JP5550585B2 - Bone density measuring device - Google Patents

Description

  The present invention relates to a bone density measuring apparatus, and more particularly to an apparatus for displaying bone density obtained by a plurality of examinations for the same subject.

  Bone density is used as an evaluation value for diagnosing osteoporosis and the like, and bone density measuring devices that perform measurement using X-rays are 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 distribution of the subject based on the detection result. The bone density measuring device obtains the bone mineral content and the bone area based on the measured bone mineral distribution. Then, the bone density is obtained by dividing the bone mineral content by the bone area, and the bone density is displayed on a display or the like. Here, the bone mineral content and the bone area from which the bone density was obtained have not been displayed in the past.

  The following Patent Document 1 describes a method and system for numerically expressing a future fracture risk by analyzing the bone mass (bone density) and bone structure of a target bone based on X-ray image data. ing. Cited Document 2 describes a device for measuring the bone density or bone mineral density of the lumbar spine. This apparatus obtains an appropriate measurement value by excluding the posterior element having a high bone density from the measurement target.

JP-T 9-508813 Japanese National Patent Publication No. 10-509075

  Since the bone density is a value obtained by dividing the amount of bone mineral by the bone area, it is a measurement value suitable for comparing the bone state among a plurality of subjects having individual differences in bone size. However, when a plurality of examinations are performed on the same subject and a change in bone state is diagnosed, it may be difficult to make an appropriate diagnosis by displaying only the bone density. For example, if the bone deforms due to a compression fracture or the like between the previous examination and the later examination, the bone area measured in the previous examination differs from the bone area measured in the later examination, and the bone mineral content is constant. Even if there is, bone density will change. Further, when the body position of the subject is different for each examination, the bone area to be measured is different for each examination, and the bone density is apparently changed even if the bone mineral content is constant. Therefore, when the measured bone density changes, it is difficult to specify whether the change is caused by a change in the amount of bone mineral or a change in the bone area.

  An object of the present invention is to display a bone density and a measurement amount based on the bone density in a manner suitable for bone diagnosis.

The present invention corresponds to a bone mineral distribution acquisition unit that acquires whole distribution data representing the distribution of bone mineral by transmitting X-rays to the subject, and corresponds to a target bone in the subject from the whole distribution data. Extraction means for extracting partial distribution data; integration processing means for obtaining a bone mineral content for the target bone based on integration processing for the partial distribution data extracted by the extraction means; and the target bone in the partial distribution data an area calculation means for calculating the area, and the integration processing mineral content were determined by means, and bone density calculating means for determining the bone density based on surface product obtained by said area calculation means, predetermined for the same subject when the bone density determined by the inspection performed every period is changed for each test, the change whether it is due to changes in bone mineral density, varying bone area And a display means for displaying the specific information for specifying whether it is due to the display means, as the specific information, obtained by the test performed the same subject per every predetermined time period A plurality of bone densities and a plurality of areas are displayed on a time axis .

  The bone density is determined based on the amount of bone mineral and the area of the target bone. Therefore, according to the processing executed by the display means, it is possible to indicate whether or not the change in bone density is caused by the change in area when the bone density is changed. The area of the target bone in the partial distribution data is defined as, for example, the projected area of the target bone on the surface where X-rays are detected. This area may be a value obtained by multiplying the actual projected area by a predetermined ratio.

In the bone density measuring apparatus according to the present invention, preferably, the display unit obtains, as the specific information, a plurality of bone densities and a plurality of areas, together with a plurality of bone density and a plurality of areas, by an examination performed every predetermined period. The plurality of bone mineral amounts obtained are displayed on the time axis.

  If the bone density changes with the change in bone mineral density, simply displaying the bone density and area makes the change in bone mineral density unknown and makes it difficult to identify the cause of the bone density change. Sometimes. Therefore, by displaying the bone mineral density on the time axis together with the bone density and area, the cause of the change in the bone density can be properly displayed.

In the bone density measuring apparatus according to the present invention, preferably, the target bone is an individual vertebra, the extraction means extracts the partial distribution data for the individual vertebra, and the integration processing means includes the individual processing vertebra. Bone mineral content is obtained for each vertebra, the area calculating means obtains the area for each individual vertebra, the bone density calculating means obtains the bone density for each individual vertebra, and the display means comprises the individual vertebrae. As for the specific information, a plurality of bone densities and a plurality of areas obtained by examination performed for the same subject every predetermined period are displayed on the time axis. In the bone density measuring apparatus according to the present invention, preferably, the display unit is configured to determine whether the individual vertebra is the same subject as information for specifying whether or not a compression fracture has occurred. A plurality of bone densities and a plurality of areas obtained by examination performed every predetermined period are displayed on the time axis. The present invention also provides bone mineral distribution acquisition means for acquiring total distribution data representing the distribution of bone mineral by transmitting X-rays to the subject, and the target bone in the subject from the total distribution data. Extraction means for extracting the corresponding partial distribution data, integration processing means for obtaining a bone mineral content for the target bone based on the integration processing for the partial distribution data extracted by the extraction means, and the partial distribution data in the partial distribution data For the same subject, an area calculating means for obtaining the area of the target bone, a bone mineral density obtained by the integration processing means, and a bone density calculating means for obtaining a bone density based on the area obtained by the area calculating means If the bone density obtained by multiple examinations changes for each examination, whether the change is due to changes in bone mineral content or due to changes in bone area Display means for displaying specific information for specifying whether the information is a plurality of bone density and a plurality of bone density determined by a plurality of examinations for the same subject as the specific information. On the time axis, the target bones are individual vertebrae, the extracting means extracts the partial distribution data for the individual vertebrae, and the integration processing means is a bone for the individual vertebrae. The amount of salt is obtained, the area calculating means obtains the area of the individual vertebrae, the bone density calculating means obtains the bone density of the individual vertebrae, and the display means determines the specific vertebra for the individual vertebrae. As information, a plurality of bone densities and a plurality of areas obtained by a plurality of examinations for the same subject are displayed on a time axis, and the display means compresses fractures for the individual vertebrae. As information for specifying whether or not there has been a change in the posture of the subject, a plurality of bone densities and a plurality of pieces obtained by a plurality of examinations for the same subject for the individual vertebrae The area is displayed on the time axis. In the bone density measuring apparatus according to the present invention, preferably, the area of the target bone is obtained as a value obtained by multiplying the projected area of the target bone on the surface where the X-ray is detected by a predetermined ratio.

  In this configuration, for each vertebra, a plurality of bone densities and a plurality of areas obtained by a plurality of examinations for the same subject are displayed on the time axis. Therefore, the states of a plurality of vertebrae can be compared with each other. Thereby, for example, the user can be made aware that a compression fracture or the like has occurred in any of the plurality of vertebrae. Further, when the body position of the subject changes for each examination, the required area changes in all of the plurality of vertebrae. Therefore, according to this structure, it can display that the area changed about all the several vertebrae, and can make a user grasp | ascertain that the posture of the subject changed for every test | inspection.

  According to the present invention, the bone density and the measurement amount based on the bone density can be displayed in a mode suitable for diagnosis of a change in bone density.

It is a figure which shows the structure of the bone density measuring apparatus which concerns on this invention. It is the figure which showed notionally the bone mineral distribution which bone mineral distribution data represent. It is a figure which shows the structure of the information memorize | stored in a memory | storage part. It is a figure which shows the example of the image displayed in bone density display mode. It is a figure which shows whether a bone density increases with respect to the change of a bone mineral amount and a bone area. It is a figure which shows the example of the image displayed in a bone density / bone area display mode. It is a figure which shows the example of the image displayed in bone density / bone area and an individual display mode. It is a figure which shows the example of the image displayed in bone density / bone area / bone mineral quantity and an individual display mode. It is a figure which shows the example which showed the bone density, the bone area, and the amount of bone mineral about the 2nd vertebra on the vertical axis | shaft, and showed the time of an examination on the horizontal axis.

  FIG. 1 shows the configuration of a bone density measuring apparatus according to an embodiment of the present invention. The bone density measuring apparatus acquires bone mineral distribution data obtained by projecting the three-dimensional spatial distribution of bone mineral on a plane based on the X-rays transmitted through the subject 16. The bone density measuring device obtains the bone density based on the bone mineral distribution data and displays the obtained bone density on the display 26.

  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 bucky table 18, a processor 22, a storage unit 24, a display 26, a system controller 28, and an operation unit 30. Within the processor 22, a bone mineral distribution data generation unit 32 that generates bone mineral distribution data based on the detection value of the X-ray detection unit 12, and a partial distribution data extraction unit 34 that extracts data to be measured from the bone mineral distribution data. A measurement value calculation unit 36 for obtaining bone density and the like based on the extracted data, and an image generation unit 38 for generating image data are 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, a bucky table 18 made of a material that transmits X-rays is disposed. A subject 16 is placed on the Bucky table 18, and a diagnostic space 20 in which the X-ray beam is scanned is formed from above the X-ray detection unit 12 to above the Bucky table 18.

  The operation unit 30 includes a mechanism for inputting information such as a keyboard, a mouse, and a trackball, and gives operation instruction information to the system controller 28 based on a user operation. The system controller 28 controls the X-ray generation unit 10, the X-ray detection unit 12, and the processor 22 based on the operation instruction information. 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 30.

  In general, a test for measuring bone density is performed for a predetermined period for the same subject. Here, the processing executed by the bone density measuring apparatus will be described for an example in which individual vertebrae constituting the lumbar vertebra are used as diagnosis target bones.

  The X-ray generation unit 10, the X-ray detection unit 12, and the bone mineral distribution data generation unit 32 acquire bone mineral distribution data of the subject 16 based on the dual energy X-ray absorption measurement method. In this measurement method, absorption rate distribution data for the subject 16 is obtained for each of two types of X-ray beams having different energies, and bone mineral distribution data is obtained from each absorption rate distribution data. Here, the absorptance distribution data represents the distribution of the absorptance for X-rays transmitted through the subject 16 on the detection surface 14.

  In the examination, the subject 16 is placed on the Bucky table 18 so that the waist is located between the X-ray generator 10 and the X-ray detector 12. The X-ray generator 10 scans the X-ray beam in the diagnostic space 20 with the energy of the emitted X-ray beam as the first value E1. 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 bone mineral distribution data generation unit 32. The bone mineral distribution data generation unit 32 obtains the absorption rate distribution data A1 for the energy E1 based on each detection value output from the X-ray detection unit 12.

  Next, the X-ray generator 10 scans the X-ray beam in the diagnostic space 20 with the energy of the radiating X-ray beam as the second value E2. 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 bone mineral distribution data generation unit 32. The bone mineral distribution data generation unit 32 obtains the absorption rate distribution data A2 for the energy E2 based on the detection value output from the X-ray detection unit 12.

  The bone mineral distribution data generation unit 32 obtains bone mineral distribution data in which the three-dimensional spatial distribution of bone mineral is projected on the detection surface 14 based on the absorption rate distribution data A1 and A2. The bone mineral distribution data obtained in the present embodiment is represented as a set of pixel data in which pixel values representing the amount of bone mineral are associated with information representing positions on the detection surface 14. The bone mineral distribution data generation unit 32 outputs the bone mineral distribution data to the partial distribution data extraction unit 34.

  FIG. 2 conceptually shows the bone mineral distribution represented by the bone mineral distribution data. The white area surrounded by the hatched area corresponds to the lumbar spine. The lumbar vertebra is composed of five vertebrae from the first vertebra to the fifth vertebra. FIG. 2 shows a part of the first vertebra L1, the second vertebra L2, the third vertebra L3, the fourth vertebra L4, and the fifth vertebra L5. A part of is shown. Here, the second vertebra to the fourth vertebra are the target bones.

  The calculation process for obtaining the bone density is executed by the partial distribution data extraction unit 34 and the measurement value calculation unit 36 shown in FIG. The partial distribution data extraction unit 34 sets the regions of interest R2 to R4 on the bone mineral distribution surface as regions including the vertebral regions. Then, partial distribution data corresponding to the regions of interest R <b> 2 to R <b> 4 are extracted from the bone mineral distribution data and output to the measurement value calculation unit 36. The measurement value calculation unit 36 integrates the pixel values of the partial distribution data and obtains the bone mineral content for each vertebra. Moreover, the measured value calculation part 36 calculates | requires the bone area of each vertebra based on each partial distribution data, and calculates | requires a bone density by remove | dividing the amount of bone minerals by a bone area. The measurement value calculation unit 36 stores the obtained measurement values in the storage unit 24 in association with the information on the examination date.

  Each measured value may be displayed numerically on the display 26. In this case, the measurement value calculation unit 36 outputs each measurement value to the image generation unit 38. The image generator 38 displays each measured value on the display 26 as a numerical value.

  Specific processing executed by the partial distribution data extraction unit 34 and the measurement value calculation unit 36 will be described. The partial distribution data extraction unit 34 sets a lumbar vertebra straight line A indicating a direction in which a plurality of vertebrae are continuous on the bone mineral distribution surface. The setting of the lumbar vertebra straight line A is performed, for example, by a calculation that linearly approximates the distribution of bone mineral. FIG. 2 shows a lumbar straight line A set in this way.

  The partial distribution data extraction unit 34 sets a minimum point where the pixel value is minimized on the lumbar vertebra line A, and sets a dividing line passing through the minimum point. The dividing straight line terminates at a position perpendicular to the lumbar straight line A and separated from the lumbar straight line A by a predetermined distance. Thereby, a dividing straight line is set between two regions corresponding to the two vertebrae. FIG. 2 shows the relationship between the first vertebra L1 and the second vertebra L2, the second vertebra L2 and the third vertebra L3, the third vertebra L3 and the fourth vertebra L4, and the fourth vertebra L4. Divided straight lines D12, D23, D34 and D45 respectively set between the first vertebra and the fifth vertebra L5 are shown.

  The partial distribution data extraction unit 34 further sets two boundary lines B1 and B2 that pass through the terminal ends on both sides of each divided straight line and are parallel to the lumbar straight line A. The partial distribution data extraction unit 34 sets a region surrounded by the dividing line D12, the dividing line D23, and the boundary lines B1 and B2 as the second vertebrae region of interest R2. In addition, a region surrounded by the dividing line D23, the dividing line D34, and the boundary lines B1 and B2 is set as the third vertebrae region of interest R3. Further, a region surrounded by the dividing line D34, the dividing line D45, and the boundary lines B1 and B2 is set as the fourth vertebrae region of interest R4.

  The partial distribution data extraction unit 34 extracts partial distribution data representing the bone mineral distribution in each region of interest from the bone mineral distribution data and outputs it to the measurement value calculation unit 36. That is, the partial distribution data extraction unit 34 extracts the L2 partial distribution data representing the bone mineral distribution in the second vertebrae region of interest R2 from the bone mineral distribution data and outputs it to the measurement value calculation unit 36. Similarly, the partial distribution data extraction unit 34 converts the bone mineral distribution in the third vertebral region of interest R3 and the bone mineral distribution in the fourth vertebrae region of interest R4 into the bone mineral distribution. The data is extracted from the data, and the L3 partial distribution data and the L4 partial distribution data are output to the measured value calculation unit 36.

  Here, the process of setting the region of interest based on the calculation process on the bone mineral distribution data has been described. In addition to such processing, the region of interest may be set based on a user operation. In this case, the bone mineral distribution data generation unit 32 outputs the bone mineral distribution data to the image generation unit 38, and the image generation unit 38 causes the display 26 to display an image of the bone mineral distribution. The user operates the operation unit 30 while referring to the bone mineral distribution image displayed on the display 26, and sets the lumbar vertebra straight line A, the divided straight lines D12, D23, D34, and D45 and the boundary lines B1 and B2. The system controller 28 causes the partial distribution data extraction unit 34 to perform processing for setting a region of interest based on an operation on the operation unit 30.

  The measurement value calculator 36 obtains the bone density for each of the second vertebra, the third vertebra, and the fourth vertebra based on the L2 partial distribution data, the L3 partial distribution data, and the L4 partial distribution data.

  The measurement value calculator 36 obtains the bone mineral content C2 of the second vertebra based on the L2 partial distribution data. That is, the bone mineral amount C2 of the second vertebra is obtained by integrating the pixel values of the L2 partial distribution data. Next, the measurement value calculator 36 obtains the bone area S2 of the second vertebra based on the L2 partial distribution data. That is, the number of pixel data whose pixel value exceeds a predetermined threshold among the pixel data included in the L2 partial distribution data is obtained. Then, the bone area S2 of the second vertebra is obtained by multiplying the obtained number by the area per pixel data. The measurement value calculation unit 36 obtains the bone density D2 of the second vertebra by dividing the bone mineral amount C2 of the second vertebra by the bone area S2.

  The measurement value calculator 36 obtains the bone mineral content C3, the bone area S3, and the bone density D3 of the third vertebra based on the L3 partial distribution data by a process similar to the process for the second vertebra. Further, the measurement value calculation unit 36 obtains the bone mineral content C4, the bone area S4, and the bone density D4 of the fourth vertebra based on the L4 partial distribution data by the same process as the process for the second vertebra. Furthermore, the measured value calculation part 36 calculates | requires the average value of bone density D2-D4 as the bone density average value DA.

  The measured value calculation unit 36 causes the storage unit 24 to store the bone density average value DA and the bone mineral amount, bone area, and bone density obtained for each vertebra in association with the examination date information.

  The examination for measuring the bone density is performed every predetermined period on the same subject, and the bone density measuring apparatus associates each measurement value obtained in each examination with the information on the examination date in the storage unit 24. Remember. FIG. 3 shows the configuration of information stored in the storage unit 24. In each column, information on the date of examination is recorded, and the bone mineral density C2 to C4, the bone areas S2 to S4, the bone density D2 to D4, and the bone density average value DA are recorded from the top.

  Next, a process of displaying any one of the measurement value groups obtained in each examination on the display 26 will be described. The bone density measuring device displays a measurement value group acquired over a plurality of examinations in accordance with an operation in the operation unit 30 in accordance with an operation (corresponding to a time (during examination)). . In the operation unit 30, designation of a period during which a measurement value to be displayed is acquired, designation of a display mode, and the like are performed. The system controller 28 controls the image generation unit 38 according to an operation on the operation unit 30. The image generation unit 38 reads information necessary for display from the storage unit 24 and performs display in the designated display mode.

  One of the display modes is a bone density display mode. In the bone density display mode, display is performed with the horizontal axis as the time of examination and the vertical axis of the bone density average value DA, which is the average value of bone density for the second to fourth vertebrae. FIG. 4 shows an example of an image displayed on the display 26 in the bone density display mode. In the bone density display mode, instead of displaying the bone density average value DA, the bone densities of the second vertebra to the fourth vertebra may be individually displayed.

  In the example shown in FIG. 4, the bone density average value DA increases from the third examination to the fourth examination. Therefore, the bone mineral content of the subject may have increased at this time. However, factors that increase the average bone density include an increase in bone mineral content, bone deformation due to compression fracture, etc., and changes in the posture of the subject for each examination. Therefore, it is difficult to determine that the bone mineral content of the subject has increased because the average bone density has increased.

  FIG. 5 shows such a problem in a generalized manner. In this figure, it is shown whether the bone density increases or decreases for each combination of the degree of change in bone mineral content and the degree of change in bone area. The degree of change in bone mineral content and bone area is classified as either reduced, weakly decreased, unchanged, weakly increased, or increased.

  Cases 1 and 2 show cases where the bone mineral density increases when the bone mineral content decreases slightly or when the bone mineral content does not change. For example, when the amount of bone mineral decreases slightly, the bone density increases when the bone area decreases (case 1).

  Cases 3 to 6 show cases where the bone mineral density increases when the bone mineral content increases or increases slightly, and when the bone density decreases when the bone mineral content decreases or weakly decreases. For example, when the amount of bone mineral is increased, the bone density is increased when the bone area is decreased, when it is weakly decreased, when it is not changed, or when it is slightly increased (case 4). ). In addition, when the bone density is decreased, the bone density is decreased in any case where the bone area is weakly decreased, not changed, slightly increased, or increased (Case 5). .

  Cases 7 and 8 show cases where the bone density decreases when the bone mineral content does not change or increases slightly. For example, when the amount of bone mineral increases slightly, the bone density decreases when the bone area increases (case 8).

  In cases 3 to 6, the increase / decrease tendency of the bone mineral density agrees with the increase / decrease tendency of the bone density, while in cases 1, 2, 7, and 8, the increase / decrease tendency of the bone mineral density does not agree with the increase / decrease tendency of the bone density. Therefore, it is difficult to make a detailed diagnosis of changes in the state of the bone only by displaying the bone density in association with the examination.

  Therefore, the bone density measuring apparatus according to the present embodiment performs display in the bone density / bone area display mode in order to eliminate such problems. In this display mode, the bone area of each vertebra is displayed in addition to the average bone density.

  FIG. 6 shows an example of an image displayed on the display 26 in the bone density / bone area display mode. In this example, the bone area S2 of the second vertebra decreases from the third examination to the fourth examination. This change is more significant than the change in bone area of the third and fourth vertebrae. According to this display, it is possible to allow the user to grasp that there is a high possibility that the bone density average value DA has increased due to the decrease in the bone area S2 of the second vertebra.

  As a display mode for expressing the temporal change in bone density in more detail, the bone density measuring apparatus performs display in the bone density / bone area / individual display mode. In this display mode, instead of displaying the average bone density value on the vertical axis as in the above-described bone density / bone area display mode, the respective bone densities of the second vertebra, the third vertebra and the fourth vertebra are plotted on the vertical axis. indicate.

  FIG. 7 shows an example of an image displayed on the display 26 in the bone density / bone area / individual display mode. In this example, the bone area S2 of the second vertebra decreases and the bone density D2 increases from the third examination to the fourth examination. This change is more significant than changes in the bone area and bone density of the third and fourth vertebrae. According to this display, the user can grasp that the bone density D2 of the second vertebra has increased due to the decrease in the bone area S2 of the second vertebra. According to the bone density / bone area / individual display mode, the bone density and the bone area of each of the second to fourth vertebrae are individually displayed. This allows the user to grasp the change in the state of each vertebra.

  As described above, the bone density is defined as the bone mineral content divided by the bone area. Therefore, when the bone mineral content is not significantly changed, the bone density decreases as the bone area decreases, and the bone area increases. As increases, bone density decreases. However, such a relationship does not necessarily hold between the bone area and the bone density when the bone mineral content changes significantly. Therefore, it may be difficult for the user to specify the cause of the bone density change only by displaying the bone density and the bone area.

  Therefore, the bone density measuring apparatus according to the present embodiment may perform display using bone density / bone area / bone mineral content / individual display mode. In this display mode, in addition to the bone density and bone area of each vertebra displayed in the above-described bone density / bone area / individual display mode, the bone mineral content of each vertebra is displayed on the vertical axis.

  FIG. 8 shows an example of an image displayed on the display 26 in the bone density / bone area / bone mineral content / individual display mode. The subject and the examination conditions are the same as those shown in FIG. In this example, the bone area S2 of the second vertebra is decreased and the bone density D2 is increased from the third examination to the fourth examination, while the bone mineral content C2 is not significantly changed. According to this display, the user can grasp that the increase in the bone density D2 of the second vertebra is caused by the decrease in the bone area S2.

  In the bone density / bone area / bone mineral amount / individual display mode, the bone density average value may be displayed together with the bone density of each vertebra or instead of displaying the bone density of each vertebra. . Further, instead of displaying the measurement value for each vertebra, the bone density, the bone area, and the one vertebra designated according to the user's operation among the second vertebra, the third vertebra, and the fourth vertebra The bone mineral content may be displayed on the vertical axis.

  FIGS. 9A and 9B show an example in which the bone density D2, the bone area S2, and the bone mineral content C2 are displayed on the vertical axis for the second vertebra. In the example shown in FIG. 9 (a), the bone area S2 of the second vertebra decreases and the bone density D2 increases from the third examination to the fourth examination, while the change in the bone mineral content C2 is as follows. Not remarkably. This display allows the user to grasp that the increase in the bone density D2 of the second vertebra is caused by the decrease in the bone area S2. In the example shown in FIG. 9 (b), the bone density D2 and the bone mineral density C2 of the second vertebra increase from the second to the fourth examination, while the change in the bone area S2 is not significant. This display allows the user to grasp that the increase in the bone density D2 of the second vertebra is due to the increase in the bone mineral content C2.

  10 X-ray generation unit, 12 X-ray detection unit, 14 detection surface, 16 subject, 18 bucky table, 20 diagnostic space, 22 processor, 24 storage unit, 26 display, 28 system controller, 30 operation unit, 32 bone mineral distribution Data generation unit, 34 Partial distribution data extraction unit, 36 Measurement value calculation unit, 38 Image generation unit.

Claims (6)

Bone mineral distribution acquisition means for acquiring whole distribution data representing the distribution of bone mineral by transmitting X-rays to the subject;
Extracting means for extracting partial distribution data corresponding to the target bone in the subject from the whole distribution data;
Based on the integration process for the partial distribution data extracted by the extraction unit, an integration processing unit for obtaining a bone mineral content for the target bone;
Area calculating means for obtaining the area of the target bone in the partial distribution data;
A bone density calculation means for calculating a bone density based on surface product obtained by the obtained bone mineral content, and the area calculation means by the integrating processing unit,
When the bone density obtained by the examination performed for the same subject every predetermined period changes for each examination, whether the change is caused by the change in the bone mineral content or the change in the bone area Display means for displaying specific information for identifying whether the object is ,
Equipped with a,
The display means displays, on the time axis, a plurality of bone densities and a plurality of areas obtained by an examination performed for the same subject every predetermined period as the specific information. . The bone density measuring device according to claim 1,
The display means displays, on the time axis, a plurality of bone mineral amounts obtained by an examination performed for a predetermined period for the same subject as the specific information together with the plurality of bone densities and the plurality of areas. A bone density measuring device characterized by the above. In the bone density measuring device according to claim 1 or 2 ,
The target bone is an individual vertebra,
The extraction means extracts the partial distribution data for the individual vertebrae,
The integration processing means obtains bone mineral content for the individual vertebrae,
The area calculating means calculates an area for the individual vertebrae,
The bone density calculating means calculates bone density for the individual vertebrae,
The display means displays, on the time axis, a plurality of bone densities and a plurality of areas obtained by examinations performed for a predetermined period for the same subject as the specific information for the individual vertebrae. Bone density measuring device. The bone density measuring device according to claim 3,
The display means includes a plurality of bone densities obtained by an examination performed on a single subject every predetermined period for the individual vertebrae as information for specifying whether or not a compression fracture has occurred for the individual vertebrae. And a bone density measuring apparatus characterized by displaying a plurality of areas on a time axis. Bone mineral distribution acquisition means for acquiring whole distribution data representing the distribution of bone mineral by transmitting X-rays to the subject;
Extracting means for extracting partial distribution data corresponding to the target bone in the subject from the whole distribution data;
Based on the integration process for the partial distribution data extracted by the extraction unit, an integration processing unit for obtaining a bone mineral content for the target bone;
Area calculating means for obtaining the area of the target bone in the partial distribution data;
Bone density calculating means for obtaining bone density based on the amount of bone mineral obtained by the integration processing means and the area obtained by the area calculating means;
If the bone density obtained by multiple tests for the same subject changes from test to test, is the change caused by changes in bone mineral content or bone area? Display means for displaying specific information for identifying
With
The display means displays on the time axis a plurality of bone densities and a plurality of areas obtained by a plurality of examinations for the same subject as the specific information,
The target bone is an individual vertebra,
The extraction means extracts the partial distribution data for the individual vertebrae,
The integration processing means obtains bone mineral content for the individual vertebrae,
The area calculating means calculates an area for the individual vertebrae,
The bone density calculating means calculates bone density for the individual vertebrae,
The display means displays, on the time axis, a plurality of bone densities and a plurality of areas obtained by a plurality of examinations for the same subject as the specific information for the individual vertebrae,
The display means, as information for specifying whether or not there has been a compression fracture with respect to the individual vertebrae and whether or not there has been a change in the body position of the subject, a plurality of times for the same subject with respect to the individual vertebrae. A bone density measuring apparatus, wherein a plurality of bone densities and a plurality of areas obtained by the inspection are displayed on a time axis. In the bone density measuring device according to any one of claims 1 to 5,
The bone density measuring apparatus, wherein the area of the target bone is obtained as a value obtained by multiplying a projected area of the target bone on a surface where the X-ray is detected by a predetermined ratio.

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