Information processing unit, information processing method and program

Abstract

To provide an information processing unit capable of acquiring a tomographic image at an appropriate imaging position according to a subject's body shape, an information processing method, and a program.SOLUTION: An information processing unit includes at least one processor. The processor leads a position to determine in a body axial direction of a subject on the basis of body information indicating body features of the subject within a prescribed range along the subject's body axial direction, leads a reference position in the body axial direction of the subject on the basis of a subject image capturing the subject, and determines a capturing position of a tomographic image on the basis of a relative positional relation between the position to determine and the reference position.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The disclosed technology relates to an information processing device, an information processing method, and a program. [Background technology]

[0002] The following technology is known for measuring the visceral fat of a subject. Patent Document 1 describes creating a three-dimensional image of the subject's body surface based on an X-ray CT image, specifying a position on the three-dimensional image of the body surface that corresponds to a predetermined visceral fat percentage measurement position on the subject's body surface, acquiring an X-ray CT image of the specified visceral fat percentage measurement position, and using the acquired X-ray CT image to calculate the visceral fat percentage of the subject.

[0003] Patent Document 2 describes a method of taking a two-dimensional X-ray transmission image for imaging planning of a subject on whose body surface a marker made of an X-ray shielding material is attached at a predetermined position for measuring visceral fat percentage, specifying the position where the marker appears on the two-dimensional X-ray transmission image as the imaging position for obtaining an X-ray CT image, and using the X-ray CT image at the specified position where the marker appears to determine the subject's visceral fat percentage. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-254932 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-254933 Summary of the Invention [Problem to be solved by the invention]

[0005] Metabolic syndrome is a syndrome characterized by the accumulation of visceral fat and the presence of at least two of the three metabolic abnormalities of hypertension, hyperglycemia, and dyslipidemia, and early diagnosis and lifestyle modification are recommended. One method for diagnosing metabolic syndrome is to measure visceral fat area using cross-sectional images taken at the level of the subject's navel using a computed tomography (CT) device.

[0006] However, in obese people, the navel is located lower than in people with a normal body type, and the pelvis is included in the tomographic image at the navel. Therefore, for obese people, it is not appropriate to measure visceral fat area using a tomographic image at the navel. For subjects with significant fat accumulation and a downward deviation of the navel, it is preferable to measure visceral fat area based on a tomographic image at the height of the midpoint between the lower edge of the ribs and the anterior superior iliac spine, for example.

[0007] The disclosed technology has been made in consideration of the above points, and aims to acquire a tomographic image at an appropriate imaging position according to the body type of a subject. [Means for solving the problem]

[0008] The information processing device according to the disclosed technology includes at least one processor that derives a target position in the body axis direction of the subject based on physical information indicating the subject's physical characteristics within a predetermined range along the body axis direction of the subject, derives a reference position in the body axis direction of the subject based on a subject image that is an image captured of the subject, and determines a capturing position of a tomographic image based on the relative positional relationship between the target position and the reference position.

[0009] The physical information may include a body thickness distribution along the body axis direction of the subject. In this case, the processor may derive, as the determination position, a position at which the body thickness in the body axis direction of the subject is greatest, identified from the body thickness distribution. The processor may acquire a distance image captured of the subject and derive the body thickness distribution based on the distance image.

[0010] The processor may acquire an optical image taken of the subject as the body information, and derive the position of the subject's navel identified from the optical image as the position to be determined.

[0011] The subject image may be a scanogram. In this case, the processor may derive the reference position as the uppermost part of the pelvic region in the body axis direction identified from the scanogram. The subject image may be an optical image. In this case, the processor may derive the reference position as the position of the subject's waist identified from the optical image.

[0012] The processor may determine a first position in the subject's body axis direction as the imaging position when the position to be determined is below the reference position in the body axis direction, and may determine a second position different from the first position as the imaging position when the position to be determined is above the reference position in the body axis direction.

[0013] When the position to be determined is below the reference position in the body axis direction, the processor may identify the position of the anterior superior iliac spine and the position of the lower edge of the ribs of the subject based on the subject image, and may determine the center of the position of the anterior superior iliac spine and the position of the lower edge of the ribs in the body axis direction as the shooting position.

[0014] When the position to be determined is below the reference position in the body axis direction, the processor may identify the fourth lumbar vertebra of the subject based on the subject image, and may determine the center of the fourth lumbar vertebra in the body axis direction as the imaging position.

[0015] When the position to be determined is below the reference position in the body axis direction, the processor may identify the position of the subject's waist based on the subject image, and may determine a predetermined position in the body axis direction identified from the waist position as the shooting position.

[0016] When the position to be determined is below the reference position in the body axis direction, the processor may identify the position of the subject's shoulders and waist based on the subject image, or may determine a predetermined position in the body axis direction identified from both the position of the shoulders and the position of the waist as the shooting position.

[0017] When the determination target position is located above the reference position in the body axis direction, the processor may determine the determination target position as the imaging position.

[0018] The information processing method according to the disclosed technology is a method in which at least one processor included in an information processing device executes the following processes: deriving a position to be determined in the body axis direction of a subject based on physical information indicating the physical characteristics of the subject within a predetermined range along the body axis direction of the subject; deriving a reference position in the body axis direction of the subject based on a subject image, which is an image taken of the subject; and determining the shooting position of a tomographic image based on the relative positional relationship between the position to be determined and the reference position.

[0019] The program relating to the disclosed technology is a program for causing at least one processor provided in an information processing device to execute the following processes: deriving a target position in the body axis direction of a subject based on physical information indicating the subject's physical characteristics within a predetermined range along the body axis direction of the subject; deriving a reference position in the body axis direction of the subject based on a subject image, which is an image taken of the subject; and determining the shooting position of a tomographic image based on the relative positional relationship between the target position and the reference position. [Effects of the Invention]

[0020] According to the disclosed technology, it is possible to acquire a tomographic image at an appropriate imaging position according to the body type of the subject. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a diagram illustrating an example of the configuration of an imaging system 1 according to an embodiment of the disclosed technique. [Figure 2]1 is a perspective view showing an example of the configuration of a CT apparatus according to an embodiment of the disclosed technique. [Figure 3] 1 is a cross-sectional view of a CT apparatus according to an embodiment of the disclosed technology. [Figure 4] FIG. 1 is a diagram illustrating an example of a hardware configuration of an information processing device according to an embodiment of the disclosed technology. [Figure 5] FIG. 1 is a functional block diagram illustrating an example of a functional configuration of an information processing device according to an embodiment of the disclosed technology. [Figure 6] FIG. 10 is a diagram illustrating an example of a body thickness distribution derived for a subject according to an embodiment of the disclosed technology. [Figure 7] FIG. 1 is a diagram illustrating an example of a scanogram according to an embodiment of the disclosed technology. [Figure 8] 1A and 1B are diagrams illustrating a body thickness distribution and a scanogram according to an embodiment of the disclosed technique. [Figure 9] 10A and 10B are diagrams illustrating an example of a mode for deriving the imaging position of a tomographic image according to an embodiment of the disclosed technique. [Figure 10] 10 is a flowchart illustrating an example of a flow of processing performed by executing a processing program according to an embodiment of the disclosed technology. [Figure 11] FIG. 10 is a diagram illustrating an example of the configuration of an imaging system according to another embodiment of the disclosed technology. [Figure 12] FIG. 10 is a diagram illustrating an example of an optical image according to another embodiment of the disclosed technology. [Figure 13] 10A and 10B are diagrams showing body thickness distribution and scanograms according to another embodiment of the disclosed technique. [Figure 14] 10A and 10B are diagrams illustrating an example of a mode for deriving the imaging position of a tomographic image according to another embodiment of the disclosed technique. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, an example of an embodiment of the disclosed technology will be described with reference to the drawings. In each drawing, the same or equivalent components and parts are given the same reference numerals, and redundant description will be omitted.

[0023] [First embodiment] 1 is a diagram showing an example of the configuration of an imaging system 1 according to an embodiment of the disclosed technique. The imaging system 1 includes a CT device 10, a distance measuring device 20, and an information processing device 30. In the following, an example will be described in which the imaging system 1 is used to measure the visceral fat of a subject.

[0024] FIG. 2 is a perspective view showing an example of the configuration of the CT device 10, and FIG. 3 is a cross-sectional view of the CT device 10. The CT device 10 has a gantry 11 and an examination table 16. The gantry 11 has a tunnel-like structure with an opening 12 in its center. Inside the gantry 11, there are provided a radiation source unit 13 that emits X-rays and a detection unit 14 that detects the X-rays and generates a radiographic image. The radiation source unit 13 and the detection unit 14 can rotate along the annular shape of the gantry 11 while maintaining a mutually opposing positional relationship. Also, inside the gantry 11, there is provided a control unit 15 that controls the operation of the CT device 10.

[0025] The examination table 16 has a base 16A fixed to the floor and a bed 16B on which the subject 200 lies. When a radiological image of the subject 200 is to be captured, the bed 16B slides, and the subject 200 lying on the bed 16B is transported into the opening 12 of the gantry 11.

[0026] The CT device 10 is capable of capturing scanograms and tomographic images. A scanogram is a radiological image that includes a predetermined range along the body axis direction of the subject 200. A scanogram is captured by irradiating radiation from the radiation source unit 13 while sliding the bed unit 16B while maintaining the radiation source unit 13 positioned directly above the subject 200. In the CT device 10, scanograms are captured prior to capturing tomographic images. A scanogram is an example of a "subject image" in the disclosed technology.

[0027] The tomographic image is a radiographic image of a cross section intersecting with the body axis direction of the subject 200. The tomographic image is obtained by reconstructing a plurality of radiographic images taken by irradiating the subject 200 with radiation from a plurality of different directions. As a reconstruction method, for example, a back projection method or an iterative image reconstruction method can be used. The scanogram and tomographic image obtained by the CT device 10 are transmitted to the information processing device 30.

[0028] The distance measuring device 20 is an imaging device capable of generating a distance image representing the distance to the surface of an object. The distance measuring device 20 may be, for example, a distance measuring camera that generates a distance image representing the distance to the surface of an object using a time-of-flight method using infrared rays. The distance measuring device 20 is placed in a position where it can acquire the body thickness distribution along the body axis direction of the subject. As shown in FIG. 3, the distance measuring device 20 may be attached to, for example, the ceiling 300 of the imaging room in which the CT device 10 is installed. By capturing distance images while sliding the bed unit 16B, distance images of a predetermined range along the body axis direction of the subject 200 can be obtained. The imaging range of the distance measuring device 20 is approximately the same as the imaging range of the scanogram. The distance image acquired by the distance measuring device 20 is transmitted to the information processing device 30.

[0029] 4 is a diagram showing an example of the hardware configuration of the information processing device 30. The information processing device 30 includes a CPU (Central Processing Unit) 101, a RAM (Random Access Memory) 102, a non-volatile memory 103, an input device 104 including a keyboard and a mouse, a display 105, and a communication interface 106. These pieces of hardware are connected to a bus 108.

[0030] The display 105 may be a touch panel display. The communication interface 106 is an interface through which the information processing device 30 communicates with the CT device 10 and the distance measuring device 20. The communication method may be either wired or wireless. For wireless communication, a method conforming to existing wireless communication standards such as Wi-Fi (registered trademark) and Bluetooth (registered trademark) can be applied.

[0031] The nonvolatile memory 103 is a nonvolatile storage medium such as a hard disk or flash memory. A processing program 110 is stored in the nonvolatile memory 103. The RAM 102 is a work memory for the CPU 101 to execute processing. The CPU 101 loads the processing program 110 stored in the nonvolatile memory 103 into the RAM 102 and executes processing in accordance with the processing program 110. The CPU 101 is an example of a "processor" in the disclosed technology.

[0032] 5 is a functional block diagram showing an example of the functional configuration of the information processing device 30. The information processing device 30 has an acquisition unit 31, a body thickness distribution deriving unit 32, a determination target position deriving unit 33, a reference position deriving unit 34, an imaging position determining unit 35, and a diagnostic information deriving unit 36. When the CPU 101 executes the processing program 110, the information processing device 30 functions as the acquisition unit 31, the body thickness distribution deriving unit 32, the determination target position deriving unit 33, the reference position deriving unit 34, the imaging position determining unit 35, and the diagnostic information deriving unit 36.

[0033] The acquisition unit 31 acquires a scanogram taken by the CT device 10. The acquisition unit 31 also acquires a distance image taken by the distance measuring device 20.

[0034] The body thickness distribution deriving unit 32 derives the body thickness distribution of the subject 200 along the body axis direction based on the distance image acquired by the acquiring unit 31. FIG. 6 is a diagram showing an example of the body thickness distribution along the body axis direction derived for the subject 200. The body thickness distribution deriving unit 32 derives the difference (L1-L2) between the distance L1 from the distance measuring device 20 to the bed unit 16B and the distance L2 from the distance measuring device 20 to the body surface of the subject 200, as shown in the distance image, for each position along the body axis direction of the subject 200, and outputs the result as the body thickness distribution along the body axis direction of the subject 200. The body thickness distribution along the body axis direction of the subject 200 is an example of "physical information" in the disclosed technology. The physical information is information indicating the physical characteristics of the subject 200.

[0035] The determination target position derivation unit 33 derives a determination target position in the body axis direction of the subject based on the body thickness distribution derived by the body thickness distribution derivation unit 32. The determination target position is a position in the body axis direction of the subject 200 for determining whether the subject 200 is obese or not. As shown in FIG. 6, the determination target position derivation unit 33 determines the position where the body thickness is greatest, which is identified from the body thickness distribution along the body axis direction of the subject 200, as the determination target position P X The position where the body thickness in the body axis direction is the largest is estimated to be the position of the navel of the subject 200.

[0036] The reference position derivation unit 34 derives a reference position in the body axis direction of the subject 200 based on the scanogram acquired by the acquisition unit 31. The reference position is a position in the body axis direction of the subject 200 that serves as a reference for determining whether the subject 200 is obese or not. In this embodiment, the uppermost part of the pelvic region in the body axis direction is set as the reference position. FIG. 7 is a diagram showing an example of a scanogram 40 acquired by the acquisition unit 31. The reference position derivation unit 34 identifies the pelvic region 41 from the scanogram 40. The reference position derivation unit 34 determines the uppermost part of the pelvic region 41 in the body axis direction identified from the scanogram 40 as the reference position P SIt should be noted that, as a technique for identifying the pelvic region 41 from the scanogram 40, it is possible to use, for example, an image recognition technique using machine learning. Alternatively, the pelvic region 41 may be identified by detecting feature points from the profile.

[0037] The imaging position determination unit 35 determines the imaging position of the tomographic image to be captured by the CT device 10 based on the relative positional relationship between the determination target position derived by the determination target position derivation unit 33 and the reference position derived by the reference position derivation unit 34. The imaging position determination unit 35 aligns the body thickness distribution along the body axis direction of the subject 200 with the scanogram 40 in the body axis direction, as shown in FIG.

[0038] The photographing position determination unit 35 determines the determination target position P X (the position of the navel) is the reference position P S If the target position P is located on the lower side (foot side) in the body axis direction relative to the target position P (the uppermost part of the pelvic region), the first position in the body axis direction of the subject is determined as the imaging position for the tomographic image. X (the position of the navel) is the reference position P S If the navel of subject 200 is located lower (toward the feet) in the body axis direction relative to the uppermost position of the pelvic region (topmost part of the pelvic region), the position of the navel of subject 200 is lower than that of a person with a standard body type, and subject 200 is estimated to be obese. In this case, the first position, which is defined as the imaging position for obese people, is determined as the imaging position for the tomographic image.

[0039] More specifically, the photographing position determination unit 35 determines the determination target position P X is the reference position P S 9, the position P1 of the anterior superior iliac spine and the position P2 of the lower rib edge of the subject 200 are identified based on the scanogram 40. The imaging position determining unit 35 determines the center in the body axis direction between the position P1 of the anterior superior iliac spine and the position P2 of the lower rib edge as the imaging position P of the tomographic image. ZAs a technique for identifying the positions P1 and P2, for example, an image recognition technique using machine learning can be used. Alternatively, the positions P1 and P2 may be identified by detecting feature points from the profile.

[0040] On the other hand, the photographing position determination unit 35 determines the determination target position P X (the position of the navel) is the reference position P S If the target position P is located above (closer to the head) in the body axis direction relative to the target position P (the uppermost part of the pelvic region), the second position in the body axis direction of the subject is determined as the imaging position for the tomographic image. X (the position of the navel) is the reference position P S If the position is located above (closer to the head) in the body axis direction relative to the uppermost position (top of the pelvic region), the body type of the subject 200 is estimated to be of a standard body type. In this case, a second position different from the first position determined as the imaging position for a person with a standard body type is determined as the imaging position for the tomographic image.

[0041] More specifically, the photographing position determination unit 35 determines the determination target position P X is the reference position P S , the position of the navel of the subject 200 is determined as the imaging position of the tomographic image. X corresponds to the position of the navel of the subject 200, the imaging position determining unit 35 determines the determination target position P X is the reference position P S If the target position is on the upper side (head side) of the body axis, X is determined as the photographing position of the tomographic image.

[0042] The imaging position determination unit 35 transmits imaging instructions for acquiring a tomographic image at the determined imaging position to the CT device 10. The CT device 10 performs radiographic imaging of the subject 200 based on the imaging instructions, and generates a tomographic image at the determined imaging position. The acquisition unit 31 acquires the tomographic image generated by the CT device 10.

[0043] The diagnostic information derivation unit 36 derives diagnostic information based on the tomographic images generated by the CT device 10. Specifically, the diagnostic information derivation unit 36 identifies visceral fat areas from the tomographic images and derives information indicating the area of the identified visceral fat areas as diagnostic information. As a technique for identifying visceral fat areas from tomographic images, for example, an image recognition technique using machine learning can be used.

[0044] FIG. 10 is a flowchart showing an example of the flow of processing carried out by the CPU 101 executing the processing program 110.

[0045] In step S1, the acquisition unit 31 acquires a scanogram captured by the CT device 10. In step S2, the acquisition unit 31 acquires a distance image captured by the distance measuring device 20.

[0046] In step S3, body thickness distribution deriving unit 32 derives the body thickness distribution along the body axis direction of subject 200 based on the distance image acquired in step S2. Body thickness distribution deriving unit 32 derives the difference (L1-L2) between distance L1 from distance measuring device 20 to bed unit 16B shown in the distance image and distance L2 from distance measuring device 20 to the body surface of subject 200 at each position along the body axis direction of subject 200, and outputs the result as the body thickness distribution along the body axis direction of subject 200.

[0047] In step S4, the determination target position deriving unit 33 derives a determination target position in the body axis direction of the subject based on the body thickness distribution derived in step S3. The determination target position deriving unit 33 determines the position where the body thickness is greatest, which is identified from the body thickness distribution along the body axis direction of the subject 200, as the determination target position P X (See FIG. 6). The position where the body thickness in the body axis direction is the largest is estimated to be the position of the navel of the subject 200.

[0048] In step S5, the reference position deriving unit 34 derives a reference position in the body axis direction of the subject 200 based on the scanogram acquired in step S1. The reference position deriving unit 34 determines the uppermost part of the pelvic region 41 in the body axis direction as the reference position P S (See Figure 7)

[0049] In step S6, the imaging position determination unit 35 determines whether the determination position derived in step S4 is located on the lower side (foot side) of the body axis direction relative to the reference position derived in step S5. If it is determined that the determination position is located on the lower side (foot side) of the body axis direction relative to the reference position, the process proceeds to step S7, and if it is determined that the determination position is located on the upper side (head side) of the body axis direction relative to the reference position, the process proceeds to step S8.

[0050] In step S7, the imaging position determination unit 35 determines the first position, which is defined as the imaging position for an obese person, as the imaging position for the tomographic image. Specifically, the imaging position determination unit 35 determines the center in the body axis direction between the position P1 of the anterior superior iliac spine and the position P2 of the lower edge of the rib as the imaging position P Z (See FIG. 9).

[0051] In step S8, the imaging position determination unit 35 determines the second position, which is defined as the imaging position for a person with a standard body type, as the imaging position for the tomographic image. Specifically, the imaging position determination unit 35 determines the position of the navel of the subject, i.e., the determination target position derived in step S4, as the imaging position for the tomographic image.

[0052] In step S9, the imaging position determination unit 35 transmits an imaging instruction to the CT device 10 to acquire a tomographic image at the imaging position determined in step S7 or step S8. The CT device 10 captures a radiographic image of the subject 200 based on the imaging instruction, and generates a tomographic image at the imaging position determined in step S7 or step S8. In step S10, the acquisition unit 31 acquires the tomographic image generated by the CT device 10.

[0053] In step S11, the diagnostic information derivation unit 36 derives diagnostic information based on the tomographic image acquired in step S10. Specifically, the diagnostic information derivation unit 36 identifies a visceral fat portion from the tomographic image, and derives information indicating the area of the identified visceral fat portion as diagnostic information.

[0054] As described above, the information processing device 30 according to an embodiment of the disclosed technology derives a position to be determined in the body axis direction of the subject based on physical information indicating the subject's physical characteristics within a predetermined range along the body axis direction of the subject, derives a reference position in the body axis direction of the subject based on a subject image, which is an image captured of the subject, and determines the shooting position of the tomographic image based on the relative positional relationship between the position to be determined and the reference position.

[0055] The relative positional relationship between the position to be determined and the reference position changes depending on the body type of the subject. According to the information processing device 30 of the embodiment of the disclosed technology, the shooting position of the tomographic image is determined based on the relative positional relationship between the position to be determined and the reference position, so that it is possible to obtain a tomographic image at an appropriate shooting position according to the body type of the subject.

[0056] Although the above description illustrates a case where the body thickness distribution is derived based on a distance image captured by the distance measuring device 20, the disclosed technology is not limited to this example. The body thickness distribution may also be measured based on one-dimensional distance information along the subject's body axis. In this case, the distance measuring device 20 may output one-dimensional distance measurement information indicating the distance to each point along the subject's body axis.

[0057] In the above description, a case has been described in which the body thickness distribution along the body axis direction of the subject 200 is used as the physical information indicating the physical characteristics of the subject 200. However, the disclosed technology is not limited to this example. The information processing device 30 may acquire optical images of the subject as the subject's physical information. The optical images may be acquired using a general digital camera. For example, when an optical image of an undressed subject is acquired as the physical information, the determination target position deriving unit 33 may derive the position of the subject's navel identified from the optical image as the determination target position. When an optical image of a clothed subject is acquired as the physical information, the determination target position deriving unit 33 may derive the position of the subject's navel estimated from the optical image by machine learning or the like as the determination target position.

[0058] In the above description, when the position to be determined is below the reference position, the center in the body axis direction between the position of the anterior superior iliac spine and the position of the lower edge of the ribs is determined as the imaging position of the tomographic image. However, the disclosed technology is not limited to this example. When the position to be determined is below the reference position, the center in the body axis direction of the fourth lumbar vertebra may be determined as the imaging position. In this case, the imaging position determination unit 35 identifies the fourth lumbar vertebra of the subject based on the scanogram and determines the center in the body axis direction of the fourth lumbar vertebra as the imaging position.

[0059] [Second embodiment] 11 is a diagram showing an example of the configuration of an imaging system 1A according to the second embodiment of the disclosed technique. The imaging system 1A includes a CT device 10, a distance measuring device 20, an optical camera 50, and an information processing device 30A.

[0060] The optical camera 50 is an imaging device capable of capturing an optical image. The optical camera may be a general digital camera. The optical camera 50 captures an optical image including a predetermined range along the body axis direction of the subject 200. The optical image captured by the optical camera 50 is an example of a "subject image" in the disclosed technology.

[0061] The information processing device 30A according to this embodiment, like the information processing device 30 according to the first embodiment, has an acquisition unit 31, a body thickness distribution derivation unit 32, a determination target position derivation unit 33, a reference position derivation unit 34, an imaging position determination unit 35, and a diagnostic information derivation unit 36 (see FIG. 5).

[0062] The acquisition unit 31 acquires a distance image taken by the distance measuring device 20 and an optical image taken by the optical camera 50. Similar to the information processing device 30 according to the first embodiment, the body thickness distribution derivation unit 32 derives the body thickness distribution along the body axis direction of the subject 200 based on the distance image acquired by the acquisition unit 31. Similar to the information processing device 30 according to the first embodiment, the determination target position derivation unit 33 determines the position of the subject 200 with the greatest body thickness identified from the body thickness distribution along the body axis direction as the determination target position P X (See Figure 6)

[0063] The reference position derivation unit 34 derives a reference position in the body axis direction of the subject 200 based on the optical image acquired by the acquisition unit 31. In this embodiment, the reference position is the position of the waist. FIG. 12 is a diagram showing an example of an optical image 60 acquired by the acquisition unit 31. The reference position derivation unit 34 identifies the waist position P3 from the optical image 60. As a technique for identifying the waist position P3 from the optical image 60, for example, an image recognition technique using machine learning can be used. Alternatively, the waist position P3 may be identified by detecting feature points from a profile. The reference position derivation unit 34 determines the waist position in the body axis direction identified from the optical image 60 as the reference position P S It is derived as:

[0064] The imaging position determination unit 35 determines the imaging position of the tomographic image to be captured by the CT device 10 based on the relative positional relationship between the determination target position derived by the determination target position derivation unit 33 and the reference position derived by the reference position derivation unit 34. The imaging position determination unit 35 aligns the body thickness distribution along the body axis direction of the subject 200 with the optical image 60 in the body axis direction, as shown in FIG.

[0065] The photographing position determination unit 35 determines the determination target position P X (the position of the navel) is the reference position P S If the target position P is located on the lower side (foot side) of the subject's body axis direction relative to the waist position, the first position in the subject's body axis direction is determined as the imaging position for the tomographic image. X (the position of the navel) is the reference position P S If the position of the navel of the subject 200 is lower (towards the feet) in the body axis direction relative to the position of the waist, the position of the navel of the subject 200 is lower than that of a person with a standard body type, and the body type of the subject 200 is estimated to be obese. In this case, the first position, which is defined as the imaging position for obese people, is determined as the imaging position for the tomographic image.

[0066] More specifically, the photographing position determination unit 35 determines the determination target position P X is the reference position P S 14, in the case where the position is on the lower side (foot side) in the body axis direction, the position of the shoulder P4 as well as the position of the waist P3 of the subject 200 is identified based on the optical image 60. As a technique for identifying the position of the waist P3 and the position of the shoulder P4, for example, an image recognition technique using machine learning can be used. Alternatively, the position of the waist P3 and the position of the shoulder P4 may be identified by detecting feature points from the profile. The imaging position determination unit 35 determines a predetermined position in the body axis direction identified from both the position of the waist P3 and the position of the shoulder P4 as the imaging position P of the tomographic image. Z For example, the position in the body axis direction where the ratio (D1:D2) of the distance D1 from the waist position P3 to the distance D2 from the shoulder position P4 is a predetermined ratio (for example, 1:9) is determined as the imaging position P Z It may be determined as:

[0067] On the other hand, the photographing position determination unit 35 determines the determination target position P X (the position of the navel) is the reference position P S If the target position P is located above (towards the head) in the body axis direction relative to the waist position, the second position in the body axis direction of the subject is determined as the imaging position for the tomographic image. X (the position of the navel) is the reference position P SIf the position is higher (head side) in the body axis direction relative to the waist position, the body type of the subject 200 is estimated to be of a standard body type. In this case, a second position different from the first position determined as the imaging position for a person with a standard body type is determined as the imaging position for the tomographic image.

[0068] More specifically, the photographing position determination unit 35 determines the determination target position P X is the reference position P S , the position of the navel of the subject 200 is determined as the imaging position of the tomographic image. X corresponds to the position of the navel of the subject 200, the imaging position determining unit 35 determines the determination target position P X is the reference position P S If the target position is on the upper side (head side) of the body axis, X is determined as the photographing position of the tomographic image.

[0069] The imaging position determination unit 35, like the information processing device 30 according to the first embodiment, transmits an imaging instruction to the CT device 10 to acquire a tomographic image at the determined imaging position. The CT device 10 captures a radiographic image of the subject 200 based on the imaging instruction, and generates a tomographic image at the determined imaging position. The acquisition unit 31 acquires the tomographic image generated by the CT device 10.

[0070] Similar to the information processing device 30 according to the first embodiment, the diagnostic information derivation unit 36 derives diagnostic information based on the tomographic image generated by the CT device 10. Specifically, the diagnostic information derivation unit 36 identifies a visceral fat portion from the tomographic image, and derives information indicating the area of the identified visceral fat portion as diagnostic information.

[0071] As described above, according to the information processing device 30A of this embodiment, similar to the information processing device 30 of the first embodiment, the shooting position of the tomographic image is determined based on the relative positional relationship between the position to be determined and the reference position, so that it is possible to acquire a tomographic image at an appropriate shooting position according to the body type of the subject.

[0072] Furthermore, according to the information processing device 30A of this embodiment, the reference position and the photographing position are derived based on the optical image. That is, the reference position and the photographing position are derived without using a scanogram. This makes it possible to reduce the radiation exposure of the subject compared to the information processing device 30 of the first embodiment.

[0073] In the above description, a predetermined position in the body axis direction where the ratio of the distance from the waist position P3 to the distance from the shoulder position P4 is a predetermined ratio is determined as the imaging position of the tomographic image, but the disclosed technology is not limited to this. The imaging position determination unit 35 specifies the center position in the body axis direction between the position of the anterior superior iliac spine and the position of the lower edge of the rib from the waist position P3 and the shoulder position P4, and determines this position as the imaging position P of the tomographic image. Z Alternatively, the imaging position determination unit 35 may determine a predetermined position in the body axis direction identified from the waist position P3 as the imaging position of the tomographic image. More specifically, a position spaced a predetermined distance above (toward the head) the waist position P3 may be determined as the imaging position.

[0074] In the above description, the imaging system 1 is used to measure the visceral fat of a subject, but the disclosed technology is not limited to this example. The disclosed technology can be applied to any examination, diagnosis, etc. that uses a tomographic image of a subject taken at a specific imaging position.

[0075] In the above embodiment, the following various processors can be used as the hardware structure of processing units that perform various processes, such as the body thickness distribution deriving unit 32, the determination target position deriving unit 33, the reference position deriving unit 34, the imaging position determining unit 35, and the diagnostic information deriving unit 36. As described above, the various processors include a CPU and a GPU, which are general-purpose processors that execute software (programs) and function as various processing units, as well as dedicated electrical circuits, such as programmable logic devices (PLDs) whose circuit configuration can be changed after manufacture, such as FPGAs, and application specific integrated circuits (ASICs), which are processors having a circuit configuration specifically designed to perform specific processes.

[0076] A single processing unit may be configured with one of these various processors, or may be configured with a combination of two or more processors of the same or different types (for example, a combination of multiple FPGAs, or a combination of a CPU and an FPGA). Also, multiple processing units may be configured with a single processor.

[0077] Examples of configuring multiple processing units with a single processor include, first, a form in which one processor is configured with a combination of one or more CPUs and software, and this processor functions as multiple processing units, as typified by computers such as client and server. Second, a form in which a processor is used to realize the functions of the entire system including multiple processing units with a single IC (Integrated Circuit) chip, as typified by systems on chips (SoCs). In this way, various processing units are configured using one or more of the above-mentioned various processors as a hardware structure.

[0078] Furthermore, more specifically, the hardware structure of these various processors can be an electric circuit that combines circuit elements such as semiconductor elements.

[0079] In the above embodiment, the processing program 110 is pre-stored (installed) in the non-volatile memory 103, but the present invention is not limited to this. The processing program 110 may be provided in a form recorded on a recording medium such as a CD-ROM (Compact Disc Read Only Memory), a DVD-ROM (Digital Versatile Disc Read Only Memory), or a USB (Universal Serial Bus) memory. The processing program 110 may also be downloaded from an external device via a network.

[0080] The following additional notes are disclosed regarding the above first and second embodiments. (Appendix 1) An information processing device having at least one processor, The processor: deriving a determination target position in the body axis direction of the subject based on physical information indicating physical characteristics of the subject within a predetermined range along the body axis direction of the subject; deriving a reference position in a body axis direction of the subject based on a subject image that is an image captured of the subject; The photographing position of the tomographic image is determined based on the relative positional relationship between the determination target position and the reference position. Information processing device.

[0081] (Appendix 2) the physical information includes a body thickness distribution along a body axis of the subject; The processor derives, as the determination target position, a position where the body thickness of the subject in the body axis direction is greatest, which is identified from the body thickness distribution. 10. The information processing device according to claim 1.

[0082] (Appendix 3) The processor: acquiring a distance image of the subject; Deriving the body thickness distribution based on the distance image. 3. The information processing device according to claim 2.

[0083] (Appendix 4) The processor: an optical image of the subject is acquired as the physical information; The position of the navel of the subject identified from the optical image is derived as the determination target position. 4. An information processing device according to any one of claims 1 to 3.

[0084] (Appendix 5) the subject image is a scanogram; The processor derives the uppermost part of the pelvic region in the body axis direction identified from the scanogram as the reference position. 5. An information processing device according to any one of claims 1 to 4.

[0085] (Appendix 6) the subject image is an optical image; The processor derives the position of the subject's waist identified from the optical image as the reference position. 5. An information processing device according to any one of claims 1 to 4.

[0086] (Appendix 7) When the position to be determined is below the reference position in the body axis direction, the processor determines a first position in the body axis direction of the subject as the imaging position, and when the position to be determined is above the reference position in the body axis direction, the processor determines a second position different from the first position as the imaging position. 7. An information processing device according to claim 1.

[0087] (Appendix 8) When the position to be determined is below the reference position in the body axis direction, the processor identifies the position of the anterior superior iliac spine and the position of the lower edge of the rib of the subject based on the subject image, and determines the center in the body axis direction between the position of the anterior superior iliac spine and the position of the lower edge of the rib as the imaging position. 8. The information processing device according to claim 7.

[0088] (Appendix 9) When the determination target position is located below the reference position in the body axis direction, the processor identifies a fourth lumbar vertebra of the subject based on the subject image, and determines the center of the fourth lumbar vertebra in the body axis direction as the imaging position. 8. The information processing device according to claim 7.

[0089] (Appendix 10) When the determination target position is located below the reference position in the body axis direction, the processor identifies a waist position of the subject based on the subject image, and determines a predetermined position in the body axis direction identified from the waist position as the imaging position. 8. The information processing device according to claim 7.

[0090] (Appendix 11) When the determination target position is located below the reference position in the body axis direction, the processor identifies a shoulder position and a waist position of the subject based on the subject image, and determines a predetermined position in the body axis direction identified from both the shoulder position and the waist position as the imaging position. 8. The information processing device according to claim 7.

[0091] (Appendix 12) When the determination target position is located above the reference position in the body axis direction, the processor determines the determination target position as the imaging position. 8. The information processing device according to claim 7.

[0092] (Appendix 13) deriving a determination target position in the body axis direction of the subject based on physical information indicating physical characteristics of the subject within a predetermined range along the body axis direction of the subject; deriving a reference position in a body axis direction of the subject based on a subject image that is an image captured of the subject; The photographing position of the tomographic image is determined based on the relative positional relationship between the determination target position and the reference position. An information processing method in which processing is executed by at least one processor included in an information processing device.

[0093] (Appendix 14) deriving a determination target position in the body axis direction of the subject based on physical information indicating physical characteristics of the subject within a predetermined range along the body axis direction of the subject; deriving a reference position in a body axis direction of the subject based on a subject image that is an image captured of the subject; The photographing position of the tomographic image is determined based on the relative positional relationship between the determination target position and the reference position. A program for causing at least one processor included in an information processing device to execute a process. [Explanation of symbols]

[0094] 1. 1A Photography System 10 CT device 11 Gantry 12 Opening 13 Source section 14 Detector 15 Control Unit 16 Examination table 16A Base 16B Sleeper Section 20 Ranging device 30, 30A Information processing equipment 31 Acquisition Department 32 Body thickness distribution derivation part 33 Judgment target position derivation unit 34 Reference position derivation part 35 Shooting position determination unit 36 Diagnostic information derivation unit 40 Scanned Images 41 Pelvic Region 50 Optical Camera 60 Optical Images 101 CPU 102 RAM 103 Non-volatile memory 104 Input Device 105 Display 106 Communication Interface 108 Bus 110 Processing Program

Claims

1. An information processing device including at least one processor, The processor: deriving a determination target position in the body axis direction of the subject based on physical information indicating physical characteristics of the subject within a predetermined range along the body axis direction of the subject; deriving a reference position in a body axis direction of the subject based on a subject image that is an image captured of the subject; The photographing position of the tomographic image is determined based on the relative positional relationship between the determination target position and the reference position. Information processing device.

2. the physical information includes a body thickness distribution along a body axis of the subject; The processor derives, as the determination target position, a position where the body thickness of the subject in the body axis direction is greatest, which is identified from the body thickness distribution. The information processing device according to claim 1 .

3. The processor: acquiring a distance image of the subject; Deriving the body thickness distribution based on the distance image. The information processing device according to claim 2 .

4. The processor: an optical image of the subject is acquired as the physical information; The position of the navel of the subject identified from the optical image is derived as the determination target position. The information processing device according to claim 1 .

5. the subject image is a scanogram; The processor derives the uppermost part of the pelvic region in the body axis direction identified from the scanogram as the reference position. The information processing device according to claim 1 .

6. the subject image is an optical image; The processor derives the position of the subject's waist identified from the optical image as the reference position. The information processing device according to claim 1 .

7. When the position to be determined is below the reference position in the body axis direction, the processor determines a first position in the body axis direction of the subject as the imaging position, and when the position to be determined is above the reference position in the body axis direction, the processor determines a second position different from the first position as the imaging position. The information processing device according to claim 1 .

8. When the position to be determined is below the reference position in the body axis direction, the processor identifies the position of the anterior superior iliac spine and the position of the lower edge of the rib of the subject based on the subject image, and determines the center in the body axis direction between the position of the anterior superior iliac spine and the position of the lower edge of the rib as the imaging position. The information processing device according to claim 7 .

9. When the determination target position is located below the reference position in the body axis direction, the processor identifies a fourth lumbar vertebra of the subject based on the subject image, and determines the center of the fourth lumbar vertebra in the body axis direction as the imaging position. The information processing device according to claim 7 .

10. When the determination target position is located below the reference position in the body axis direction, the processor identifies a waist position of the subject based on the subject image, and determines a predetermined position in the body axis direction identified from the waist position as the imaging position. The information processing device according to claim 7 .

11. When the determination target position is located below the reference position in the body axis direction, the processor identifies a shoulder position and a waist position of the subject based on the subject image, and determines a predetermined position in the body axis direction identified from both the shoulder position and the waist position as the imaging position. The information processing device according to claim 7 .

12. When the determination target position is located above the reference position in the body axis direction, the processor determines the determination target position as the imaging position. The information processing device according to claim 7 .

13. deriving a determination target position in the body axis direction of the subject based on physical information indicating physical characteristics of the subject within a predetermined range along the body axis direction of the subject; deriving a reference position in a body axis direction of the subject based on a subject image that is an image captured of the subject; The photographing position of the tomographic image is determined based on the relative positional relationship between the determination target position and the reference position. An information processing method in which processing is executed by at least one processor included in an information processing device.

14. deriving a determination target position in the body axis direction of the subject based on physical information indicating physical characteristics of the subject within a predetermined range along the body axis direction of the subject; deriving a reference position in a body axis direction of the subject based on a subject image that is an image captured of the subject; The photographing position of the tomographic image is determined based on the relative positional relationship between the determination target position and the reference position. A program for causing at least one processor included in an information processing device to execute a process.

Images