding to the position of the fault, For each set tomography , using the image enlargement ratio, the tomographic image after reconstruction processing corresponding to the region of interest does not change the center position of the image, and the width of the image is the panoramic tomographic image. A tomographic image width normalization processing unit that generates a normalized tomographic image by performing a normalization process to be equal to the width of the region of interest , and the normalized tomographic image for each set tomographic image Is a panorama image processing program for causing the output means to continuously display the image as a display control means , wherein the panorama image processing means performs the normalization process as the set tomogram. In addition, by expanding or reducing the plurality of processed frame images extracted and processed corresponding to the region of interest of the panoramic tomographic image only in the width direction at the image enlargement ratio according to the position of the tomographic image, By generating a normalized frame image whose height is the same as the height of the post-processing frame image, and multiplying the value of the overlap width according to the position of the tomography by the image enlargement ratio according to the position of the tomography. A tomographic image normalized to the same shape as the height and width of the region of interest is calculated by calculating a second overlapping width and reconstructing the generated normalized frame image with the second overlapping width. generated and characterized in that. By being configured in this way, a computer in which this program is installed can realize each function based on this program.

  According to the present invention, the digital panorama imaging apparatus sets the width of the tomographic image after the reconstruction processing to be equal to the width of the region of interest for each tomography set in the depth direction of the designated region of interest on the panoramic tomographic image. It can output continuously. Therefore, it is possible to generate an image that is easy to use for the user who views the display.

  The best mode for carrying out the digital panorama photographing apparatus of the present invention (hereinafter referred to as “embodiment”) will be described below in detail with reference to the drawings.

[Configuration of Digital Panorama Camera]
FIG. 1 is a configuration diagram schematically showing a digital panorama photographing apparatus according to an embodiment of the present invention. The digital panoramic imaging apparatus 1 captures an X-ray image of a predetermined tomography along the dentition of the maxilla / mandible of a subject (person) K by panoramic radiography (panoramic X-ray tomography), and obtains a dental tomographic image. As shown in FIG. 1, the X-ray source 2, the X-ray imaging means 3, the turning drive means 4, the A / D conversion means 5, the large-capacity frame image storage means 6, Panorama image processing means 7, processed image storage means 8, all-image display storage means 9, output means 10, and input means 17 are provided.

[Tomographic image]
Here, the tomographic image generated and displayed will be described with reference to FIG. FIG. 2 is an explanatory diagram showing a plurality of slices assigned to correspond to a dentition as a subject. In the state shown in FIG. 2, the X-ray source 2 emits X-rays from the front tooth portion c side of the dentition of the person who is the subject K (see FIG. 1), and X-rays are emitted from the molar portion d side of the dentition. Although the imaging means 3 receives light, the X-ray source 2 and the X-ray imaging means 3 rotate and the position of the rotation center a slides during imaging. In FIG. 2, the basic fault b ₀ is taken at the center in the depth direction before and after the dentition, the lingual fault b _m on the rear side (inner side) of the dentition in the depth direction, and the buccal fault b _n on the front side (outer side). Illustrated. Here, m is identification information (m = −1, −2, −3,...) Of the tongue side direction, and n is identification information (n = 1, 2, 3,...) Of the buccal direction. Each is shown. However, in FIG. 2, one each of the lingual-side fault and the buccal-side fault is illustrated. When the dentition of the human body is a subject, the basic tomography b ₀ is, for example, a distance from the rotation center a to the first central incisor on the anterior tooth c side of about 50 mm, a lingual direction tomography, cheek side The directional fault is preferably set in a region from the basic fault b ₀ to about ± 30 mm, for example.

FIG. 3 is an explanatory view showing a tomographic image generated by the digital panoramic imaging apparatus according to the embodiment of the present invention, in which (a) is a tomographic image corresponding to each tomogram of the dentition shown in FIG. b) shows that a tomographic image is formed by overlapping a plurality of frame images while shifting them. The buccal direction tomographic image B _n shown in FIG. 3A is an example of a tomographic image in the buccal side tomographic b _n shown in FIG. A basic tomographic image B ₀ shown in FIG. 3A is an example of a tomographic image of the basic tomographic b ₀ shown in FIG. In the following, when referred to as a panoramic tomographic image, this basic tomographic image B ₀ is indicated. Further, the lingual tomographic image B _m shown in FIG. 3A is an example of a tomographic image of the lingual tomographic b _m shown in FIG.

As shown in FIG. 3A, the image widths (horizontal widths) of the tomographic images are different, and are longer from the rotation center a (see FIG. 2) in the cheek side direction. For example, as shown in FIG. 3B, the basic tomographic image B ₀ is obtained by joining a number of frame images (simple X-ray images) g having a predetermined frame width at a predetermined interval (a predetermined overlap). (Overlapping width showing the shifting width of time). Although FIG. 3B illustrates 13 frame images g, an actual tomographic image is constructed by synthesizing several hundred to several thousand frame images g. In other words, several to several tens of other frame images are superimposed on one frame image, so when focusing on one frame image, the part that actually overlaps with the other frame image It cannot be defined unless the number of frames ahead of the current frame image is specified. On the other hand, the shift width when overlapping can be defined only by the relationship between the frame image of interest and the next frame image. Therefore, in this sense, the shift width is referred to as “overlap width”. As shown in FIG. 3B, all the frame images g may be overlapped at equal intervals, or may be overlapped by changing the overlap width.

[Configuration of each part of Digital Panorama Camera]
Returning to FIG. 1, the configuration of each part of the digital panorama photographing apparatus 1 will be described.
The X-ray source 2 has a slit (not shown), and irradiates the subject K with a slit beam (X-ray beam) generated by irradiating X-rays through the slit at a predetermined timing. .

  The X-ray imaging means 3 receives X-rays emitted from the X-ray source 2 and transmitted through the subject K, and images a portion of the subject K where X-rays are transmitted at a predetermined frame rate. The X-ray imaging means 3 is an X-ray image sensor, an X-ray detector, or a combination thereof. Here, the image sensor is, for example, a CCD (Charge Coupled Device) image sensor, a CMOS image sensor, a TFT (Thin Film Transistor) sensor, a CdTe sensor, or the like. The X-ray detector is an X-ray image intensifier (I.I.), a flat panel detector (FPD), or the like. In the present embodiment, the X-ray imaging unit 3 will be described as a CMOS image sensor. In this case, one pixel size can be set to 100 μm, for example.

  The turning drive means 4 holds the X-ray source 2 and the X-ray imaging means 3 on the arm at a predetermined interval, and turns the arm so as to rotate at a predetermined angular velocity by driving a motor, an actuator or the like. This interval is set to, for example, 30 cm to 1 m so that the subject K is accommodated between the X-ray source 2 and the X-ray imaging means 3. In addition, the irradiation part of the X-ray source 2 and the light-receiving surface of the X-ray imaging means 3 are arranged to face each other. Further, the arm is configured to be rotatable around the rotation center a, and is further configured to be able to perform a slide operation for moving the rotation center a. Accordingly, the X-ray imaging unit 3 can capture a tomographic image in an arbitrary direction around the subject K while maintaining a predetermined distance between the X-ray source 2 and the X-ray imaging unit 3. The turning drive means 4, the X-ray source 2, and the X-ray imaging means 3 are controlled by a controller (not shown), and the X-ray source 2 emits X-rays while the turning drive means 4 turns the arm. The X-ray imaging unit 3 continuously captures a frame image (simple X-ray image) as an X-ray image of the subject K in synchronization with the X-ray irradiation timing and outputs it to the A / D conversion unit 5. To do. The A / D conversion means 5 acquires the output signal of the X-ray imaging means 3, performs A / D conversion (analog to digital translation), and outputs it to the panorama image processing means 7.

The input means 17 is composed of, for example, a mouse, a keyboard, a disk drive device, and the like. In this embodiment, the input unit 17 uses the panoramic tomographic image B reconstructed with respect to the basic tomographic b ₀ as information input to the panoramic image processing unit 7 in order to designate a tomographic image to be generated and displayed. ROI on _0: 2-dimensional coordinate values for the range of (ROI region of interest) and the total number of faults that are set in the depth direction showing the inner and outer base tomographic b ₀ corresponding to the region of interest, The input of the interval in the depth direction between the set faults is accepted.

  The large-capacity frame image storage means 6, the panorama image processing means 7, the processed image storage means 8, and the all-image display storage means 9 can be realized by, for example, a general computer (computer), and CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), and an input / output interface.

  The large-capacity frame image storage means (frame image storage means) 6 stores a frame image (simple X-ray image) as an X-ray image of the subject K imaged by the X-ray imaging means 3 and A / D converted. It is composed of a general image memory, hard disk, and the like.

  The panorama image processing means 7 acquires a frame image as an output signal of the A / D conversion means 5 and stores it in the large-capacity frame image storage means 6. The panoramic image processing means 7 has a reconstruction processing function and a normalization processing function. The panoramic image processing means 7 is a function of reconstruction processing, which develops a plurality of frame images stored in the large-capacity frame image storage means 6 in the processed image storage means 8 and superimposes them in the horizontal direction. The image of each fault is reconstructed for a plurality of specified faults. The reconstructed tomographic image is output to the output means 10 via the entire image display storage means 9. A specific example of this reconstruction process will be described later.

Further, the panoramic image processing unit 7 performs pre-processing of normalization processing based on the horizontal direction values of the two-dimensional coordinate values input by the input unit 17 for all frame images constituting the panoramic tomographic image B ₀ . Among them, a frame image constituting the region of interest is extracted. Further, the panoramic image processing means 7 develops the extracted frame image in the memory of the processed image storage means 8 and extracts the frame image based on the vertical value of the two-dimensional coordinate value input by the input means 17. Processing is performed to delete an excess portion from each frame image so that the size in the height direction of each frame image becomes equal to the size in the height direction of the region of interest. This extracted and processed frame image is called a processed frame image.

The panoramic image processing means 7 performs normalization processing after the above preprocessing. Normalization processing refers to the width of a tomographic image after reconstruction processing based on a plurality of post-processing frame images and the overlap width corresponding to the position of the tomographic image for each tomographic image corresponding to the generated and displayed tomographic image. Means the process of making the width of the region of interest of the panoramic tomographic image B ₀ equal. A specific example of normalization processing will be described later.

  The processed image storage unit 8 is a storage unit used for image reconstruction processing or the like by the panorama image processing unit 7 and includes a general image memory or the like. The processed image storage unit 8 stores a frame image (processed frame image) processed by the panoramic image processing unit 7 and the like.

  The all-image display storage unit 9 stores a tomographic image (a tomographic image or a panoramic tomographic image corresponding to a designated tomographic image) generated as a result of the reconstruction processing by the panoramic image processing unit 7 and to be displayed on the output unit 10. It is composed of a general image memory or the like. This tomographic image is represented by a luminance value, for example.

  The output unit 10 includes, for example, a CRT (Cathode Ray Tube), a liquid crystal display (LCD), a PDP (Plasma Display Panel), an EL (Electronic Luminescence), and the like. The output means 10 continuously outputs the tomographic images normalized by the panoramic image processing means 7 for each tomogram corresponding to the tomographic image specified and generated by the input means 17.

[Functional block of image processing means for panorama]
FIG. 4 is a block diagram showing functions of the panorama image processing means of the digital panorama photographing apparatus according to the embodiment of the present invention. As shown in FIG. 4, the panorama image processing means 7 includes an input information discrimination control means 11, a frame image extraction processing means 12, an image reconstruction means 13, an enlargement ratio calculation means 14, and a tomographic image width normalization. Processing means 15 and display control means 16 are provided.

  Here, information stored in each of the storage units 6, 8, and 9 as information referred to by the panorama image processing unit 7 or information of a processing result will be described. As shown in FIG. 4, the information stored in the storage means includes, for example, a frame image 21, a panoramic tomographic image 22, image reconstruction information 23, a post-processing frame image 24, an enlargement ratio 25, normalization processing information 26, normalization information A converted tomographic image 27 is included. In FIG. 4, in order to distinguish the types of information, the codes are described one by one. However, each piece of information does not exist one by one, but a plurality of pieces of information are generically named. However, the panoramic tomographic image 22 is single.

The frame image 21 is an image for each frame in which a predetermined area of the subject K (see FIG. 1) is imaged by the X-ray imaging unit 3 and is taken in via the A / D conversion unit 5 and the large-capacity frame image storage unit 6. And used for pre-processing of normalization processing and reconstruction processing.
The panoramic tomographic image 22 is a tomographic image that has undergone reconstruction processing on the basic tomography by the image reconstructing means 13, is stored in the entire image display storage means 9, and outputs means for accepting designation of a region of interest (ROI). 10 is displayed.

The image reconstruction information 23 indicates various data (tomographic identification information, frame image identification information, overlapping width, etc.) referred to in the reconstruction processing by the image reconstruction means 13 and image information during the reconstruction processing. .
The post-processing frame image 24 is a processing result of the frame image extraction processing means 12, and is used for reconstruction processing and normalization processing.
The enlargement factor 25 is a processing result of the enlargement factor calculator 14 and is used for normalization processing and reconstruction processing. The enlargement factor 25 is stored in association with the fault identification information.

  The normalization process information 26 indicates information that is referred to in the normalization process by the tomographic image width normalization processing unit 15 and image information that is being executed. Here, the reference information includes, for example, the progress state (unprocessed and processed) of normalization processing (enlargement or reduction) corresponding to various data (tomographic identification information, frame image identification information, overlap width, etc.). . The image reconstruction information 23, the processed frame image 24, the enlargement ratio 25, and the normalization processing information 26 are stored in the processed image storage unit 8.

  The normalized tomographic image 27 is a tomographic image that has been normalized by the tomographic image width normalization processing unit 15 for each specified tomographic image, is stored in the entire image display storage unit 9, and is processed for the designation of the accepted ROI. As a response of the result, it is continuously displayed on the output means 10.

  Hereinafter, in the description of each part of the panoramic image processing means 7 shown in FIG. 4, for convenience of explanation, first, the reconstruction processing by the image reconstruction means 13 will be specifically described, and then the functions of other parts will be sequentially described. Will be explained.

(Reconstruction processing of image reconstruction means)
The image reconstructing unit 13 appropriately changes the combination of the frame images 21 when combining the frame images 21 stored in the large-capacity frame image storage unit 6 and superimposes the panoramic tomographic images corresponding to the basic tomographic b _0. B ₀ is generated. The image reconstruction unit 13 reconstructs a tomographic image corresponding to tomographic images having a predetermined interval in the depth direction by superimposing data of each frame image g constituting the panoramic tomographic image B ₀ on the memory. In the present embodiment, the image reconstruction unit 13 performs the reconstruction process using the frame skipping method and the frame minute movement method. Hereinafter, an outline of this reconstruction process will be described using a specific example. FIG. 5 is an explanatory diagram modeling the principle of tomographic image reconstruction by the digital panoramic imaging apparatus according to the embodiment of the present invention. In FIG. 5, for the sake of simplicity, it is assumed that the subject K is a cylindrical object. FIG. 5 is a view of the subject K as viewed from above.

<Prerequisites>
Here, in the subject K shown in FIG. 5, the tomography K ₁ whose distance from the center axis of the cylinder (the center of the circle in FIG. 5) is r ₁ and the tomography K whose distance from the center axis of the cylinder is r _{2. 2} and a fault K ₃ whose distance from the central axis of the cylinder is r ₃ . On the extension of the central axis of the cylinder, the rotation center a of the arm of the turning drive means 4 (see FIG. 1) is disposed (in FIG. 5, the center of the circle coincides with the rotation center). In actual panoramic photography, the turning drive means 4 (see FIG. 1) rotates the arm at a predetermined angle by rotating the arm around the rotation center “a” and imaginarily dividing the dentition into a circular arc. Since the operation of sliding the position of the arm is performed as possible, the rotation center a moves during panoramic photography.

Further, the intersections of the straight line Q ₁ connecting the X-ray source 2 and the X-ray imaging means 3 with the tomography K ₁ , the tomography K _2, and the tomography K ₃ are point X ₁ , point X ₂ and point X ₃ , respectively. To do. Note that the points X ₁ , X _2, and X ₃ correspond to portions obtained by slicing the fault planes on the fault K ₁ , the fault K _2, and the fault K ₃ linearly, respectively. Here, for example, the X-ray imaging means 3 is a CMOS image sensor, and the size of one pixel of the CMOS image sensor is 100 μm. For example, the distance r ₁ = 300 mm, the distance r ₂ = 150 mm, and the distance r ₃ = 100 mm.

<Frame skipping method>
When the tomography K ₁ (circumference 1884 mm) of the subject K is taken stepwise while shifting one pixel at a time (360 μm) at a shooting angle of 360 °, or continuously shot, 18840 frames per frame An image is obtained. The identification information obtained by arranging these frame images in time series is assumed to be i (i = 1 to 18840). All frame images are stored in the large-capacity frame image storage means 6.

The image reconstruction means 13 uses all the frame images of the identification information i = 1 to 18840 in order of i = 1, 2, 3,... (Number of interlaced frames k = 1), and 1 of the CMOS image sensor. A tomographic image of the tomography K ₁ (radius 300 mm) is generated by superimposing by shifting the pixel size (100 μm).

Further, the image reconstruction means 13 reads the stored frame images every other frame (number of skipped frames k = 2), and these frame images (identification information i = 1, 3,..., 18837, 18839). The tomographic image of the tomographic image K ₂ (radius 150 mm) is generated by using the CMOS image sensor so as to be shifted one pixel size at a time.

Further, the image reconstruction means 13 reads the stored frame images every two frames (frame skipping number k = 3), and reads these frame images (identification information i = 1, 4,..., 18836, 18839). The tomographic image of the tomographic image K ₃ (radius of 100 mm) is generated by using the CMOS image sensor and shifting it by one pixel size. In the following, it is possible to generate a tomographic image of the inner tomographic image in the same manner. Table 1 shows the relationship between the number of interlaced frames k and the fault radius at that time.

That is, the image reconstruction unit 13 superimposes the accumulated frame images every (k−1) frames based on a predetermined reference, for example, a distance r ₁ (radius 300 mm) indicating the tomographic image K _{1 of the} subject K. By combining them (number of frames skipped k), a tomographic image of a tomography having a radius of “r ₁ / k” mm is generated.

<Frame minute movement method>
Here, the fault (radius 50 mm) when k = 6 is defined as the basic fault. In this example, 18840 frame images were acquired with the distance r ₁ (radius 300 mm) indicating the tomography K _{1 of the} subject K as a subject of imaging, but these include all X-ray information within a radius of 300 mm. Each reconstructed tomographic image can be called a tomographic image with the most focus. Therefore, as an example, the fault (radius 50 mm) when k = 6 was used as the basic fault. Then, a fault (for example, a radius of 50.5 mm) between the fault when k = 6 (radius 50 mm) and the fault when k = 5 (radius 60 mm) is generated as a buccal direction fault. . For convenience of calculation, the lingual-side fault is a fault between the fault when k = 6 (radius 50 mm) and the fault when k = 10 (radius 30 mm) (for example, radius 49.5 mm). ).

Hereinafter, as an example, processing for a fault (buccal side direction fault) between a fault (radius 50 mm) when k = 6 and a fault (radius 60 mm) when k = 5 will be described.
In this case, frame images every 5 frames are used in accordance with the smaller radius (the tomogram when k = 6 (radius 50 mm)). The number of frame images for each frame to be used is 3140 (= 18840/6).

Each frame image (identification information i = 1 to 18840) stored in the large-capacity frame image storage means 6 is given an address on the memory for each pixel (100 μm) of the CMOS image sensor. As shown in FIG. 5, if the X-ray irradiation range is an area sandwiched between the straight line Q ₁ and the straight line Q ₂ , a part on the tomography corresponding to the area is imaged by one pixel (100 μm). . Here, for example, 10 addresses on the memory are assigned. The numerical values indicating these addresses are associated with the frame image identification information i and are set to j _i (j _i = 1 to 10).

The image reconstruction means 13 is a numerical value λ _{1 obtained} by performing a predetermined conversion on a numerical value j ₁ (j ₁ = 1 to 10) indicating an address (Addr) of “i = 1 frame image” to be read from the accumulated frame image. Is set in another address space on the memory (second address: second Addr), and image information for each pixel size (first first pixel to last tenth pixel) constituting “i = 1 frame image” Is associated with this second address. A specific example is shown in Table 2. Here, for example, “image information of the second pixel” and “image information of the third pixel” on the right side are actually information of positions separated by one pixel (100 μm), but the memory address (Addr) In FIG. 2, the difference between the numerical values indicating the addresses is “address 1”. On the other hand, in the second address space, “image information of the second pixel” is associated with address “100”, and “image information of the third pixel” is associated with address “200”. That is, the numerical value difference (100) of the address of the second address space is converted so as to correspond to the actually separated distance (100 μm). The conversion to the numerical value indicating the address is for shifting the image information of one pixel size (first first pixel to last tenth pixel) of the frame image while shifting them by 101 μm. In this sense, the address of the first first pixel may be a numerical value before conversion in the second address space.

  Here, since there is no density data (pixel image information) between the coordinates of the arranged frame images of i = 1 (between the addresses of the second address space), the density between the arranged coordinates is not the same. Data is interpolated using density data at the head (left side) between arranged coordinates. For example, between “address 1” and “address 100” in the second address space, the density data from “address 2” to “address 99” is the density data of “address 1” (image information of the first pixel). ) To interpolate. The interpolation process is the same for other frame images. In addition to this interpolation method, a linear interpolation method between coordinates can also be used. In this case, the density data from “2nd address” to “99th address” is the density data of “1st address” (image information of the first pixel) according to the distance between “1st address” and “100th address”. And density data (image information of the second pixel) at “address 100” are prorated.

Next, the image reconstruction means 13 reads a numerical value j ₇ (address) indicating the address (Addr) of “i = 7 frame image” to be read from the stored frame image every 5 frames from “i = 1 frame image”. j ₇ = 1 to 10) is set to the second address space (second Addr), and a numerical value λ ₇ obtained by performing a predetermined conversion is set, and image information for each pixel size constituting “i = 7 frame image” is obtained. , It is associated with this second address. A specific example is shown in Table 3. Here, “image information of the first pixel” of the frame image of i = 7 is associated with the address “101” in the second address space. On the other hand, the “image information of the second pixel” of the frame image with i = 1 is associated with the address “100” in the second address space. That is, in the second address space, the numerical value (101) of the address of the “first pixel image information” that is the head of the i = 7 frame image is the “second pixel image” of the i = 1 frame image. It is larger than the numerical value (100) of the “information” address by “1 address (1 μm)”. Further, the second pixel is separated from the first pixel by “100 address (100 μm)”. Therefore, in the second address space, the frame image with i = 7 is shifted and overlapped by 101 μm to the right from the frame image with i = 1.

Further, the image reconstruction unit 13 sets the numerical value j ₁₃ (j ₁₃ = 1 to 10) indicating the address (Addr) of the “i = 13 frame image” to be read every 5 frames from the “i = 7 frame image”. A numerical value λ ₁₃ subjected to a predetermined conversion is set as a second address (second Addr), and image information for each pixel size constituting “i = 13 frame image” is associated with the second address. A specific example is shown in Table 4. Here, “image information of the first pixel” of the frame image of i = 13 is associated with address “202” in the second address space. On the other hand, the “image information of the first pixel” of the frame image of i = 7 is associated with the address “101” in the second address space. That is, in the second address space, the numerical value (202) of the “first pixel image information” that is the head of the i = 13 frame image is the “first pixel image” of the i = 7 frame image. It is larger by “101 address (101 μm)” than the numerical value (101) of the “information” address. Therefore, in the second address space, the frame image of i = 13 is shifted and overlapped by 101 μm to the right from the frame image of i = 7.

Similarly, the image information is changed to the second address λ _i while converting the numerical value j _i (j _i = 1 to 10) indicating the addresses of 3140 frame images corresponding to the frame skipping number k = 6. Can be associated. Finally, the image reconstructing means 13 superimposes all (3140) pieces of image information for each pixel size constituting the frame image read out every five frames on the second address, so that the radius 50. A tomographic image (image information for 360 ° of a circumference having a radius of 50.5 mm) can be generated on a 5 mm slice.

  If the processing performed on the fault (outer fault) having a radius of 50.5 mm increased by 0.5 mm with a radius of 50 mm as a basic fault is applied to the desired radius R, as shown in Table 5, the radius is 51 mm, A tomographic image can be generated on a 51.5 mm,. Further, if the radius 50 mm is applied to the inner fault as a basic fault, as shown in Table 5, a tomographic image can be similarly generated on a fault having a radius of 49.5 mm, 49.0,.

  As for a tomography with a radius of 60 mm, if 3140 frame images are used, the overlap width is 120 μm as shown in Table 5, but a tomography with a radius of 60 mm corresponds to “the number of skipped frames k = 5”. Therefore, if 3768 frame images are used, the overlap width is 100 μm (one pixel size). Also, for a tomography with a radius of 30 mm, if 3140 frame images are used, the overlap width is 60 μm as shown in Table 5, but the tomography with a radius of 30 mm corresponds to “the number of frame jumps k = 10”. Therefore, if 1884 frame images are used, the overlap width is 100 μm (one pixel size).

Next, with reference to the normalization process of the panorama image processing means 7 and the preprocessing thereof, each part other than the image reconstruction means 13 of the panorama image processing means 7 will be described with reference to FIG.
(Input information discrimination control means)
The input information discrimination control means 11 has a two-dimensional coordinate value as a region of interest on the panoramic tomographic image reconstructed with respect to the basic tomography, and a depth direction indicating the inside and outside of the basic tomography corresponding to the region of interest. As an input information, the number of faults to be set in (2) and the interval in the depth direction between the set faults are received. This input information discrimination control means 11 takes in the frame image acquired by the X-ray imaging means 3 and operates the command or data specified by the input means 17 in accordance with the information input to the panoramic image processing means 7. Discrimination of input information, input / output management of information such as data stored in the storage means 6, 8, 9 are performed.

  Here, designation of a region of interest (ROI) as operation input information designated by the input means 17 will be described. FIG. 6 is a diagram illustrating an example of an input region of interest (ROI), where (a) is an ROI designated on the panoramic tomographic image, and (b) is a depth direction corresponding to the designated ROI. Each fault area is shown. A region of interest (ROI) 601 is designated as a region where a user wants to obtain a tomographic image (region to be displayed), and is reconstructed with respect to a basic tomography as indicated by a broken line in FIG. For example, it is indicated by a rectangular area on the panoramic tomographic image. The range of the region of interest is specified by a two-dimensional coordinate value. When the user selects the region of interest 601 by, for example, clicking and dragging with the mouse, the panoramic image processing means 7 detects the coordinate value of the selected region.

  The region of interest (ROI) 601 is specified by specifying each tomographic image of each tomography in the depth direction as shown in a fan shape in FIG. 6B. That is, the left boundary line 602 and the right boundary line 603 of the region of interest 601 in FIG. 6A are represented by points on the basic fault in FIG. 6B. And designation of the left boundary line 602 or the right boundary line 603 represented by points on the basic fault in FIG. 6B means that the straight lines 604 and 605 are designated in FIG. 6B. . Although it is possible to designate the entire panoramic tomographic image as the region of interest (ROI) 601, in the following, when the region of interest is designated, the region of interest is set in a part of the panoramic tomographic image, and the region of interest is designated. When there is no area of interest, a region of interest is set for the entire panoramic tomographic image.

  FIG. 7 is a diagram showing an example of the number of steps and the number of divisions specified for assigning a slice to a dentition, where (a) is an example of an input operation display screen, and (b) is the number of steps, the number of divisions and the teeth. The correspondence relationship between the faults in each row is shown. The number of divisions indicates the number of tomographic images set in the depth direction indicating the inside and outside of the basic tomography corresponding to the region of interest 601, that is, the number of tomographic images. In this example, the number of divisions is “10”. The number of steps indicates the ratio of shifting the fault from the basic fault to the lingual side and the buccal side, that is, the interval in the depth direction between the set faults. The numerical value of the number of steps is associated with the interval on the subject (actual patient's dentition) in advance. In the present embodiment, the digital panoramic imaging apparatus 1 prevents the display of a tomography with a dental arch from being enlarged or displayed depending on the position in the tomography, so-called, Assume that it has an automatic scaling function. For this reason, the enlargement ratio at the molar portion d (see FIG. 2) of the dental arch is variable, and the enlargement ratio (actually the reduction ratio) at the front tooth portion c (see FIG. 2) is also variable. The digital panorama photographing apparatus 1 performs the process using the conversion table for associating the step number “0.1” with the actual distance “2 mm” along the dental arch as the automatic enlargement / reduction function. It is possible to associate the numerical value with the interval on the actual patient's dentition. However, it is also possible to employ a simple configuration in which the digital panorama photographing apparatus 1 does not have an automatic enlargement / reduction function. In this case, the number of steps “0.1” can be associated with the actual distance “2 mm” without using a conversion table (not shown). In the present embodiment, it is possible to specify an arbitrary numerical value for the number of steps and the number of divisions. However, in the following, default values prepared in advance as standard values when the number of steps and the number of divisions are not specified. Is set.

(Frame image extraction processing means)
The frame image extraction processing means 12 extracts a frame image constituting a region of interest from all frame images constituting the panoramic tomographic image based on the horizontal value of the input two-dimensional coordinate value, and obtains a two-dimensional coordinate value Based on the vertical value of, extra height is extracted from the extracted frame image so that the height size and position of the extracted frame image are equal to the height size and position of the region of interest. Processing to delete the part is performed.

FIG. 8 is an explanatory diagram showing processing in which the panorama image processing means of the digital panorama photographing apparatus according to the embodiment of the present invention extracts and processes a frame image from the ROI. As shown in FIG. 8, the two-dimensional coordinate values of the upper left point of the rectangular region of interest on the panoramic tomographic image and the lower right point that is the diagonal thereof are detected as (x, y) and (x ₁ , y ₁ ), respectively. is the case were the frame image extraction processing unit 12, among all frame images constituting the entire panoramic tomogram B _0, in the right side in the drawing in the panoramic tomogram B ₀ from the point of the horizontal coordinate x A plurality of frame images constituting a part of the region of width (x ₁ −x) are specified as frame images to be extracted. Then, the frame image extraction processing means 12 has a width from the point of the coordinate y in the vertical direction to the lower side in the drawing in the rectangular frame image g on the coordinate space when the panoramic tomographic image B ₀ is assumed to be decomposed. A post-processing frame image G is generated by deleting the remaining part other than the part of the (y-y ₁ ) area. The processed frame image G is stored as the processed frame image 24. Thereby, the size and position in the height direction of the processed frame image G are equal to the size and position in the height direction of the region of interest.

When the image reconstruction unit 13 performs reconstruction processing on each tomography using the processed frame image G processed by the frame image extraction processing unit 12, a tomographic image shown in FIG. 9 is generated. Here, the image reconstruction unit 13 reconstructs a plurality of post-processed frame images with an overlap width corresponding to the position of the tomography set for the subject for each tomography for which the number and interval are input. FIG. 9 is an explanatory diagram illustrating processing in which the panoramic image processing unit of the digital panoramic imaging apparatus according to the embodiment of the present invention reconstructs each tomographic image using the processed frame image. Note that an image reconstructed with the frame image g is denoted as “tomographic image”, and an image reconstructed with the processed frame image G is denoted as “tomographic image”. As shown in FIG. 9, based on the image width of the tomographic image t ₀ of the basic tomography, the tomographic image t _m becomes narrower toward the inner side (tongue side direction) of the depth direction, and the outer side (cheek side). image width of the tomographic image becomes wider tomographic image t _n direction). Note that the height of each tomographic image is equal.

(Enlargement rate calculation means, tomographic image width normalization processing means)
Therefore, as shown in FIG. 10, the tomographic image width normalization processing unit 15 uses the image width of the tomographic image t ₀ of the basic tomographic image as a reference, and the tomographic image t _{m in the} lingual direction has the image width as the normalization processing. The tomographic image t _n in the buccal side direction is widened, and a normalized tomographic image (stored as the normalized tomographic image 27) is generated by performing processing for narrowing the image width.
For this purpose, the enlargement ratio calculation means 14 performs a reconstruction process for each set tomography with a value of the width of the region of interest, with a plurality of processed frame images overlapped according to the position of the tomography set for the subject. By dividing by the value of the width of the tomographic image (reconstructed tomographic image) formed at this time, the enlargement ratio (image enlargement ratio) of the image width corresponding to the position of the tomography is calculated. This image enlargement ratio is stored as an enlargement ratio 25. Details of the enlargement ratio calculation and normalization processing will be described later. In addition, in the case of an enlargement rate, a numerical value of 1 or less indicating that the image is substantially reduced is included. The tomographic image width normalization processing unit 15 uses the image enlargement ratio, and the tomographic image after the reconstruction process does not change the center position of the image, so that the width of the image is the width of the region of interest of the panoramic tomographic image. A normalization process is performed to make them equal.

(Display control means)
FIG. 11 is a diagram showing a display method of normalized tomographic images of each tomogram normalized by the panoramic image processing means of the digital panoramic imaging apparatus according to the embodiment of the present invention, wherein (a) is a list display; (B) shows movie display respectively.
The display control unit 16 continuously displays the tomographic images normalized by the tomographic image width normalization processing unit 15 on the output unit 10 for each set tomography.

  When “list display” is designated as the display form of the normalized tomographic image, the display control means 16 normalizes the tomogram from the left to the right on the monitor screen as shown in FIG. MPR (Multi Planer Reconstruction) display in which images (still images) are arranged in the order of “tongue side tomographic image → basic tomographic image → cheek side tomographic image” is performed. In addition, when it does not fit on one line on the monitor screen, it is displayed following the next line, and when it does not fit on one page, it is displayed continuously on the next page. Further, the display order can be displayed in the order of “cheek-side tomographic image → basic tomographic image → tongue-side tomographic image”.

  In addition, when “movie display” is designated as the display form of the normalized tomographic image, the display control unit 16 converts the normalized tomographic image into the “lingual-side tomographic image” as shown in FIG. "Basic tomographic image-> cheek-side tomographic image" are displayed in order in the order of "overlapping in time" on the monitor screen. Further, the order of superimposing may be the order of “buccal side tomographic image → basic tomographic image → tongue side tomographic image”. Further, the range to be reproduced may be “basic tomographic image → tongue side direction tomographic image”, “basic tomographic image → cheek side direction tomographic image”. Corresponding to this “movie display”, in the present embodiment, for example, a playback time (frame advance time) can be set as operation input information from the input means 17. The reproduction time is input to the display control means 16 via the input information discrimination control means 11. The playback range can also be input.

  Further, in the present embodiment, when performing “movie display”, the display control unit 16 includes a movie window 1202 for displaying a moving image of the normalized tomographic image in the monitor screen 1201, as shown in FIG. In this movie window 1202, an animation window 1203 for displaying an animation following the image displayed at that time is displayed side by side. The animation displayed in the animation window 1203 navigates the position of the slice so that the slice currently displayed in the movie window 1202 can be identified.

  In the animation window 1203, a plurality of slices along the dentition as a subject are indicated by broken lines, and only the positions of the slices displayed in the movie at that time are displayed by solid lines instead of broken lines. The position of the solid line indicating the tomography in this animation window 1203 moves in the lingual or cheek side direction in accordance with the movie display operation. In this embodiment, the animation window 1203 includes a small window for enlarging and displaying only the region of interest of the dentition, in addition to the animation corresponding to the entire dentition.

  Here, in the animation, the line type is changed as an example of the method for indicating the position of the tomographic image displayed at that time, but the present invention is not limited to this. For example, a change in line thickness, a change in line brightness, or a blinking display of the line may be used. In the case of color display, variations including changes in color types are also included.

  The panoramic image processing means 7 has its function realized by a CPU developing and executing a predetermined program stored in a ROM or the like on a RAM. Therefore, the panorama image processing means 7 can also be realized by executing a program that causes a general computer to execute the functions of the panorama image processing means 7 described above. This program can be provided via a communication line, or can be written on a recording medium such as a CD-ROM and distributed.

[Operation of Digital Panorama Camera]
The operation of the panorama image processing means 7 will be mainly described as the operation of the digital panorama photographing apparatus 1 shown in FIG. 1 with reference to FIG. 13 (refer to FIGS. 1 and 4 as appropriate). FIG. 13 is a flowchart showing the operation of the panorama image processing means of the digital panorama photographing apparatus according to the embodiment of the present invention. First, the digital panorama photographing apparatus 1 acquires a panoramic tomographic image (step S1). That is, in the digital panorama photographing apparatus 1, the panorama image processing means 7 generates a panoramic tomographic image 22 by reconstructing a number of frame images acquired and stored by panoramic photographing of the subject K by the image reconstruction means 13. Then, it is displayed by the output means 10 and waits for accepting designation of a region of interest (ROI) or the like. When the panoramic image processing means 7 determines that the command for instructing generation and display of the tomographic image has been received by the input information discrimination control means 11, there is an instruction of a two-dimensional coordinate value indicating the region of interest (ROI). Is determined (step S2).

  If there is an instruction of the region of interest (ROI) in step S2 (step S2: Yes), the panoramic image processing means 7 sets the region of interest (ROI) as a processing target range. On the other hand, when there is no instruction of the region of interest (ROI) (step S2: No), the panoramic image processing means 7 sets the region of interest (ROI) to the entire panoramic tomographic image. Subsequent to step S3 or step S4, the panorama image processing means 7 determines whether or not there is an input of an arbitrary number of steps and divisions by the input information determination control means 11 (step S5). When there is an input of an arbitrary step number and division number (step S5: Yes), the panoramic image processing means 7 sets the input step number and division number as processing conditions (step S6). On the other hand, when there is no input of an arbitrary step number and division number (step S5: No), the panoramic image processing means 7 sets default values as processing conditions for the step number and the division number (step S7).

  Subsequent to step S6 or step S7, the panoramic image processing means 7 uses the frame image extraction processing means 12 to extract a plurality of frame images (frame data) that constitute the region of interest from the set region of interest and make it necessary. Processing is performed accordingly (step S8). Then, the panoramic image processing means 7 reconstructs the tomographic image by adding the predetermined overlap width for each tomographic image using the extracted frame by the image reconstructing means 13, and the image acquired at this time The reconstruction information 23 (tomographic identification information, frame image identification information, overlap width, etc.) is stored in the processed image storage means 8 (step S9). In step S9, the tomographic image is reconstructed on the memory to acquire information necessary for calculating the enlargement ratio, and the tomographic image itself reconstructed on the memory is not displayed.

  The panorama image processing means 7 then enlarges the width of each tomographic image corresponding to each tomographic image from the width of the basic tomographic image (ROI width) based on the image reconstruction information 23 by the enlargement ratio calculating means 14. The rate is calculated and stored in the processed image storage unit 8 as the enlargement rate 25 (step S10). Then, the panoramic image processing means 7 performs a process of normalizing the width of each tomographic image corresponding to each tomographic image based on the normalization processing information 26 by the tomographic image width normalizing process means 15. The corresponding normalized tomographic image 27 is stored in the entire image display storage unit 9 (step S11). Here, as the processing for normalizing the width of each tomographic image, a method for enlarging or reducing the tomographic image after reconstruction (normalization processing method 1), and a tomographic image after enlarging or reducing the post-processing frame and the overlapping width. Any method of reconstructing an image (normalization processing method 2) can be employed. The normalization processing method 1 and the normalization processing method 2 will be described later.

  Next, the panoramic image processing means 7 determines whether or not there is an instruction for the display form of the tomographic image by the input information determination control means 11 (step S12). If there is no indication of the display form, the generated normalized tomographic image 27 is saved, for example, and the process is terminated. In step S12, when there is an instruction of “list display” as the display form, the panoramic image processing unit 7 arranges the still images of the tomographic images normalized by the display control unit 16 and displays the region of interest ( ROI) is displayed on the output means 10 (step S13). In step S12, when there is an instruction of “movie display” as the display form, the panorama image processing means 7 displays an animation for navigating the currently displayed tomographic position by the display control means 16. The region of interest (ROI) is displayed as a movie on the output means 10 using the generated normalized tomographic image 27 (step S14). The panoramic image processing means 7 may perform the process of step S14 after the process of step S13.

[Normalization processing method 1]
FIG. 14 is an explanatory diagram showing a first specific example of normalization processing performed by the panorama image processing means of the digital panorama photographing apparatus according to the embodiment of the present invention. Normalization (normalization in the horizontal direction of the image) is to expand the width of the reconstructed image (tomographic image) of each tomography (tongue side direction fault, buccal side direction fault) to match the horizontal width of the basic tomographic image / It is to reduce. Although the basic fault is described as a form in which normalization processing is performed formally, since the enlargement ratio is multiplied by “1”, there is substantially no change due to normalization. Further, the image height does not change during normalization.

  The size of the frame data (processed frame image) illustrated in the first column in FIG. 14 is assumed to be a height H and a width F. This post-processed frame image is determined within the region of interest. The frame image based on the processed frame image is an apparatus-specific value (fixed value) determined by the image receiving area of the X-ray imaging unit 3 (see FIG. 1).

In the normalization processing method 1, the image reconstruction unit 13 performs reconstruction processing before the tomographic image width normalization processing unit 15 performs enlargement or reduction processing. Here, it is assumed that the image reconstruction unit 13 adds four pieces of frame data. First, as a reference, when the image reconstruction unit 13 performs the image reconstruction (reconstruction process) in which the four frame data are superimposed with the overlap width f ₀ in the basic slice shown in the middle stage in FIG. As shown in the second column, the width of the tomographic image t ₀ is w ₀ . The image width w ₀ is the same value as the width of the region of interest, and serves as a reference for the enlargement factor calculation means 14 to calculate the image enlargement factor α.

Further, in the lingual direction faults shown in the upper stage in FIG. 14, the image reconstruction unit 13, when the image reconstruction superposing width f _m overlapping four frame data (reconstruction process) of FIG. 14 As shown in the second column, the width of the tomographic image t _m is w _m . Width w _m of the tomographic image t _m lingual direction, since narrower than the width w ₀ of the basic tomographic image t _0, the overlapping width f _m of the lingual direction tomographic image t _m, overlapped basic tomographic image t ₀ densely than the width f _0. The image enlargement ratio α _m of the lingual tomographic _slice is expressed by Expression (1). The enlargement factor calculating means 14 calculates the image enlargement factor α _m from the equation (1).
α _m = w ₀ / w _m Formula (1)

Similarly, when the image reconstruction unit 13 performs image reconstruction (reconstruction processing) in which four pieces of frame data are overlapped with the overlap width f _n in the buccal direction cross section shown in the lower part of FIG. As shown in the second column, the width of the tomographic image t _n is w _n . Width w _n of the tomographic image t _n buccal direction, since wider than the width w ₀ of the basic tomographic image t _0, the overlapping width f _n of the tomographic image t _n buccal direction, overlapping of the basic tomographic image t ₀ It is sparser than the width f ₀ . The buccal direction tomographic image enlargement ratio α _n is expressed by equation (2). The enlargement factor calculating means 14 calculates the image enlargement factor α _n from the equation (2). Note that the expression for the image enlargement ratio α with respect to a general tomographic width w including a basic tomography is expressed by Expression (3) without depending on the direction (n, m) of the tomography.
α _n = w ₀ / w _n Formula (2)
α = w ₀ / w ... Formula (3)

Thus, after the image reconstruction unit 13 performs the reconstruction process, the enlargement / reduction process performed by the tomographic image width normalization unit 15, that is, “normalization of the reconstructed image” shown in the third column of FIG. Will be described. First, in the basic fault shown in the middle stage in FIG. 14, the basic fault regular tomographic image width normalization processing means 15 with respect to the width w ₀ of the tomographic image t _0, was generated by applying a formal enlargement ratio "1" the width of the image of T ₀ is the same as the width w ₀ of the tomographic image t _0.

Next, in the lingual direction tomogram shown in the upper part of FIG. 14, the lingual direction normalization generated by the tomographic image width normalization processing unit 15 by multiplying the width w _m of the tomographic image t _{m by} the enlargement factor “α _m ”. The width w _rm of the tomographic image T _m is the same as the width w ₀ of the tomographic image t ₀ .
Similarly, in the buccal side direction slice shown in the lower part of FIG. 14, the buccal side direction normalization processing unit 15 generates the buccal side direction normalization generated by multiplying the width w _n of the tomographic image t _{n by} the enlargement factor “α _n ”. The width w _rn of the tomographic image T _n is the same as the width w ₀ of the tomographic image t ₀ . Thereby, normalization in the horizontal direction of the image is realized.

  Here, as shown in the fourth column in FIG. 14, the frame data generated when the normalized reconstructed image is decomposed (reduced) into frame images (processed frame images) has the following properties. Have The frame data shown in the fourth column in FIG. 14 is the same as the “one frame size” shown in the first column in FIG. 14 in the basic fault shown in the middle stage in FIG.

On the other hand, the following relational expressions (4) and (5) are derived from the lingual tomographic fault shown in the upper part of FIG. As shown in four column 14, the width F _rm frame data to be generated, a value obtained by multiplying the image enlargement ratio alpha _m in width F of shown in the first column in FIG. 14, "1 frame size" . Further, as shown in the third column in FIG. 14, the overlap width f _rm when the normalized reconstructed image is reduced to frame data is the image having the overlap width f _m shown in the second column in FIG. 14. It is a value multiplied by the enlargement ratio α _m .
F _rm = F × α _m (4)
_{f rm = f m × α m} ... (5)

Similarly, in the buccal side cross section shown in the lower part of FIG. 14, the following relational expressions (6) and (7) are derived. As shown in the fourth column in FIG. 14, the width F _rn of the generated frame data is a value obtained by multiplying the width F of “1 frame size” shown in the first column in FIG. 14 by the image enlargement ratio α _n. . Further, as shown in the third column in FIG. 14, the overlap width f _rn when the normalized reconstructed image is reduced to frame data is the same as the overlap width f _n shown in the second column in FIG. A value obtained by multiplying the enlargement ratio α _n .
F _rn = F × α _n (6)
f _rn = f _n × α _n (7)

Incidentally, without depending on the fault direction (n, m), when the basic fault also included, the width F _r and overlapping width f _r of general frame data to be decomposed after normalization (reduction), the image enlargement Relational expressions with the rate α are expressed by Expression (8) and Expression (9), respectively. Here, F and f are the width and the overlap width of normal frame data at the time of reconstruction processing.
F _r = F × α (8)
f _r = f × α (9)

[Normalization processing method 2]
FIG. 15 is an explanatory diagram showing a second specific example of the normalization process performed by the panorama image processing unit of the digital panorama photographing apparatus according to the embodiment of the present invention. In the normalization processing method 2, after the tomographic image width normalization processing means 15 enlarges or reduces the post-processing frame and the overlap width, the image reconstruction means 13 performs the reconstruction processing (in the procedure indicated by the broken line in FIG. 4). Process).

  The viewpoints of the expressions (1) to (3) described in the normalization processing method 1 perform normalization (normalization) of the reconstructed tomographic image in the image horizontal direction. In addition, the viewpoints of the above-described formulas (4) to (9) indicate the change in the horizontal width of the frame data when the normalized tomographic image is temporarily decomposed (reduced). This change is the same as the change in the normalization processing method 2 when the process of enlargement or reduction of the processed frame data is performed and then the addition (synthesis) process is performed as the process in the reverse direction of the decomposition (reduction). Is equivalent. Therefore, FIG. 15 for explaining the normalization processing method 2 is similar to FIG. 14 for explaining the normalization processing method 1. However, the contents of the third and fourth columns in FIG. 15 correspond to the contents obtained by exchanging the contents of the fourth and third columns in FIG. Therefore, the description of the same contents in FIG.

  The pre-normalized frame data (processed frame image) exemplified in the first column of FIG. 15 is the same as the content of the first column in FIG. However, in the normalization processing method 2, this frame data is a target whose size is enlarged or reduced.

  Although not actually performed in the second column in FIG. 15, for the purpose of comparison with the fourth column, if the image is reconstructed before normalization (before changing the frame data size or overlap width) Is shown. Therefore, it is the same as the contents of the second column in FIG.

  The third column in FIG. 15 shows one frame size when the width of the frame data (processed frame image) exemplified in the first column is multiplied by the enlargement factor. This process is based on the above-described equations (4), (6), and (8).

  In the fourth column of FIG. 15, the normalized frame data (normalized processed frame image) exemplified in the third column is shifted by the overlap width when the normal overlap width is multiplied by the enlargement ratio. In addition, a tomographic image generated by addition (a tomographic image subjected to reconstruction processing) is shown. This process is based on the above-described equations (5), (7), and (9). Thereby, also in the normalization processing method 2, normalization in the horizontal direction of the image is realized as in the normalization processing method 1.

[Screen display example 1]
FIG. 16 shows an example of a screen display that is displayed as a list on the monitor in an experiment corresponding to the region of interest 601 shown in FIG. As listed in FIG. 16, the horizontal width of each tomographic image is equal because it is normalized. According to the tomographic images in this list, for example, when attention is paid to the region above the teeth, it is possible to observe the change of each tissue tomography without the position of the tissue at the corresponding position moving to the left and right. In the example of FIG. 16, a metal crown is put on some teeth and the luminance is higher than other parts.

[Screen display example 2]
FIG. 17 shows an example of transition of an example of an experimental screen for movie display provided with an animation window. In this experiment, the subject was photographed in a state where the subject was indirectly biting the metal ball with the upper and lower teeth. The region of interest displayed in the movie corresponds to a position slightly shifted downward from the region of interest 601 shown in FIG. As shown in the movie display transition in FIG. 17, the horizontal width of each tomographic image is equal because it is normalized. In the movie window, the position of the solid line indicating the fault in the animation window follows the basic transition from the lingual fault by following the display from the lingual fault to the buccal fault. After that, it moved to the buccal fault. In the example of FIG. 17, a cushion material is shown around the metal sphere displayed in the approximate center of the movie window.

  According to the present embodiment, the digital panoramic imaging apparatus 1 receives input of a range of a region of interest on a panoramic tomographic image, a desired number of slices, and an interval thereof, extracts and processes a frame image constituting the region of interest, and Normalization processing can be performed to make the width of each tomographic image after the reconstruction processing equal to the width of the region of interest without moving the center. Therefore, when the normalized tomographic image after the reconstruction process is continuously output, the displayed image becomes an image that is easy to use for the user who views the display.

  In addition, according to the present embodiment, when the digital panorama photographing apparatus 1 extracts a frame image constituting the region of interest, only the region of interest designated by processing the raw data of the frame image to the height of the region of interest. Since the reconstruction process is performed, the time required for the process of creating the tomographic image can be shortened. In addition, since the reconstruction process is performed only on the designated region of interest, even if a plurality of regions of interest are designated successively, the calculation time can be reduced each time. Therefore, even when the user performs an operation of continuously observing a plurality of regions of interest, the work time can be shortened, and the diagnosis by the user can be supported by such an operation.

  Further, the digital panorama imaging apparatus 1 can detect the position of a fault to be displayed, such as “basic fault lingual side direction fault”, “basic fault ⇔ cheek side direction fault”, and “buccal side direction fault lingual side direction fault”. For example, when the dentist excises the lesioned part of the patient, it is useful for determining a treatment policy such as whether to cut from the buccal side or from the lingual side. In addition, according to the present embodiment, the digital panorama photographing apparatus 1 can display a movie as a form in which normalized tomographic images are continuously output, and a user who observes the movie display can change without changing the viewpoint. The region of interest can be observed. Therefore, the digital panorama photographing apparatus 1 of the present embodiment is excellent in usability and can improve performance related to diagnosis using a tomographic image.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this, It can implement in the range which does not change the meaning. For example, in the present embodiment, the frame skipping method and the frame minute movement method are used for the tomographic image reconstruction processing. However, the present invention is not limited to this, and various reconstruction processing methods are used. Is applicable. However, since the frame skipping method and the frame minute movement method can make the tomographic interval minute, it is preferable to adopt this particularly for movie display.

  Further, in the present embodiment, the arm of the turning drive means 4 is configured to be rotatable around the rotation center a, and is further configured to be capable of sliding to move the rotation center a. In the digital panorama apparatus, a sliding operation for moving the rotation center a is not essential, and the arm of the turning driving means 4 can be configured to perform only an operation for rotating around the rotation center a.

In the present embodiment, the panoramic image processing means 7 has been described as having both a reconstruction processing function and a normalization processing function, but they may be provided separately.
In the present embodiment, the dental digital panoramic imaging apparatus 1 has been described. However, the present invention is not limited to dental X-ray imaging, and can be used for general medical purposes. For example, the present invention may be applied to a chest digital panoramic photographing apparatus for internal medicine. In the present invention, the subject is not limited to the human body, and may be, for example, a naturally occurring object such as a mineral or a product of various industries. In this case, various types of analysis and inspection for damage can be performed.

1 is a configuration diagram schematically illustrating a digital panorama photographing apparatus according to an embodiment of the present invention. It is explanatory drawing which shows the some tomography allocated so as to correspond to the dentition as a to-be-photographed object. It is explanatory drawing which shows the tomogram produced | generated with the digital panorama imaging device which concerns on embodiment of this invention, Comprising: (a) is a tomogram corresponding to each tomogram of the dentition shown in FIG. 2, (b) is two or more. It is shown that a tomographic image is formed by superimposing the frame images while shifting them. It is a block diagram which shows the function of the image processing means for panoramas of the digital panorama imaging device which concerns on embodiment of this invention. It is explanatory drawing which models and shows the principle of the reconstruction of the tomogram by the digital panorama imaging device which concerns on embodiment of this invention. It is a figure which shows an example of the input region of interest (ROI), Comprising: (a) is ROI designated on the panoramic tomographic image, (b) is the area | region of each tomography of the depth direction corresponding to the designated ROI. Each is shown. It is a figure which shows an example of the step number and division number designated in order to assign a slice to a dentition, (a) is an example of an input operation display screen, (b) is the step number and division number, and a tomographic slice. The correspondence relationship is shown respectively. It is explanatory drawing which shows the process which the image processing means for panoramas of the digital panorama imaging device which concerns on embodiment of this invention extracts and processes a frame image from ROI. It is explanatory drawing which shows the process which the image processing means for panoramas of the digital panorama imaging device which concerns on embodiment of this invention each reconstructs the image of each tomography using a post-processed frame image. It is explanatory drawing which shows the normalization process which arranges the width | variety of each tomographic image which the image processing means for panorama of the digital panorama imaging device which concerns on embodiment of this invention reconstructs. It is a figure which shows the display method of the normalization tomographic image of each tomogram normalized by the image processing means for panorama of the digital panorama imaging device which concerns on embodiment of this invention, (a) is a list display, (b) is a list display. Each movie display is shown. The figure which shows an example of the window screen for the movie of the normalization tomographic image displayed on the same screen by the image processing means for panorama of the digital panoramic imaging device concerning the embodiment of the present invention, and the window screen for animation of the tomographic position It is. It is a flowchart which shows operation | movement of the image processing means for panoramas of the digital panorama imaging device which concerns on embodiment of this invention. It is explanatory drawing which shows the 1st specific example of the normalization process which the image processing means for panorama of the digital panorama imaging device which concerns on embodiment of this invention performs. It is explanatory drawing which shows the 2nd specific example of the normalization process which the image processing means for panorama of the digital panorama imaging device which concerns on embodiment of this invention performs. It is a figure which shows an example of the screen which displayed the list of the normalization tomographic image of each tomogram normalized by the panorama image processing means of the digital panorama imaging device according to the embodiment of the present invention. It is a figure which shows the example of a transition of the screen which displayed the normalization tomographic image of each tomogram normalized by the panorama image processing means of the digital panorama imaging device according to the embodiment of the present invention as a movie.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Digital panorama imaging device 2 X-ray source 3 X-ray imaging means 4 Rotation drive means 5 A / D conversion means 6 Large capacity frame image storage means (frame image storage means)
7 panoramic image processing means 8 processed image storage means 9 all image display storage means 10 output means 11 input information discrimination control means 12 frame image extraction processing means 13 image reconstruction means 14 enlargement ratio calculation means 15 tomographic image width normalization processing means 16 Display control means 17 Input means 21 Frame image 22 Panoramic tomographic image 23 Image reconstruction information 24 Processed frame image 25 Magnification factor 26 Normalization processing information 27 Normalized tomographic image

Claims (4)

An X-ray source that irradiates the subject with X-rays;
X-ray imaging means for receiving X-rays transmitted through the subject;
Swivel driving means for rotating an arm that holds the X-ray source and the X-ray imaging means at a predetermined interval so as to accommodate the subject around a predetermined rotation center;
Frame image storage means for storing a plurality of frame images acquired by the X-ray imaging means by performing panoramic imaging of a tomographic image of the subject,
The stored tomographic frame images are reconstructed by adding the plurality of stored frame images while shifting them by a predetermined overlap width with respect to the specified tomographic slice of the subject. A digital panoramic imaging apparatus for generating a reconstructed tomographic image relating to:
A two-dimensional coordinate value is set as a region of interest on a panoramic tomographic image reconstructed with respect to a predetermined basic fault, and is set in the depth direction indicating the inner side and the outer side of the basic fault corresponding to the region of interest. An input means for receiving an input of the number of faults and an interval in the depth direction between the set faults;
Based on the input two-dimensional coordinate value in the horizontal direction, a frame image constituting the region of interest is extracted from all frame images constituting the panoramic tomographic image, and the two-dimensional coordinate value in the vertical direction is extracted. Based on the value, an extra portion is extracted from the extracted frame image so that the size and position in the height direction of the extracted frame image are equal to the size and position in the height direction of the region of interest. Do the processing to delete,
For each fault and the number and spacing is set is input, the panoramic said plurality of post-process frame image processed is extracted corresponding to the region of interest of the tomographic image corresponding to the position of the tomographic overlapping width The width of the region of interest in the panoramic tomographic image is divided by the value of the width of the reconstructed tomographic image corresponding to the region of interest, which is formed when the reconstruction process is performed at Calculate the image magnification,
For each set tomography , using the image enlargement ratio, the tomographic image after reconstruction processing corresponding to the region of interest does not change the center position of the image, and the width of the image is the panoramic tomographic image. Panoramic image processing means for generating a normalized tomographic image by performing normalization processing so as to be equal to the width of the region of interest;
Output means for continuously outputting the normalized tomographic image for each tomographic set ,
The panoramic image processing means includes:
As the normalization process, the plurality of post-processed frame images extracted and processed corresponding to the region of interest of the panoramic tomographic image for each set tomographic image, according to the position of the tomographic image only in the width direction. By enlarging or reducing at the image enlargement ratio, a normalized frame image having the same height as the post-processed frame image is generated, and the position of the tomography is set to the overlap width value corresponding to the position of the tomography The second overlap width is calculated by multiplying the image enlargement ratio in accordance with the above, and the generated normalized frame image is reconstructed with the second overlap width, whereby the height and width of the region of interest are calculated. A digital panoramic imaging apparatus characterized by generating a tomographic image normalized to the same shape as in FIG. The panoramic image processing means includes:
By sequentially switching the position of each tomographic section as time passes, the normalized tomographic images for the switched tomographic sections are sequentially output to the output means, and the time lapses An animation screen that guides the position of the tomographic image displayed in the tomographic image at the time following the position of each tomographically continuously switched with the output means,
The output means performs movie display by sequentially outputting the normalized tomographic images to a monitor screen, and simultaneously displays the animation screen on the monitor screen for performing the movie display. Item 4. The digital panorama photographing apparatus according to Item 1 . The frame image storage means captures and acquires a first tomogram of the subject that is separated from the rotation center by a distance r ₁ while shifting the first tomographic image by the length of one pixel of the X-ray imaging means. Memorize frame images,
The panoramic image processing means includes:
Of the n frame images, only (n / k) frames are sequentially read out every (k-1) frames in the order of photographing, and the length of one pixel of the X-ray imaging unit is used as the overlap width to read each frame. Generating a tomographic image of the second tomogram of the subject whose distance from the rotation center is (r ₁ / k) by a reconstruction process using a frame skipping method of superimposing images;
In order to perform reconstruction processing using (n / k) frame images read every (k−1) frames in a third tomography different from the first and second tomograms of the subject, By multiplying the length of one pixel of the X-ray imaging means by the value of the ratio of the distance from the rotation center to the third tomography and the distance from the rotation center to the second tomography, A second overlap width is calculated as a new overlap width corresponding to the distance from the center of rotation to the third fault, and the (n / k) frame images are overlapped with the calculated second overlap width. the reconstruction process using the frame small moving method, digital panoramic imaging apparatus of claim 1 or claim 2, characterized in that generating a third fault tomographic image of the subject. A plurality of frame images acquired by panoramic imaging of a tomographic image of a subject are added while shifting by a superposition width indicating a predetermined shift width when the predetermined cross-section of the subject is overlapped. In order to generate a reconstructed tomographic image relating to the designated tomographic image by reconstructing, a computer comprising frame image storage means for storing the plurality of frame images,
A two-dimensional coordinate value is set as a region of interest on a panoramic tomographic image reconstructed with respect to a predetermined basic fault, and is set in the depth direction indicating the inner side and the outer side of the basic fault corresponding to the region of interest. Input information discrimination control means for receiving, as input information, the number of faults and the distance in the depth direction between the set faults;
Based on the input two-dimensional coordinate value in the horizontal direction, a frame image constituting the region of interest is extracted from all frame images constituting the panoramic tomographic image, and the two-dimensional coordinate value in the vertical direction is extracted. Based on the value, an extra portion is extracted from the extracted frame image so that the size and position in the height direction of the extracted frame image are equal to the size and position in the height direction of the region of interest. Frame image extraction processing means for performing processing to be deleted;
For each fault and the number and spacing is set is input, the panoramic said plurality of post-process frame image processed is extracted corresponding to the region of interest of the tomographic image corresponding to the position of the tomographic overlapping width An image reconstruction means for generating a reconstructed tomographic image corresponding to the region of interest by reconstructing with
By dividing the value of the width of the region of interest of the panoramic tomographic image by the value of the width of the reconstructed tomographic image corresponding to the region of interest for each set tomographic image, the image enlargement ratio corresponding to the position of the tomographic image Enlargement ratio calculating means for calculating
For each set tomography , using the image enlargement ratio, the tomographic image after reconstruction processing corresponding to the region of interest does not change the center position of the image, and the width of the image is the panoramic tomographic image. A tomographic image width normalization processing unit that generates a normalized tomographic image by performing a normalization process to be equal to the width of the region of interest,
Display control means for continuously displaying the normalized tomographic image on the output means for each of the set tomograms;
Panorama image processing program to function as
The panoramic image processing means includes:
As the normalization process, the plurality of post-processed frame images extracted and processed corresponding to the region of interest of the panoramic tomographic image for each set tomographic image, according to the position of the tomographic image only in the width direction. By enlarging or reducing at the image enlargement ratio, a normalized frame image having the same height as the post-processed frame image is generated, and the position of the tomography is set to the overlap width value corresponding to the position of the tomography The second overlap width is calculated by multiplying the image enlargement ratio in accordance with the above, and the generated normalized frame image is reconstructed with the second overlap width, whereby the height and width of the region of interest are calculated. A panoramic image processing program characterized by generating a tomographic image normalized to the same shape as in FIG.