Information processor

Abstract

To provide display in which it is easy to see how characteristics of the spine shown by a bone density image have changed in measurement between the past and the present.SOLUTION: A controller 38 obtains and displays an intervertebral line to be a straight line passing between the vertebras on a bone density image of the spine obtained by measuring with an X-ray measurement apparatus. A user corrects the displayed intervertebral line when it is not appropriate. When it is confirmed that all the intervertebral lines become appropriate, the user performs operation of setting registration. Thus, data of the intervertebral lines are registered with a database in association with the bone density image. The controller 38 superimposes an intervertebral line group set relative to the bone density image at the time of previous measurement of the same subject on an intervertebral line group set relative to the current bone density image for display. Display modes of the intervertebral lines differ between the previous time and the current time.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a medical information processing device, and more particularly to diagnostic support based on bone density images of the spine. [Background technology]

[0002] A bone densitometer generally measures and calculates the bone density of bones in a subject based on dual-energy X-ray absorptiometry (DEXA). In a bone densitometer, for example, a fan beam of X-rays that spreads radially in two dimensions is mechanically scanned in a direction perpendicular to the fan's surface, and the X-rays that have passed through the subject are detected in parallel. More specifically, low-energy X-rays and high-energy X-rays are alternately irradiated while the beam is scanned, thereby obtaining low-energy X-ray detection values ​​and high-energy X-ray detection values ​​that are alternately arranged in the mechanical scanning direction. Based on the bone density measurement results, the bone densitometer generates and displays a bone density image showing the distribution of bone density.

[0003] In the examination or diagnosis of the spine, such as the lumbar vertebrae, using a bone densitometer, a doctor or technician interprets bone density images of the spine to determine the risk of compression fractures, etc. Patent Document 1 discloses an example of a device for assisting spinal diagnosis.

[0004] The device disclosed in Patent Document 1 forms a two-dimensional image of a test site, including a spine, based on measurement data obtained by irradiating the test site with X-rays. The device also calculates, based on the spine image in the two-dimensional image, multiple representative coordinates that reflect changes in the spine image in a direction intersecting the longitudinal direction at multiple positions along the longitudinal direction of the spine image. The device then generates a diagnostic aid image for assisting in the diagnosis of the spine image based on the multiple representative coordinates. The multiple representative coordinates include at least one representative coordinate of a vertebral body image and at least one representative coordinate of an intervertebral image. The device also allows automatic or manual setting of section lines along each intervertebral space for a region of interest (ROI) that includes several vertebral bodies of interest.

[0005] Patent Document 2 discloses a technology for assisting diagnosis by superimposing and displaying information about a region obtained in a previous bone density measurement on an image obtained in a current measurement. Specifically, the device disclosed in Patent Document 2 superimposes a bone region of interest, which is segmentation information obtained in a previous bone density measurement, on a fluoroscopic image for the current bone density measurement when positioning a subject for bone density measurement. The operator references the bone region of interest superimposed on the fluoroscopic image and performs positioning so that the bone region shown in the fluoroscopic image for the current measurement matches the bone region of interest from the previous measurement. Because the bone region of interest is accurate information generated based on corrected edges corrected by the operator from automatically extracted edge information, referencing the bone region of interest allows the current positioning conditions to be quickly and accurately aligned with the previous positioning conditions.

[0006] In addition, in the device disclosed in Patent Document 3, when a line is set on a bone density image, the corresponding profile is displayed as a one-dimensional bone density distribution. The positions of one or more feature points are identified by analyzing the profile. These positions are displayed as markers on the profile and on the bone density image. When the line is moved, the profile is updated, and the content of each graphic image is also updated in real time. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-106720 [Patent Document 2] Patent Publication No. 2021-037225 [Patent Document 3] Japanese Patent Application Laid-Open No. 2013-153999 Summary of the Invention [Problem to be solved by the invention]

[0008] Some bone density measuring devices display the bone density image obtained in the current measurement alongside a bone density image obtained in a previous measurement (e.g., the previous measurement) so that the two can be compared. However, it is very difficult to judge the onset and progression of symptoms by comparing the two bone density images displayed side by side.

[0009] If the current and past bone density images were displayed overlapping each other, for example by changing the colors of the spine, it would be easier to grasp the changes from the past to the present than if they were displayed side by side or top and bottom. However, because bone density images contain a large amount of information, it is often difficult to determine which parts have changed and how when bone density images are overlapped.

[0010] The present invention aims to provide an easily understandable display of how the characteristics of the spine shown in a bone density image have changed between the past and the current measurement. [Means for solving the problem]

[0011] The information processing device of the present invention includes a setting unit that sets intervertebral lines for each intervertebral space of the spine on a bone density image of the spine obtained by measuring the subject; a registration unit that registers intervertebral line data representing the set intervertebral lines for each intervertebral space in a database in association with the subject and the time of the measurement; and a display processing unit that performs processing to superimpose and display, in a distinguishable display manner, a first intervertebral line image, which is an image of the intervertebral lines for each intervertebral space set by the setting unit, and a second intervertebral line image, which is an image of the intervertebral lines for each intervertebral space represented in the subject's past intervertebral line data obtained from the database.

[0012] In the present invention, intervertebral lines representing the characteristics of each intervertebral space in a bone density image are superimposed on intervertebral lines of bone density images measured in the past. When a bone density image obtained by measurement is superimposed on a bone density image obtained in the past, the amount of information becomes too great and it becomes difficult to see how the image has changed. However, by comparing the intervertebral lines, it becomes easier to see how the image has changed since the past.

[0013] In one aspect, the information processing device further includes a boundary determination unit that determines the position of the boundary between the bone and soft tissue on each intervertebral line for each of the intervertebral lines based on the bone density image, and the position of the boundary on each intervertebral line determined by the boundary determination unit is displayed on each intervertebral line for each of the intervertebral lines in the first intervertebral line image, and the position of the boundary determined by the boundary determination unit based on the subject's past bone density image that served as the basis for the second intervertebral line image is displayed on each intervertebral line for each of the intervertebral lines in the second intervertebral line image.

[0014] This type of display allows the viewer to grasp how the position of the bone boundary on the intervertebral line has changed since the past, making it easier to understand the state of spinal deformation.

[0015] Here, the display processing unit may further display information indicating an amount of deviation between the position of the boundary on the intervertebral line in the first intervertebral line image and the position of the boundary on the corresponding intervertebral line in the second intervertebral line image. By displaying the amount of deviation, changes from the past can be quantitatively grasped.

[0016] In another aspect, the setting unit may calculate and display a bone density profile, which indicates changes in bone density along an intervertebral line set by a user, from the bone density image. By displaying the bone density profile along the intervertebral line, the condition of bones other than the vertebral bodies can be presented.

[0017] Here, the setting unit may further display the bone density profile along an intervertebral line corresponding to the intervertebral line set by the user among the intervertebral lines in the second intervertebral line image, the bone density profile being calculated from a previous bone density image of the subject on which the second intervertebral line image was based. The previous bone density profile serves as a reference for setting the intervertebral line for the bone density image obtained by measurement.

[0018] In yet another aspect, the information processing device may further include a compression fracture determination unit that determines the risk of a compression fracture based on changes between the set intervertebral line for each intervertebral space and the intervertebral line for each intervertebral space represented in the subject's past intervertebral line data, and outputs the result of the determination.

[0019] Here, the compression fracture assessment unit may assess the risk of compression fracture for the vertebral body between the adjacent intervertebral lines based on changes in the spacing between the set intervertebral lines for each intervertebral space and the intervertebral lines for each intervertebral space represented in the subject's past intervertebral line data. [Effects of the Invention]

[0020] It is possible to provide an easy-to-understand display of how the spinal characteristics shown in the bone density image have changed between the past and current measurements. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a perspective view of the appearance of an X-ray measurement device. [Figure 2] FIG. 2 is a diagram schematically illustrating the internal configuration of the X-ray measurement device as seen from the side. [Figure 3] FIG. 2 is a diagram for explaining setting of an ROI (region of interest) on a bone density image. [Figure 4] FIG. 10 is a diagram for explaining an intervertebral line set on a bone density image. [Figure 5] FIG. 10 illustrates another example of an intervertebral line. [Figure 6] FIG. 2 is a diagram illustrating an example of the contents of measurement data registered in a database. [Figure 7] FIG. 10 is a diagram illustrating an example of the contents of intervertebral line data registered in a database. [Figure 8] FIG. 10 is a diagram illustrating an example of the contents of data on bone boundaries on intervertebral lines registered in a database. [Figure 9] FIG. 10 is a diagram showing an example of superimposed display of the current and previous intervertebral lines. [Figure 10]10A and 10B are diagrams illustrating the effect of displaying intervertebral lines as dashed lines in a superimposed display. [Figure 11] FIG. 10 is a diagram showing an example of displaying numerical information of intervertebral lines. [Figure 12] FIG. 10 is a diagram showing an example of displaying numerical information of bone boundaries. [Figure 13] FIG. 10 is a diagram showing an example of a display of a determination result of the possibility of a compression fracture. [Figure 14] FIG. 10 is a diagram showing an example of a display of a bone density profile. [Figure 15] FIG. 10 is a diagram showing an example of displaying the previous and current bone density profiles side by side. DETAILED DESCRIPTION OF THE INVENTION

[0022] <Example of device configuration> 1 shows a perspective view of an example of an X-ray measurement device 10 to which the display function according to the present disclosure can be applied, and a Bucky table 18 used therewith. The X-ray measurement device 10 is an example of a medical X-ray measurement device according to the present invention.

[0023] The X-ray measurement device 10 includes a main body 12 that generates X-rays 20, an arm 14 that detects the X-rays 20, and a support 16 that supports the arm 14 above the main body 12. The space surrounded by the main body 12, the support 16, and the arm 14 forms a measurement space 22 in which a subject is placed. The subject is received in the measurement space 22 from the side where the support 16 is not present, toward the positive direction of the y-axis.

[0024] The X-ray measurement device 10 is placed so that the main body 12 fits under the table base of the Bucky table 18. In the measurement space 22, the subject lies on the Bucky table 18, leaving some space at the front side in FIG. 1. The X-ray measurement device 10 measures bone density, body fat percentage, muscle percentage (hereinafter, the measured quantity that combines the body fat percentage and muscle percentage will be referred to as the fat / muscle percentage), etc. based on the detection value of X-rays 20 that are emitted from the main body 12, pass through the subject, and are detected by the arm 14.

[0025] Here, an embodiment is described in which the X-ray measurement device 10 and the Bucky table 18 are separate entities, but the upper surface of the main body 12 of the X-ray measurement device 10 may serve as a Bucky table on which the subject lies, and the X-ray measurement device 10 and the Bucky table may be integrated into one configuration.

[0026] FIG. 2 shows a schematic side view of the X-ray measurement device 10. In FIG. 2, the up-down direction is the x-direction, the left-right direction is the y-direction, and the direction perpendicular to the paper surface is the z-direction. This figure shows the main internal configuration of the main body 12 and the arm 14. The X-ray measurement device 10 includes an X-ray generator 26 housed in a main body housing 24 and an X-ray detector 30 housed in an arm housing 28. The X-ray beam emitted by the X-ray generator 26 may have a planar beam shape with a width in the z-direction. For example, a planar beam shape parallel to the zx plane is one example. The beam shape may also be a fan-shaped beam whose width increases in the z-axis direction with increasing distance from the X-ray generator 26. The X-ray generator 26 is an example of an irradiation unit that irradiates an object with X-rays, and the X-ray detector 30 is an example of a detection unit that detects the intensity of X-rays that have passed through the object.

[0027] The X-ray generator 26 and the X-ray detector 30 are transported horizontally within the main body 12 and the arm 14 by a transport mechanism (not shown), while maintaining a mutually opposing positional relationship. This transport achieves X-ray beam scanning in the y direction. Therefore, the y direction is the transport direction in which the transport mechanism transports the measurement system, in other words, the direction of mechanical scanning due to the transport. In the illustrated example, the X-ray generator 26 and the X-ray detector 30 (hereinafter collectively referred to as the "measurement system") are transported from the rightmost end of the transport range to the left. During this transport, when the X-ray generator 26 and the X-ray detector 30 are located in an area where no subject 32 is present between them, the X-ray generator 26 detects X-rays. The detected values ​​are acquired as reference data for the DEXA method. The X-ray measurement device 10 calculates the distribution of absorption rates for the subject 32 based on the detection values ​​acquired by the X-ray detector 30 while scanning the area where the subject 32 is present and the reference data. Here, the absorptance distribution refers to the distribution in the horizontal plane (yz plane) of the absorptance of X-rays passing upward through the subject 32. The absorptance is defined as the value indicated by the reference data divided by the detection value of X-rays detected by the X-ray detector 30. The smaller the detection value of X-rays detected by the X-ray detector 30, the greater the absorptance. The absorptance distribution can also be said to be a distribution equivalent to the reciprocal of the detection value of X-rays detected by the X-ray detector 30. The X-ray measurement device 10 obtains the absorptance distribution for each of two types of X-rays with different energies by the operation described below, and measures bone density, fat / muscle ratio, etc. from each absorptance distribution.

[0028] The specific configuration of the X-ray measurement device 10 will be described. A control device 38 is connected to the X-ray measurement device 10. The control device 38 includes a control unit 40, an operation panel 42, a display 44, an analysis unit 46, a setting processing unit 48, a display processing unit 50, and a DB processing unit 52. The operation panel 42 as an operation unit includes, for example, a keyboard, a mouse, a drag ball, a lever, etc. The control unit 40 controls the measurement mechanisms of the X-ray measurement device 10, such as the X-ray generator 26, the X-ray detector 30, and a transport mechanism for transporting them. The analysis unit 46 generates a bone density image by analyzing measurement result data (e.g., a map of X-ray detection values). The analysis unit 46 also analyzes the bone density image to determine the positions of markers, intervertebral lines, bone boundary positions, a bone density profile, etc. (described later). The setting processing unit 48 sets the positions of markers, intervertebral lines, bone boundary positions, etc. on the bone density image based on the analysis results of the analysis unit 46 and user confirmation or correction thereto. The display processing unit 50 performs processing to generate an image for diagnostic support based on the processing results of the analysis unit 46 and the setting processing unit 48. The DB processing unit 52 performs processing to register and read data in the database 60. For example, the DB processing unit 52 executes processing to register, in the database 60, measurement result data such as a bone density image, the positions of markers set by the setting processing unit 48, the positions of intervertebral lines and bone boundaries, etc. The DB processing unit 52 also performs processing to acquire past data of the subject 32 from the DB 60 for use in generating an image for diagnostic support by the display processing unit 50.

[0029] The control device 38 is an example of an information processing device according to the present invention. The control device 38 is configured as a computer including a processor, memory, etc., and operates according to a pre-stored program. The control device 38 may be integrated with the X-ray measurement device 10 or configured separately. The control device 38 may also be configured as a plurality of computers interconnected via a network, etc. In this case, the plurality of computers constituting the control unit 40 exchange data with each other and cooperate to execute the processing of the control device 38, which will be described later. Note that the functions of the analysis unit 46, setting processing unit 48, display processing unit 50, and DB processing unit 52 may be provided to a computer independent of the X-ray measurement device 10 (i.e., a computer that does not control the X-ray measurement device 10).

[0030] The database 60 stores data on the measurement results of the subject 32. The database 60 is connected to the control device 38 via a data communication network such as a local area network.

[0031] An X-ray tube or the like that generates X-rays is used as the X-ray generator 26. The control unit 40 controls the tube voltage or tube current of the X-ray tube to change the energy, radiation amount (intensity), etc. of the generated X-rays. The top plate of the main body housing 24 is made of a material that is transparent to X-rays, and X-rays are emitted upward from the X-ray generator 26 through the top plate.

[0032] The bottom plate 58 of the arm housing 28 is formed from a material that transmits X-rays, and X-rays emitted from the main body 12 toward the arm 14 are detected by the X-ray detector 30 through the bottom plate 58.

[0033] The X-ray detector 30 uses a conversion device such as an electron tube that converts X-rays into electrical energy or a photodiode that operates at X-ray wavelengths. The X-ray detector 30 is configured, for example, by arranging a plurality of conversion devices in multiple rows, with the row direction being perpendicular to the transport direction and horizontal (positive direction of the z-axis), and outputting detection values ​​from the plurality of conversion devices. The X-ray detector 30 may also be configured to output detection values ​​at each detection point by mechanically linearly scanning one conversion device in the z-axis direction.

[0034] In this configuration, the X-ray generator 26 is housed in the main body housing 24 and the X-ray detector 30 is housed in the arm housing 28, but the X-ray measurement device 10 may also be configured such that the X-ray generator 26 is housed in the arm housing 28 and the X-ray detector 30 is housed in the main body housing 24.

[0035] In the following, an example will be described in which the X-ray measurement device 10 is used to measure the spine, particularly the lumbar spine, of a human subject.

[0036] <Setting the region of interest> The setting of the region of interest by the setting processing unit 48 will be described with reference to FIG.

[0037] FIG. 3 schematically shows a bone density image 100 of a person's lumbar region generated by the X-ray measurement device 10. Generally, like ordinary X-ray images, bone density images are black and white images in which the brightness increases as the amount of X-ray absorption increases. However, the bone density images 100 in FIG. 3 and in FIG. 4 (described later) are shown in a reversed black and white state to make leader lines and the like more visible. The bone density image 100 shows the upper part of the ilium 104 and the first through fifth lumbar vertebrae L1-L5 arranged above it. Bone parts such as the ilium 104 and lumbar vertebrae L1-L5 have a significantly higher X-ray absorption rate than the surrounding soft tissues 102, such as internal organs, muscles, and fat. Therefore, the bone parts and soft tissues 102 are clearly distinguishable in the bone density image 100 by the difference in brightness (or density). In a bone density image 100 of FIG. 3, which is shown in black and white inversion from a normal X-ray image, bones such as lumbar vertebrae L2 to L4 have a significantly higher black density than soft tissue 102.

[0038] In order to set a region of interest (hereinafter abbreviated as ROI, where ROI is an abbreviation for Region Of Interest), markers M1 and M2 are first set. The illustrated example shows a case where the second lumbar vertebra L2 to the fourth lumbar vertebra L4 are the subject of examination. In this case, the upper marker M1 is set at the intervertebral space between the first lumbar vertebra L1 and the second lumbar vertebra L2, and the lower marker M2 is set at the intervertebral space between the fourth lumbar vertebra L4 and the fifth lumbar vertebra L5. More specifically, the y coordinates (i.e., abscissa) of the markers M1 and M2 are set to the y coordinate of the center line of the lumbar vertebrae, the z coordinate (i.e., ordinate) of the marker M1 is set to the height of the intervertebral space between the lumbar vertebrae L1 and L2, and the z coordinate of the marker M2 is set to the height of the intervertebral space between the lumbar vertebrae L4 and L5. The positions of the markers M1 and M2 can be automatically calculated by the analysis unit 46 from the bone density image 100.

[0039] For example, the center line of the lumbar vertebrae is a straight line parallel to the z-axis that passes through the center position in the y-direction of the images of lumbar vertebrae L1 to L5 in the bone density image 100. The analysis unit 46 can calculate such a center line from the bone density image 100 using a conventionally known method. Furthermore, for example, the analysis unit 46 can identify the point with the lowest bone density between lumbar vertebrae L1 and L2 in the distribution of bone density along the calculated lumbar center line as the position of marker M1. The position of marker M2 can also be identified in a similar manner.

[0040] The display processing unit 50 displays a graphic representing the markers M1 and M2 at the positions of the markers M1 and M2 calculated by the analysis unit 46 on the bone density image 100 displayed on the display 44. In FIG. 3, this graphic is a cross mark. A user (e.g., a medical technician) looks at this display and confirms whether the positions of the markers M1 and M2 are appropriate. If they are inappropriate, the user moves the markers M1 and M2 to appropriate positions by operating a pointing device such as a mouse. When the user confirms that the automatically calculated positions of the markers M1 and M2 or the user-corrected positions of the markers M1 and M2 are appropriate, the user performs an operation indicating confirmation (e.g., pressing a “Confirm” button, not shown). In response to this confirmation operation, the setting processing unit 48 sets the confirmed markers M1 and M2 on the bone density image 100. That is, the setting processing unit 48 generates data for the markers M1 and M2 and instructs the DB processing unit 52 to register this data in the database 60. The DB processing unit 52 registers the data of the markers M1 and M2 in the database 60.

[0041] The ROI is determined based on the markers M1 and M2 set in this way. That is, the ROI is a rectangular area enclosed by a line parallel to the y-axis passing through a point a predetermined height (for example, 1 cm) above marker M1, a line parallel to the y-axis passing through a point a predetermined height below marker M2, and two lines parallel to the z-axis located a predetermined distance (for example, 6 cm) to the left and right of the center line of the lumbar vertebrae. The ROI includes the lower part of L1, the upper parts of L2, L3, L4, and L5, and the intervertebral spaces between each of these lumbar vertebrae (i.e., vertebral bodies). The display processing unit 50 determines an ROI from the markers M1 and M2, and displays an ROI frame 110, which is the rectangular periphery of the ROI, on the bone density image 100.

[0042] <Intervertebral line setting> The setting of the intervertebral lines by the setting processing unit 48 will be described with reference to FIGS. 4 and 5 (and FIG. 3).

[0043] Intervertebral lines are straight line segments extending longitudinally between adjacent vertebrae. Intervertebral lines are set for each intervertebral space within the ROI. In the example shown in FIGS. 3 and 4, the ROI includes four intervertebral spaces: L1-L2, L2-L3, L3-L4, and L4-L5. The analysis unit 46 calculates an intervertebral line for each of these four intervertebral spaces. The intervertebral lines can be calculated using a known method, such as the method for calculating division lines described in Patent Document 1. The display processing unit 50 displays the four intervertebral lines DH, CG, BF, and AE calculated by the analysis unit 46 on the bone density image 100. A, B, C,...H are identification codes assigned to the intersections of each intervertebral line and the ROI frame 110. In this example, the intervertebral lines do not extend outside the ROI, so points A, B,..., H may be considered as the endpoints of the intervertebral lines. The identification codes A to H of the end points may or may not be displayed on the bone density image 100.

[0044] The user looks at this display and checks whether each intervertebral line DH, CG, BF, and AE is appropriate. If any intervertebral line is inappropriate, the user adjusts it to be appropriate, for example, by moving the end point of the intervertebral line using a pointing device. In this example, the midpoint of the intervertebral line is fixed, and moving the end point rotates the intervertebral line around the midpoint as the center of rotation. It is also possible to select the middle of the intervertebral line by clicking, etc., and translate the intervertebral line up or down. Note that the operations illustrated here are merely examples.

[0045] After adjusting all intervertebral lines to be in an appropriate state, the user performs an operation indicating confirmation. In response to this confirmation operation, the setting processing unit 48 sets the confirmed intervertebral lines in the bone density image 100. That is, the setting processing unit 48 generates data for each intervertebral line and instructs the DB processing unit 52 to register this data in the database 60. The data for an intervertebral line is, for example, a set of coordinates of the two endpoints of the intervertebral line. As another example, the data identifying an intervertebral line may be a set of the coordinates of the midpoint between the endpoints of the intervertebral line and the slope of the intervertebral line. The DB processing unit 52 registers the data for the intervertebral lines in the database 60.

[0046] FIG. 5 shows an example of an intervertebral line when there is significant deformity in some lumbar vertebrae (e.g., L3).

[0047] <Bone boundary setting> The setting of bone boundaries by the setting processing unit 48 will be described with reference to FIG.

[0048] The bone boundary here refers to the boundary between the bone portion (i.e., the lumbar vertebrae in this case) and the surrounding soft tissue. In this embodiment, the analysis unit 46 determines the bone boundary on the intervertebral line based on the bone density image 100. The bone density values ​​of the bone portion and the soft tissue differ greatly. The analysis unit 46 determines a bone density profile (details will be described later) on the intervertebral line from the bone density image 100 and detects the point on the intervertebral line where the bone density profile suddenly changes as the bone boundary. Detection of the bone boundary based on the bone density profile is highly accurate and is not highly necessary, but it may be possible to allow the user to confirm and correct the position of the bone boundary. The bone boundary is determined at two locations, the right and left ends of the bone portion of the intervertebral area. Due to the three-dimensional shape of the vertebral body, bone portions also exist on the intervertebral line.

[0049] The setting processing unit 48 sets the determined bone boundaries in the bone density image 100. That is, the setting processing unit 48 generates bone boundary data and instructs the DB processing unit 52 to register this data in the database 60. The bone boundary data is, for example, a set of coordinates of the left and right bone boundaries. The DB processing unit 52 registers the bone boundary data in the database 60.

[0050] 4 and 5, bone boundaries are shown as vertical bars that run perpendicular to the intervertebral lines DH, etc. For example, on the intervertebral line DH, a bone boundary DHL on the left side of the intervertebral line DH and a bone boundary DHR on the right side of the intervertebral line DH are shown.

[0051] <Database example> Examples of measurement data registered in the database 60 will be described with reference to FIGS.

[0052] 6 illustrates bone density measurement data for individual subjects (i.e., patients) registered in database 60. Each row of the illustrated tabular data is a record for each measurement date. One record includes the measurement date, image ID, marker 1, marker 2, intervertebral line data, and bone boundary data.

[0053] The measurement date is the date on which the bone density measurement was performed. The image ID is the ID (identification information) of the bone density image data obtained by that measurement. The database 60 stores the actual data of the bone density image in association with the image ID. Markers 1 and 2 indicate the coordinates of the two upper and lower markers M1 and M2, respectively, which define the region of interest.

[0054] The intervertebral line data ID is identification information that identifies the actual data of the intervertebral line data registered in the database 60. Fig. 7 shows an example of the actual data of the intervertebral line data. In this example, the intervertebral line data includes the coordinates of both left and right endpoints for each of the four intervertebral lines within the ROI, in association with the name of the intervertebral line.

[0055] The bone boundary data ID is identification information that identifies the actual data of the bone boundary data registered in the database 60. An example of the actual data of the bone boundary data is shown in Fig. 8. In this example, the intervertebral line data includes the coordinates of two bone boundaries (left and right) for each of the four intervertebral lines, in association with the intervertebral line name.

[0056] <Comparison display> The display processing unit 50 has a function of displaying an image obtained by the current measurement and an image obtained by a previous measurement, etc., in a manner that allows comparison between them, in order to assist diagnosis. In particular, in this embodiment, the display processing unit 50 displays an image of the intervertebral lines set for the bone density image 100 obtained by the current measurement, superimposed on an image of the intervertebral lines obtained during a previous (e.g., previous) measurement. The following describes an example in which the image of the current intervertebral lines and the image of the previous intervertebral lines are superimposed and displayed.

[0057] An example of this superimposed display is shown in Figure 9. In this example, current intervertebral lines 150, 152, 154, and 156 and previous intervertebral lines 160, 162, 164, and 166 are displayed superimposed and aligned within the ROI frame 110. Due to limitations on representation in drawings, in Figure 9, the current intervertebral lines 150-156 and the previous intervertebral lines 160-166 are distinguished by differences in line thickness. In an actual display, the previous and current intervertebral lines may be distinguished by differences in display mode other than line thickness, for example, line color.

[0058] Furthermore, bone boundaries on the respective intervertebral lines are displayed on the current intervertebral lines 150 to 156 and the previous intervertebral lines 160 to 166. For example, a left bone boundary 170L and a right bone boundary 170R on the current intervertebral line 150 are displayed on the intervertebral line 150, and a left bone boundary 180L and a right bone boundary 180R on the previous intervertebral line 160 are displayed on the intervertebral line 160.

[0059] The positions of the bone boundaries on each intervertebral line at the time of the previous measurement may be obtained, for example, from the data of the bone boundaries (see FIG. 8) obtained at the time of the previous measurement and registered in the database 60. As another example, the analysis unit 46 may identify the positions of the bone boundaries on each intervertebral line from the previous bone density image and the previous data of each intervertebral line stored in the database 60.

[0060] Although the horizontal width of the ROI is the same between the current and previous images, the vertical length of the ROI is not necessarily the same. Therefore, when superimposing the current and previous images of the intervertebral line, it is generally not possible to superimpose them so that the ROI frames 110 match. Therefore, the following method, for example, may be used for superimposing.

[0061] Since the width of the ROI is the same this time as it was last time, the methods exemplified below align the images of the intervertebral lines horizontally so that the right and left sides of the ROI frame 110 coincide with each other. On the other hand, there are several possible variations in the method of alignment vertically.

[0062] In the first method, the display processing unit 50 performs vertical alignment so that the total deviation (for example, the total squared deviation) of the positions of the intervertebral line endpoints A, B, C, . . . , H between the current and previous images is minimized. This makes it easier to see which endpoints have small and large changes in position between the previous and current images.

[0063] The second method vertically aligns the intervertebral line images so that the bottom edges of the ROI frames 110 match between the previous and current images. This takes into consideration the following: Because the thoracic vertebrae curve backward, while the lumbar vertebrae curve forward, compression fractures are likely to occur near the first lumbar vertebra L1 where these curves intersect. In contrast, the areas around the lowest lumbar vertebrae, the fourth and fifth lumbar vertebrae L4 and L5, are less likely to develop compression fractures than the first lumbar vertebra L1 and tend to have a more stable shape. By aligning the bottom edges of these stable shapes, it becomes easier to see how the lumbar vertebrae curve upward, where compression fractures are more likely to occur. Therefore, this second method aligns the bottom edges of the ROI frames 110 located near the lowest lumbar vertebrae.

[0064] The display processing unit 50 aligns and overlays the previous and current intervertebral line images according to any of these methods.

[0065] 9 may be displayed superimposed on, for example, the current display of bone density image 100. Furthermore, in response to an instruction from the user, the display method may be switched, such as displaying the superimposed image of the intervertebral lines on the bone density image 100, or erasing the bone density image 100 and displaying only the superimposed image of the intervertebral lines.

[0066] In this overlapping display, the previous and current intervertebral lines may be displayed as dashed lines with the same pitch but shifted by half a period from each other. Such dashed line display will be described with reference to FIG.

[0067] Figure 10 shows an enlarged view of a portion of the overlapping display of the previous and current intervertebral line images shown in Figure 9. However, the dotted frame line 190 in Figure 10 is an auxiliary line to make it easier to understand the pitch of the dashed lines indicating the intervertebral lines, and does not appear in the image displayed on the display 44.

[0068] 10, the dashed line of the current intervertebral line 152 (thick line in the figure) and the dashed line of the previous intervertebral line 162 (thin line in the figure) have one cycle (i.e., pitch) in the horizontal direction equivalent to two rectangles of the frame line 190. The dashed line of the current intervertebral line 152 and the dashed line of the previous intervertebral line 162 are shifted by half a cycle, making them easy to distinguish from each other when displayed overlaid. Furthermore, displaying the intervertebral lines 152 and 162 in different display modes (for example, different colors) can make them even easier to distinguish from each other.

[0069] 10, a bone boundary 172R is displayed on the current intervertebral line 152, and a bone boundary 182R is displayed on the previous intervertebral line 162. In this display example, the pitch of the intervertebral lines 152 and 162 is constant, so the lateral deviation between the previous bone boundary 182 and the current bone boundary 172 can be quantitatively determined by counting the number of dashed lines between them. This leads to a quantitative evaluation of the deformation of the lumbar vertebrae from the previous to the current time.

[0070] <Numeric display> The control device 38 has a function to display information such as numerical values ​​regarding the intervertebral line in addition to the graphical display exemplified in FIG.

[0071] An example of a numerical display provided by the control device 38 is shown in FIG. 11. The display example shown in FIG. 11 provides numerical comparison information of the intervertebral lines between the previous and current measurements. In this example, the characteristics of the intervertebral lines from the previous measurement (February 20, 2023) and the current measurement (February 21, 2024) are displayed in a table format. This table shows, for example, the lengths of each intervertebral line (DH, CG, BF, AE) for the previous measurement and the current measurement, as well as the difference in these lengths between the previous measurement and the current measurement. The table also shows the distances between the endpoints of adjacent intervertebral lines on the left and right sides of the ROI for the previous measurement and the current measurement, and the difference in these distances between the previous measurement and the current measurement. For example, the distance between adjacent endpoints B and C corresponds to the left side of the lumbar vertebra (i.e., vertebral body) L3, and the distance between endpoints F and G corresponds to the right side of the lumbar vertebra L3. For example, if there is a significant compression deformity on the right side of the lumbar vertebra L3, as shown in FIG. 5, the distance between B and C will be significantly longer, while the distance between F and G will be significantly shorter. Because the width of the ROI is significantly larger than the width of the vertebral body, if the vertebral body deforms to the left or right, that deformation is magnified by the distance between the endpoints of the intervertebral line above and below that vertebral body on the left and right sides of the ROI frame 110. For example, if the previous state was as shown in Figure 4 and the current state is as shown in Figure 5, there will be a noticeable decrease in the distance between endpoints FG on the right side of the ROI and an increase in the distance between endpoints BC on the left side. The user can quantitatively grasp the changes by looking at the values ​​of the distance between the previous and current values, and the numerical difference between the previous and current values.

[0072] Another example of the numerical display provided by the control device 38 is shown in FIG. 12. The display example shown in FIG. 12 provides numerical comparison information of each bone boundary on the intervertebral line between the previous and current measurements. In this example, the coordinates of each bone boundary from the previous and current measurements and the amount of deviation between the previous and current measurements are shown. In the illustrated example, the amount of deviation is expressed as a pair of deviation in the y direction and deviation in the z direction. By looking at this display, the user can quantitatively grasp the degree of deviation of each bone boundary between the previous and current measurements.

[0073] Another example of a display provided by the control device 38 is shown in Fig. 13. The display example shown in Fig. 13 indicates the likelihood of a compression fracture for each of the lumbar vertebrae L2, L3, and L4 within the ROI. The likelihood of a compression fracture is determined by the analysis unit 46.

[0074] This determination is made based on the change in the distance between the endpoints of the ROI frame 110 of the upper and lower intervertebral lines of the lumbar vertebrae from the previous time to the current time. The amount of change in the distance is compared with, for example, a threshold value to determine whether the possibility of a compression fracture is high or low.

[0075] For example, in the determination of the lumbar vertebra L3, the analysis unit 46 calculates the change between the previous and current distances of the distances between the left and right endpoints BC and FG of the lumbar vertebra L3. If at least one of the two changes has decreased, the analysis unit 46 determines that the lumbar vertebra L3 is highly likely to have a compression fracture if the magnitude of the decrease (i.e., the change is a negative value) is equal to or greater than a predetermined threshold. Conversely, if the magnitude of the decrease is less than the threshold, the analysis unit 46 determines that the lumbar vertebra L3 is unlikely to have a compression fracture.

[0076] Note that lumbar compression fractures can occur when one of the lumbar vertebrae is compressed strongly, either on the right or left side, or when both lumbar vertebrae are compressed equally. If one of the left or right vertebrae is compressed and fractured between the previous and current fractures, the intervertebral line will be more tilted than before, and the distance between the endpoints on the compressed side (between endpoints F and G in the example in Figure 5) will be significantly narrower than before. Conversely, the distance between the endpoints on the uncompressed side will be wider.

[0077] On the other hand, when the left and right sides are compressed equally, the distance between the adjacent endpoints on both sides becomes narrower than before. In this case, the inclination of the intervertebral line is small, so the decrease in the distance between the adjacent endpoints is smaller than when only the left and right sides are compressed equally.

[0078] Therefore, the threshold used to determine whether the possibility of a compression fracture is high or low may be different when the distance between one of the left and right endpoints decreases while the other increases, and when the distances between both endpoints decrease. For example, the threshold used when the distance between one of the left and right endpoints decreases while the other increases may be higher than the threshold used when the distances between both endpoints decrease.

[0079] <Display bone density profile> The control device 38 may have a function to display a bone density profile along the intervertebral line. The bone density profile along the intervertebral line is a curve that connects the bone density values ​​at each point on the intervertebral line. The analysis unit 46 generates the bone density profile by identifying pixels corresponding to each point on the intervertebral line in the bone density image 100 and arranging the values ​​(i.e., bone density) of each pixel. FIG. 14 shows an example of a displayed bone density profile 300. In the graph shown in FIG. 14, the horizontal axis indicates the position along the length of the intervertebral line, and the vertical axis indicates bone density. The bone density profile 300 shown in FIG. 14 is for the intervertebral line between lumbar vertebrae L1 and L2 (e.g., intervertebral line DH in the example of FIG. 5). In addition to the vertebral bodies, lumbar vertebrae have bony parts such as transverse processes and spinous processes. Since the intervertebral line passes through these bony parts other than the vertebral bodies, there are areas on the intervertebral line that have a certain degree of high bone density.

[0080] For example, when a user selects an intervertebral line by clicking or the like on a screen displaying the bone density image 100 and the intervertebral line, the control device 38 displays the bone density profile on that intervertebral line, for example, next to the bone density image 100 or in a pop-up display.

[0081] For example, when displaying the bone density image 100 obtained in the current measurement for the first time, the control device 38 receives the setting of markers M1 and M2 from the user and displays the ROI frame 110. At this time, the analysis unit 46 calculates the intervertebral lines of each intervertebra and displays them on the screen. The user then checks whether each displayed intervertebral line is valid, for example, one by one. During this check, the user selects one intervertebral line by clicking or the like, and the analysis unit 46 generates a bone density profile 300 of the selected intervertebral line. The display processing unit 50 displays the bone density profile 300 on the screen, for example, next to the bone density image 100.

[0082] The user uses the displayed bone density profile 300 as a basis for determining the appropriateness of the selected intervertebral line. Since lumbar vertebrae are generally symmetrical, if the intervertebral line is set appropriately, the bone density profile 300 on the intervertebral line will have a nearly symmetrical shape with a concave center. Conversely, if the shape of the bone density profile 300 on the intervertebral line is far from symmetrical, the intervertebral line is likely to be inappropriate. The user determines whether the intervertebral line is appropriate by looking at the density distribution near the selected intervertebral line on the bone density image 100 and the bone density profile 300 of the intervertebral line. If the intervertebral line is inappropriate, the user adjusts the position and inclination of the intervertebral line by performing operations such as moving the endpoints. When the user manipulates the intervertebral line, the analysis unit 46 calculates a new bone density profile 300 on the intervertebral line after the manipulation. This updates the bone density profile 300 displayed on the screen. The user then re-determines whether the intervertebral line is appropriate while referring to the image of the area around the intervertebral line after the manipulation and the updated bone density profile 300. The user repeats this cycle until a suitable intervertebral line is obtained.

[0083] When the user has finished adjusting all intervertebral lines appropriately, he / she instructs the control device 38 to set and register those intervertebral lines. In response to this instruction, the setting processing unit 48 registers data on those intervertebral lines in the database 60.

[0084] The display processing unit 50 may also display a bone density profile of a previous intervertebral line corresponding to the intervertebral line selected by the user on the current bone density image 100. For example, if the user selects an intervertebral line DH, the display processing unit 50 displays a bone density profile 300 on the intervertebral line DH in the current bone density image 100 so that it can be compared with the bone density profile on the intervertebral line DH in the previous bone density image 100. A display that allows comparison may be performed by, for example, displaying the current and previous bone density profiles side by side, either vertically or horizontally. FIG. 15 shows an example in which the current bone density profile 300 and the previous bone density profile 310 are displayed side by side.

[0085] As explained above, a properly set bone density profile 300 on an intervertebral line will have a shape that is nearly symmetrical across a central depression. However, this is an ideal case. However, due to lumbar vertebral deformity or other factors, the bone density profile 300 may not be nearly symmetrical regardless of how the intervertebral line is set. In such cases, even if the shape of the bone density profile 300 is not nearly symmetrical, the user can determine the most appropriate intervertebral line by comprehensively considering the shape of the bone density profile 300 and the density distribution of the bone density image 100 near the intervertebral line. In this case, the previous bone density profile 310 serves as a reference. That is, the previous bone density profile 310 is determined by the user to be appropriate based on the results of the previous measurement, and is therefore used as one piece of reference information. When adjusting the position and inclination of the intervertebral line on the current bone density image 100, the user can also use the degree to which the bone density profile 300 of the intervertebral line resembles the previous bone density profile 300 as a basis for making a decision.

[0086] Furthermore, by viewing the bone density profile along the intervertebral line, the user can understand the state of bone density of bone parts other than the vertebral bodies, such as the transverse processes and spinous processes.

[0087] Furthermore, the display processing unit 50 may have a function to display on the same screen bone density profiles for all intervertebral lines set on the bone density image 100. For example, if the bone density profiles for all intervertebral lines are not bilaterally symmetrical but are biased to the same side, it is possible that the subject's posture during measurement was tilted to the left or right, and it is therefore necessary to repeat the measurement. [Explanation of symbols]

[0088] 10 X-ray measuring device, 14 arm unit, 24 main body housing, 26 X-ray generator, 30 X-ray detector, 38 control device, 40 control unit, 42 operation panel, 44 display, 46 analysis unit, 48 setting processing unit, 50 display processing unit, 52 DB processing unit, 60 database.

Claims

1. a setting unit that sets intervertebral lines for each intervertebra of the spine on a bone density image of the spine obtained by measurement of the subject; a registration unit that registers intervertebral line data representing the set intervertebral lines for each intervertebral space in a database in association with the subject and the time of measurement; a display processing unit that executes processing to superimpose and display a first intervertebral line image, which is an image of the intervertebral line for each intervertebral space set by the setting unit, and a second intervertebral line image, which is an image of the intervertebral line for each intervertebral space represented in the past intervertebral line data of the subject acquired from the database, in a display manner that allows them to be distinguished from each other; An information processing device comprising:

2. a boundary determining unit that determines the position of a boundary between a bone portion and a soft tissue on each intervertebral line for each of the intervertebral spaces based on the bone density image; the position of the boundary on the intervertebral line determined by the boundary determination unit is displayed on the intervertebral line for each intervertebral space in the first intervertebral line image; the position of the boundary determined by the boundary determination unit based on the previous bone density image of the subject on which the second intervertebral line image is based is displayed on the intervertebral line of each intervertebra in the second intervertebral line image; 2. The information processing apparatus according to claim 1, wherein:

3. The display processing unit and further displaying information indicating a deviation amount of a position of the boundary on the intervertebral line in the first intervertebral line image relative to a position of the boundary on the corresponding intervertebral line in the second intervertebral line image.

3. The information processing apparatus according to claim 2, wherein:

4. The setting unit a bone density profile showing changes in bone density along an intervertebral line set by a user is calculated from the bone density image and displayed; 4. The information processing device according to claim 1, wherein the information processing device is a computer.

5. The setting unit further displaying the bone density profile along an intervertebral line, which corresponds to the intervertebral line set by the user among the intervertebral lines in the second intervertebral line image, calculated from a past bone density image of the subject on which the second intervertebral line image was based; 5. The information processing apparatus according to claim 4,

6. a compression fracture determination unit that determines whether there is a risk of a compression fracture based on a change between the set intervertebral line for each intervertebral space and the intervertebral line for each intervertebral space represented in the past intervertebral line data of the subject, and outputs the result of the determination.

3. The information processing device according to claim 1 or 2.

7. the compression fracture assessment unit assesses the risk of compression fracture for a vertebral body between the set intervertebral lines for each intervertebral space based on a change in the spacing between adjacent intervertebral lines between the set intervertebral lines for each intervertebral space and the intervertebral lines for each intervertebral space represented in the subject's past intervertebral line data.

7. The information processing apparatus according to claim 6,

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