Patent Description:
In general, so-called tomosynthesis imaging is known which irradiates an object with radiation emitted from a radiation source at each of a plurality of irradiation positions having different irradiation angles to capture a plurality of radiographic images of the object at different irradiation positions.

In the tomosynthesis imaging, as an irradiation angle range, which is the range of irradiation angles at a plurality of irradiation positions where imaging is performed, becomes wider, the resolution of a tomographic image generated using the obtained plurality of projection images becomes higher. However, a region irradiated with radiation varies depending the irradiation angle due to the influence of the oblique incidence of the radiation. Therefore, as the irradiation angle becomes larger, the irradiation region is more likely to be affected by the oblique incidence of the radiation, and an object region included in the projection image becomes smaller. In the generation of a tomographic image from a plurality of projection images, in a case in which an object region reconstructed as the tomographic image is referred to as a reconstructed region, the reconstructed region becomes narrower as the irradiation angle range becomes wider. The reason is that the reconstruction needs to be performed using a plurality of projection images obtained by imaging the same region of the object while changing the irradiation angle and the reconstructed region is limited to the region of the subject which is common to all of the plurality of projection images used for the reconstruction. Therefore, as the irradiation angle becomes larger, the region of the object included in the projection image becomes narrower. As a result, as the irradiation angle range becomes wider, the reconstructed region becomes narrower. On the contrary, as the irradiation angle range becomes narrower, the irradiation region is more unlikely to be affected by the oblique incidence of the radiation on the object. Therefore, the reconstructed region becomes wide.

That is, as the irradiation angle range becomes wider, the reconstructed region is more limited to a part of the object, but the resolution of the tomographic image becomes higher. As the irradiation angle range becomes narrower, the reconstructed region becomes wider to include the entire object, but the resolution of the tomographic image becomes lower.

Therefore, a technique is known which performs tomosynthesis imaging while changing the irradiation angle range. For example, <CIT> discloses a technique that performs two types of tomosynthesis imaging in a standard mode and a high-resolution mode in which an irradiation angle range is wider than that in the standard mode.

<CIT> discloses a technique that combines two types of tomographic imaging in a narrow angle and a wide angle. The two series of projection images can be acquired in any order.

In the above-mentioned technique according to the related art <CIT>, a tomographic image is generated from a projection image group obtained by the tomosynthesis imaging in the standard mode in order to obtain two types of tomographic images having different reconstructed regions and resolutions. In addition, a tomographic image is generated from a projection image group obtained by the tomosynthesis imaging in the high-resolution mode.

As described above, in the technique according to the related art, the tomographic image is generated from each of the projection image groups obtained by each tomosynthesis imaging operation.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an image processing device according to claim <NUM>, a radiography system according to claim <NUM>, an image processing method according to claim <NUM>, and an image processing program according to claim <NUM>, that can generate a high-resolution tomographic image and a tomographic image including the entire object from a projection image group including a plurality of projection images obtained by tomosynthesis imaging in an irradiation angle range in which the entire object is not included in the tomographic image in a case in which the tomographic image is generated using all of the projection images.

In order to achieve the above object, according to a first aspect of the present disclosure, there is provided an image processing device that is used in a radiography apparatus performing tomosynthesis imaging which irradiates an object with radiation emitted from a radiation source at each of a plurality of irradiation positions having different irradiation angles to capture projection images of the object at each of the irradiation positions. The image processing device comprises at least one processor. The processor acquires a projection image group including a plurality of projection images obtained by the tomosynthesis imaging in an irradiation angle range wider than an overall imaging irradiation angle range in which a tomographic image including an entire object is obtainable in a case in which the tomographic image is generated using the projection images obtained at each of the plurality of irradiation positions, generates a plurality of first tomographic images including a part of the object, using a plurality of projection images obtained by the tomosynthesis imaging in a first irradiation angle range wider than the overall imaging irradiation angle range among the projection images included in the projection image group, and generates a plurality of second tomographic images including the entire object, using a plurality of projection images obtained by the tomosynthesis imaging in a second irradiation angle range that is equal to or narrower than the overall imaging irradiation angle range among the projection images included in the projection image group.

According to a second aspect of the present disclosure, in the image processing device according to the first aspect, the processor may acquire a plurality of projection images obtained by one tomosynthesis imaging operation as the projection image group.

According to a third aspect of the present disclosure, in the image processing device according to the first aspect or the second aspect, the processor may generate the plurality of second tomographic images using some of the plurality of projection images used to generate the first tomographic images.

According to a fourth aspect of the present disclosure, in the image processing device according to any one of the first to third aspects, the processor may display the first tomographic image and the second tomographic image side by side.

According to a fifth aspect of the present disclosure, in the image processing device according to any one of the first to fourth aspects, the processor may display information indicating a range of the object included in the first tomographic image so as to be superimposed on the second tomographic image.

According to a sixth aspect of the present disclosure, in the image processing device according to any one of the first to third aspects, the processor may generate at least one of a first composite two-dimensional image obtained by combining at least some of the plurality of first tomographic images or a second composite two-dimensional image obtained by combining at least some of the plurality of second tomographic images and may display at least one of the plurality of first tomographic images or the first composite two-dimensional image and at least one of the plurality of second tomographic images or the second composite two-dimensional image side by side.

According to a seventh aspect of the present disclosure, in the image processing device according to any one of the first to third aspects, the processor may generate a second composite two-dimensional image obtained by combining at least some of the plurality of second tomographic images and may display information indicating a range of the object included in the first tomographic image so as to be superimposed on the second composite two-dimensional image.

According to an eighth aspect of the present disclosure, in the image processing device according to any one of the first to seventh aspects, the processor may set a slice thickness of the plurality of first tomographic images to be smaller than a slice thickness of the plurality of second tomographic images.

According to a ninth aspect of the present disclosure, in the image processing device according to any one of the first to eighth aspects, the processor may acquire overall imaging information indicating the overall imaging irradiation angle range which is determined on the basis of at least one of a thickness of the object or an area of the object and may specify the second irradiation angle range on the basis of the acquired overall imaging information.

According to a tenth aspect of the present disclosure, in the image processing device according to the ninth aspect, the object may be a breast that is placed on an imaging table and is compressed by a compression member, and the area of the object is a contact area of the breast with the imaging table or a contact area of the breast with the compression member.

According to an eleventh aspect of the present disclosure, in the image processing device according to any one of the first to tenth aspects, the radiation source may include a plurality of radiation tubes that are disposed at each of the plurality of irradiation positions and generate the radiation, and the radiography apparatus may sequentially generate the radiation from the plurality of radiation tubes to perform the tomosynthesis imaging.

According to a twelfth aspect of the present disclosure, in the image processing device according to any one of the first to tenth aspects, the radiation source may include a radiation tube that generates the radiation, and the radiography apparatus may move the radiation source to the plurality of irradiation positions to perform the tomosynthesis imaging.

Further, in order to achieve the above object, according to a thirteenth aspect of the present disclosure, there is provided an imaging control device that is used in a radiography apparatus performing tomosynthesis imaging which irradiates an object with radiation emitted from a radiation source at each of a plurality of irradiation positions having different irradiation angles to capture projection images of the object at each of the irradiation positions. The imaging control device comprises at least one processor. The processor acquires overall imaging information indicating an overall imaging irradiation angle range determined on the basis of at least one of a thickness of the object or an area of the object and controls the radiography apparatus such that the tomosynthesis imaging is performed in an irradiation angle range wider than the overall imaging irradiation angle range corresponding to the acquired overall imaging information.

Furthermore, in order to achieve the above object, according to a fourteenth aspect of the present disclosure, there is provided a radiography system comprising: a radiation source that generates radiation; a radiography apparatus that performs tomosynthesis imaging which irradiates an object with the radiation emitted from the radiation source at each of a plurality of irradiation positions having different irradiation angles to capture projection images of the object at each of the irradiation positions; and the image processing device according to the present disclosure.

Moreover, in order to achieve the above object, according to a fifteenth aspect of the present disclosure, there is provided an image processing method that is executed by a computer and is used in a radiography apparatus performing tomosynthesis imaging which irradiates an object with radiation emitted from a radiation source at each of a plurality of irradiation positions having different irradiation angles to capture projection images of the object at each of the irradiation positions. The image processing method comprising: acquiring a projection image group including a plurality of projection images obtained by the tomosynthesis imaging in an irradiation angle range wider than an overall imaging irradiation angle range in which a tomographic image including an entire object is obtainable in a case in which the tomographic image is generated using the projection images obtained at each of the plurality of irradiation positions; generating a plurality of first tomographic images including a part of the object, using a plurality of projection images obtained by the tomosynthesis imaging in a first irradiation angle range wider than the overall imaging irradiation angle range among the projection images included in the projection image group; and generating a plurality of second tomographic images including the entire object, using a plurality of projection images obtained by the tomosynthesis imaging in a second irradiation angle range that is equal to or narrower than the overall imaging irradiation angle range among the projection images included in the projection image group.

In addition, in order to achieve the above object, according to a sixteenth aspect of the present disclosure, there is provided an image processing program that is used in a radiography apparatus performing tomosynthesis imaging which irradiates an object with radiation emitted from a radiation source at each of a plurality of irradiation positions having different irradiation angles to capture projection images of the object at each of the irradiation positions. The image processing program causes a computer to perform a process comprising: acquiring a projection image group including a plurality of projection images obtained by the tomosynthesis imaging in an irradiation angle range wider than an overall imaging irradiation angle range in which a tomographic image including an entire object is obtainable in a case in which the tomographic image is generated using the projection images obtained at each of the plurality of irradiation positions; generating a plurality of first tomographic images including a part of the object, using a plurality of projection images obtained by the tomosynthesis imaging in a first irradiation angle range wider than the overall imaging irradiation angle range among the projection images included in the projection image group; and generating a plurality of second tomographic images including the entire object, using a plurality of projection images obtained by the tomosynthesis imaging in a second irradiation angle range that is equal to or narrower than the overall imaging irradiation angle range among the projection images included in the projection image group.

According to the present disclosure, it is possible to generate a high-resolution tomographic image and a tomographic image including the entire object from a projection image group including a plurality of projection images obtained by tomosynthesis imaging in an irradiation angle range in which the entire object is not included in the tomographic image in a case in which the tomographic image is generated using all of the projection images.

Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the drawings. In addition, this embodiment does not limit the present disclosure.

First, an example of the overall configuration of a radiography system according to this embodiment will be described. <FIG> is a diagram illustrating an example of the overall configuration of a radiography system <NUM> according to this embodiment. As illustrated in <FIG>, the radiography system <NUM> according to this embodiment comprises a mammography apparatus <NUM> and a console <NUM>.

First, the mammography apparatus <NUM> according to this embodiment will be described. <FIG> is a side view illustrating an example of the outward appearance of the mammography apparatus <NUM> according to this embodiment. In addition, <FIG> illustrates an example of the outward appearance of the mammography apparatus <NUM> as viewed from the left side of a subject.

The mammography apparatus <NUM> according to this embodiment is an apparatus that is operated under the control of the console <NUM> and irradiates the breast of the subject as an object with radiation R (for example, X-rays) to capture a radiographic image of the breast. In addition, the mammography apparatus <NUM> may be an apparatus that images the breast of the subject not only in a state in which the subject is standing (standing state) but also in a state in which the subject is sitting on, for example, a chair (including a wheelchair) (sitting state).

Furthermore, the mammography apparatus <NUM> according to this embodiment has a function of performing normal imaging that captures images at an irradiation position where a radiation source <NUM> is disposed along a normal direction to a detection surface 20A of a radiation detector <NUM> and so-called tomosynthesis imaging that captures images while moving the radiation source <NUM> to each of a plurality of irradiation positions.

The radiation detector <NUM> detects the radiation R transmitted through the breast which is the object. Specifically, the radiation detector <NUM> detects the radiation R that has entered the breast of the subject and an imaging table <NUM> and reached the detection surface 20A of the radiation detector <NUM>, generates a radiographic image on the basis of the detected radiation R, and outputs image data indicating the generated radiographic image. In the following description, in some cases, a series of operations of emitting the radiation R from the radiation source <NUM> and generating a radiographic image using the radiation detector <NUM> is referred to as "imaging". The type of the radiation detector <NUM> according to this embodiment is not particularly limited. For example, the radiation detector <NUM> may be an indirect-conversion-type radiation detector that converts the radiation R into light and converts the converted light into charge or a direct-conversion-type radiation detector that directly converts the radiation R into charge.

As illustrated in <FIG>, the radiation detector <NUM> is disposed in the imaging table <NUM>. In the mammography apparatus <NUM> according to this embodiment, in a case in which imaging is performed, the breast of the subject is positioned on an imaging surface 24A of the imaging table <NUM> by a user.

A compression plate <NUM> that is used to compress the breast in a case in which imaging is performed is attached to a compression unit <NUM> that is provided in the imaging table <NUM>. Specifically, the compression unit <NUM> is provided with a compression plate driving unit (not illustrated) that moves the compression plate <NUM> in a direction (hereinafter, referred to as an "up-down direction") toward or away from the imaging table <NUM>. A support portion <NUM> of the compression plate <NUM> is detachably attached to the compression plate driving unit and is moved in the up-down direction by the compression plate driving unit to compress the breast of the subject between the compression plate <NUM> and the imaging table <NUM>. The compression plate <NUM> according to this embodiment is an example of a compression member according to the present disclosure.

As illustrated in <FIG>, the mammography apparatus <NUM> according to this embodiment comprises the imaging table <NUM>, an arm portion <NUM>, a base <NUM>, and a shaft portion <NUM>. The arm portion <NUM> is held by the base <NUM> so as to be movable in the up-down direction (Z-axis direction). In addition, the arm portion <NUM> can be rotated with respect to the base <NUM> by the shaft portion <NUM>. The shaft portion <NUM> is fixed to the base <NUM>, and the shaft portion <NUM> and the arm portion <NUM> are rotated integrally.

Gears are provided in each of the shaft portion <NUM> and the compression unit <NUM> of the imaging table <NUM>. The gears can be switched between an engaged state and a non-engaged state to switch between a state in which the compression unit <NUM> of the imaging table <NUM> and the shaft portion <NUM> are connected and rotated integrally and a state in which the shaft portion <NUM> is separated from the imaging table <NUM> and runs idle. In addition, components for switching between the transmission and non-transmission of the power of the shaft portion <NUM> are not limited to the gears, and various mechanical elements may be used.

Each of the arm portion <NUM> and the imaging table <NUM> can be relatively rotated with respect to the base <NUM>, using the shaft portion <NUM> as a rotation axis. In this embodiment, engagement portions (not illustrated) are provided in each of the base <NUM>, the arm portion <NUM>, and the compression unit <NUM> of the imaging table <NUM>. The state of the engagement portions is switched to connect each of the arm portion <NUM> and the compression unit <NUM> of the imaging table <NUM> to the base <NUM>. One or both of the arm portion <NUM> and the imaging table <NUM> connected to the shaft portion <NUM> are integrally rotated on the shaft portion <NUM>.

In a case in which the mammography apparatus <NUM> performs the tomosynthesis imaging, the radiation source <NUM> of a radiation emitting unit <NUM> is sequentially moved to each of a plurality of irradiation positions having different irradiation angles by the rotation of the arm portion <NUM>. The radiation source <NUM> includes a radiation tube <NUM> that generates the radiation R, and the radiation tube <NUM> is moved to each of the plurality of irradiation positions with the movement of the radiation source <NUM>. <FIG> is a diagram illustrating an example of the tomosynthesis imaging. In addition, the compression plate <NUM> is not illustrated in <FIG>. In this embodiment, as illustrated in <FIG>, the radiation source <NUM> is moved to irradiation positions <NUM>k (k = <NUM>, <NUM>,. ; the maximum value is <NUM> in <FIG>) with different irradiation angles which are arranged at an interval of a predetermined angle θ, that is, positions where the radiation R is incident on the detection surface 20A of the radiation detector <NUM> at different angles. At each of the irradiation positions <NUM>k, the radiation source <NUM> emits the radiation R to a breast W in response to an instruction from the console <NUM>, and the radiation detector <NUM> captures a radiographic image. In the radiography system <NUM>, in a case in which the tomosynthesis imaging that moves the radiation source <NUM> to each of the irradiation positions <NUM>k and captures radiographic images at each of the irradiation positions <NUM>k is performed, <NUM> radiographic images are obtained in the example illustrated in <FIG>. In addition, in the following description, in the tomosynthesis imaging, in a case in which a radiographic image captured at each irradiation position <NUM> is distinguished from other radiographic images, it is referred to as a "projection image". Further, in a case in which a radiographic image is generically referred to regardless of the type, such as a projection image and a tomographic image which will be described below, it is simply referred to as a "radiographic image". Furthermore, in the following description, in a case in which the irradiation positions <NUM>k are generically referred to, a reference letter k for distinguishing each irradiation position is omitted, and the irradiation positions <NUM>k are referred to as "irradiation positions <NUM>".

In addition, as illustrated in <FIG>, the incident angle of the radiation R means an angle α formed between a normal line CL to the detection surface 20A of the radiation detector <NUM> and a radiation axis RC. The radiation axis RC means an axis that connects the focus of the radiation tube <NUM> of the radiation source <NUM> at each irradiation position <NUM> and a preset position such as the center of the detection surface 20A. Further, here, it is assumed that the detection surface 20A of the radiation detector <NUM> is substantially parallel to the imaging surface 24A. Hereinafter, a predetermined range in which the incident angles are different in the tomosynthesis imaging as illustrated in <FIG> is referred to as an "irradiation angle range". Furthermore, in this embodiment, the "incident angle" and the "irradiation angle" of the radiation R are synonymous.

Further, <FIG> illustrates object regions <NUM><NUM>, <NUM><NUM>, <NUM><NUM>, <NUM><NUM>, <NUM><NUM> which are included in projection images <NUM><NUM>, <NUM><NUM>, <NUM><NUM>, <NUM><NUM>, and <NUM><NUM> obtained in a case in which the radiation source <NUM> is located at the irradiation positions <NUM><NUM>, <NUM><NUM>, <NUM><NUM>, <NUM><NUM>, and <NUM><NUM>, respectively. The object region <NUM> corresponds to the irradiation field of the radiation R on the detection surface 20A of the radiation detector <NUM>. In this embodiment, in a case in which the object regions <NUM>, the projection images <NUM>, and the tomographic images <NUM> have a correspondence relationship with the irradiation positions <NUM>, numbers "<NUM> to <NUM>" indicating the irradiation positions <NUM><NUM> to <NUM><NUM>, respectively, are added to the reference numerals. For example, in a case in which the radiation source <NUM> is located at the seventh irradiation position <NUM><NUM>, the projection image <NUM><NUM> including the object region <NUM><NUM> is obtained. Further, in the following description, for simplicity, the projection image <NUM> obtained in a case in which the radiation source <NUM> is located at a certain irradiation position <NUM> is simply referred to as a "projection image <NUM> obtained at the irradiation position <NUM>".

The object region <NUM><NUM> which is included in the projection image <NUM><NUM> obtained at the seventh irradiation position <NUM><NUM> along the normal line CL where the irradiation angle is <NUM> degrees has the range and size in which the entire image of the breast W, which is the object, can be captured.

As the angle α becomes larger, in other words, as the incident angle of the radiation R obliquely incident on the detection surface 20A of the radiation detector <NUM> becomes larger, the influence of the oblique incidence of the radiation R becomes larger, and the radiation field of the radiation R becomes narrower. Therefore, as illustrated in <FIG>, as the angle α becomes larger, the object region <NUM> included in the projection image <NUM> becomes narrower. In other words, in a case in which the radiation source <NUM> is located at the irradiation position <NUM> having a relatively large irradiation angle, the influence of the oblique incidence of the radiation R becomes large. Therefore, the object region <NUM> included in the obtained projection image <NUM> is narrower than the object region <NUM><NUM>. In the example illustrated in <FIG>, both the object region <NUM><NUM> included in the projection image <NUM><NUM> obtained at the irradiation position <NUM><NUM> having the largest irradiation angle and the object region <NUM><NUM> included in the projection image <NUM><NUM> obtained at the irradiation position <NUM><NUM> are narrower than the object region <NUM><NUM>. Specifically, the object region <NUM><NUM> and the object region <NUM><NUM> have a shape in which a region on the side where the radiation source <NUM> is located during imaging has missed. As described above, for example, the size of the object region <NUM> included in the projection image <NUM> varies depending on the irradiation position <NUM>.

In a case in which a tomographic image <NUM> is reconstructed using a plurality of projection images <NUM> obtained by the tomosynthesis imaging, a reconstructed region depends on the object region <NUM> in each projection image <NUM>. Specifically, the reconstructed region is limited to a common partial region (hereinafter, referred to as a "partial region") of the object regions <NUM> included in all of the projection images <NUM> used to generate the tomographic image <NUM>.

As illustrated in <FIG>, in the case of the irradiation position <NUM> where the irradiation angle is relatively small, even though the radiation R emitted from the radiation source <NUM> is obliquely incident on the detection surface 20A of the radiation detector <NUM>, the object region <NUM> having the same shape and size as the object region <NUM><NUM> is obtained. In a case in which the object region <NUM> included in the projection image <NUM> obtained at each of the plurality of irradiation positions <NUM> is equivalent to the object region <NUM><NUM>, a partial region <NUM>, that is, a reconstructed region <NUM> is also equivalent to the object region <NUM><NUM>. In this case, since the entire object region <NUM> included in each projection image <NUM> is regarded as the partial region <NUM>, it cannot be said to be a "part" in a strict sense, but is referred to as a "part" for convenience of explanation. In a case in which the reconstructed region <NUM> is equivalent to the object region <NUM><NUM>, the tomographic image <NUM> is an image in which the entire object is included. Further, the "entire object" included in the tomographic image <NUM> means, for example, a portion captured by the radiation detector <NUM> in a case in which radiation is emitted at the irradiation position where the irradiation angle α is <NUM> degrees in the object to be imaged such as the breast. Furthermore, the entire object is about a plane in which the radiation R is projected onto the object. The entire object does not mean, for example, the entire breast, but means at least the entire region of the object desired by the user for interpretation. For example, the entire object also includes a region in which an end portion of the object that is not required for interpretation or the like has missed.

As described above, the irradiation angle range, which is the range of the irradiation positions <NUM> where the projection images <NUM> that can make the reconstructed region <NUM> in the tomographic image <NUM> equivalent to the object region <NUM><NUM> are obtained, is referred to as an overall imaging irradiation angle range ARa (See <FIG>). That is, the overall imaging irradiation angle range ARa means an irradiation angle range in which the tomographic image <NUM> including the entire object can be obtained in a case in which the tomographic image <NUM> is generated using the projection images <NUM> obtained at each of the plurality of irradiation positions <NUM>. Strictly speaking, the overall imaging irradiation angle range ARa means the maximum irradiation angle range in which the tomographic image <NUM> including the entire object can be obtained.

In a case in which the irradiation angle range is wider than the overall imaging irradiation angle range ARa, the reconstructed region <NUM> in the tomographic image <NUM> is narrower than the object region <NUM><NUM>. Therefore, the tomographic image <NUM> is an image including a part of the object.

In <FIG>, a first irradiation angle range AR<NUM> is illustrated as an irradiation angle range wider than the overall imaging irradiation angle range ARa. In a case in which the irradiation angle range is the first irradiation angle range AR<NUM>, a partial region <NUM><NUM> common to the object regions <NUM><NUM> to <NUM><NUM> included in the projection images <NUM><NUM> to <NUM><NUM> obtained at each of the irradiation positions <NUM><NUM> to <NUM><NUM> corresponds to a reconstructed region <NUM><NUM> in a case in which a first tomographic image <NUM><NUM> is generated. The partial region <NUM><NUM>, that is, the reconstructed region <NUM><NUM> is smaller than the object regions <NUM><NUM> to <NUM><NUM> included in the projection images <NUM><NUM> to <NUM><NUM>.

In the first tomographic image <NUM><NUM>, the reconstructed region <NUM><NUM> is a region in which the object can be included. Therefore, the first tomographic image <NUM><NUM> is an image in which a part of the object is included. For example, <FIG> illustrates the first tomographic image <NUM><NUM> in which a part of the breast W, which is the object, is included.

The resolution of the tomographic image <NUM> depends on the irradiation angle range. As the irradiation angle range becomes wider, the resolution of the tomographic image <NUM> becomes higher. Therefore, the first tomographic image <NUM><NUM> generated by the plurality of projection images <NUM><NUM> to <NUM><NUM> obtained by the tomosynthesis imaging in the first irradiation angle range AR<NUM> is a high-resolution image.

On the other hand, in a case in which the irradiation angle range is equal to or narrower than the overall imaging irradiation angle range ARa, the reconstructed region <NUM> in the tomographic image <NUM> is equivalent to the object region <NUM><NUM>. Therefore, the tomographic image <NUM> is an image in which the entire object is included.

In <FIG>, a second irradiation angle range AR<NUM> is illustrated as an irradiation angle range that is equal to or narrower than the overall imaging irradiation angle range ARa. In a case in which the irradiation angle range is the second irradiation angle range AR<NUM>, a partial region <NUM><NUM> common to the object regions <NUM><NUM> to <NUM><NUM> included in the projection images <NUM><NUM> to <NUM><NUM> obtained at each of the irradiation positions <NUM><NUM> to <NUM><NUM> corresponds to the reconstructed region <NUM><NUM> in a case in which a second tomographic image <NUM><NUM> is generated. The partial region <NUM><NUM>, that is, the reconstructed region <NUM><NUM> is equivalent to the object regions <NUM><NUM> to <NUM><NUM> included in the projection images <NUM><NUM> to <NUM><NUM>.

In the second tomographic image <NUM><NUM>, the reconstructed region <NUM><NUM> is a region in which the object can be included. Therefore, the second tomographic image <NUM><NUM> is an image in which the entire object is included. For example, <FIG> illustrates the second tomographic image <NUM><NUM> in which the entire breast W which is the object is included.

The resolution of the tomographic image <NUM> depends on the irradiation angle range. As the irradiation angle range becomes narrower, the resolution of the tomographic image <NUM> becomes lower. Therefore, the second tomographic image <NUM><NUM> generated by the plurality of projection images <NUM><NUM> to <NUM><NUM> obtained by the tomosynthesis imaging in the second irradiation angle range AR<NUM> has a lower resolution than the first tomographic image <NUM><NUM>.

As described above, in a case in which the irradiation angle range is equal to or narrower than the overall imaging irradiation angle range ARa, the tomographic image <NUM> generated by the projection images <NUM> obtained at each irradiation position <NUM> is a tomographic image in which the entire object is included. In a case in which the irradiation angle range is wider than the overall imaging irradiation angle range ARa, the tomographic image <NUM> generated by the projection images <NUM> obtained at each irradiation position <NUM> is a tomographic image which includes a part of the object, but has a high resolution.

Further, <FIG> is a block diagram illustrating an example of the configuration of the mammography apparatus <NUM> and the console <NUM> according to the embodiment. As illustrated in <FIG>, the mammography apparatus <NUM> according to this embodiment further comprises a control unit <NUM>, a storage unit <NUM>, an interface (I/F) unit <NUM>, an operation unit <NUM>, and a radiation source moving unit <NUM>. The control unit <NUM>, the storage unit <NUM>, the I/F unit <NUM>, the operation unit <NUM>, and the radiation source moving unit <NUM> are connected to each other through a bus <NUM>, such as a system bus or a control bus, such that they can transmit and receive various kinds of information.

The control unit <NUM> controls the overall operation of the mammography apparatus <NUM> under the control of the console <NUM>. The control unit <NUM> comprises a central processing unit (CPU) 40A, a read only memory (ROM) 40B, and a random access memory (RAM) 40C. For example, various programs including an imaging program <NUM> which is executed by the CPU 40A and performs control related to the capture of a radiographic image are stored in the ROM 40B in advance. The RAM 40C temporarily stores various kinds of data.

For example, the image data of the radiographic image captured by the radiation detector <NUM> and various other kinds of information are stored in the storage unit <NUM>. A specific example of the storage unit <NUM> is a hard disk drive (HDD), a solid state drive (SSD), or the like. The I/F unit <NUM> transmits and receives various kinds of information to and from the console <NUM> using wireless communication or wired communication. The image data of the radiographic image captured by the radiation detector <NUM> in the mammography apparatus <NUM> is transmitted to the console <NUM> through the I/F unit <NUM> by wireless communication or wired communication.

Each of the control unit <NUM>, the storage unit <NUM>, and the I/F unit <NUM> according to this embodiment is provided in the imaging table <NUM>.

In addition, the operation unit <NUM> is provided as a plurality of switches in, for example, the imaging table <NUM> of the mammography apparatus <NUM>. Further, the operation unit <NUM> may be provided as a touch panel switch or may be provided as a foot switch that is operated by the feet of the user such as a doctor or a radiology technician.

The radiation source moving unit <NUM> has a function of moving the radiation source <NUM> to each of the plurality of irradiation positions <NUM> under the control of the control unit <NUM> in a case in which the tomosynthesis imaging is performed as described above. Specifically, the radiation source moving unit <NUM> rotates the arm portion <NUM> with respect to the imaging table <NUM> to move the radiation source <NUM> to each of the plurality of irradiation positions <NUM>. The radiation source moving unit <NUM> according to this embodiment is provided inside the arm portion <NUM>.

On the other hand, the console <NUM> according to this embodiment has a function of controlling the mammography apparatus <NUM> using, for example, an imaging order and various kinds of information acquired from a radiology information system (RIS) through a wireless communication local area network (LAN) and instructions input by the user through an operation unit <NUM> or the like.

For example, the console <NUM> according to this embodiment is a server computer. As illustrated in <FIG>, the console <NUM> comprises a control unit <NUM>, a storage unit <NUM>, an I/F unit <NUM>, the operation unit <NUM>, and a display unit <NUM>. The control unit <NUM>, the storage unit <NUM>, the I/F unit <NUM>, the operation unit <NUM>, and the display unit <NUM> are connected to each other through a bus <NUM>, such as a system bus or a control bus, such that they can transmit and receive various kinds of information.

The control unit <NUM> according to this embodiment controls the overall operation of the console <NUM>. The control unit <NUM> comprises a CPU 50A, a ROM 50B, and a RAM 50C. Various programs including an imaging control program 51A and an image generation program 51B executed by the CPU 50A are stored in the ROM 50B in advance. The RAM 50C temporarily stores various kinds of data. In this embodiment, the CPU 50A is an example of a processor according to the present disclosure, and the console <NUM> is an example of an image processing device and an imaging control device according to the present disclosure. In addition, the image generation program 51B according to this embodiment is an example of an image processing program according to the present disclosure.

For example, the image data of the radiographic image captured by the mammography apparatus <NUM> and various other kinds of information are stored in the storage unit <NUM>. A specific example of the storage unit <NUM> is an HDD, an SSD, or the like.

The operation unit <NUM> is used by the user to input instructions, which are related to, for example, the capture of a radiographic image and include an instruction to emit the radiation R, various kinds of information, and the like. The operation unit <NUM> is not particularly limited. Examples of the operation unit <NUM> include various switches, a touch panel, a touch pen, and a mouse. The display unit <NUM> displays various kinds of information. In addition, the operation unit <NUM> and the display unit <NUM> may be integrated into a touch panel display.

The I/F unit <NUM> transmits and receives various kinds of information to and from the mammography apparatus <NUM>, the RIS, and a picture archiving and communication system (PACS) using wireless communication or wired communication. In the radiography system <NUM> according to this embodiment, the console <NUM> receives the image data of the radiographic image captured by the mammography apparatus <NUM> from the mammography apparatus <NUM> through the I/F unit <NUM>, using wireless communication or wired communication.

The console <NUM> according to this embodiment has a function of controlling the irradiation angle range in the tomosynthesis imaging. Further, the console <NUM> according to this embodiment has a function of generating a tomographic image from the projection images obtained by the tomosynthesis imaging. <FIG> is a functional block diagram illustrating an example of the configuration of the console <NUM> according to this embodiment related to the function of controlling the irradiation angle range and the function of generating a tomographic image. As illustrated in <FIG>, the console <NUM> comprises an information acquisition unit <NUM>, an irradiation angle range control unit <NUM>, an image acquisition unit <NUM>, a first tomographic image generation unit <NUM>, a first composite two-dimensional image generation unit <NUM>, a second tomographic image generation unit <NUM>, a second composite two-dimensional image generation unit <NUM>, and a display control unit <NUM>. For example, in the console <NUM> according to this embodiment, the CPU 50A of the control unit <NUM> executes the imaging control program 51A stored in the ROM 50B to function as the information acquisition unit <NUM> and the irradiation angle range control unit <NUM>. Further, in the console <NUM>, the CPU 50A of the control unit <NUM> executes the image generation program 51B stored in the ROM 50B to function as the information acquisition unit <NUM>, the image acquisition unit <NUM>, the first tomographic image generation unit <NUM>, the first composite two-dimensional image generation unit <NUM>, the second tomographic image generation unit <NUM>, the second composite two-dimensional image generation unit <NUM>, and the display control unit <NUM>.

The information acquisition unit <NUM> has a function of acquiring overall imaging information indicating the overall imaging irradiation angle range ARa. As described above, the overall imaging irradiation angle range ARa is the irradiation angle range in which the projection images <NUM> capable of generating the tomographic image <NUM> including the entire object can be obtained. The overall imaging irradiation angle range ARa depends on the thickness of the object and the area of the object. The "thickness of the object" means the thickness of the breast compressed by the compression plate <NUM>. In this embodiment, the "thickness of the object" means the distance from the imaging surface 24A of the imaging table <NUM> to a compression surface of the compression plate <NUM> which compresses the breast.

In the example illustrated in <FIG>, in a case in which the radiation source <NUM> is located at the irradiation position <NUM><NUM>, both the entire breast WH1 having a thickness H1 and the entire breast WH2 having a thickness H2 larger than the thickness H1 are present in a region R<NUM> to which the radiation R is emitted. Therefore, the projection image <NUM> obtained at the irradiation position <NUM><NUM> includes both the entire breast WH1 and the entire breast WH2.

On the other hand, in a case in which the radiation source <NUM> is located at an irradiation position <NUM>H, the entire breast WH1 is present in a region RH in which the radiation R is emitted. On the other hand, the breast WH2 does not fall within the region RH in which the radiation R is emitted and is present outside the region RH. Therefore, the projection image <NUM> obtained at the irradiation position <NUM>H includes the entire breast WH1 and a part of the breast WH2.

As described above, as the thickness of the object becomes larger, the irradiation angle of the radiation R capable of capturing an image including the entire object becomes smaller. Therefore, in a case in which the thickness of the object is large, the overall imaging irradiation angle range ARa is narrow.

In addition, the "area of the object" means the area of the breast that is compressed by the compression plate <NUM> and is irradiated with the radiation R. In this embodiment, the "area of the object" means the contact area of the breast with the imaging surface 24A of the imaging table <NUM> or the contact area of the breast with the compression plate <NUM>.

As the area of the breast becomes larger, the width of the breast becomes larger. Therefore, in the example illustrated in <FIG>, the area of a breast WL2 having a width L2 is larger than that of a breast WL1 having a width L1. In a case in which the radiation source <NUM> is located at the irradiation position <NUM><NUM>, both the entire breast WL1 having the width L1 and the entire breast WL2 having the width L2 larger than the width L1 are present in the region R<NUM> in which the radiation R is emitted. Therefore, the projection image <NUM> obtained at the irradiation position <NUM><NUM> includes both the entire breast WL1 and the entire breast WL2. However, in a case in which the radiation source <NUM> is located at an irradiation position <NUM>L, the entire breast WL1 is present in a region RL in which the radiation R is emitted. On the other hand, the breast W<NUM> does not fall within the region RL in which the radiation R is emitted and is present outside the region RL. Therefore, the projection image <NUM> obtained at the irradiation position <NUM>L includes the entire breast WL1 and a part of the breast WL2.

As described above, as the area of the object becomes larger, the irradiation angle of the radiation R capable of capturing an image including the entire object becomes smaller. Therefore, in a case in which the area of the object is large, the overall imaging irradiation angle range ARa is narrow.

As described above, since the overall imaging irradiation angle range ARa changes depending on the thickness of the breast and the area of the breast, the information acquisition unit <NUM> according to this embodiment acquires the overall imaging information indicating the overall imaging irradiation angle range ARa.

For example, in this embodiment, irradiation angle range correspondence relationship information in which the thickness of the breast and the area of the breast are associated with the overall imaging irradiation angle range ARa is obtained in advance. The information acquisition unit <NUM> acquires the overall imaging information indicating the overall imaging irradiation angle range ARa with reference to the irradiation angle range correspondence relationship information.

First, the information acquisition unit <NUM> acquires the thickness and area of the breast compressed by the compression plate <NUM>. A method by which the information acquisition unit <NUM> acquires the thickness of the breast is not particularly limited. For example, in this embodiment, the information acquisition unit <NUM> acquires the thickness of the breast on the basis of the amount of movement of the compression plate <NUM> by the compression unit <NUM> in a case in which the breast is compressed.

Further, a method by which the information acquisition unit <NUM> acquires the area of the breast is not particularly limited. For example, in this embodiment, the information acquisition unit <NUM> acquires the area of the breast on the basis of the size of the breast input by the user through the operation unit <NUM> of the console <NUM>. Specifically, area correspondence relationship information in which information indicating the size of the breast, such as a large size, a medium size, and a small size, and the average area of the breast at the size are associated with each other is obtained in advance. The information acquisition unit <NUM> acquires the area of the breast corresponding to the size of the breast input by the user through the operation unit <NUM> with reference to the area correspondence relationship information.

A method by which the information acquisition unit <NUM> acquires the area of the breast is not limited to this aspect. For example, a contact sensor may be provided in the surface of the imaging table <NUM> or the compression plate <NUM> which comes into contact with the breast, and the information acquisition unit <NUM> may acquire the area of the breast according to the range in which the contact sensor detects the contact of the breast. In addition, for example, a visible light imaging device that captures an image with visible light may be used, and the information acquisition unit <NUM> may acquire a visible light image of a compressed surface of the breast compressed by the compression plate <NUM> and acquire the area of the breast according to the size of a breast region included in the visible light image.

In addition, the information acquisition unit <NUM> acquires the overall imaging information indicating the overall imaging irradiation angle range ARa which corresponds to the thickness and area of the breast with reference to the irradiation angle range correspondence relationship information. Then, the information acquisition unit <NUM> outputs the acquired overall imaging information to the irradiation angle range control unit <NUM>, the image acquisition unit <NUM>, and the second tomographic image generation unit <NUM>.

The irradiation angle range control unit <NUM> has a function of directing the mammography apparatus <NUM> to execute control to perform the tomosynthesis imaging in an irradiation angle range which is wider than the overall imaging irradiation angle range ARa corresponding to the overall imaging information. The irradiation angle range control unit <NUM> according to this embodiment sets, as the irradiation angle range, the first irradiation angle range AR<NUM> wider than the overall imaging irradiation angle range ARa corresponding to the overall imaging information input from the information acquisition unit <NUM> for the mammography apparatus <NUM>. In the mammography apparatus <NUM>, the control unit <NUM> directs the radiation source moving unit <NUM> to move the radiation source <NUM> and performs the tomosynthesis imaging in the irradiation angle range set by the console <NUM>. Therefore, the mammography apparatus <NUM> performs the tomosynthesis imaging in the first irradiation angle range AR<NUM> as the irradiation angle range. In addition, the extent to which the irradiation angle range control unit <NUM> makes the first irradiation angle range AR<NUM> wider than the overall imaging irradiation angle range ARa is not particularly limited. That is, a difference between the first irradiation angle range AR<NUM> and the overall imaging irradiation angle range ARa is not particularly limited. For example, the difference between the first irradiation angle range AR<NUM> and the overall imaging irradiation angle range ARa may be a predetermined value, such as ±<NUM> degrees, or a value corresponding to the desired resolution.

The image acquisition unit <NUM> has a function of acquiring a projection image group including a plurality of projection images <NUM> obtained by the tomosynthesis imaging in an irradiation angle range wider than the overall imaging irradiation angle range ARa. Specifically, the image acquisition unit <NUM> according to this embodiment acquires the projection images <NUM><NUM> to <NUM><NUM> obtained by the tomosynthesis imaging in the first irradiation angle range AR<NUM> as the irradiation angle range wider than the overall imaging irradiation angle range ARa corresponding to the overall imaging information input from the information acquisition unit <NUM>. The image acquisition unit <NUM> outputs image data indicating the acquired projection images <NUM><NUM> to <NUM><NUM> to the first tomographic image generation unit <NUM> and the second tomographic image generation unit <NUM>.

The first tomographic image generation unit <NUM> has a function of generating a plurality of first tomographic images <NUM><NUM> including a part of the object, using a plurality of projection images <NUM><NUM> to <NUM><NUM> obtained by the tomosynthesis imaging in the first irradiation angle range AR<NUM> among the projection images included in the projection image group acquired by the image acquisition unit <NUM>. A method by which the first tomographic image generation unit <NUM> generates the plurality of first tomographic images <NUM><NUM> is not particularly limited, and a known method may be used. For example, reconstruction may be performed by a back projection method, such as a filter back projection (FBP) method or an iterative reconstruction method, or a known technique may be applied. The slice thickness (hereinafter, referred to as a "first slice thickness") of the tomographic images <NUM><NUM> generated by the first tomographic image generation unit <NUM> is not particularly limited. In addition, as the resolution of the tomographic image becomes higher, the slice thickness can become smaller. Therefore, in this embodiment, the first slice thickness is smaller than the slice thickness of the second tomographic image <NUM><NUM> (hereinafter, referred to as a "second slice thickness"). Specifically, the first slice thickness can be determined according to, for example, the size of a region of interest, the quality of the radiographic image, the processing load of arithmetic processing in the generation, and an instruction from the user. The first tomographic image generation unit <NUM> outputs image data indicating the generated plurality of first tomographic images <NUM><NUM> to the first composite two-dimensional image generation unit <NUM> and the display control unit <NUM>.

The first composite two-dimensional image generation unit <NUM> has a function of generating a first composite two-dimensional image obtained by combining at least some of the plurality of first tomographic images <NUM><NUM>. The first composite two-dimensional image generation unit <NUM> outputs image data indicating the generated first composite two-dimensional image to the display control unit <NUM>.

A method by which the first composite two-dimensional image generation unit <NUM> generates the first composite two-dimensional image is not particularly limited, and a known method may be used. For example, the first composite two-dimensional image generation unit <NUM> uses the method described in the specification of <CIT>. <CIT> discloses a technique that blends (combines) a region of interest (ROI) detected from a tomographic image with a two-dimensional image to a composite two-dimensional image in which a lesion or the like detected from the tomographic image has been reflected. In addition, a method for detecting the region of interest from the tomographic image is not particularly limited. For example, a method that extracts the region of interest from the tomographic image using a known computer-aided diagnosis (hereinafter, referred to as CAD) algorithm is given as an example. In the CAD algorithm, preferably, the probability (for example, likelihood) that a pixel in the tomographic image will be the region of interest is derived, and the pixel is detected as a pixel constituting the image of the region of interest in a case in which the probability is equal to or greater than a predetermined threshold value. Further, for example, a method may be used which extracts the region of interest from the tomographic image by a filtering process or the like using a filter for extracting the region of interest.

Further, as a method by which the first composite two-dimensional image generation unit <NUM> generates the first composite two-dimensional image, for example, a method may be used which generates a composite two-dimensional image by projecting a plurality of tomographic images, or at least one of the plurality of tomographic images and at least one of a plurality of projection images in a depth direction in which the tomographic planes of the breast are arranged or by using a minimum intensity projection method, which is disclosed in <CIT>. In addition, for example, a method may be used which generates a composite two-dimensional image by reconstructing a plurality of tomographic images or at least one of the plurality of tomographic images and at least one of a plurality of projection images using any one of a filtered back projection method, a maximum likelihood reconstruction method, an iterative reconstruction method, a reconstruction method using an algebraic method, or a three-dimensional reconstruction method, which is disclosed in <CIT>.

On the other hand, the second tomographic image generation unit <NUM> has a function of generating a plurality of second tomographic images <NUM><NUM> including the entire object, using a plurality of projection images <NUM><NUM> to <NUM><NUM> obtained by the tomosynthesis imaging in the second irradiation angle range AR<NUM> among the projection images included in the projection image group acquired by the image acquisition unit <NUM>. Specifically, the second tomographic image generation unit <NUM> acquires the projection images <NUM><NUM> to <NUM><NUM> obtained by the tomosynthesis imaging in the second irradiation angle range AR<NUM> which is an irradiation angle range equal to or narrower than the overall imaging irradiation angle range ARa corresponding to the overall imaging information input from the information acquisition unit <NUM> from the image acquisition unit <NUM>. Then, the second tomographic image generation unit <NUM> generates a plurality of second tomographic images <NUM><NUM> using the acquired projection images <NUM><NUM> to <NUM><NUM>. The second slice thickness of the second tomographic image <NUM><NUM> is not particularly limited. However, in this embodiment, as described above, the second slice thickness is larger than the first slice thickness. Specifically, the second slice thickness can be determined according to, for example, the size of the region of interest, the quality of the radiographic image, the processing load of arithmetic processing in the generation, and an instruction from the user. In addition, a method by which the second tomographic image generation unit <NUM> generates the plurality of second tomographic images <NUM><NUM> is not particularly limited. For example, the same method as that by which the first tomographic image generation unit <NUM> generates the first tomographic image <NUM><NUM> may be applied. The second tomographic image generation unit <NUM> outputs image data indicating the generated plurality of second tomographic images <NUM><NUM> to the second composite two-dimensional image generation unit <NUM> and the display control unit <NUM>.

The second composite two-dimensional image generation unit <NUM> has a function of generating a second composite two-dimensional image obtained by combining at least some of the plurality of second tomographic images <NUM><NUM>. The second composite two-dimensional image generation unit <NUM> outputs image data indicating the generated second composite two-dimensional image to the display control unit <NUM>. A method by the second composite two-dimensional image generation unit <NUM> generates the second composite two-dimensional image is not particularly limited. For example, the same method as that by which the first composite two-dimensional image generation unit <NUM> generates the first composite two-dimensional image may be applied.

The display control unit <NUM> has a function of displaying at least one of the first tomographic image <NUM><NUM>, the second tomographic image <NUM><NUM>, the first composite two-dimensional image, or the second composite two-dimensional image on the display unit <NUM>. The display form of these images by the display control unit <NUM> will be described in detail below.

Next, the operation of the console <NUM> in the tomosynthesis imaging will be described with reference to the drawings. After directing the mammography apparatus <NUM> to perform the tomosynthesis imaging (<FIG>, Step S10), the console <NUM> generates various radiographic images using the projection image group obtained by the tomosynthesis imaging and displays the radiographic images on, for example, the display unit <NUM> (See <FIG>, Step S12).

First, the operation of the console <NUM> directing the mammography apparatus <NUM> to perform the tomosynthesis imaging in Step S10 of <FIG> will be described. In a case in which the tomosynthesis imaging is performed, the user positions the breast as the object on the imaging table <NUM> of the mammography apparatus <NUM> and compresses the breast with the compression plate <NUM>. In a case in which the compression of the breast is completed, the console <NUM> performs an imaging control process illustrated in <FIG>. Specifically, in a case in which the console <NUM> receives information indicating that the compression of the breast has been completed in a state in which an instruction to perform the tomosynthesis imaging is included in the imaging menu acquired from RIS, the console <NUM> performs the imaging control process illustrated in <FIG> is a flowchart illustrating an example of the flow of the imaging control process performed by the console <NUM> according to this embodiment. In the console <NUM> according to this embodiment, for example, the CPU 50A of the control unit <NUM> executes the imaging control program 51A stored in the ROM 50B to perform the imaging control process whose example is illustrated in <FIG>.

In Step S100 of <FIG>, the information acquisition unit <NUM> acquires the thickness of the breast. As described above, the information acquisition unit <NUM> according to this embodiment acquires the thickness of the breast on the basis of the amount of movement of the compression plate <NUM> by the compression unit <NUM> in a case in which the breast is compressed.

Then, in Step S102, the information acquisition unit <NUM> acquires the area of the breast. As described above, the information acquisition unit <NUM> according to this embodiment acquires the area of the breast on the basis of the size of the breast input by the user through the operation unit <NUM> of the console <NUM>.

Then, in Step S104, the information acquisition unit <NUM> acquires the overall imaging information indicating the overall imaging irradiation angle range ARa. As described above, the information acquisition unit <NUM> according to this embodiment acquires the overall imaging information corresponding to the thickness of the breast acquired in Step S100 and the area of the breast acquired in Step S102 with reference to the irradiation angle range correspondence relationship information.

Then, in Step S106, the irradiation angle range control unit <NUM> sets the irradiation angle range in the tomosynthesis imaging for the mammography apparatus <NUM>. As described above, the irradiation angle range control unit <NUM> according to this embodiment specifies the first irradiation angle range AR<NUM> on the basis of the overall imaging information acquired by the information acquisition unit <NUM> in Step S104 and sets the specified first irradiation angle range AR<NUM> as the irradiation angle range in the mammography apparatus <NUM>. In a case in which the process in Step S106 ends, the imaging control process illustrated in <FIG> ends. Therefore, in the mammography apparatus <NUM>, the radiation source <NUM> is moved to each of the irradiation positions <NUM><NUM> to <NUM><NUM>, and the tomosynthesis imaging in the first irradiation angle range AR<NUM> is performed to capture the projection images <NUM><NUM> to <NUM><NUM>.

In a case in which the tomosynthesis imaging by the mammography apparatus <NUM> ends, the generation and display of various radiographic images by the console <NUM> in Step S12 of <FIG> are performed. The operation of the console <NUM> in the generation and display of various radiographic images will be described.

For example, in a case in which the tomosynthesis imaging ends, the mammography apparatus <NUM> according to this embodiment outputs the image data of the captured projection image group to the console <NUM>. The console <NUM> stores the image data of the projection image group input from the mammography apparatus <NUM> in the storage unit <NUM>.

After storing the image data of the projection image group in the storage unit <NUM>, the console <NUM> performs image processing illustrated in <FIG> is a flowchart illustrating an example of the flow of the image processing performed by the console <NUM> according to this embodiment. In the console <NUM> according to this embodiment, for example, the CPU 50A of the control unit <NUM> executes the image generation program 51B stored in the ROM 50B to perform the image processing whose example is illustrated in <FIG>.

In Step S200 of <FIG>, the image acquisition unit <NUM> acquires the projection image group. As described above, the image acquisition unit <NUM> according to this embodiment acquires, as the projection image group, the projection images <NUM><NUM> to <NUM><NUM> obtained by the tomosynthesis imaging in the first irradiation angle range AR<NUM> as the irradiation angle range wider than the overall imaging irradiation angle range ARa corresponding to the overall imaging information input from the information acquisition unit <NUM>.

Then, in Step S202, the first tomographic image generation unit <NUM> generates the first tomographic image <NUM><NUM>. As described above, the first tomographic image generation unit <NUM> according to this embodiment generates a plurality of first tomographic images <NUM><NUM> including a part of the object with the first slice thickness, using the plurality of projection images <NUM><NUM> to <NUM><NUM> obtained by the tomosynthesis imaging in the first irradiation angle range AR<NUM> among the projection images included in the projection image group acquired in Step S200.

Then, in Step S204, the first composite two-dimensional image generation unit <NUM> generates the first composite two-dimensional image. As described above, the first composite two-dimensional image generation unit <NUM> according to this embodiment combines at least some of the plurality of first tomographic images <NUM><NUM> generated in Step S202 to generate the first composite two-dimensional image.

Then, in Step S206, the second tomographic image generation unit <NUM> generates the second tomographic image <NUM><NUM>. As described above, the second tomographic image generation unit <NUM> according to this embodiment generates a plurality of second tomographic images <NUM><NUM> including the entire object, using a plurality of projection images <NUM><NUM> to <NUM><NUM> obtained by the tomosynthesis imaging in the second irradiation angle range AR<NUM> among the projection images included in the projection image group acquired in Step S200.

Then, in Step S208, the second composite two-dimensional image generation unit <NUM> generates the second composite two-dimensional image. As described above, the second composite two-dimensional image generation unit <NUM> according to this embodiment combines at least some of the plurality of second tomographic images <NUM><NUM> generated in Step S206 to generate the second composite two-dimensional image.

Then, in Step S210, the display control unit <NUM> displays various radiographic images. Specifically, the display control unit <NUM> performs control to display the plurality of first tomographic image <NUM><NUM> generated in Step S202, the first composite two-dimensional image generated in Step S204, the plurality of second tomographic images <NUM><NUM> generated in Step S206, and the second composite two-dimensional image generated in Step S208 on the display unit <NUM>.

For example, first, the display control unit <NUM> according to this embodiment displays the first tomographic image <NUM><NUM> and the second tomographic image <NUM><NUM> side by side on the display unit <NUM>. <FIG> illustrates an example of a state in which the first tomographic image <NUM><NUM> and the second tomographic image <NUM><NUM> are displayed on the display unit <NUM>. As illustrated in <FIG>, one first tomographic image <NUM><NUM> and a slider bar <NUM><NUM> are displayed on the display unit <NUM>. In a case in which the user operates the operation unit <NUM> to move a bar of the slider bar <NUM><NUM> along a slider, the first tomographic image <NUM><NUM> having a height corresponding to the position of the bar is displayed on the display unit <NUM>. Further, the second tomographic image <NUM><NUM> and a slider bar <NUM><NUM> are displayed on the display unit <NUM>. In a case in which the user operates the operation unit <NUM> to move a bar of the slider bar <NUM><NUM> along a slider, the second tomographic image <NUM><NUM> having a height corresponding to the position of the bar is displayed on the display unit <NUM>. In addition, the display control unit <NUM> according to this embodiment performs control to align the tomographic planes of the first tomographic image <NUM><NUM> and the second tomographic image <NUM><NUM> displayed on the display unit <NUM>. In other words, the display control unit <NUM> performs control to align the heights of the first tomographic image <NUM><NUM> and the second tomographic image <NUM><NUM> displayed on the display unit <NUM>. Therefore, in a case in which the user operates either the slider bar <NUM><NUM> or the slider bar <NUM><NUM> to change the height of either the first tomographic image <NUM><NUM> or the second tomographic image <NUM><NUM> displayed on the display unit <NUM>, the height of the other of the first tomographic image <NUM><NUM> and the second tomographic image <NUM><NUM> displayed on the display unit <NUM> is also changed. Further, unlike this embodiment, the tomographic planes of the first tomographic image <NUM><NUM> and the second tomographic image <NUM><NUM> displayed on the display unit <NUM> may be different from each other, or a configuration that enables the user to switch whether or not to align the tomographic planes may be used.

Furthermore, as illustrated in <FIG>, in a case in which the first tomographic image <NUM><NUM> is displayed, the display control unit <NUM> according to this embodiment displays reconstructed region information <NUM> indicating the reconstructed region <NUM><NUM> of the first tomographic image <NUM><NUM> so as to be superimposed on the first tomographic image <NUM><NUM>. This display of the reconstructed region information <NUM> indicating the reconstructed region <NUM><NUM> on the first tomographic image <NUM><NUM> makes it easy for the user to compare the first tomographic image <NUM><NUM> with the second tomographic image <NUM><NUM>. In addition, the reconstructed region information <NUM> according to this embodiment is an example of information indicating a range of an object according to the present disclosure.

Further, as illustrated in <FIG>, the display control unit <NUM> according to this embodiment displays switching buttons <NUM><NUM> and <NUM><NUM> on the display unit <NUM>. In a case in which the operation of the switching button <NUM><NUM> by the user through the operation unit <NUM> is received, the display control unit <NUM> performs control to switch the radiographic image displayed on the display unit <NUM> from one of the first tomographic image <NUM><NUM> and the first composite two-dimensional image <NUM><NUM> to the other. In a case in which the user operates the switching button <NUM><NUM> in the state illustrated in <FIG>, the first composite two-dimensional image <NUM><NUM> is displayed on the display unit <NUM> instead of the first tomographic image <NUM><NUM>, as illustrated in <FIG>. On the other hand, in a case in which the operation of the switching button <NUM><NUM> by the user through the operation unit <NUM> is received, the display control unit <NUM> performs control to switch the radiographic image displayed on the display unit <NUM> from one of the second tomographic image <NUM><NUM> and the second composite two-dimensional image <NUM><NUM> to the other. In a case in which the user operates the switching button <NUM><NUM> in the state illustrated in <FIG>, the second composite two-dimensional image <NUM><NUM> is displayed on the display unit <NUM> instead of the second tomographic image <NUM><NUM>, as illustrated in <FIG>. In the example illustrated in <FIG>, the reconstructed region information <NUM> is displayed on the second composite two-dimensional image <NUM><NUM>. This display of the reconstructed region information <NUM> on the second composite two-dimensional image <NUM><NUM> makes it easy for the user to compare the first tomographic image <NUM><NUM> or the first composite two-dimensional image <NUM><NUM> with the second composite two-dimensional image <NUM><NUM>.

In a case in which the process in Step S210 ends in this way, the image processing illustrated in <FIG> ends.

As described above, the console <NUM> according to the above-described embodiment is used in the mammography apparatus <NUM> performing the tomosynthesis imaging which irradiates the breast with the radiation R emitted from the radiation source <NUM> at each of the plurality of irradiation positions <NUM> having different irradiation angles to capture the projection images <NUM> of the breast at each of the irradiation positions <NUM>. The console <NUM> comprises the CPU 50A as at least one processor. The CPU 50A acquires a projection image group including a plurality of projection images <NUM> obtained by the tomosynthesis imaging in an irradiation angle range wider than the overall imaging irradiation angle range ARa in which the tomographic image <NUM> including the entire breast can be obtained in a case in which the tomographic image <NUM> is generated using the projection images <NUM> obtained at each of the plurality of irradiation positions <NUM>. The CPU 50A generates a plurality of first tomographic images <NUM><NUM> including a part of the breast, using a plurality of projection images <NUM><NUM> to <NUM><NUM> obtained by the tomosynthesis imaging in the first irradiation angle range AR<NUM> wider than the overall imaging irradiation angle range ARa among the projection images <NUM> included in the projection image group. The CPU 50A generates a plurality of first tomographic images <NUM><NUM> including the entire breast, using a plurality of projection images <NUM><NUM> to <NUM><NUM> obtained by the tomosynthesis imaging in the second irradiation angle range AR<NUM> which is equal to or narrower than the overall imaging irradiation angle range ARa among the projection images <NUM> included in the projection image group.

As described above, the console <NUM> according to the above-described embodiment generates two types of tomographic images <NUM> from the projection image group obtained by the tomosynthesis imaging in an irradiation angle range wider than the overall imaging irradiation angle range ARa. The first tomographic image <NUM> is the first tomographic image <NUM><NUM> corresponding to the tomosynthesis imaging in the first irradiation angle range AR<NUM> wider than the overall imaging irradiation angle range ARa. Since the first irradiation angle range AR<NUM> is wider than the overall imaging irradiation angle range ARa, the first tomographic image <NUM><NUM> is an image in which a part of the object is included, but is a high-resolution image. The second tomographic image <NUM> is the second tomographic image <NUM><NUM> corresponding to the tomosynthesis imaging in the second irradiation angle range AR<NUM> that is equal to or narrower than the overall imaging irradiation angle range ARa. Since the second irradiation angle range AR<NUM> is equal to or narrower than the overall imaging irradiation angle range ARa, the second tomographic image <NUM><NUM> has a lower resolution than the first tomographic image <NUM><NUM>, but is an image in which the entire object is included.

Therefore, the console <NUM> according to the above-described embodiment can generate a high-resolution tomographic image and a tomographic image including the entire object from the projection image group including a plurality of projection images obtained by the tomosynthesis imaging in the irradiation angle range in which the entire object is not included in the tomographic image in a case in which the tomographic image is generated using all of the projection images.

Further, in the above-described embodiment, the tomosynthesis imaging in the first irradiation angle range AR<NUM> and the tomosynthesis imaging in the second irradiation angle range AR<NUM> can be performed by one tomosynthesis imaging operation. Therefore, even in an aspect in which the tomosynthesis imaging in the first irradiation angle range AR<NUM> and the tomosynthesis imaging in the second irradiation angle range AR<NUM> are performed separately, that is, an aspect in which the tomosynthesis imaging is performed twice, it is possible to reduce the time until two tomosynthesis imaging operations end. In addition, the movement of the object can be suppressed by suppressing the time until imaging ends.

In this embodiment, "one tomosynthesis imaging operation" means at least tomosynthesis imaging that is performed with the breast compressed by the compression plate <NUM>. Therefore, the one tomosynthesis imaging operation also includes a case in which, after the tomosynthesis imaging in the first irradiation angle range AR<NUM> is performed with the breast compressed by the compression plate <NUM>, the tomosynthesis imaging in the second irradiation angle range AR<NUM> is performed with the breast compressed by the compression plate <NUM>. Alternatively, the "one tomosynthesis imaging" means tomosynthesis imaging that is performed from the start of the capture of the projection image <NUM> at the irradiation position <NUM> defined as a start position to the end of the capture of the projection image <NUM> at the irradiation position <NUM> defined as an end position by, for example, the imaging menu.

For one tomosynthesis imaging operation, an example different from the above-mentioned aspect will be described with reference to <FIG>. First, the breast W is compressed by the compression plate <NUM> (not illustrated in <FIG>), the radiation source <NUM> is moved from the irradiation position <NUM><NUM> defined as the start position to the irradiation position <NUM><NUM> in a movement direction M1, and the tomosynthesis imaging in the first irradiation angle range AR<NUM> is performed. Then, the radiation source <NUM> is moved from the irradiation position <NUM><NUM> to the irradiation position <NUM><NUM> in a movement direction M2 in a state in which the breast W is compressed by the compression plate <NUM>. In a case in which the radiation source <NUM> reaches the irradiation position <NUM><NUM>, the radiation source <NUM> is moved from the irradiation position <NUM><NUM> to the irradiation position <NUM><NUM> defined as the end position in a movement direction M3 in a state in which the breast W is compressed, and the tomosynthesis imaging in the second irradiation angle range AR<NUM> is performed. As described above, two types of tomosynthesis imaging are performed in a state in which the breast W is compressed by the compression plate <NUM>. Therefore, it is possible to suppress the movement of the breast due to body movement during each tomosynthesis imaging operation.

Further, in the above-described embodiment, the projection images <NUM><NUM> to <NUM><NUM> obtained by the tomosynthesis imaging in the first irradiation angle range AR<NUM> are used as the projection images <NUM><NUM> to <NUM><NUM> obtained by the tomosynthesis imaging in the second irradiation angle range AR<NUM>. As described above, the console <NUM> according to the above-described embodiment uses one projection image <NUM> to generate the first tomographic image <NUM><NUM> and the second tomographic image <NUM><NUM>. Therefore, it is possible to reduce the number of times the projection image <NUM> is captured in the entire tomosynthesis imaging and to shorten the time related to the entire tomosynthesis imaging until the two types of tomosynthesis imaging end.

In addition, in the above-described embodiment, the aspect in which projection images <NUM><NUM> to <NUM><NUM> obtained at the irradiation positions <NUM><NUM> to <NUM><NUM> in the second irradiation angle range AR<NUM> are used to generate both the first tomographic image <NUM><NUM> and the second tomographic image <NUM><NUM> has been described. However, the present disclosure is not limited to this aspect. Each of the projection images <NUM><NUM> to <NUM><NUM> may be used to generate either the first tomographic image <NUM><NUM> or the second tomographic image <NUM><NUM>. For example, the irradiation positions <NUM><NUM> and <NUM><NUM> may be used to generate the first tomographic image <NUM><NUM>, and the irradiation positions <NUM><NUM>, <NUM><NUM>, and <NUM><NUM> may be used to generate the second tomographic image <NUM><NUM>. In other words, the irradiation positions <NUM> in the first irradiation angle range AR<NUM> may be the irradiation positions <NUM><NUM> to <NUM><NUM>, <NUM><NUM>, <NUM><NUM>, and <NUM><NUM> to <NUM><NUM>, and the irradiation positions <NUM> in the second irradiation angle range AR<NUM> may be the irradiation positions <NUM><NUM>, <NUM><NUM>, and <NUM><NUM>.

Further, in the above-described embodiment, the aspect in which the radiation source <NUM> of the mammography apparatus <NUM> comprises one radiation tube <NUM> and is moved to each irradiation position <NUM> to perform the tomosynthesis imaging has been described. However, the radiation source <NUM> comprising a plurality of radiation tubes <NUM> may be used, and the tomosynthesis imaging may be performed without moving the radiation source <NUM>. <FIG> illustrates an example of the radiation source <NUM> comprising the plurality of radiation tubes <NUM>. In addition, <FIG> illustrates the radiation source <NUM> comprising nine radiation tubes <NUM>. However, the number of radiation tubes <NUM> comprised in the radiation source <NUM> is not limited to this aspect. The nine radiation tubes <NUM> are divided such that three radiation tubes <NUM> are accommodated in each of three housings <NUM><NUM> to <NUM><NUM>. The three housings <NUM><NUM> to <NUM><NUM> are disposed in the radiation emitting unit <NUM> in a state of being accommodated in a radiation source accommodation portion <NUM>.

In a case in which the mammography apparatus <NUM> performs the tomosynthesis imaging, the radiation source <NUM> of the radiation emitting unit <NUM> sequentially emits radiation at each of the plurality of irradiation positions having different irradiation angles. The radiation source <NUM> includes a plurality of radiation tubes <NUM>, and each of the plurality of radiation tubes <NUM> is disposed at the irradiation positions <NUM>.

<FIG> is a diagram illustrating an example of the tomosynthesis imaging performed using the radiation source <NUM> illustrated in <FIG>. In addition, the compression plate <NUM> is not illustrated in <FIG>. In this embodiment, as illustrated in <FIG>, the radiation tubes <NUM><NUM> to <NUM>j (j = <NUM>,. , the maximum value is <NUM> in <FIG>) of the radiation source <NUM> are disposed at predetermined irradiation positions <NUM>j. In other words, in the example illustrated in <FIG>, the radiation tubes <NUM><NUM> to <NUM><NUM> are disposed at the irradiation positions <NUM><NUM> to <NUM><NUM> where the radiation R is incident on the detection surface 20A of the radiation detector <NUM> at different angles. At each of the irradiation positions <NUM><NUM> to <NUM><NUM>, the radiation R is sequentially emitted from the radiation source <NUM> to the breast W in response to an instruction from the console <NUM>, and the radiation detector <NUM> captures projection images. In the radiography system <NUM>, the radiation R is sequentially emitted from the radiation tubes <NUM><NUM> to <NUM><NUM> to sequentially capture the projection images <NUM><NUM> to <NUM><NUM>. In the example illustrated in <FIG>, nine projection images are obtained.

In a case in which the irradiation angle range is the first irradiation angle range AR<NUM> wider than the overall imaging irradiation angle range ARa, a partial region <NUM><NUM> common to object regions <NUM><NUM> to <NUM><NUM> included in projection images <NUM><NUM> to <NUM><NUM> obtained at each of the irradiation positions <NUM><NUM> to <NUM><NUM> corresponds to a reconstructed region <NUM><NUM> in a case in which a first tomographic image <NUM><NUM> is generated. The partial region <NUM><NUM>, that is, the reconstructed region <NUM><NUM> is smaller than the object regions <NUM><NUM> to <NUM><NUM> included in the projection images <NUM><NUM> to <NUM><NUM>. Therefore, in this aspect, the first tomographic image <NUM><NUM> is an image in which a part of the object is included. For example, <FIG> illustrates the first tomographic image <NUM><NUM> in which a part of the breast W, which is the object, is included.

Since the first irradiation angle range AR<NUM> is wider than the overall imaging irradiation angle range ARa, the first tomographic image <NUM><NUM> generated using a plurality of first projection images <NUM><NUM> to <NUM><NUM> obtained by the tomosynthesis imaging in the first irradiation angle range AR<NUM> is a high-resolution image.

In a case in which the irradiation angle range is the second irradiation angle range AR<NUM>, a partial region <NUM><NUM> common to the object regions <NUM><NUM> to <NUM><NUM> included in the projection images <NUM><NUM> to <NUM><NUM> obtained at each of the irradiation positions <NUM><NUM> to <NUM><NUM> corresponds to a reconstructed region <NUM><NUM> in a case in which a second tomographic image <NUM><NUM> is generated. The partial region <NUM><NUM>, that is, the reconstructed region <NUM><NUM> is equivalent to the object regions <NUM><NUM> to <NUM><NUM> included in the projection images <NUM><NUM> to <NUM><NUM>. Therefore, in this embodiment, the second tomographic image <NUM><NUM> is an image in which the entire object is included. For example, <FIG> illustrates the second tomographic image <NUM><NUM> in which the entire breast W, which is the object, is included.

As described above, in a case in which the radiation source <NUM> includes the plurality of radiation tubes <NUM> and each of the plurality of radiation tubes <NUM> is disposed at the irradiation positions <NUM>, it is possible to perform the tomosynthesis imaging without moving the radiation source <NUM>, that is, the radiation tubes <NUM> to each irradiation position <NUM>. In addition, in the example illustrated in <FIG>, the aspect in which the radiation tubes <NUM><NUM> to <NUM><NUM> are arranged in a straight line has been described. However, the specific arrangement of the radiation tubes <NUM><NUM> to <NUM><NUM> is not limited to this aspect. For example, the radiation tubes <NUM><NUM> to <NUM><NUM> may be disposed in a state in which the axes connecting the focuses of the radiation tubes <NUM><NUM> to <NUM><NUM> and a preset position, such as the center of the detection surface 20A, have the same length. In this case, since the positions where the radiation tubes <NUM><NUM> to <NUM><NUM> are disposed are the irradiation positions <NUM>, the radiation tubes <NUM><NUM> to <NUM><NUM> are disposed so as to draw an arc like the irradiation positions <NUM><NUM> to <NUM><NUM> illustrated in <FIG>.

Further, in the above-described embodiment, the aspect in which the console <NUM> is an example of the image processing device and the imaging control device according to the present disclosure has been described. However, devices other than the console <NUM> may have the functions of the image processing device and the imaging control device according to the present disclosure. In other words, a device, such as the mammography apparatus <NUM> or an external device, other than the console <NUM> may have some or all of the functions of the information acquisition unit <NUM>, the irradiation angle range control unit <NUM>, the image acquisition unit <NUM>, the first tomographic image generation unit <NUM>, the first composite two-dimensional image generation unit <NUM>, the second tomographic image generation unit <NUM>, the second composite two-dimensional image generation unit <NUM>, and the display control unit <NUM>. In addition, in the above-described embodiment, the aspect in which one device has the functions of the image processing device and the imaging control device has been described. However, different devices may have the functions of the image processing device and the imaging control device. Further, for example, a device other than the console <NUM> or a plurality of devices including the console <NUM> may have some or all of the functions of the image processing device and the imaging control device.

In addition, in the above-described embodiment, the aspect in which the breast is applied as an example of the object according to the present disclosure and the mammography apparatus <NUM> is applied as an example of the radiography apparatus according to the present disclosure has been described. However, the object is not limited to the breast, and the radiography apparatus is not limited to the mammography apparatus. For example, the object may be the chest, the abdomen, or the like, and radiography apparatuses other than the mammography apparatus may be applied.

Further, in the above-described embodiment, for example, the following various processors can be used as the hardware structure of processing units performing various processes such as the information acquisition unit <NUM>, the irradiation angle range control unit <NUM>, the image acquisition unit <NUM>, the first tomographic image generation unit <NUM>, the first composite two-dimensional image generation unit <NUM>, the second tomographic image generation unit <NUM>, the second composite two-dimensional image generation unit <NUM>, and the display control unit <NUM>. The various processors include, for example, a programmable logic device (PLD), such as a field programmable gate array (FPGA), that is a processor whose circuit configuration can be changed after manufacture and a dedicated electric circuit, such as an application specific integrated circuit (ASIC), that is a processor having a dedicated circuit configuration designed to perform a specific process, in addition to the CPU that is a general-purpose processor which executes software (programs) to function as various processing units as described above.

One processing unit may be configured by one of the various processors or 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). Further, a plurality of processing units may be configured by one processor.

A first example of the configuration in which a plurality of processing units are configured by one processor is an aspect in which one processor is configured by a combination of one or more CPUs and software and functions as a plurality of processing units. A representative example of this aspect is a client computer or a server computer. A second example of the configuration is an aspect in which a processor that implements the functions of the entire system including a plurality of processing units using one integrated circuit (IC) chip is used. A representative example of this aspect is a system-on-chip (SoC). As described above, various processing units are configured using one or more of the various processors as a hardware structure.

In addition, specifically, an electric circuit (circuitry) obtained by combining circuit elements, such as semiconductor elements, can be used as the hardware structure of the various processors.

Claim 1:
An image processing device that is used in a radiography apparatus (<NUM>) performing tomosynthesis imaging by irradiating a breast that is placed on an imaging table and is compressed by a compression member with radiation emitted from a radiation source (<NUM>) at each of a plurality of irradiation positions (<NUM><NUM> to <NUM><NUM>, <NUM>H, <NUM>L) having different irradiation angles to capture projection images of the compressed breast at each of the irradiation positions (<NUM><NUM> to <NUM><NUM>, <NUM>H, <NUM>L), the image processing device comprising:
at least one processor that is configured to:
acquire overall information corresponding to the thickness and the area of the compressed breast and determine an overall imaging irradiation angle (ARa) on the basis of the acquired overall imaging information, wherein the overall imaging irradiation angle range is a maximum irradiation angle range in which the tomographic image including the entire compressed breast, using the projection images obtained at each of the plurality of irradiation positions, can be obtained;
acquire a projection image group including a plurality of projection images (<NUM><NUM> to <NUM><NUM>) obtained by the tomosynthesis imaging in an irradiation angle range wider than the overall imaging irradiation angle range (ARa);
generate a plurality of first tomographic images (<NUM><NUM>) including a part of the compressed breast, using a first group of projection images (<NUM><NUM> to <NUM><NUM>) obtained by the tomosynthesis imaging in a first irradiation angle range (AR<NUM>) wider than the overall imaging irradiation angle range (ARa) among the projection images (<NUM><NUM> to <NUM><NUM>) included in the projection image group; and
generate a plurality of second tomographic images (<NUM><NUM>) including the entire compressed breast,
using a second group of projection images (<NUM><NUM> to <NUM><NUM>) obtained by the tomosynthesis imaging in a second irradiation angle range (AR<NUM>) that is equal to or narrower than the overall imaging irradiation angle range (ARa) among the projection images (<NUM><NUM> to <NUM><NUM>) included in the projection image group.