IMAGING APPARATUS, IMAGING SYSTEM, CONTROL METHOD, AND CONTROL PROGRAM

An imaging apparatus including: an imaging table having an imaging surface on which at least one marker is disposed; a compression member for putting a breast disposed on the imaging surface into a compressed state; and an ultrasound probe that obtains an ultrasound image of the breast put into the compressed state by the compression member.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from Japanese Application No. 2023-038157, filed on Mar. 10, 2023, the entire disclosure of which is incorporated herein by reference.

BACKGROUND

Technical Field

The present disclosure relates to an imaging apparatus, an imaging system, a control method, and a control program.

Related Art

In the related art, a mammography apparatus that captures a radiation image of a breast is known. In addition, in the terms of improving the detection accuracy of a specific type of a lesion and improving the efficiency of an examination, an apparatus that can capture an ultrasound image of a breast in addition to a radiation image is proposed. For example, JP2020-192181A discloses that a radiation image of a breast in a compressed state is captured and then an ultrasound image of the breast is continuously captured in a state of maintaining the compressed state. In addition, for example, JP2006-280444A discloses a method of using an X-ray apparatus, an MR apparatus, and a treatment apparatus to easily specify the same lesion position among the X-ray apparatus, the MR apparatus, and the treatment apparatus while the breast is compressed. JP2006-280444A describes that an image marker for position registration is provided in a compression plate, a bed, a chair, a patient, or the like in order to specify the lesion position.

By the way, in the ultrasound image, according to the principle of irradiating an object with ultrasound and receiving the reflected waves, the image is less clear as a distance from an irradiation unit is increased. Therefore, as described in JP2020-192181A, in a case in which the breast put into the compressed state between the imaging table and a compression member is irradiated with the ultrasound from above the compression member, the ultrasound image is less clear as a distance from the compression member side is increased and a distance from the imaging table side is decreased. Theoretically, in a case of ultrasound measurement, the distance from the irradiation unit and a resolution can be approximately calculated. However, there are individual differences in a size of the breast and a composition of the breast (for example, a ratio and a distribution of a fat tissue and a mammary gland tissue), and there is a possibility that the calculated resolution remains at about a reference value. Then, there is a need for a technique that can check whether or not the ultrasound image with sufficient accuracy can be captured in the breast of an examination target, particularly in a portion away from the irradiation unit of the ultrasound.

SUMMARY

The present disclosure provides an imaging apparatus, an imaging system, a control method, and a control program that can support capturing of an ultrasound image with the accuracy that enables to read a marker provided on an imaging table.

A first aspect of the present disclosure relates to an imaging apparatus comprising: an imaging table having an imaging surface on which at least one marker is disposed; a compression member for putting a breast disposed on the imaging surface into a compressed state; and an ultrasound probe that obtains an ultrasound image of the breast put into the compressed state by the compression member.

In the first aspect, the marker may be formed of a material having a different acoustic impedance from at least a region adjacent to the marker on the imaging surface.

In the first aspect, the marker may be a portion formed in a recess shape or a protrusion shape with respect to the imaging surface.

In the first aspect, three or more markers having different intervals between adjacent markers may be disposed on the imaging surface.

In the first aspect, the imaging apparatus may further comprise a radiation source that irradiates the breast put into the compressed state by the compression member with radiation, in which the marker is disposed on the imaging surface in a region other than an irradiation field of the radiation.

A second aspect of the present disclosure relates to an imaging system comprising: the imaging apparatus according to the first aspect; and a control apparatus including at least one processor, in which the processor acquires the ultrasound image of the breast obtained by the ultrasound probe, detects the marker from the ultrasound image, and gives a warning in a case in which the marker is not detectable from the ultrasound image.

In the second aspect, the processor may acquire a tomographic image on each of a plurality of tomographic planes of the breast put into the compressed state by the compression member, may specify a depth position in a compression direction from a contact surface between the compression member and the breast for a region of interest included in the breast based on a plurality of the tomographic images, and may give a warning in a case in which the depth position of the region of interest is equal to or greater than a predetermined threshold value and the marker is not detectable from the ultrasound image.

A third aspect of the present disclosure relates to a control method comprising: acquiring an ultrasound image of a breast that is disposed on an imaging surface, on which at least one marker is disposed, of an imaging table having the imaging surface, and is put into a compressed state by a compression member; detecting the marker from the ultrasound image; and giving a warning in a case in which the marker is not detectable from the ultrasound image.

A fourth aspect of the present disclosure relates to a control program for causing a computer to execute a process comprising: acquiring an ultrasound image of a breast that is disposed on an imaging surface, on which at least one marker is disposed, of an imaging table having the imaging surface, and is put into a compressed state by a compression member; detecting the marker from the ultrasound image; and giving a warning in a case in which the marker is not detectable from the ultrasound image.

According to the aspects described above, the imaging apparatus, the imaging system, the control method, and the control program according to the present disclosure can support capturing of the ultrasound image with the accuracy that enables to read the marker provided on the imaging table.

DETAILED DESCRIPTION

Hereinafter, a description of an embodiment of the present disclosure will be made with reference to the accompanying drawings.

First, a description of a configuration of an imaging system1will be made with reference toFIG.1.FIG.1is a view showing an example of a schematic configuration of the imaging system1. As shown inFIG.1, the imaging system1comprises an imaging apparatus10and a console50. The imaging apparatus10and the console50, and the console50and an external radiology information system (RIS)6are configured to be connected to each other via a wired or wireless network.

In the imaging system1, the console50acquires an imaging order or the like from the RIS6, and controls the imaging apparatus10in accordance with the imaging order, an instruction from the user, and the like. The imaging apparatus10acquires a radiation image and an ultrasound image of a breast of an examinee put into a compressed state by a compression member40as a subject. The console50is an example of a control apparatus according to the present disclosure.

Next, a description of a schematic configuration of the imaging apparatus10will be made with reference toFIG.2.FIG.2is a side view showing an example of an appearance of the imaging apparatus10, and is a view in a case in which the imaging apparatus10is viewed from a right side of the examinee. As shown inFIG.2, the imaging apparatus10comprises a radiation source17R, a radiation detector28, an imaging table16disposed between the radiation source17R and the radiation detector28, the compression member40that compresses the breast between the compression member40and the imaging table16, and an ultrasound probe30disposed between the radiation source17R and the compression member40. In the imaging apparatus10, a user, such as a doctor or a technician, positions the breast of the examinee on an imaging surface16A of the imaging table16.

The imaging apparatus10comprises an arm part12, a base14, and a shaft part15. The arm part12is held to be movable in an up-down direction (Z direction) by the base14. The shaft part15connects the arm part12to the base14. The arm part12is relatively rotatable with respect to the base14with the shaft part15as a rotation axis. In addition, the arm part12may be relatively rotatable with respect to the base14with the shaft part15as the rotation axis separately between an upper part comprising a radiation emitting unit17and a lower part comprising the imaging table16.

The arm part12comprises the radiation emitting unit17and the imaging table16. The radiation emitting unit17comprises the radiation source17R, and is configured to change an irradiation field of radiation (for example, X-rays) emitted from the radiation source17R. For example, the change of the irradiation field may be performed by the user operating an operation unit26, or may be performed by a controller20in accordance with a type of the attached compression member40. The radiation source17R irradiates the breast put into the compressed state by the compression member40with radiation R.

The imaging table16comprises the controller20, a storage unit22, an interface (I/F) unit24, the operation unit26, and the radiation detector28. The controller20controls an overall operation of the imaging apparatus10in accordance with the control of the console50. The controller20comprises a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and the like (none shown). The ROM stores in advance various programs including a program executed by the CPU for performing the control related to the acquisition of the radiation image and the ultrasound image. The RAM transitorily stores various data.

Data of the radiation image and the ultrasound image, various types of other information, and the like are stored in the storage unit22. The storage unit22is realized by, for example, a storage medium, such as a hard disk drive (HDD), a solid state drive (SSD), and a flash memory.

The I/F unit24performs communication of various types of information with the console50by wired or wireless communication. Specifically, the I/F unit24receives information related to the control of the imaging apparatus10from the console50. Further, the I/F unit24transmits the data of the radiation image and the ultrasound image to the console50.

The operation unit26is a part that is provided on the imaging table16or the like and can be operated by the user with a hand, a foot, or the like, and is, for example, a switch, a button, or a touch panel. For example, the operation unit26may receive a voice input from the user.

The radiation detector28is disposed in the imaging table16, detects the radiation R transmitted through the breast and the imaging table16, generates the radiation image based on the detected radiation R, and outputs image data indicating the generated radiation image. It should be noted that a type of the radiation detector28is not particularly limited and may be, for example, an indirect conversion type radiation detector that converts the radiation R into light and converts the converted light into a charge, or a direct conversion type radiation detector that directly converts the radiation R into a charge.

A probe unit38and a compression unit48are connected to the arm part12. A support part36that attachably and detachably supports the ultrasound probe30is attached to the probe unit38. The support part36(ultrasound probe30) is moved in the up-down direction (Z direction) and a horizontal direction (X direction and Y direction) by a driving unit (not shown) provided in the probe unit38. It is preferable that the support part36is formed of a material that transmits the radiation R.

The ultrasound probe30is used to obtain the ultrasound image of the breast put into the compressed state by the compression member40, is disposed between the radiation source17R and the compression member40, irradiates the breast with ultrasound via the compression member40, and receives the reflected waves from the breast. Specifically, the ultrasound probe30comprises an ultrasound transducer array. The ultrasound transducer array is configured such that a plurality of ultrasound transducers are arranged one-dimensionally or two-dimensionally. The ultrasound transducer is formed, for example, such that electrodes are formed on both ends of a piezoelectric body, such as a piezoelectric ceramic represented by lead (Pb) zirconate titanate (PZT) or a polymer piezoelectric element represented by polyvinylidene difluoride (PVDF). The probe unit38includes a converter (not shown) that converts the reflected waves from the breast received by the ultrasound probe30into the ultrasound image, and the ultrasound image is obtained by the converter.

In addition, a plurality of types of the ultrasound probes30different from each other may be attachable to the imaging apparatus10. For example, depending on a physique of the examinee (for example, a size of the breast), a tissue composition of the breast (for example, a fat mass and a mammary gland mass), a type of imaging (for example, magnification imaging and spot imaging), and the like, the ultrasound probes30having different types from each other may be prepared and can be attached to and detached from the imaging apparatus10. For example, the ultrasound probes30having different performances and dimensions from each other may be selectively used, such as a linear probe having a center frequency of about 7.5 MHz (for superficial use or the like), a convex probe having a center frequency of about 3.5 MHz (for abdomen or the like), and a sector probe having a center frequency of about 2.5 MHz (for heart or the like).

A support part46that supports the compression member40is attachably and detachably attached to the compression unit48. The support part46(compression member40) is moved in the up-down direction (Z direction) by a driving unit (not shown) provided in the compression unit48.

The compression member40is used to put the breast disposed on the imaging surface16A into the compressed state. Specifically, the compression member40is disposed between the radiation source17R and the imaging table16and interposes the breast between the compression member40and the imaging table16to put the breast into the compressed state.FIG.3shows a three-orthographic view of an example of the compression member40. The three-orthographic view ofFIG.3includes a top view of the compression member40as viewed from above (radiation emitting unit17side), a side view thereof as viewed from the examinee side, and a side view thereof as viewed from the right side of the examinee. As shown inFIG.3, the compression member40includes a compression part42and the support part46.

The support part46includes an attachment part47and an arm49. The attachment part47attaches the compression member40to the imaging apparatus10, specifically, the driving unit of the compression unit48. The arm49supports the compression part42.

The compression part42includes a bottom part43formed to be substantially flat and surrounded by a wall part44having a substantially uniform height, and has a cross section shape formed in a recess shape. It is preferable that the compression part42is formed of an optically transparent or translucent material in order to perform positioning and check of the compressed state in the compression of the breast. In addition, it is preferable that the compression part42is formed of a material excellent in a transmittance of the radiation R and the ultrasound. In addition, it is preferable that the compression part42is formed of, for example, a material excellent in strength, such as drop strength and compression strength.

As such a material, for example, resin, such as polymethylpentene (PMP), polycarbonate (PC), acryl, polypropylene (PP), and polyethylene terephthalate (PET), can be used. In particular, in the polymethylpentene, an acoustic impedance, which affects the transmittance and the reflectivity of the ultrasound, is closer to an acoustic impedance of a human body (breast) than other materials, and a proportion of the noise on the ultrasound image can be decreased. Therefore, as the material of the compression part42, the polymethylpentene is suitable.

In addition, a plurality of types of the compression members40different from each other may be attachable to the imaging apparatus10. For example, depending on a physique of the examinee (for example, a size of the breast), a tissue composition of the breast (for example, a fat mass and a mammary gland mass), a type of imaging (for example, magnification imaging and spot imaging), and the like, compression members40having different types from each other may be prepared and can be attached to and detached from the imaging apparatus10. Specifically, a compression member in accordance with the size of the breast, a compression member for axilla imaging, a compression member for magnification imaging, and a compression member for so-called spot imaging that captures the radiation image of only a region in which a lesion exists, and the like may be used. That is, the compression member40is not limited to the compression member that compresses the entire breast, and may have a smaller size than the breast to compress a part of the breast.

FIG.4shows a three-orthographic view of a compression member40S for a small breast as an example of another form different from the compression member40ofFIG.3. The three-orthographic view ofFIG.4includes a top view of the compression member40S as viewed from above (radiation emitting unit17side), a side view thereof as viewed from the examinee side, and a side view thereof as viewed from the right side of the examinee The compression member40S includes the compression part42and the support part46, as in the compression member40inFIG.3. In the compression member40S, the bottom part43is not flat, and the attachment part47side is higher than a chest wall side (side away from the attachment part47). In addition, the height of the wall part44is not uniform, and a height of a part of the chest wall side is lower than a height of other parts. Due to such a shape, the compression member40S can easily perform the positioning and the compression even for the small breast.

As described above, in the imaging apparatus10, at least one of the compression member40for putting the breast into the compressed state or the ultrasound probe30for acquiring the ultrasound image may be attachable and detachable. That is, a plurality of types of the compression members40and the ultrasound probes30having different dimensions from each other may be attachable to the imaging apparatus10. In this case, the imaging apparatus10may detect the types of the compression member40and the ultrasound probe30that are attached.

For example, the attachment part47of the compression member40may be provided with a plurality of pins having different dispositions for each type of the compression member40as identification information, and the identification information may be read by a sensor (for example, a photointerrupter) that can detect the disposition of the pins provided in the compression unit48. In addition, for example, a marker (for example, a bar code and a two-dimensional code) in accordance with the type of the compression member40may be provided at any position of the compression member40as identification information, and the identification information may be read by a sensor (for example, a charge coupled device (CCD) sensor) that can detect the marker.

In addition, for example, a radio frequency identification (RFID) tag having identification information in accordance with the type of the compression member40may be provided at any position of the compression member40, and the identification information may be read by an RFID reader that can read the RFID tag. In addition, for example, a weight of each type of the compression member40and identification information may be stored in the storage unit22in advance in association with each other, the weight of the attached compression member40may be measured by a sensor that can detect the weight, and the identification information (type of the compression member40) may be specified based on a measured value.

Similarly, for the ultrasound probe30, the type of the attached ultrasound probe30may be identified in accordance with, for example, the pin, the marker, the RFID tag, or the weight.

It should be noted that a gel-like or liquid medium having an ultrasound transmittance may be applied to an upper surface43A of the bottom part43of the compression member40and/or a contact surface43B with the breast. As such a medium, for example, a known jelly for an ultrasound examination, which has the acoustic impedance close to the acoustic impedance of the human body (breast), can be applied. That is, the imaging apparatus10may acquire the ultrasound image of the breast put into the compressed state by the compression member40in a state of being coated with the gel-like or liquid medium having the ultrasound transmittance, via the compression member40. In this case, it is possible to suppress entry of air into an interface between an ultrasound radiation surface of the ultrasound probe30and the upper surface43A and/or an interface between the contact surface43B and the breast, and it is possible to reduce a difference in the acoustic impedance at each interface, so that the proportion of the noise applied to the ultrasound image can be decreased.

The imaging table16has the imaging surface16A on which at least one marker18is disposed.FIGS.5and6show examples of a partially magnified view of the imaging surface16A on which the marker18is disposed.FIG.5is a view showing a case in which the imaging apparatus10is viewed from the right side of the examinee.FIG.6is a view showing a case in which the imaging apparatus10is viewed from the chest wall side to a nipple side of the examinee InFIGS.5and6, some components that are not necessary for description will be omitted.

As described above, in the ultrasound image, according to the principle of irradiating the breast2with ultrasound U and receiving the reflected waves, the obtained image less clear as a distance from the ultrasound probe30is increased. Then, the imaging apparatus10according to the present disclosure includes, on the imaging surface16A, a marker18for checking whether or not the ultrasound image with sufficient accuracy can be captured in the breast2that is an examination target, particularly in a portion on the imaging surface16A side away from the ultrasound probe30. That is, in a case in which the marker18is included in the captured ultrasound image, it can be seen that the ultrasound image with sufficient accuracy up to the portion on the imaging surface16A side can be captured.

It is desirable that the marker18can be read in the ultrasound image but has a small influence on the radiation image. Hereinafter, a description of a specific example of the marker18will be made.

For example, the marker18may have a different shape from at least a region adjacent to the marker18on the imaging surface16A. For example, as shown inFIGS.5and6, the marker18may be a portion that is formed in a protrusion shape with respect to the imaging surface16A. On the other hand, for example, the marker18may be a portion that is formed in a recess shape with respect to the imaging surface16A. That is, the marker18can be detected in the ultrasound image by making a depth of the marker18different from the surrounding region. In a case in which the marker18is formed of the same material with unevenness, this case is a specific example in which the influence on the radiation image is small.

In addition, for example, the marker18may be formed of a different material from at least the region adjacent to the marker18on the imaging surface16A. Specifically, the different material is a material having a different acoustic impedance. That is, it is preferable that the marker18is formed of a material having a different acoustic impedance from at least the region adjacent to the marker18on the imaging surface16A. For example, the marker18may be made of polycarbonate, and the surrounding region of the marker18on the imaging surface16A may be made of polymethylpentene. By making the material (that is, acoustic impedance) of the marker18different from the material of the surrounding region, the marker18can be more easily detected in the ultrasound image.

More specifically, it is preferable that the material of the marker18has a large difference in acoustic attenuation coefficient (suitably, equal to or greater than 0.2) from the material forming the adjacent region in the imaging surface16A and has a small difference in X-ray absorption coefficient (suitably, equal to or smaller than 0.1). Selecting this material makes it possible to obtain the marker18that can be read in the ultrasound image but has a small influence on the radiation image. Examples of a combination of such materials include a combination of polyamide 6 (PA6) and polycarbonate. In particular, a case in which the material of the marker18is a material in which the absolute value of the X-ray absorption coefficient is significantly small (suitably, equal to or smaller than 0.2) is suitable because the marker18that has a particularly small influence on the radiation image can be obtained.

In addition, it is preferable that the material of the marker18has a small number of atoms and has the acoustic impedance greater than the acoustic impedance of the human body. Specific examples of such a material include beryllium (Be), graphite, and aluminum, and Be is particularly suitable. In a case in which the material having a small number of atoms is selected, it is possible to obtain the marker18that has a small influence on the radiation image. In addition, the difference from the breast in the ultrasound image is easily seen by selecting the material having the acoustic impedance greater than the acoustic impedance of the human body. It should be noted that the acoustic impedance is about 1.46 MRayl in the human body, is about 30.1 MRayl in Be, is about 39.6 MRayl in graphite, and is about 17.2 MRayl in aluminum.

In addition, for example, the marker18may be formed by adding an additive to the material that forms the region adjacent to the marker18on the imaging surface16A. Examples of the additive include fibers, such as carbon, glass, rockwool (mineral glass), and cellulose. In a case in which the additive is added, the density and the stiffness are changed, and the acoustic impedance is also changed. Therefore, the change can be captured in the ultrasound image. In addition, in a case in which the additive is added to the extent, the change in the X-ray transmittance remains small, so that the influence on the radiation image can be reduced.

It should be noted that, in a case in which the material of the marker18is different from the material forming the adjacent region as described above, the marker18does not have to have a different shape (such as the protrusion shape or the recess shape) from the surrounding region. For example, the marker18may be embedded in the imaging surface16A to form a plane continuous with the imaging surface16A, or may be a thin film-like marker disposed on the imaging surface16A.

In addition, for example, it is preferable that the marker18is disposed on the imaging surface16A in a region other than the irradiation field of the radiation R as shown inFIG.5. With this configuration, the marker18is not imaged in the radiation image and it is not necessary to be aware of the influence of the marker18on the radiation image, so that it is possible to increase a degree of freedom in selecting the material.

In addition, for example, three or more markers having different intervals between adjacent markers may be disposed on the imaging surface16A. For example,FIG.6shows an example in which four markers18A to18D having different intervals d1to d3between the adjacent markers are disposed on the imaging surface16A. In a case in which the intervals d1to d3between the adjacent markers are made different from each other in this manner, it is possible to check the resolution of the ultrasound image in addition to checking whether or not the ultrasound image can be captured up to a sufficient depth. For example, in the ultrasound image, in a case in which the markers18A and18B can be detected as different markers, but the markers18C and18D are integrally detected (seeFIG.9), it can be seen that the resolution is equal to or smaller than d2and equal to or greater than d3.

It should be noted that the method of imaging the breast via the imaging apparatus10is not particularly limited. For example, cranio-caudal (CC) imaging, medio-lateral oblique (MLO) imaging, the magnification imaging and the spot imaging for imaging a part of the breast, and the like may be performed. The CC imaging is a method of imaging the breast in the compressed state by interposing the breast between the imaging table16and the compression member40in the up-down direction (Z direction). The MLO imaging is a method of imaging the breast in the compressed state including an axilla portion by interposing the breast between the imaging table16and the compression member40in a tilted state in which a rotation angle of the arm part12with respect to the base14is equal to or greater than 45 degrees and smaller than 90 degrees.

In addition, for example, the imaging apparatus10may perform tomosynthesis imaging. In the tomosynthesis imaging, the radiation R is emitted from each of a plurality of irradiation positions having different irradiation angles toward the breast by the radiation source17R, to capture a plurality of radiation images of the breast. That is, in the tomosynthesis imaging, the imaging is performed by changing the rotation angle of the radiation emitting unit17with respect to the base14while fixing the angles of the imaging table16, the compression member40, the breast, and the like.

In addition, in the imaging apparatus10, the breast of the examinee may be positioned not only in a state in which the examinee is standing (standing state) but also in a state in which the examinee is sitting on a chair, a wheelchair, or the like (sitting state).

The console50has a function of controlling the imaging apparatus10to acquire the radiation image in accordance with the imaging order acquired from the RIS6, the instruction from the user, and the like. The console50has a function of detecting the marker18from the ultrasound image of the breast obtained by the ultrasound probe30and giving a warning in a case in which the marker18cannot be detected. Hereinafter, a description of the console50will be made.

A description of an example of a hardware configuration of the console50will be made with reference toFIG.7. As shown inFIG.7, the console50includes a CPU51, a non-volatile storage unit52, and a memory53as a transitory storage region. In addition, the console50includes a display54, such as a liquid crystal display, an operation unit55, such as a touch panel, a keyboard, and a mouse, and an I/F unit56. The I/F unit56performs wired or wireless communication with the imaging apparatus10, the RIS6, and other external apparatuses. The CPU51, the storage unit52, the memory53, the display54, the operation unit55, and the OF unit56are connected to each other via a bus58, such as a system bus and a control bus, so that various types of information can be exchanged.

The storage unit52is realized by, for example, a storage medium, such as an HDD, an SSD, and a flash memory. A control program57in the console50is stored in the storage unit52. The CPU51reads out the control program57from the storage unit52to deploy the control program57into the memory53, and executes the deployed control program57. As the console50, for example, a personal computer, a server computer, a smartphone, a tablet terminal, a wearable terminal, or the like can be applied as appropriate.

In addition, the storage unit52stores the image data of the radiation image and the ultrasound image acquired by the imaging apparatus10, various types of other information, and the like. The image data of the radiation image and the ultrasound image may be stored in association with at least one of the imaging order or the imaging information. The imaging information may be, for example, at least one of examinee information and an imaging item that are included in the imaging order, photographer information indicating a photographer (for example, the user, such as the doctor or the technician) who performs the imaging, or date and time information indicating date and time when the imaging is performed.

A description of an example of a functional configuration of the console50will be made with reference toFIG.8. As shown inFIG.8, the console50includes an acquisition unit60, a detection unit62, and a controller64. In a case in which the CPU51executes the control program57, the CPU51functions as the acquisition unit60, the detection unit62, and the controller64.

The acquisition unit60acquires the radiation image captured by irradiating the breast put into the compressed state by the compression member40with the radiation R, from the imaging apparatus10. Specifically, the acquisition unit60may acquire the radiation image stored in the storage unit22of the imaging apparatus10via the I/F unit56, may acquire the radiation image stored in the storage unit52, or may acquire the radiation image stored in the external apparatus.

In addition, the acquisition unit60acquires the ultrasound image obtained by performing ultrasound imaging on the breast put into the compressed state by the compression member40with the ultrasound probe30, from the imaging apparatus10.FIG.9shows an example of an ultrasound image98. As shown inFIGS.5and6, the ultrasound image98ofFIG.9is an image obtained by performing the ultrasound imaging on the breast disposed on the imaging surface16A having the four markers18A to18D. However, the markers18C and18D disposed on the imaging surface16A at the relatively close interval d3are an integrated marker18CD on the ultrasound image98. The ultrasound image98includes a region of interest4.

The detection unit62detects the marker18from the ultrasound image98acquired by the acquisition unit60. For example, inFIG.9, the detection unit62detects a plurality of markers18A,18B, and18CD from the ultrasound image98. In this case, the detection unit62determines that the two markers18A and18B among the four markers18A to18D can be appropriately detected, but the two markers18C and18D cannot be appropriately detected. It should be noted that, for example, in a case in which the number of detected markers is different from a predetermined number (four in the example ofFIG.9), the detection unit62may determine that the markers cannot be appropriately detected. In addition, for example, the detection unit62may measure the size of each of the detected markers18A,18B, and18CD, and may determine that some markers are integrated and cannot be appropriately detected in a case in which there is the marker having the size equal to or larger than a predetermined threshold value.

For example, in a case in which the breast is large and thick or has a high-density mammary gland (dense breast), there is a possibility that no marker can be detected. Also in this case, the detection unit62determines that the marker18cannot be appropriately detected from the ultrasound image98.

The controller64performs control of giving a warning in a case in which the detection unit62cannot detect the marker from the ultrasound image98. For example, the controller64may perform control of displaying a warning sentence on the display54, or may give notification by voice or the like. The controller64may perform control of displaying the radiation image and the ultrasound image acquired by the acquisition unit60on the display54in association with each other.

FIG.10shows an example of a screen D1displayed on the display54by the controller64. On the screen D1, a mammography image (radiation image)90and the ultrasound image98are displayed in association with each other. In the ultrasound image98, the position of the imaging surface16A specified from the markers18A,18B, and18CD detected by the detection unit62is highlighted by a highlight99. Since the detection unit62determines that the two markers18C and18D cannot be appropriately detected, a warning sentence indicating that the resolution is not sufficient is displayed.

The controller64may store the radiation image and the ultrasound image acquired by the acquisition unit60in the storage unit52of the console50, the storage unit22of the imaging apparatus10, an external storage device, or the like, in association with each other.

Modification Example

The form is described in which a warning is given depending on whether or not the marker18can be detected from the ultrasound image, but the present disclosure is not limited to this. For example, even in a case in which the marker18cannot be detected, in a case in which the region of interest suspected to be abnormal is in a relatively shallow region near the compression member40, a warning may not be necessary. Then, the console50may change whether or not to give a warning in accordance with the depth position of the region of interest, in addition to the detection result of the marker18. Hereinafter, a description of a specific example of such a case will be made.

The acquisition unit60acquires a tomographic image on each of a plurality of tomographic planes of the breast put into the compressed state by the compression member40, from the imaging apparatus10.FIG.11shows an example of a plurality of tomographic images T1to Tm indicating any tomographic planes of the breast2, respectively. These tomographic images T1to Tm are obtained by, for example, the tomosynthesis imaging. In the example ofFIG.11, a certain tomographic image Tx includes the region of interest4suspected to be abnormal in the breast2. The tomographic image T1inFIG.11is a tomographic image on the contact surface between the compression member40and the breast2.

The detection unit62specifies, for the region of interest4included in the breast2, the depth position in the compression direction from the contact surface between the compression member40and the breast2based on the plurality of tomographic images T1to Tm acquired by the acquisition unit60. In the example ofFIG.11, the detection unit62derives a distance from the tomographic image T1to the tomographic image Tx including the region of interest4in accordance with a slice thickness or the like, and specifies the derived distance as the depth position.

It should be noted that, as the method of specifying the position of the region of interest4, for example, a method using a known computer aided detection/diagnosis (CAD) technique can be applied as appropriate. As the method of specifying the region of interest using the CAD technique, for example, a method using a learning model, such as a convolutional neural network (CNN), may be applied. For example, the detection unit62may specify the position of the region of interest in each of the tomographic images T1to Tm by using a learning model trained to receive each of the tomographic images T1to Tm as an input and then extract and output the region of interest included in each of the tomographic images T1to Tm. In addition, for example, the detection unit62may specify the region designated by the user via the operation unit55as the region of interest.

The controller64performs the control of giving a warning in a case in which the depth position of the region of interest4detected by the detection unit62is equal to or greater than the predetermined threshold value and the marker18cannot be detected from the ultrasound image by the detection unit62. As the threshold value, for example, the depth position or the like known in advance that a sufficient resolution is ensured can be set as appropriate regardless of individual differences in the breast.

Next, a description of an action of the console50according to the present embodiment will be made with reference toFIG.12. In the console50, the CPU51executes the control program57to execute a control process shown inFIG.12. The control process is executed, for example, in a case in which the user gives an instruction to start the execution via the operation unit55.

In step S10, the acquisition unit60acquires the ultrasound image captured by the imaging apparatus10. In step S12, the detection unit62attempts to detect the marker18from the ultrasound image acquired in step S10. In a case in which the marker18can be detected in step S12, the present control process is terminated.

On the other hand, in a case in which the marker18cannot be detected in step S12(in a case in which there are the plurality of markers18, even a part of the markers18cannot be detected), the process proceeds to step S14. In step S14, the acquisition unit60acquires the tomographic image on each of the plurality of tomographic planes of the breast put into the compressed state by the compression member40, from the imaging apparatus10. In step S16, the detection unit62specifies, for the region of interest included in the breast, the depth position in the compression direction from the contact surface between the compression member40and the breast based on the plurality of tomographic images T1to Tm acquired in step S14.

In step S18, the controller64determines whether or not the depth position of the region of interest specified in step S16is equal to or greater than the predetermined threshold value. In a case in which the depth position of the region of interest is smaller than the predetermined threshold value in step S18, the marker18cannot be detected, but the region of interest is in a relatively shallow region close to the compression member40. Therefore, a warning is not necessary, and the present control process is terminated.

On the other hand, in a case in which the depth position of the region of interest is equal to or greater than the predetermined threshold value in step S18, the process proceeds to step S20. In step S20, the controller64performs the control of giving a warning by determining that the depth position of the region of interest is equal to or greater than the predetermined threshold value and the marker18cannot be detected from the ultrasound image. In a case in which step S20is completed, the present control process is terminated.

As described above, the imaging apparatus10according to the aspect of the present disclosure comprises the imaging table16having the imaging surface16A on which at least one marker18is disposed, the compression member40for putting the breast2disposed on the imaging surface16A into the compressed state, and the ultrasound probe30that obtains the ultrasound image of the breast2put into the compressed state by the compression member40.

That is, with the imaging apparatus10according to the present embodiment, by checking whether or not the marker18can be detected from the captured ultrasound image, it is possible to check whether or not the ultrasound image with sufficient accuracy can be captured particularly for the portion (imaging table16side) away from the ultrasound probe30in the breast2that is the examination target. Therefore, it is possible to support the capturing of the ultrasound image with the accuracy that enables to read the marker provided on the imaging table.

It should be noted that, in the embodiment described above, the form is described in which the console50is an example of a control apparatus according to the present disclosure, but an apparatus other than the console50may have the function of the control apparatus according to the present disclosure. In other words, an apparatus other than the console50, such as the imaging apparatus10and the external apparatus, may have a part or all of the functions of the acquisition unit60, the detection unit62, and the controller64.

In the embodiment described above, for example, as hardware structures of processing units that execute various types of processes, such as the controller20, the acquisition unit60, the detection unit62, and the controller64, various processors shown below can be used. As described above, in addition to the CPU that is a general-purpose processor that executes software (program) to function as various processing units, the various processors include a programmable logic device (PLD) that is a processor of which a circuit configuration can be changed after manufacture, such as a field programmable gate array (FPGA), and a dedicated electric circuit that is a processor having a circuit configuration that is designed for exclusive use in order to execute a specific process, such as an application specific integrated circuit (ASIC).

One processing unit may be configured by using one of the various processors or may be configured by using a combination of two or more processors of the same type or different types (for example, a combination of a plurality of FPGAs or a combination of a CPU and an FPGA). Moreover, a plurality of processing units may be configured of one processor.

A first example of the configuration in which the plurality of processing units are configured by using one processor is a form in which one processor is configured by using a combination of one or more CPUs and the software and this processor functions as the plurality of processing units, as represented by computers, such as a client and a server. Second, as represented by a system on chip (SoC) or the like, there is a form in which the processor is used in which the functions of the entire system which includes the plurality of processing units are realized by a single integrated circuit (IC) chip. In this way, as the hardware structure, the various processing units are configured by using one or more of the various processors described above.

Further, the hardware structure of these various processors is, more specifically, an electric circuit (circuitry) in which circuit elements such as semiconductor elements are combined.

In addition, in the embodiment described above, the aspect is described in which the various programs in the imaging apparatus10are stored (installed) in the ROM included in the controller20in advance, and the control program57in the console50is stored in the storage unit52in advance, but the present disclosure is not limited to this. The various programs and the control program57in the imaging apparatus10may be provided in a form of being recorded in a recording medium, such as a compact disc read only memory (CD-ROM), a digital versatile disc read only memory (DVD-ROM), and a universal serial bus (USB) memory. In addition, a form may be adopted in which the various programs and the control program57in the imaging apparatus10are downloaded from an external apparatus via the network. Further, the technique of the present disclosure extends to a storage medium that non-transitorily stores a program in addition to the program.

In the technique of the present disclosure, the embodiment and the examples described above can be combined as appropriate. The above-described contents and the above-shown contents are detailed description for parts according to the technique of the present disclosure, and are merely examples of the technique of the present disclosure. For example, the above description related to the configuration, the function, the action, and the effect is the description related to the examples of the configuration, the function, the action, and the effect of the parts according to the technique of the present disclosure. As a result, it is needless to say that unnecessary parts may be deleted, new elements may be added, or replacements may be made with respect to the above-described contents and the above-shown contents within a range that does not deviate from the gist of the technique of the present disclosure.