Bone density measurement system and program

Abstract

This system provides support for operating bone density measurement devices using data obtained from past measurements. [Solution] When performing a measurement, the control unit of the bone density measuring device determines whether measurement data obtained from past bone density measurements of the subject is registered in the database (S10, S12). The control unit has several "high-resolution" conditions registered, such as the condition that bone density is above a threshold and the condition that measurements are performed regularly. If past measurement data is found, the control unit determines whether the past data satisfies each of the "high-resolution" conditions (S14). If at least one "high-resolution" condition is met (the result of the determination in S16 is Yes), the control unit sets the mode of the current measurement to high-resolution mode (S18).

Description

[Technical Field]

[0001] The present disclosure relates to a bone density measurement system, and particularly to a technology for supporting measurement work. [Background Art]

[0002] Patent Document 1 discloses an apparatus that enables confirmation of various imaging conditions by performing general imaging (called pre-imaging) before performing DXA imaging. Further, the document describes that positioning of the subject from the previous measurement can be reproduced this time by comparing the previous pre-shot image and the current pre-shot image (see, for example, paragraphs 0054 and 0057). The document also describes that "if there is curvature of the lumbar spine or the like, attention may be drawn to positioning" (paragraph 0054 of the same document). The document also describes that the body thickness of the site (lumbar spine or femur) may be estimated from a still image obtained by pre-imaging, and the dose during DXA imaging may be adjusted (see, for example, paragraph 0057).

[0003] Patent Document 2 describes that the L value (that is, bone length) of a target bone is automatically measured from an X-ray captured image, the L value measured this time is compared with a stored past L value, and warning information is displayed when the two values differ greatly. In addition, the document describes that "if the two values differ greatly, measurement errors, errors in imaging conditions, etc. can be reviewed" (see paragraphs 0030-0031 and 0084-0086 of the same document).

[0004] The apparatus disclosed in Patent Document 3 compares the radiation exposure conditions set this time with stored past radiation exposure conditions, and issues a warning when the two conditions are different.

[0005] The apparatus disclosed in Patent Document 4 stores abnormal shadow candidates in a diagnostic history when the abnormal shadow candidates are detected. Further, when the same abnormal shadow candidate of the same patient as the detected abnormal shadow candidate is stored in the diagnostic history, this apparatus compares the position, size, and shape of the abnormal shadow candidate to determine whether there is a temporal change in the abnormal shadow candidate. [Prior Art Documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2023-183893 [Patent Document 2] Japanese Patent Publication No. 2013-169213 [Patent Document 3] Japanese Patent Publication No. 2007-222447 [Patent Document 4] Japanese Patent Publication No. 2004-046594 [Overview of the project] [Problems that the invention aims to solve]

[0007] This disclosure aims to provide a system that can assist in the operation of a bone density measurement device using data obtained from past measurements. [Means for solving the problem]

[0008] The bone density measurement system according to this disclosure comprises a bone density measuring device and a processor, wherein the processor registers measurement data obtained from the measurement of a subject by the bone density measuring device in a database, and when the bone density measuring device measures a subject, it determines the measurement mode to be used for the measurement based on the subject's past measurement data registered in the database.

[0009] Here, the measurement data may include the measured values ​​obtained by the bone density measuring device.

[0010] The aforementioned measurement is, for example, bone density, or an index value corresponding to bone density.

[0011] Here, the processor may, in the process of determining the measurement mode to be used in the measurement, decide to use the high-resolution mode as the measurement mode if the bone density or the index value is above a threshold.

[0012] Furthermore, in the process of determining the measurement mode to be used in the measurement, the processor may decide to use the high-definition mode as the measurement mode if it is determined from the bone density or index value in past measurements that the bone density of the subject is on an upward trend.

[0013] Furthermore, in the process of determining the measurement mode to be used in the measurement, the processor may decide to use the high-resolution mode as the measurement mode if it is determined from the bone density or index value in the soft tissue that vascular calcification has occurred.

[0014] Furthermore, the measured value is the thickness of the soft tissue, and in the process of determining the measurement mode to be used in the measurement, it may be decided to use the high-resolution mode as the measurement mode if the thickness is greater than or equal to a threshold.

[0015] Furthermore, the measurement data is data indicating the time when the measurement was performed, and the processor may, in the process of determining the measurement mode to be used in the measurement, determine from the data indicating the time of measurement that the subject is performing measurements periodically, to use the high-definition mode as the measurement mode.

[0016] Furthermore, the measurement data may include input data entered by the user in correspondence with the measurement values ​​obtained by the bone density measuring device, and the processor may, in the process of determining the measurement mode to be used for the measurement, decide to use the high-definition mode as the measurement mode if the input data indicates at least one of the following: that an implant is provided, that vascular calcification is observed, or that the measurement is for the evaluation of the therapeutic effect.

[0017] Furthermore, when the bone density measuring device measures a subject, the processor may also present the user with information regarding the subject's posture based on the subject's past measurement data registered in the database.

[0018] Here, when it is determined from the past measurement data that there is a compression fracture, the processor may be configured to present, as the information related to the body position, a message prompting attention to the body position of the subject during measurement.

[0019] Further, when it is determined from the past measurement data that the rotation angle of the lower limb is inappropriate, the processor may be configured to present, as the information related to the body position, a message prompting appropriate setting of the rotation angle of the lower limb of the subject during measurement.

[0020] Further, when it is determined from the past measurement data that the curvature of the lumbar spine is excessive, the processor may be configured to present, as the information related to the body position, a message prompting appropriate setting of the body position of the lumbar region of the subject during measurement.

[0021] Further, a program according to the present disclosure is a program for causing a computer to operate so as to: register measurement data obtained from measurement of a subject by a bone densitometer in a database; and when measuring the subject with the bone densitometer, determine a measurement mode to be used in the measurement based on the past measurement data of the subject registered in the database. [Effects of the Invention]

[0022] According to the device of the present disclosure, it is possible to support mode selection for bone density measurement using data obtained from past measurements. Brief Description of the Drawings

[0023] [Figure 1] It is a perspective view of the external appearance of a bone densitometer. [Figure 2] It is a diagram illustrating an example of the functional configuration of a bone density measurement system. [Figure 3] It is a diagram illustrating an example of measurement data of a subject registered in a database. [Figure 4]This diagram illustrates the relationship between ROI and intervertebral lines in bone density images. [Figure 5] This diagram illustrates the procedure for determining the mode for the current measurement based on past measurement data. [Figure 6] This diagram illustrates a procedure for providing advice on body positioning during the current measurement based on past measurement data. [Figure 7] This figure shows an example of a screen that provides advice regarding body positioning. [Figure 8] This figure shows another example of a screen that provides advice on body positioning. [Figure 9] This figure shows yet another example of a screen that provides advice on body positioning. [Modes for carrying out the invention]

[0024] <Example of device configuration> Figure 1 shows an example of a bone densitometry device 10 to which the control described herein is applied, and a perspective view of a Bucky table 18 used with it.

[0025] The bone densitometer 10 comprises a main body 12 that generates X-rays 20, an arm 14 that detects the X-rays 20, and a support column 16 that supports the arm 14 above the main body 12. The space enclosed by the main body 12, the support column 16, and the arm 14 forms a measurement space 22 in which the subject is placed. The subject is received into the measurement space 22 from the side where the support column 16 is not present, facing in the positive y-axis direction.

[0026] The bone densitometer 10 is positioned so that its main body 12 fits under the tabletop of the Bucky table 18. Within the measurement space 22, the subject is laid on the Bucky table 18, leaving some space on the front side as shown in Figure 1. The bone densitometer 10 measures bone density, body fat percentage, muscle mass, etc., based on the detection values ​​of X-rays 20 emitted from the main body 12, which pass through the subject and are detected by the arm 14.

[0027] Here, we have described an embodiment in which the bone densitometry device 10 and the Bucky table 18 are separate components. However, the upper surface of the main body 12 of the bone densitometry device 10 may be used as a Bucky table on which the subject lies, and the bone densitometry device 10 and the Bucky table may be integrated into a single unit.

[0028] Figure 2 illustrates the functional configuration of a bone densitometry system including a bone densitometry device 10 and a control device 38. In Figure 2, the vertical direction is the x-direction, the horizontal direction is the y-direction, and the direction perpendicular to the plane of the paper is the z-direction. This figure shows the main internal configuration of the main body 12 and the arm 14. The bone densitometry device 10 comprises an X-ray generator 26 housed in the main body housing 24 and an X-ray detector 30 housed in the arm housing 28. The X-ray beam emitted by the X-ray generator 26 may have a planar beam shape with width in the z-direction. For example, a planar beam shape parallel to the zx plane is one such example. Alternatively, the beam shape may be a fan-shaped shape, widening in the z-axis direction as it moves away from the X-ray generator 26. The X-ray generator 26 is an example of an irradiation unit that irradiates the subject 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 subject.

[0029] The X-ray generator 26 and the X-ray detector 30 are transported horizontally within the main body 12 and arm 14, respectively, by a transport mechanism (not shown) while maintaining a relative position opposite to each other. This transport enables scanning of the X-ray beam in the y-direction. Therefore, the y-direction is the transport direction in which the transport mechanism transports the measurement system, or in other words, the direction of the mechanical scanning caused by that 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 far right of the transport range toward the left. As the scanning in the y-direction progresses in accordance with this transport, the X-ray beam passes through a region a1 containing only air (i.e., a region where the subject 32 is not present), then through a region b where the subject 32 is present, and then again through a region a2 containing only air. Irradiation with an X-ray beam from the X-ray generator 26 begins when the scanning position of the measurement system is at the scanning start position in the initial air-only region a1, and continues until the scanning position reaches the scanning end position in region a2 after region b. The detected value when the X-rays irradiated from the X-ray generator 26 are detected by the X-ray detector 30 while the scanning position of the measurement system is in region a1 is acquired as reference data in the DXA method (also called DEXA method).

[0030] The bone densitometer 10 determines the distribution of absorption rate for the subject 32 based on the detected values ​​acquired by the X-ray detector 30 during the scanning period of region b and the above-mentioned reference data. Here, the distribution of absorption rate refers to the distribution of absorption rate in the horizontal plane (yz plane) for X-rays passing upward through region b. Absorption rate is defined as the value obtained by dividing the value shown in the reference data by the detected value of the X-rays detected by the X-ray detector 30. The smaller the detected value of the X-rays detected by the X-ray detector 30, the greater the absorption rate. The distribution of absorption rate can also be said to be a distribution that corresponds to the reciprocal of the detected value of the X-rays detected by the X-ray detector 30. The bone densitometer 10 alternately irradiates high-energy and low-energy X-rays according to the DXA method, determines the distribution of absorption rate for each of the two types of X-rays with different energies, and measures bone density, fat-muscle ratio, etc. from the respective distributions of absorption rate.

[0031] A control device 38 is connected to the bone densitometry device 10. The control device 38 comprises 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 database processing unit 52. The operation panel 42, which serves as the operation unit, includes, for example, a keyboard, mouse, drag ball, lever, etc. The control unit 40 controls the measurement mechanism of the bone densitometry device 10, including the X-ray generator 26, the X-ray detector 30, and the transport mechanism that transports them. The analysis unit 46 generates a bone densitometry image by analyzing the measurement result data (for example, a map of X-ray detection values). The analysis unit 46 also performs analysis of the bone densitometry image. This analysis is, for example, a process for estimating the position of markers and the intervertebral lines. The setting processing unit 48 sets the position of markers, intervertebral lines, etc., for the bone densitometry image based on the analysis results of the analysis unit 46 and confirmations and corrections from the user. The display processing unit 50 performs a process 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 data registration and retrieval processing for the database 60. For example, the DB processing unit 52 performs processing to register measurement result data such as bone density images and the positions of markers set by the setting processing unit 48, intervertebral lines, and bone boundaries into the database 60. The DB processing unit 52 also performs processing to retrieve past data of the subject 32 from DB 60 for use in generating images for diagnostic support by the display processing unit 50.

[0032] The control device 38 is configured as a computer equipped with a processor, memory, etc., and operates according to a pre-stored program. The control device 38 may be integrated with the bone densitometer 10 or configured separately. The control device 38 may also be composed of multiple computers interconnected via a network or the like. In this case, the multiple computers constituting the control unit 40 cooperate to execute the processing of the control device 38, which will be described later, while exchanging data with each other. The functions of the analysis unit 46, the setting processing unit 48, the display processing unit 50, and the DB processing unit 52 may be provided by a computer independent of the bone densitometer 10 (i.e., a computer that does not control the bone densitometer 10).

[0033] The database 60 stores measurement result data 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.

[0034] The X-ray generator 26 uses an X-ray tube or the like to generate X-rays. 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 allows X-rays to pass through, and X-rays are emitted upward from the X-ray generator 26 through the top plate.

[0035] The bottom plate 58 of the arm housing 28 is made of an X-ray-transmitting material, and X-rays emitted from the main body 12 toward the arm 14 are detected by the X-ray detector 30 via the bottom plate 58.

[0036] 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 with respect to the X-ray wavelength. The X-ray detector 30 can be configured such that multiple conversion devices are arranged in multiple columns perpendicular to the transport direction and with the horizontal direction (positive z-axis direction) as the column direction, and detection values ​​are output from these multiple conversion devices. Alternatively, the X-ray detector 30 may be configured to output detection values ​​at each detection point by mechanically linearly scanning one conversion device in the z-axis direction.

[0037] 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. However, the bone densitometer 10 may also have a configuration in which 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.

[0038] <Database> Figure 3 shows an example of data registered in database 60. The example shown shows data for a single patient. Patient data is registered in association with the patient ID, which is the patient's identification information. In the example shown in the figure, one row of data is a record consisting of data items obtained from a measurement performed on a certain measurement day. Here, the measurement day is an example of information indicating the time of measurement. The date and time of measurement may be recorded instead of the measurement day.

[0039] The items that make up a record include, for example, the target area, raw data ID, image ID, bone mineral density, bone density, bone width, %YAM, T-score, soft tissue thickness, soft tissue width, ROI location, intervertebral line information, compression fracture information, implant information, vascular calcification information, internal and external rotation information, and lumbar curvature information.

[0040] The target area is the area to be measured on the day of measurement. The target area is selected from the lumbar spine and the proximal femur.

[0041] The raw data ID is the identification information for the raw data obtained from that measurement. Raw data refers to data showing the distribution of detected high-energy X-rays and low-energy X-rays in the DXA method. The raw data itself is stored in database 60, associated with the raw data ID.

[0042] The image ID is the identification information for the bone density image, which shows the distribution of bone density obtained from that measurement. The bone density image data itself is stored in database 60, associated with the image ID.

[0043] Bone mineral density is the total bone mineral content within the measurement range (e.g., ROI described below). Bone density is the average bone density across the entire bone within the measurement range. Bone width is the width of the bone determined by the measurement. Bone width may be the average value across the entire bone within the measurement range, or it may be the width of a specific bone within the measurement range.

[0044] %YAM is a value that shows the percentage of bone density relative to the Young Adult Mean. The Young Adult Mean is the average bone density of healthy same-sex adults in the range of 20-44 years for the lumbar spine and 20-29 years for the proximal femur. The T-score is a value that expresses the standard deviation of how far the bone density deviates from the Young Adult Mean. %YAM and the T-score are examples of index values ​​corresponding to bone density.

[0045] Soft tissue thickness is the thickness of the soft tissue determined by the measurement, i.e., the length of the soft tissue in the direction from the front to the back of the body. Soft tissue width is the width of the soft tissue determined by the measurement, i.e., the length of the soft tissue in the direction from the right side to the left side of the body. Soft tissue thickness may be the average value for all soft tissue within the ROI, the average value for all soft tissue including outside the ROI, or a value for a specific area.

[0046] The ROI location is information that identifies the location of the ROI (Region of Interest). For example, in lumbar spine measurements, if bone density is measured from L2 (second lumbar vertebra) to L4 (fourth lumbar vertebra), the range including L2 to L4 is set as the ROI. The shape of the ROI is, for example, a rectangle. For example, markers are set between L1 (first lumbar vertebra) and L2, and between L4 and L5 (fifth lumbar vertebra), and the upper, lower, left, and right ends of the ROI are determined according to predetermined rules based on these markers. For example, the left and right ends of the ROI are set at positions a predetermined length (for example, 6 cm) to the left and right of the line connecting these markers (so to speak, the center line of L2 to L4). In this example, the ROI location is a pair of coordinates of two markers. Of course, this method is just one example. The markers are set after confirmation by the user, such as a medical technologist or physician.

[0047] Intervertebral line information is one type of information used for measurements targeting the lumbar spine. Here, an intervertebral line is a straight line segment extending longitudinally between adjacent vertebral bodies (i.e., lumbar vertebrae). Intervertebral lines are set for each intervertebral space within the ROI. Each intervertebral line is estimated by, for example, the analysis unit 46 through analysis of bone density images, and is set after confirmation and modification by the user, such as a medical technologist or physician.

[0048] Intervertebral line information is information that identifies each of the set intervertebral lines, and is, for example, a set of coordinates of the intersection points between each intervertebral line and the left and right ends of the ROI.

[0049] Figure 4 schematically shows a bone density image 100, markers M1 and M2, ROI, and intervertebral lines. Generally, bone density images are black and white images, similar to normal X-ray images, where brightness increases with greater X-ray absorption. However, the bone density image 100 in Figure 4 is shown with the colors reversed to make leader lines and other elements easier to see. In this example, marker M1 is set between L2 and L1, and marker M2 is set between L4 and L5, both vertebrae in the bone area 104 where the bone density value is significantly higher than that of the soft tissue 102. Based on these markers M1 and M2, an ROI is set, enclosed by edges parallel to the x and y directions of the image. The dashed lines DH, CG, BF, and AE are the set intervertebral lines. For example, a set of coordinates for the endpoints A, B, C, ..., G, H of these intervertebral lines is registered in the database 60 as intervertebral line information.

[0050] Compression fracture information is one piece of information regarding measurements, for example, of the lumbar spine, and includes information indicating the presence or absence of a compression fracture. The presence or absence of a compression fracture can be determined, for example, by analyzing bone density images using a known method. This analysis is performed, for example, by the analysis unit 46. The analysis unit 46 may present an analysis result indicating a risk of compression fracture, and the user may evaluate the bone density image in response to this presentation to ultimately determine the presence or absence of a compression fracture. Alternatively, the presence or absence of a compression fracture may not be automatically determined, and the determination may be made solely by the user. The result of the automatic determination by the analysis unit 46, or the result of the determination by the user, is registered in the database 60 as compression fracture information.

[0051] The implant information includes information indicating the presence or absence of implants. Implants are components embedded in the body to replace or reinforce bone, and are generally made of metal. Since the bone density value of implants is significantly higher than that of bone, the presence or absence of implants can be easily determined. This determination is performed, for example, by the analysis unit 46. Alternatively, the presence or absence of implants may be determined by the user from bone density images, etc., instead of automatic determination. The results of the automatic determination by the analysis unit 46, or the results of the determination by the user, are registered as implant information in the database 60.

[0052] Vascular calcification information indicates whether or not there is significant vascular calcification that affects bone density measurement. Calcified blood vessels may show bone density so high that they are difficult to distinguish from bone. For example, it may be difficult to distinguish between osteophytes and transverse processes formed by bone deformation and the surrounding calcified blood vessels on a bone density image. To accurately calculate bone density, it is necessary to accurately differentiate between areas where X-rays have passed only through soft tissue (i.e., not through bone) and areas where they have passed through bone, but this differentiation can be difficult if vascular calcification is significant. Therefore, in bone density measurement, if the user determines from the obtained bone density image that there is significant vascular calcification, or if the analysis unit 46 detects significant calcification using a known method, information indicating this is registered in the database 60 as vascular calcification information.

[0053] Internal and external rotation information is one of the pieces of information for measurements targeting the proximal femur. It is known that external and internal rotation of the hip joint greatly affects bone density measurements. For accurate measurement, it is necessary to set the rotation angle of the lower limb so that the lesser trochanter appears small in the image. Conversely, if the lesser trochanter is large in the image, external rotation is strong, and if the lesser trochanter is not visible at all, internal rotation is strong. In either case, the angle of the femoral neck, which is the target of measurement, becomes inappropriate, and accurate measurement is not possible. Therefore, whether the lesser trochanter is visible at an appropriate size in the bone density image is determined by automatic analysis by the analysis unit 46 or evaluation by the user, and the result of this determination is registered as internal and external rotation information in the database 60. In addition, for example, if it is determined from the bone density image taken during the first measurement that there is excessive internal or external rotation, the rotation state of the lower limb may be corrected and a remeasurement may be performed. In that case, even if there is no excessive internal or external rotation in the remeasurement, the internal and external rotation information in the database 60 may record that the remeasurement was due to excessive internal or external rotation.

[0054] Lumbar spine curvature information is one type of information related to measurements of the lumbar spine. Lumbar spine bone density measurement is performed with the subject lying supine on a Bucky table 18. In some cases, if the subject lies supine in their usual sleeping position, their lower back may be excessively arched upward, resulting in a strong curvature of the lumbar spine and reducing the accuracy of the bone density measurement. Whether the lumbar spine curvature due to the arching of the lower back is within the normal range or excessive can be determined by the user from the bone density image. In some cases, it can also be determined by the automatic analysis of the analysis unit 46. The result of the determination by the user or the analysis unit 46 is registered in the database 60 as lumbar spine curvature information. If excessive curvature is detected and a remeasurement is performed, the lumbar spine curvature information in the database 60 may also record that the remeasurement was due to excessive lumbar spine curvature.

[0055] When the control unit 40 performs a bone density measurement, it registers the data obtained from the measurement, such as images and numerical values, as well as data such as comments entered by the user who observed and evaluated the measurement results, into the database 60.

[0056] <Control based on past data> The control of the bone densitometry device using past measurement data in the database 60 will be described below. In this embodiment, past measurement data is used in two main ways: determining the measurement mode of the bone densitometry device 10 and displaying advice information about the body position during measurement.

[0057] (1) Determination of Measurement Mode In bone densitometry, the slower the transport speed of the measurement system, the more detailed the bone density measurement becomes. However, the longer the measurement time and the greater the radiation exposure to the subject. Therefore, the bone densitometry device 10 is equipped with several measurement modes with different transport speeds of the measurement system, depending on the purpose of the measurement. For example, in addition to the standard mode used for normal examinations, there may be a high-resolution mode for more detailed measurements and a high-speed mode suitable for short-time examinations such as health checkups. In this example, the transport speed of the measurement system is highest in the high-speed mode, followed by the standard mode and then the high-resolution mode. The bone density image obtained in the high-speed mode is less detailed than that obtained in the standard mode. For example, in examinations of individuals with symptoms due to decreased bone density, either the standard mode or the high-resolution mode is often used.

[0058] In this embodiment, when measuring a subject, the control unit 40 refers to the subject's past measurement data in the database 60 to determine the measurement mode for that measurement. An example of the processing procedure of the control unit 40 at this time is shown in Figure 5. The example in Figure 5 is an example of the processing procedure for a measurement targeting a subject with symptoms of decreased bone density, not for health checkup purposes, and the measurement mode is selected from standard mode and high-definition mode.

[0059] The processing procedure in Figure 5 is triggered, for example, by the user entering the patient ID of the subject to be measured into the control unit 40. The control unit 40 queries the database 60 to see if there is past measurement data (hereinafter referred to as "past data") corresponding to that patient ID (S10). If the query receives a response that past data exists (i.e., the result of the determination in step S12 is YES), the control unit 40 compares the past data with the "high resolution" condition (S14).

[0060] The "high-definition" condition is the requirement for selecting the high-definition mode as the measurement mode. The "high-definition" condition specifies, for example, which items in the past data must have what values ​​for the high-definition mode to be selected.

[0061] The matching in step S14 is performed, for example, using data from the previous measurement. However, this is just one example, and all past data of the subject may be used instead. In the following explanation, for the sake of brevity, the case where data from the previous measurement is used will be the main example.

[0062] One example of a "high-resolution" condition is that the soft tissue thickness obtained in the previous measurement is above a predetermined threshold. When soft tissue is thick, the amount of X-rays that pass through the body decreases. Therefore, if the soft tissue is extremely thick, it can negatively affect the accuracy of bone density measurements. To address this, if the soft tissue thickness obtained in the previous measurement is above the threshold, selecting the high-resolution mode in the current measurement increases the amount of transmitted X-rays and ensures the accuracy of bone density measurements.

[0063] Another example of a "high-resolution" condition is that the bone density (in this case, the average value, not the distribution) obtained in the previous measurement, or its corresponding index value (e.g., %YAM or T-score), is above a predetermined threshold. When bone density is extremely high, the amount of X-rays transmitted through the body decreases, which can negatively affect the accuracy of the bone density measurement. Therefore, by selecting high-resolution mode when the bone density or its corresponding index value is above a predetermined threshold, the transmitted X-ray dose is increased, ensuring the accuracy of the measured bone density.

[0064] Another example of a "high-resolution" condition is when the implant information obtained during the previous measurement indicates the presence of an implant. When an implant is present, there are often problems such as the spine not being straight, so selecting high-resolution mode improves the accuracy of the measurement.

[0065] Another example of a "high-resolution" condition is that past measurements can be considered regular. When measurements are taken regularly, it is highly likely that the effectiveness of treatment (e.g., medication) is being evaluated. In such cases, selecting high-resolution mode enables a more precise evaluation. Whether past measurements are regular can be determined by checking whether the interval between adjacent measurement dates in the past data is within a predetermined error range. This condition is determined when there are n or more records with different measurement dates in the subject's past data (where n is a predetermined integer of 3 or more).

[0066] Another example of a "high-resolution" condition is when the vascular calcification information from the previous measurement indicates "calcification present." In subjects with calcification, obtaining a high-resolution bone density image by measuring in high-resolution mode makes it easier to distinguish between bone and soft tissue.

[0067] Another example of a "high-resolution" condition is when the most recent bone density or %YAM measurement is on an upward trend. An upward trend in the most recent measurement means that the measurement values ​​in a predetermined number of previous measurements can be considered to be increasing as an overall trend (for example, monotonically increasing). When the bone density or other measurement values ​​in the most recent and nearest set of measurements are on an upward trend, it is highly likely that the effect of treatment (for example, medication) is being evaluated. In such cases, selecting the high-resolution mode enables a more precise evaluation.

[0068] Furthermore, although not shown in Figure 3, information indicating whether or not the treatment effect is being evaluated may be recorded as an item in the measurement data in the database 60, and if the value of the item in the previous measurement indicates that "the treatment effect is being evaluated," the high-definition mode may be selected for the current measurement. The information indicating whether or not the treatment effect is being evaluated can be entered into the database 60 by the user via the control unit 40, for example.

[0069] The control unit 40 has one or more of the "high-definition" conditions exemplified above, and in step S14, it determines whether the past data corresponding to the input patient ID satisfies each of those "high-definition" conditions.

[0070] The control unit 40 determines in step S14 whether at least one "high-definition" condition has been met (S16). If the determination result in step S16 is YES, the control unit 40 sets the measurement mode to high-definition mode (S18). Alternatively, in step S18, instead of automatically setting the high-definition mode, the control unit 40 may display a dialog screen with a message recommending the high-definition mode and set the measurement mode selected by the user on that dialog screen.

[0071] If the result of step S16 is No, that is, if the subject's past data does not meet any of the provided "high-resolution" conditions, the control unit 40 sets the standard mode as the measurement mode for this time (S20). Alternatively, in step S20, instead of automatically setting the standard mode, the control unit 40 may display a dialog screen with a message recommending the standard mode and set the measurement mode selected by the user on that dialog screen.

[0072] In the procedure illustrated in Figure 5, the process proceeds to step S18 if at least one "high resolution" condition is met, but this is just one example. Alternatively, the process could proceed to step S18 if, for example, n or more (where n is a predetermined integer greater than or equal to 2) "high resolution" conditions are met.

[0073] (2) Display of advice information regarding body position The control unit 40 also displays a screen showing advice on the body position of the subject lying supine on the Bucky table 18 for the current measurement, based on the subject's past data. Figure 6 illustrates the processing procedure for displaying this advice. The processing procedure in Figure 6 is a continuation of the processing procedure shown in Figure 5, but the execution order of the processing procedure in Figure 5 and the processing procedure in Figure 6 is not limited to this.

[0074] In the processing procedure shown in Figure 6, the control unit 40 determines whether there is information indicating the presence of a compression fracture in the subject's past data (S22). If the result of this determination is Yes, the control unit 40 instructs the display processing unit 50 to display an advice screen for cases where a compression fracture is present (S24).

[0075] An example of the screen displayed at this time is shown in Figure 7. The settings screen 200 illustrated in Figure 7 is a user interface screen for receiving input of setting information for the measurement to be performed. For example, information such as the patient ID of the subject being measured is entered into this settings screen 200. In the example in Figure 7, in step S24, an advice screen 202 displaying advice for cases of compression fracture is superimposed on the settings screen 200. The advice screen 202 displays a message indicating that a compression fracture of the lumbar spine was observed in a previous measurement, and therefore care should be taken regarding the subject's position during the measurement.

[0076] If the result of step S22 is No, or after step S24, the control unit 40 determines whether there is any internal or external rotation information in the subject's past data indicating excessive internal or external rotation (S26). If the result of this determination is Yes, the control unit 40 instructs the display processing unit 50 to display an advice screen for cases where a compression fracture is present (S28).

[0077] An example of the screen displayed at this time is shown in Figure 8. In the example in Figure 8, at step S28, an advice screen 204, which displays advice for cases where internal and external rotation is present, is superimposed on the setting screen 200. The advice screen 204 displays a message advising the user to appropriately set the rotation angle of the lower limb using an assistive device. In addition, explanatory information 206 illustrating precautions regarding the rotation angle of the lower limb is displayed within the setting screen 200.

[0078] If the result of step S26 is No, or after step S28, the control unit 40 determines whether there is lumbar curvature information in the subject's past data indicating excessive physiological curvature of the lumbar spine (S30). If the result of this determination is Yes, the control unit 40 instructs the display processing unit 50 to display an advice screen for cases where the lumbar curvature is excessive (S32).

[0079] An example of the screen displayed at this time is shown in Figure 9. In the example in Figure 9, in step S32, an advice screen 208, which displays advice for when the curvature of the lumbar spine is excessive, is superimposed on the setting screen 200. The advice screen 208 displays a message advising the user to use an assistive device to set the angle of the waist appropriately. In addition, explanatory information 210 illustrating how to use the assistive device is displayed within the setting screen 200.

[0080] In this embodiment, each process is executed on any computer. Furthermore, any computer may execute these processes using a processor as hardware, a program as software, or a combination thereof. In that case, the processor is configured to work in cooperation with the program to execute the various processes in this embodiment, and can function as a unit or means in this embodiment. Also, the execution order of the processes by the processor is not limited to the order described and may be changed as appropriate. Any computer may be a general-purpose computer, a computer designed for a specific purpose, a workstation, or any other system capable of executing each process.

[0081] A processor may consist of one or more hardware components, and the type of hardware is not limited. For example, a processor may consist of a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a programmable logic device such as an FPGA (Field Programmable Gate Array), a dedicated circuit for executing a specific process such as an ASIC (Application Specific Integrated Circuit), a GPU (Graphic Processing Unit), or an NPU (Neural Processing Unit). Furthermore, the type of hardware may be a combination of different types of hardware. When multiple hardware components are configured to execute one or more processes of a given processor, these components may reside in physically separate devices or in the same device. Also, in any embodiment, the order of each process performed by the processor is not limited to the order described above and may be changed as appropriate. Hardware is composed of electrical circuits (circuitry) that combine circuit elements such as semiconductor elements.

[0082] Furthermore, the program may be firmware or software such as microcode. Alternatively, the program may be, for example, a set of program modules, each function of which may be implemented by a processor configured to perform its respective function. The program may be program code or multiple code segments stored on one or more non-temporary computer-readable media (e.g., storage media or other storage). The program may be divided and stored on multiple non-temporary computer-readable media located on physically separate devices. Program code or code segments may represent any combination of procedures, functions, subprograms, routines, subroutines, modules, software packages, classes, or instructions, data structures, or program statements. Program code or code segments may be connected to other code segments or hardware circuits by sending and receiving information, data, arguments, parameters, or memory contents. [Explanation of symbols]

[0083] 10 Bone densitometer, 14 Arm unit, 24 Main unit 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. Equipped with a bone density measuring device and a processor, The aforementioned processor, The measurement data obtained from the measurement of the subject using the bone density measuring device is registered in a database. When measuring a subject's bone density using the bone density measuring device, the measurement mode to be used for the measurement is determined based on the subject's past measurement data registered in the database. A bone density measurement system characterized by the following features.

2. The bone density measurement system according to claim 1, wherein the measurement data includes the measured value obtained by the bone density measuring device.

3. The aforementioned measurement is bone density, or an index value corresponding to bone density. The bone density measurement system according to claim 2.

4. In the process of determining the measurement mode to be used in the measurement, the processor decides to use the high-definition mode as the measurement mode if the bone density or the index value is above a threshold. The bone density measurement system according to feature 3.

5. In the process of determining the measurement mode to be used in the measurement, the processor determines, based on the bone density or index value from past measurements, that the subject's bone density is on an upward trend, and decides to use the high-definition mode as the measurement mode. The bone density measurement system according to feature 3.

6. In the process of determining the measurement mode to be used in the measurement, the processor determines that high-resolution mode should be used as the measurement mode if it is determined from the bone density or index value in the soft tissue that vascular calcification has occurred. The bone density measurement system according to feature 3.

7. The aforementioned measurement is the thickness of the soft tissue. In the process of determining the measurement mode to be used in the measurement, if the thickness is greater than or equal to a threshold, it is determined that the high-resolution mode will be used as the measurement mode. The bone density measurement system according to claim 2.

8. The aforementioned measurement data is data indicating the time when the measurement was performed. In the process of determining the measurement mode to be used in the measurement, the processor determines, based on data indicating the measurement timing, that the subject is performing measurements periodically, and decides to use the high-resolution mode as the measurement mode. The bone density measurement system according to feature 1.

9. The measurement data includes input data entered by the user in correspondence with the measurement values ​​obtained by the bone density measuring device. In the process of determining the measurement mode to be used in the measurement, the processor determines to use the high-definition mode as the measurement mode if the input data indicates at least one of the following: that an implant is provided, that vascular calcification is observed, or that the measurement is for the evaluation of the therapeutic effect. The bone density measurement system according to feature 1.

10. The aforementioned processor further, When measuring a subject's bone density using the bone density measuring device, the device presents the user with information regarding the subject's posture based on the subject's past measurement data registered in the database. The bone density measurement system according to feature 1.

11. If the processor determines from the past measurement data that there is a compression fracture, it will display a message as information regarding the subject's position during the measurement, prompting the user to pay attention to the subject's position during the measurement. The bone density measurement system according to claim 10.

12. If the processor determines from the past measurement data that the rotation angle of the lower limbs is inappropriate, it will present a message as information regarding the body position, prompting the user to appropriately set the rotation angle of the subject's lower limbs during measurement. The bone density measurement system according to claim 10.

13. If the processor determines from the past measurement data that the curvature of the lumbar spine is excessive, it will present a message as information regarding the body position, prompting the user to appropriately set the body position of the subject's lumbar region during the measurement. The bone density measurement system according to claim 10.

14. The measurement data obtained from the subject's bone density measurement device is registered in a database. When measuring a subject's bone density using the bone density measuring device, the measurement mode to be used for the measurement is determined based on the subject's past measurement data registered in the database. A program used to operate a computer.

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