JP5102888B2 - Bone diagnostic image display device - Google Patents

Description

  The present invention relates to a bone diagnostic image display apparatus, and more particularly to an apparatus that acquires bone mineral distribution image data representing a distribution of bone mineral using two types of X-rays having different energies.

  As evaluation values for diagnosing osteoporosis and the like, there are a bone mineral density and a bone density, and a bone density measuring apparatus that performs the measurement by X-ray is widely used. The bone density measuring device detects X-rays emitted from an X-ray generator and transmitted through a subject with an X-ray detector, and measures the bone mineral content of the subject based on the detection result. Further, the bone area which is the projected area of the bone on the X-ray generator is obtained, and the bone density is obtained by dividing the bone mineral content by the bone area.

  There is a dual energy X-ray absorption measurement (DXA) method for measuring the bone mineral content by the bone density measuring device. In this measurement method, transmission X-ray image data for a subject is acquired for each of two types of X-rays having different energies, and bone mineral distribution image data is obtained from these transmission X-ray image data. The bone mineral distribution image data represents a bone mineral distribution image obtained by projecting a three-dimensional spatial distribution of bone mineral in the subject onto a plane. The bone density measuring device obtains the bone mineral content, bone area, bone density, and the like of the bone to be diagnosed based on the bone mineral distribution image data, displays the numerical value on the display, and displays the bone mineral distribution image on the display.

  Patent Document 1 describes an X-ray diagnostic imaging apparatus with a bone density distribution measurement function. This apparatus displays a bone density distribution image and an X-ray transmission image side by side or in a superimposed manner. Patent Document 2 describes an X-ray image diagnostic apparatus. This device generates a bone image in which bone tissue is emphasized based on two radiographic images acquired using two types of radiation having different energies. Patent Document 3 describes an X-ray tomography apparatus. This apparatus generates these difference images based on two X-ray images acquired using two types of X-rays having different energies. Then, at least one of the two X-ray images and the difference image are displayed.

JP 2005-34539 A JP-A-10-155115 JP 2008-86543 A

  In diagnosis of osteoporosis and the like, bone mineral distribution images may be referred to in addition to numerical values such as bone mineral content, bone area, and bone density. The user can visually recognize that the bone has been deformed due to a compression fracture or the like by referring to the bone mineral distribution image. However, in the bone mineral distribution image, the distinction between the bone tissue and the soft tissue may be unclear in an area where the bone mineral content is small. The bone mineral distribution image is not intended to represent the soft tissue of the subject. For this reason, it may be difficult for a user who is constantly performing bone diagnosis based on a transmitted X-ray image to perform bone diagnosis using only a bone mineral distribution image.

  An object of this invention is to display the image acquired when measuring the amount of bone minerals in the aspect suitable for the diagnosis of a bone.

The present invention generates first X-ray image data based on the first X-ray transmitted through the subject, has an energy different from the energy of the first X-ray, and based on the second X-ray transmitted through the subject. A transmission X-ray image data generation unit that generates second X-ray image data, and bone mineral distribution image data representing the distribution of bone mineral in the subject based on the first X-ray image data and the second X-ray image data A bone mineral distribution image data generation unit that generates a background, and a background that selects any one of the first X-ray image data, the second X-ray image data, and the bone mineral distribution image data as background image data representing a background image an image selection unit, and the background image display unit for displaying the background image on the display unit, the region of interest setting unit that sets a region of interest relative to the background image, said background image is displayed on the display means The Rutoki, as a region of interest data for displaying an image of the region of interest, wherein the 1X-ray image data, wherein the 2X-ray image data, or any one of the bone mineral distribution image data, the operation of the user A region-of-interest image selection unit that selects according to the above-mentioned image, and a composite image generation unit that causes a display unit to display a composite image in which a portion of the background image corresponding to the region of interest is replaced with an image based on the region-of-interest data The synthetic image generation unit includes a smoothing processing unit that performs a smoothing process on the region-of-interest data, and a region of the background image corresponding to the region of interest has been subjected to the smoothing process. A smoothed composite image replaced with an image based on the data, and a portion of the background image corresponding to the region of interest is the smoothing Comparison display means for causing the display means to display a non-smoothing composite image replaced with an image based on the region-of-interest data that has not been processed, and image display based on the comparison display means are performed. in accordance with the operation by the user, and wherein the Rukoto and a display state maintaining means for displaying on said display means either the smoothing composite image or the non-smoothing composite image in time. According to the present invention, first X-ray image data is generated based on the first X-ray transmitted through the subject, and the second X-ray transmitted through the subject has energy different from the energy of the first X-ray. A transmission X-ray image data generation unit that generates second X-ray image data based on the bone X-ray image data generation unit, and a bone salt distribution that represents the distribution of bone mineral in the subject based on the first X-ray image data and the second X-ray image data A bone mineral distribution image data generation unit that generates image data, and any one of the first X-ray image data, the second X-ray image data, and the bone mineral distribution image data is selected as background image data representing a background image A background image selection unit that performs a region of interest setting unit that sets a region of interest for the background image, and a portion of the background image that corresponds to the region of interest is an image based on the first X-ray image data. The replaced first X-ray composite image, the second X-ray composite image replaced with the image based on the second X-ray image data, and the bone mineral distribution composite image replaced with the image based on the bone mineral distribution image data. A composite image generation unit for generating the display, and the composite image generation unit includes a display unit for comparison that causes the display unit to display the first X-ray composite image, the second X-ray composite image, and the bone mineral distribution composite image. Display state maintaining means for causing the display means to display any one of these composite images in response to an operation by the user when the display by the comparison display means is being performed, and the composite image The generation unit includes a smoothing processing unit that performs processing on the composite image displayed by the display state maintaining unit and a second comparison display unit, and the smoothing unit The processing unit performs a smoothing process on the region of interest data corresponding to the region of interest, and the second comparison display unit performs the smoothing process on a portion of the background image corresponding to the region of interest. A smoothed composite image replaced with an image based on the region-of-interest data, and a portion corresponding to the region of interest in the background image is replaced with an image based on the region-of-interest data that has not been subjected to the smoothing process. Smoothing synthesized image is displayed on the display means, and the display state maintaining means is configured to display the smoothing synthesized image or the smoothing synthesized image according to an operation by the user when the image display based on the second comparison display means is being performed. Any one of the non-smoothing composite images is displayed on the display means. According to the present invention, first X-ray image data is generated based on the first X-ray transmitted through the subject, and the second X-ray transmitted through the subject has energy different from the energy of the first X-ray. A transmission X-ray image data generation unit that generates second X-ray image data based on the bone X-ray image data generation unit, and a bone salt distribution that represents the distribution of bone mineral in the subject based on the first X-ray image data and the second X-ray image data A bone mineral distribution image data generation unit that generates image data, and any one of the first X-ray image data, the second X-ray image data, and the bone mineral distribution image data is selected as background image data representing a background image A background image selection unit, a region of interest setting unit that sets a region of interest for the background image, and region of interest data for displaying an image of the region of interest, the first X-ray image data, A region-of-interest image selection unit that selects either 2X-ray image data or the bone mineral distribution image data, and a portion corresponding to the region of interest in the background image is replaced with an image based on the region-of-interest data. A synthesized image generating unit that displays the synthesized image on the display unit, and the synthesized image generating unit performs smoothing processing on the region-of-interest data, and applies the smoothing processing unit to the region of interest in the background image. The smoothed composite image in which the corresponding portion is replaced with the image based on the region-of-interest data subjected to the smoothing process, and the portion corresponding to the region of interest in the background image is not subjected to the smoothing process A non-smoothing composite image replaced with an image based on the region-of-interest data; A display for displaying either the smoothed synthesized image or the non-smoothed synthesized image in response to an operation by the user when the image display based on the comparison display means and the image display based on the comparison display means is performed. And a state maintaining means.

In the present invention, a composite image in which a portion set as a region of interest in the background image is replaced with an image based on any of the first X-ray image data, the second X-ray image data, or the bone mineral distribution image data is provided. Is displayed. A plurality of X-ray images and bone mineral distribution images acquired with X-rays having different energies have disadvantages and advantages for visibility, respectively. According to the present invention, the disadvantage of the background image can be compensated by the advantage of the image of the region of interest. Alternatively, the disadvantages of the image of the region of interest can be compensated for by the advantages of the background image. Furthermore, according to such a configuration, the user can designate an image to be fixedly displayed after comparing each of the case where the smoothing process is used and the case where the smoothing process is not used.

  In the bone diagnosis image display device according to the present invention, preferably, the background image selection unit uses either the first X-ray image data or the second X-ray image data as an absorptance for the X-ray of the subject. The process of selecting based on is executed.

  According to such a configuration, the X-ray image is selected according to the X-ray absorption rate of the subject, and the visibility of the displayed background image can be improved.

  In the bone diagnosis image display device according to the present invention, preferably, a bone representing a boundary line between a bone tissue and a soft tissue in the subject based on the first X-ray image data and the second X-ray image data. A bone tissue line data generation unit that generates bone tissue line data, and the composite image generation unit causes the display unit to display a boundary line represented by the bone tissue line data on the composite image.

  In an X-ray image, an image of a soft tissue appears around an image of a bone tissue, and the boundary between the bone tissue and the soft tissue may be unclear. Therefore, the disadvantages of the X-ray image can be compensated by displaying the boundary line represented by the bone tissue line data superimposed on the composite image.

In the bone diagnosis image display device according to the present invention, preferably, a soft tissue line that generates soft tissue line data representing a boundary line between the soft tissue and air of the subject based on the first X-ray image data. The composite image generation unit includes a data generation unit, and causes the display unit to display a boundary line represented by the soft tissue line data on the composite image.

  In the bone mineral distribution image, since the soft tissue does not appear, the boundary between the soft tissue and the air may be unclear. Therefore, the disadvantage of the bone mineral distribution image can be compensated by displaying the boundary line represented by the soft tissue line data so as to overlap the composite image.

  In the bone diagnosis image display device according to the present invention, preferably, the region-of-interest image selection unit includes an image based on the first X-ray image data, an image based on the second X-ray image data, and the bone mineral distribution image. A cyclic display means for cyclically displaying an image based on the data on the display means in a predetermined order, and when the image display based on the cyclic display means is being performed, the first X-ray image data, A cyclic image designating unit that allows the user to designate either the second X-ray image data or the bone mineral distribution image data.

  According to such a configuration, the user can change the image of the region of interest into an image based on the first X-ray image, an image based on the second X-ray image, and an image based on the bone mineral distribution image. By comparing each of them, a composite image to be fixedly displayed can be designated.

  ADVANTAGE OF THE INVENTION According to this invention, the image acquired when measuring bone mineral content can be displayed in the aspect suitable for the diagnosis of a bone.

It is a figure which shows the structure of the bone density measuring apparatus which concerns on embodiment of this invention. It is a flowchart which shows the process which a bone density measuring apparatus performs in an image display process. It is a figure which shows the example in which the bone mineral distribution image was displayed as a background image, and the example in which the high transmission X-ray image was displayed as a background image. It is a figure which shows the bone mineral distribution image displayed as a background image, and the low transmission X-ray image displayed as a background image. It is a figure which shows the bone mineral distribution image displayed as a background image, and the low transmission X-ray image displayed as a background image. It is a figure which shows a display state when a region of interest is set. It is a figure which shows the display state of a synthesized image when a high transmission X-ray image is displayed as a background image and bone mineral distribution image data is selected as image data for region of interest display. It is a figure which shows a synthetic | combination image when a region of interest is set with respect to a background image and low transmission X-ray image data is selected as image data for region of interest display. It is a flowchart which shows the process which a bone density measuring apparatus performs in the image display process which concerns on an application example. It is a flowchart which shows the process which a bone density measuring apparatus performs in the image display process which concerns on a 2nd application example. It is a figure which shows the example of a smoothing image and a non-smoothing image. It is a flowchart which shows the process which a bone density measuring apparatus performs in the image display process which concerns on a 3rd application example. It is a figure which shows the example which displayed the bone part tissue line in the region of interest. It is a figure which shows the example which displayed the soft tissue line | wire in the region of interest.

  FIG. 1 shows the configuration of a bone density measuring apparatus according to an embodiment of the present invention. The bone density measuring device acquires transmitted X-ray image data and bone mineral distribution image data based on the X-rays transmitted through the subject 16. The bone density measuring device obtains the bone mineral content, the bone area, and the bone density based on the bone mineral distribution image data, and displays these values on the display 32. Further, a transmission X-ray image or a bone mineral distribution image is displayed on the display 32 in accordance with a user operation.

  A specific configuration of the bone density measuring apparatus will be described. The bone density measuring apparatus includes an X-ray generation unit 10, an X-ray detection unit 12, a subject placement table 18, a processor 22, a storage unit 26, a display 32, an operation unit 34, and a system controller 36. In the processor 22, calculation blocks for obtaining the bone mineral content, bone area and bone density based on the detection value of the X-ray detection unit 12, and transmission X-ray based on the detection value of the X-ray detection unit 12. Each calculation block for generating image data and bone mineral distribution image data is configured.

  The X-ray generator 10 is arranged with the X-ray radiation direction facing upward. The X-ray detector 12 is arranged with the detection surface 14 facing down and facing the X-ray generator 10. Between the X-ray generation unit 10 and the X-ray detection unit 12, an object mounting base 18 made of a material that transmits X-rays is disposed. A subject 16 is placed on the subject mounting table 18, and a diagnostic space 20 in which an X-ray beam is scanned is formed from above the X-ray generator 10 to above the subject mounting table 18.

  The operation unit 34 includes a mechanism for inputting information such as a keyboard, a mouse, and a trackball, and gives information for instructing an operation to the system controller 36 based on a user operation. The system controller 36 controls the X-ray generation unit 10, the X-ray detection unit 12, and the processor 22 based on information given from the operation unit 34. As a result, the X-ray generation unit 10, the X-ray detection unit 12, and the processor 22 execute processing according to the operation on the operation unit 34.

  Processing executed by the bone density measuring apparatus will be described. The X-ray generation unit 10, the X-ray detection unit 12, and the image data generation unit 24 acquire transmission X-ray image data and bone mineral distribution image data of the subject 16 based on the dual energy X-ray absorption measurement method. . In this measurement method, transmitted X-ray image data for the subject 16 is obtained for each of two types of X-ray beams having different energies, and bone mineral distribution image data is obtained from each transmitted X-ray image data.

  The subject 16 is placed between the X-ray generation unit 10 and the X-ray detection unit 12. The X-ray generator 10 scans the X-ray beam in the diagnostic space 20 by setting the energy of the radiated X-ray beam to a low value EL. The X-ray detection unit 12 detects X-rays at each detection position on the detection surface 14 and outputs a detection value at each detection position to the image data generation unit 24. The image data generation unit 24 obtains low transmission X-ray image data for the energy EL based on each detection value output from the X-ray detection unit 12.

Further, the X-ray generator 10, the energy of the X-ray beam emitted by a low value E L is greater than the high value EH, to scan the X-ray beam in a diagnostic space 20. The X-ray detection unit 12 detects X-rays at each detection position on the detection surface 14 and outputs a detection value at each detection position to the image data generation unit 24. The image data generation unit 24 obtains high transmission X-ray image data for the energy EH based on the detection value output from the X-ray detection unit 12.

  Note that the low transmission X-ray image data and the high transmission X-ray image data may be obtained by alternately switching the energy of the X-ray beam in a time division manner. That is, the energy of the X-ray beam scanned by the X-ray generation unit 10 is alternately switched between the low value EL and the high value EH, and the X-ray of the energy EL and the X-ray of the energy EH are changed at each detection position on the detection surface 14. The low transmission X-ray image data and the high transmission X-ray image data may be obtained by detecting alternately.

Images data generating unit 24 on the basis of the low transmission X-ray image data and the high transmission X-ray image data, determine the bone mineral distribution image data. The image data generation unit 24 stores the low transmission X-ray image data, the high transmission X-ray image data, and the bone mineral distribution image data in the storage unit 26.

  The measurement value calculation unit 28 reads the bone mineral distribution image data stored in the storage unit 26. Then, the bone mineral content is obtained by integrating the pixel values of the bone mineral distribution image data. Further, the number of pixels whose pixel values exceed a predetermined threshold among the pixels indicated by the bone mineral distribution image data is obtained, and the bone area is obtained by multiplying the number by the area per unit pixel. The measurement value calculation unit 28 obtains the bone density by dividing the bone mineral content by the bone area, and outputs the bone mineral content, the bone area, and the bone density to the image generation unit 30. The image generation unit 30 displays the bone mineral content, bone area, and bone density on the display 32 as numerical values.

  Next, image display processing of the bone density measuring device will be described. In the image display process, image data for displaying a background image is selected from the bone mineral distribution image data, the low transmission X-ray image data, or the high transmission X-ray image data. Then, a background image is displayed on the display 32 based on the selected image data. After the background image is displayed, a region of interest is set on the background image based on a user operation. Then, image data for displaying the region of interest is selected from the bone mineral distribution image data, the low transmission X-ray image data, or the high transmission X-ray image data based on the user's operation, and the image based on the selected image data A composite image in which the region of interest is replaced is displayed on the display 32.

  FIG. 2 shows a flowchart showing processing executed by the bone density measuring device in the image display processing. First, the background image display mode is set in the operation unit 34 (S101). Background image display modes include a bone mineral distribution mode, a low transmission X-ray mode, a high transmission X-ray mode, and an automatic selection mode. The bone mineral distribution mode, the low transmission X-ray mode, and the high transmission X-ray mode are display modes in which the bone mineral distribution image, the low transmission X-ray image, and the high transmission X-ray image are background images, respectively. In the automatic selection mode, either a low transmission X-ray image or a high transmission X-ray image is used, and the amount of X-ray photons transmitted through the subject (pixels of the low transmission X-ray image or the high transmission X-ray image). Value) and a selected image is used as a background image. Since the amount of X-ray photons transmitted through the subject, that is, the pixel value depends on the X-ray absorption rate of the subject, the automatic selection mode is a mode in which processing based on the X-ray absorption rate of the subject is executed. It can be said that there is.

  The system controller 36 gives background image mode information indicating the set background image display mode to the image generation unit 30. The image generation unit 30 determines whether or not the automatic selection mode is set based on the background image mode information (S102). When it is determined that a display mode other than the automatic selection mode is set, a background image corresponding to the set display mode is displayed on the display 32 (S104). That is, when the bone mineral distribution mode is set, the image generation unit 30 reads the bone mineral distribution image data from the storage unit 26 and causes the display 32 to display the bone mineral distribution image as a background image. When the low transmission X-ray image mode is set, the image generation unit 30 reads the low transmission X-ray image data from the storage unit 26 and causes the display 32 to display the low transmission X-ray image as a background image. When the high transmission X-ray image mode is set, the image generation unit 30 reads the high transmission X-ray image data from the storage unit 26 and causes the display 32 to display the high transmission X-ray image as a background image.

  When the image generation unit 30 determines that the automatic selection mode is set, based on the following processing, either the low transmission X-ray image or the high transmission X-ray image is used as the background image. (S103). The image generation unit 30 reads the low transmission X-ray image data from the storage unit 26. Then, the number of pixels whose pixel value is equal to or less than a predetermined threshold among the pixels of the low transmission X-ray image data is obtained. The image generation unit 30 selects a high transmission X-ray image as a background image when the obtained number is equal to or less than a predetermined value, and selects the low transmission X-ray image as a background when the obtained number exceeds the predetermined value. Select as an image. Such selection processing may be performed using high transmission X-ray image data instead of low transmission X-ray image data. In this case, the number of pixels having a pixel value equal to or greater than a predetermined threshold among the pixels of the high transmission X-ray image data is obtained. The image generation unit 30 selects a low transmission X-ray image as a background image when the obtained number is equal to or greater than a predetermined value, and selects a high transmission X-ray image when the obtained number is less than the predetermined value. Select as background image.

  The image generation unit 30 displays the image selected in step S103 on the display 32 as a background image (S104). That is, when the high transmission X-ray image is selected, the image generation unit 30 displays the high transmission X-ray image on the display 32 based on the high transmission X-ray image data. On the other hand, when the low transmission X-ray image is selected, the image generation unit 30 causes the display 32 to display the low transmission X-ray image based on the low transmission X-ray image data.

  FIG. 3A schematically shows an example in which a bone mineral distribution image is displayed as a background image. The diagnosis target in this example is the forearm of the subject. The white area | region of Fig.3 (a) shows a bone tissue. FIG. 3B schematically shows an example in which a high transmission X-ray image is displayed as a background image. The white area | region of FIG.3 (b) shows a bone part structure | tissue, and the area | region which has shaded around it shows a soft part structure | tissue. In the low transmission X-ray image, the bone tissue region and the soft tissue region are displayed darker than this.

  FIG. 4A shows a bone mineral distribution image displayed as a background image, and FIG. 4B shows a low transmission X-ray image displayed as a background image. 5 (a) and 5 (b) show the subject's ribs as the object to be diagnosed. FIG. 5A shows a bone mineral distribution image displayed as a background image, and FIG. 5B shows a low transmission X-ray image displayed as a background image.

  Note that the processing in the automatic selection mode in step S102 of FIG. 2 may be performed based on physique data relating to the physique of the subject, or data indicating a diagnostic site or the like. For example, when the weight of the subject exceeds a predetermined reference value, or when the subject's abdominal circumference exceeds a predetermined reference value, the image generation unit 30 selects the high transmission X-ray image as a background image. . When the diagnosis site is a thick site such as a lumbar spine, the image generation unit 30 selects a high transmission X-ray image as a background image. In this case, the user inputs the physique data of the subject or the data indicating the diagnosis part or the like prior to diagnosis by operating the operation unit 34. The system controller 36 reads the physique data or data indicating the diagnostic site from the operation unit 34 and stores the data in the storage unit 26. The image generation unit 30 executes the automatic selection mode process based on the data stored in the storage unit 26.

  Returning to FIG. 2, the flowchart will be described again. In step S104, the background image is displayed on the display 32, and the system controller 36 and the image generation unit 30 enter a state of waiting for setting of the region of interest and selection of image data for displaying the region of interest. In this state, the user refers to the display 32 and operates the operation unit 34 to display a cursor on the background image and set a region of interest (S105). Furthermore, the user selects image data for displaying the region of interest from the bone mineral distribution image data, the low transmission X-ray image data, or the high transmission X-ray image data by operating the operation unit 34 (S106). When an operation for setting a region of interest is performed, the system controller 36 provides range information indicating the range of the region of interest to the image generation unit 30. Further, when an operation for selecting image data for displaying a region of interest is performed, the system controller 36 provides the image generation unit 30 with image type information indicating the type of the selected image data.

  The image generation unit 30 uses the image data identified by the image type information among the bone mineral distribution image data, the low transmission X-ray image data, or the high transmission X-ray image data as the region-of-interest display image data. Then, based on the image data for displaying the background image, the region-of-interest display image data, and the range information, a composite image is displayed in which the portion of the region of interest in the background image is replaced with the image of the region-of-interest display image data. Image data is generated (S107). The image generation unit 30 displays the composite image on the display 32 based on the composite image data (S108).

  FIG. 6A shows a display state when a region of interest is set in step S105 when a bone mineral distribution image is displayed as a background image. A broken line in FIG. 6A indicates the region of interest 38. FIG. 6B shows a composite image display state when high transmission X-ray image data is selected as region-of-interest display image data. FIG. 7 shows a display state of a composite image when a high transmission X-ray image is displayed as a background image and bone mineral distribution image data is selected as region-of-interest display image data.

  FIG. 8A shows a composite image when a region of interest is set with respect to the background image shown in FIG. 4A and low transmission X-ray image data is selected as the region-of-interest display image data. Has been. FIG. 8B shows a composite image in a case where a region of interest is set for the background image shown in FIG. 5A and low transmission X-ray image data is selected as the region-of-interest display image data. It is shown.

  According to such processing, the disadvantage of the background image can be compensated for by the advantage of the image of the region of interest. Alternatively, the disadvantages of the image of the region of interest can be compensated for by the advantages of the background image. Advantages of the bone mineral distribution image, the low transmission X-ray image, and the high transmission X-ray image are as follows.

  The bone mineral distribution image has, for example, advantages as shown in the following (1) and (2) and disadvantages as shown in (3). (1) The bone tissue can be clearly displayed. (2) The distribution of bone mineral can be visually recognized by the user. However, the bone mineral distribution image has a disadvantage that (3) it is difficult to distinguish a portion having a low bone density from a soft tissue.

  For example, the low transmission X-ray image and the high transmission X-ray image have the following advantages (1) to (3). (1) Diagnosis is easy for a user who regularly performs bone diagnosis based on transmitted X-ray images. (2) Noise is smaller than the bone mineral distribution image. (3) Soft tissue appears in the image. Therefore, it becomes easy to grasp the size of the bone.

  Further, the low transmission X-ray image has advantages such that a portion having a low bone density is likely to appear compared to the bone mineral distribution image, and the contrast is clear compared to the high transmission X-ray image. In addition, the high transmission X-ray image has noise higher than that of the bone mineral distribution image and the low transmission X-ray image, which can obtain an image that can be easily diagnosed even at a site having a high bone density or a thick site. There are advantages such as being small. The bone mineral distribution image, the low transmission X-ray image, and the high transmission X-ray image can be in a relationship that compensates for each other's disadvantages.

  For example, in FIG. 8A, a region including the ulnar styloid process is set as a region of interest, and the region of interest is displayed by low transmission X-ray image data. Thereby, in the region of interest, the positional relationship between the soft tissue and the ulnar styloid process, which is the position reference of the bone, becomes clear. In the background image, the distribution of bone mineral is visually represented. In FIG. 8B, a region having a low bone density is set as a region of interest, and the region of interest is displayed by low transmission X-ray image data. As a result, the bone tissue and soft tissue whose bone density is low and whose shape does not appear in the bone mineral distribution image can be displayed with a low transmission X-ray image.

  Next, image display processing according to an application example will be described. FIG. 9 is a flowchart showing image display processing according to the application example. In this image display processing, when the image data for displaying the region of interest is the bone mineral distribution image data, the low transmission X-ray image data, and the high transmission X-ray image data, respectively, the composite image The bone mineral distribution / composite image, the low X-ray / composite image, and the high X-ray / composite image are cyclically displayed. When such a cyclic display is performed, if a display fixing operation (such as a mouse click) is performed on the operation unit 34, the display of the composite image displayed at that time is maintained.

  First, the processes shown in steps S101 to S105 in FIG. 2 are executed. In step S104, the background image is displayed on the display 32, and the system controller 36 and the image generation unit 30 are in a state of waiting for the setting of the region of interest. In this state, the user refers to the display 32 and operates the operation unit 34 to display a cursor on the background image and set a region of interest (S105). When an operation for setting a region of interest is performed, the system controller 36 provides range information indicating the range of the region of interest to the image generation unit 30.

  Based on the bone mineral distribution image data, the low transmission X-ray image data, the high transmission X-ray image data, the image data for displaying the background image, and the range information, the image generation unit 30 X-ray / composite image data and high X-ray / composite image data are generated (S201 to S203). Here, the bone mineral distribution / composite image data, the raw X-ray / composite image data, and the high X-ray / composite image data are respectively low transmission when the image data for displaying the region of interest is the bone mineral distribution image data. These are the combined image data in the case of X-ray image data and in the case of high-transmission X-ray image data.

  The image generation unit 30 displays the bone mineral distribution / composite image on the display 32 for a predetermined display time t1 (S204). Then, until the display time t1 elapses after the bone mineral distribution / composite image is displayed on the display 32, whether or not the display fixing operation is performed in the operation unit 34 and display fixing information is given from the system controller 36 is determined. Determination is made (S205). When the display fixing information is given from the system controller 36, the image generation unit 30 maintains the state in which the bone mineral distribution / composite image is displayed on the display 32 (S210).

When the display fixing information is not given from the system controller 36, the image generation unit 30 displays the high X-ray / composite image on the display 32 for a predetermined display time t2 (S206). Then, until the display time t2 elapses after the high X-ray / composite image is displayed on the display 32, whether or not the display fixing operation is performed in the operation unit 34 and display fixing information is given from the system controller 36 is determined. Determination is made (S207). When the display fixing information is given from the system controller 36, the image generation unit 30 maintains the state in which the high X-ray / composite image is displayed on the display 32 (S210).

When the display fixing information is not given from the system controller 36, the image generation unit 30 displays the raw X-ray / composite image on the display 32 for a predetermined display time t3 (S208). Then, a display fixing operation is performed in the operation unit 34 after the raw X-ray / composite image is displayed on the display 32 until the display time t3 elapses, and whether or not display fixing information is given from the system controller 36 is determined. Determine (S209). When the display fixing information is given from the system controller 36, the image generation unit 30 maintains the state in which the raw X-ray / composite image is displayed on the display 32 (S210). When the display fixing information is not given from the system controller 36, the image generating unit 30 returns to step S204.

  According to such processing, the bone mineral distribution / composite image, the raw X-ray / composite image, and the high X-ray / composite image are cyclically displayed with the display times t1, t2, and t3. When any one of these composite images is displayed and a display fixing operation is performed by the user, the display state is maintained. Thus, the user can determine a composite image to be fixedly displayed after comparing the bone mineral distribution / composite image, the low X-ray / composite image, and the high X-ray / composite image. Note that the display times t1, t2, and t3 may be set based on an operation on the operation unit 34 such as between 1 second and 10 seconds. In addition, here, the process of cyclically displaying the composite image in the order of bone mineral distribution / composite image, low X-ray / composite image, and high X-ray / composite image is taken up, but the display order is limited to this. Absent.

  Next, image display processing according to the second application example will be described. FIG. 10 shows a flowchart showing image display processing according to the second application example. In this image display processing, after the composite image is displayed, smoothing processing is performed on the data that displays the region of interest in the composite image data, and a smoothed composite image is generated. Here, the smoothing process refers to a process of averaging each pixel. This averaging is performed, for example, by replacing the pixel value of one pixel with the average value of the pixel values of neighboring pixels of the one pixel. Here, the neighboring pixels are defined as pixels within a range away from one pixel by a predetermined number of pixels in the up and down, left and right, and diagonal directions, for example. In the image display processing according to this application example, after a smoothed composite image is generated, a smoothed composite image and a non-smoothed composite image (a normal composite image that has not been subjected to the smoothing process) are alternately switched and displayed. . When a display fixing operation is performed in the operation unit 34 while the switching display is performed, the display of the composite image displayed at that time is maintained.

  First, the processing shown in steps S101 to S108 in FIG. 2 is executed. The image generation unit 30 extracts region-of-interest data for displaying the region of interest from the composite image data (S301), and performs a smoothing process on the region-of-interest data (S302). Then, the data for displaying the region of interest in the original composite image data is replaced with the region-of-interest data that has been subjected to the smoothing process to generate smoothed composite image data (S303).

  The image generation unit 30 displays the smoothed composite image on the display 32 for a predetermined display time t4 (S304). Then, until the display time t4 elapses after the smoothed composite image is displayed on the display 32, it is determined whether or not a display fixing operation is performed in the operation unit 34 and display fixing information is given from the system controller 36 ( S305). When the display fixing information is given from the system controller 36, the image generation unit 30 maintains the state in which the smoothed synthesized image is displayed on the display 32 (S308).

  When the display fixing information is not given from the system controller 36, the image generation unit 30 displays the non-smoothing composite image on the display 32 for a predetermined display time t5 (S306). Then, until the display time t5 elapses after the non-smoothing composite image is displayed on the display 32, it is determined whether or not the display fixing operation is performed in the operation unit 34 and display fixing information is given from the system controller 36. (S307). When the display fixing information is given from the system controller 36, the image generation unit 30 maintains the state in which the non-smoothing composite image is displayed on the display 32 (S308). When the display fixing information is not given from the system controller 36, the image generating unit 30 returns to step S304.

  According to such processing, the smoothed synthesized image and the non-smoothed synthesized image are alternately displayed with the display times t4 and t5, respectively. When any of these composite images is displayed and the display is fixed by the user, the display is maintained. Thus, the user can determine a composite image to be fixedly displayed after comparing the smoothed composite image and the non-smoothed composite image. The display times t4 and t5 may be set based on an operation on the operation unit 34.

  When the region of interest is a high transmission X-ray image or a low transmission X-ray image, the contour of the bone tissue becomes clear in the non-smoothing composite image. On the other hand, in the non-smoothing composite image, the outline of the soft tissue becomes clear. Therefore, according to the image display processing according to this application example, either the smoothed synthesized image or the non-smoothed image can be displayed according to the purpose of diagnosis.

In the above description, the example in which the processing after step S301 is executed after the processing shown in steps S101 to S108 in FIG. 2 is executed has been described. Instead of such processing, after the image display processing according to the second application example is performed, i.e., after the process shown in step S210 of FIG. 9 is performed, step S301 and executes subsequent processing May be.

  FIGS. 11A and 11B show examples of a non-smoothing image and a smoothing image, respectively. In this example, a mouse is used as a subject. The background image is a bone mineral distribution image, and the region of interest is a low transmission X-ray image. As shown in FIG. 11A, in the non-smoothing image, the outline of the bone tissue appearing in the region of interest becomes clear. On the other hand, as shown in FIG. 11B, in the smoothed image, the outline of the soft tissue that appears in the region of interest becomes clear.

  Next, image display processing according to the third application example will be described. FIG. 12 is a flowchart showing processing executed by the bone density measuring device in the image display processing according to the third application example. In this image display process, when the background image is a bone mineral distribution image and the region of interest is a low transmission X-ray image or a high transmission X-ray image, the bone that is the boundary line between the bone tissue and the soft tissue is used. Bone tissue line data representing the tissue line is generated. Then, an image in which the bone tissue line is superimposed on the region of interest of the composite image is displayed on the display 32. On the other hand, when the background image is a low transmission X-ray image or a high transmission X-ray image and the region of interest is a bone mineral distribution image, the soft tissue that is the boundary line (outline of the soft tissue) between the soft tissue and the air Soft tissue line data representing the line is generated. Then, an image in which the soft tissue line is superimposed on the region of interest of the composite image is displayed on the display 32. In the following description, the term of the transmission X-ray image is used as a term including both the low transmission X-ray image and the high transmission X-ray image.

  First, the processing shown in steps S101 to S108 in FIG. 2 is executed. The image generation unit 30 determines whether the background image is a bone mineral distribution image and the region of interest is a transmission X-ray image (S401). If the determination in step S401 is affirmative, the image generation unit 30 obtains bone tissue line data based on the low transmission X-ray image data and the high transmission X-ray image data (S402). Then, based on the composite image data and the bone tissue line data, an image in which the bone tissue line is superimposed on the region of interest of the composite image is displayed on the display 32 (S403).

  When the determination in step S401 is negative, the image generation unit 30 determines whether the background image is a transmitted X-ray image and the region of interest is a bone mineral distribution image (S404). When the determination in step S404 is affirmative, the image generation unit 30 obtains soft tissue line data based on the low transmission X-ray image data (S405). Based on the composite image data and the soft tissue line data, an image in which the soft tissue line is superimposed on the region of interest of the composite image is displayed on the display 32 (S406).

  When the determination in step S404 is negative, the image generation unit 30 displays a composite image in which the bone tissue line and the soft tissue line are not superimposed on the display 32 (S407).

  In a transmission X-ray image, an image of a soft tissue appears around an image of a bone tissue, and the boundary between the bone tissue and the soft tissue may be unclear. According to step S403, when the region of interest is a transmission X-ray image, the bone tissue line is displayed. Therefore, the shortcomings when the region of interest is a transmission X-ray image can be compensated for by the bone tissue line.

  In addition, in the bone mineral distribution image, since the soft tissue does not appear, the boundary between the soft tissue and air may be unclear. According to step S406, the soft tissue line is displayed when the region of interest is a bone mineral distribution image. Therefore, the shortcomings when the region of interest is a bone mineral distribution image can be compensated by the soft tissue line.

  FIG. 13 schematically shows an example in which a bone tissue line 40 is displayed in a region of interest when the background image is a bone mineral distribution image and the region of interest is a high transmission X-ray image. FIG. 14 schematically shows an example in which the soft tissue line 42 is displayed in the region of interest when the background image is a high-transmission X-ray image and the region of interest is a bone mineral distribution image. In both figures, the bone to be diagnosed is the forearm of the subject. In FIG. 13, the bone tissue line is shown as a black solid line, and in FIG. 14, the soft tissue line is shown as a black solid line. When the composite image is a black and white image, the bone tissue line and the soft tissue line may be displayed in a color with good visibility such as yellow or blue.

  Here, an example in which either a bone tissue line or a soft tissue line is displayed according to the type of the background image and the image of the region of interest has been taken up. In addition to such processing, processing for displaying either or both of the bone tissue line and the soft tissue line is performed according to the operation in the operation unit 34, regardless of the type of the background image and the region of interest image. May be. Further, the bone tissue line and the soft tissue line may be displayed not only in the region of interest but also over the entire synthesized image.

  Further, in the above description, the example in which the processing after step S401 is executed after the processing shown in steps S101 to S108 in FIG. 2 is executed has been described. Instead of such processing, after the image display processing according to the second application example is executed, that is, after the processing shown in step S210 of FIG. 9 is executed, the processing after step S401 is executed. Also good. Furthermore, after the image display process according to the third application example is executed, that is, after the process shown in step S308 of FIG. 10 is executed, the processes after step S401 may be executed.

  DESCRIPTION OF SYMBOLS 10 X-ray generation part, 12 X-ray detection part, 14 Detection surface, 16 Subject, 18 Subject mounting base, 20 Diagnostic space, 22 Processor, 24 Image data generation part, 26 Storage part, 28 Measurement value calculation part, 30 Image generation unit, 32 display, 34 operation unit, 36 system controller, 38 region of interest, 40 bone tissue line, 42 soft tissue line.

Claims (6)

First X-ray image data is generated based on the first X-ray transmitted through the subject, and the second X-ray image is generated based on the second X-ray having energy different from the energy of the first X-ray and transmitted through the subject. A transmission X-ray image data generation unit for generating data;
A bone mineral distribution image data generation unit that generates bone mineral distribution image data representing the distribution of bone mineral in the subject based on the first X-ray image data and the second X-ray image data;
A background image selection unit that selects any one of the first X-ray image data, the second X-ray image data, and the bone mineral distribution image data as background image data representing a background image;
A background image display unit for displaying the background image on a display means;
A region-of-interest setting unit that sets a region of interest for the background image;
When the background image is displayed on the display means, the first X-ray image data, the second X-ray image data, or the bone mineral distribution is used as region-of-interest data for displaying the image of the region of interest. A region-of-interest image selection unit that selects any one of the image data in accordance with a user operation;
A composite image generating unit that causes a display unit to display a composite image in which a portion corresponding to the region of interest in the background image is replaced with an image based on the region of interest data;
Equipped with a,
The composite image generation unit
Smoothing processing means for performing a smoothing process on the region of interest data;
A portion corresponding to the region of interest in the background image is replaced with a smoothed synthesized image in which the image based on the region-of-interest data subjected to the smoothing process is applied, and a portion corresponding to the region of interest in the background image A comparison display means for causing the display means to display a non-smoothing composite image replaced with an image based on the region-of-interest data that has not been subjected to the smoothing process,
Display state maintaining means for causing the display means to display either the smoothed synthesized image or the non-smoothed synthesized image in response to an operation by the user when the image display based on the comparison display means is performed;
Bone diagnostic image display device comprising Rukoto equipped with. First X-ray image data is generated based on the first X-ray transmitted through the subject, and the second X-ray image is generated based on the second X-ray having energy different from the energy of the first X-ray and transmitted through the subject. A transmission X-ray image data generation unit for generating data;
A bone mineral distribution image data generation unit that generates bone mineral distribution image data representing the distribution of bone mineral in the subject based on the first X-ray image data and the second X-ray image data;
A background image selection unit that selects any one of the first X-ray image data, the second X-ray image data, and the bone mineral distribution image data as background image data representing a background image;
A region-of-interest setting unit that sets a region of interest for the background image;
A first X-ray composite image in which a portion corresponding to the region of interest in the background image is replaced with an image based on the first X-ray image data, and a second X-ray composite in which an image based on the second X-ray image data is replaced A composite image generating unit that generates an image and a bone mineral distribution composite image replaced with an image based on the bone mineral distribution image data;
With
The composite image generation unit
A comparison display means for displaying the first X-ray composite image, the second X-ray composite image, and the bone mineral density composite image on a display means;
A display state maintaining means for displaying any one of these composite images on the display means in response to an operation by the user when the display by the comparison display means is performed;
Equipped with a,
The composite image generation unit
Smoothing processing means for processing the composite image displayed by the display state maintaining means and display means for second comparison;
The smoothing processing means includes
Performing a smoothing process on the region-of-interest data corresponding to the region of interest;
The second comparison display means is:
A portion corresponding to the region of interest in the background image is replaced with a smoothed synthesized image in which the image based on the region-of-interest data subjected to the smoothing process is applied, and a portion corresponding to the region of interest in the background image A non-smoothing composite image replaced with an image based on the region-of-interest data that has not been subjected to the smoothing process, and displayed on the display means,
The display state maintaining means includes
In response to an operation by a user at the time when image display based on the second comparing display means is being performed, characterized Rukoto to display either on the display means of the smoothing composite image or the non-smoothing composite image A bone diagnosis image display device. First X-ray image data is generated based on the first X-ray transmitted through the subject, and the second X-ray image is generated based on the second X-ray having energy different from the energy of the first X-ray and transmitted through the subject. A transmission X-ray image data generation unit for generating data;
A bone mineral distribution image data generation unit that generates bone mineral distribution image data representing the distribution of bone mineral in the subject based on the first X-ray image data and the second X-ray image data;
A background image selection unit that selects any one of the first X-ray image data, the second X-ray image data, and the bone mineral distribution image data as background image data representing a background image;
A region-of-interest setting unit that sets a region of interest for the background image;
A region-of-interest image selection unit that selects any one of the first X-ray image data, the second X-ray image data, and the bone mineral distribution image data as the region-of-interest data for displaying the image of the region of interest; ,
A composite image generating unit that causes a display unit to display a composite image in which a portion corresponding to the region of interest in the background image is replaced with an image based on the region of interest data;
With
The composite image generation unit
Smoothing processing means for performing a smoothing process on the region of interest data;
A portion corresponding to the region of interest in the background image is replaced with a smoothed synthesized image in which the image based on the region-of-interest data subjected to the smoothing process is applied, and a portion corresponding to the region of interest in the background image A comparison display means for causing the display means to display a non-smoothing composite image replaced with an image based on the region-of-interest data that has not been subjected to the smoothing process,
Display state maintaining means for causing the display means to display either the smoothed synthesized image or the non-smoothed synthesized image in response to an operation by the user when the image display based on the comparison display means is performed;
A bone diagnosis image display device comprising: The bone diagnosis image display device according to any one of claims 1 to 3 ,
The background image selection unit
A bone diagnostic image display apparatus, which performs a process of selecting either the first X-ray image data or the second X-ray image data based on an absorption rate of the subject with respect to X-rays. The bone diagnosis image display device according to any one of claims 1 to 4 ,
A bone tissue line data generator that generates bone tissue line data representing a boundary line between a bone tissue and a soft tissue in the subject based on the first X-ray image data and the second X-ray image data; ,
The composite image generation unit
A bone diagnostic image display apparatus, wherein a boundary line represented by the bone tissue line data is displayed on the display unit so as to be superimposed on a composite image. The bone diagnosis image display device according to any one of claims 1 to 5 ,
A soft tissue line data generation unit that generates soft tissue line data representing a boundary line between the soft tissue and air of the subject based on the first X-ray image data;
The composite image generation unit
A bone diagnosis image display device, wherein a boundary line represented by the soft tissue line data is superimposed on a composite image and displayed on the display means.