Patent Publication Number: US-10786218-B2

Title: Image displaying device, image processing device, radiographic imaging system, sectional image displaying method, and non-transitory computer readable medium

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. application Ser. No. 14/868,396, filed Sep. 29, 2015, issued as U.S. Pat. No. 9,993,214 on Jun. 12, 2018, which claims priority under 35 U.S.C. § 119 from Japanese Patent Application No. 2014-201558, filed on Sep. 30, 2014. Each of the applications listed above is incorporated by reference, in its entirety, into the present application. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to an image displaying device, an image processing device, a radiographic imaging system, a sectional image displaying method, and a non-transitory computer readable medium storing a sectional image displaying program. 
     Description of the Related Art 
     For medical diagnostic purposes, radiation is irradiated onto an imaging target of an examinee, who is a patient, and radiographic images are imaged using a radiographic imaging device. There are known examples of such radiographic imaging devices that image radiographic images of the breasts of an examinee, in what is referred to as mammography. 
     As such imaging methods, tomosynthesis imaging is known in which radiation is irradiated onto a breast from plural directions so as to image radiographic images, and a sectional image is generated based on the imaged radiographic images. 
     In tomosynthesis imaging, since plural sectional images are generally generated, there is technology to display to a user, such as a doctor who is reading a sectional image for diagnosis or the like, which position (slice) the sectional image being read corresponds to. 
     SUMMARY OF THE INVENTION 
     The present invention provides an image displaying device, an image processing device, a radiographic imaging system, a sectional image displaying method, and a non-transitory computer readable medium storing a sectional image displaying program that are, in cases in which a pair of related sectional images are displayed, coupled to switching slice position of one sectional image, capable of smoothly switching display of the other sectional image. 
     A first aspect of the present invention is an image displaying device, including: a display section that displays a pair of mutually related sectional images; a reception section that, for one sectional image of the pair of sectional images being displayed at the display section, receives a successive change instruction for a slice position; a generation section that generates a combined sectional image, corresponding to the slice position of the one sectional image, from the other sectional image of the pair of sectional images; and a controller that, in cases in which the reception section has received the successive change instruction, effects control so as to switch display of the one sectional image from the one sectional image being displayed to the one sectional image that corresponds to the slice position indicated in the successive change instruction, and, in conjunction with the switching, so as to successively switch display of the other sectional image from the other sectional image that is being displayed to the combined sectional image. 
     In a second aspect of the present invention, in the above aspect, the generation section, by combining two frames of the other sectional image that are close to a slice position corresponding to the combined sectional image at a combination proportion, may generate the combination proportion according to a slice position corresponding to the combined sectional image and slice positions corresponding to the two frames of the other sectional image. 
     In a third aspect of the present invention, in the above aspects, in cases in which the reception section has received the successive change instruction, the generation section may generate a combined sectional image, corresponding to the slice position of the one sectional image, from the other sectional image of the pair of sectional images; and the controller may effect control so as to switch display of the one sectional image from the one sectional image begin displayed to the one sectional image that corresponds to the slice position indicated in the successive change instruction, and, in conjunction with the switching, so as to successively switch display of the other sectional image from the other sectional image being displayed to the combined sectional image. 
     In a fourth aspect of the present invention, in the above aspects, after the reception section has finished receiving the successive change instruction, the controller may switch display of the other sectional image from the combined sectional image being displayed to the other sectional image corresponding to a slice position that is closest to a slice position corresponding to the combined sectional image. 
     In a fifth aspect of the present invention, in the above aspects, in cases in which the slice position indicated in the successive change instruction is a slice position having the largest value in the one sectional image, the controller may employ the other sectional image corresponding to the largest value of the other slice positions for display of the other sectional image; and in cases in which the slice position indicated in the successive change instruction is a slice position having the smallest value in the one sectional image, the controller may employ the other sectional image corresponding to the smallest value of the other slice positions for display of the other sectional image. 
     In a sixth aspect of the present invention, in the above aspects, the generation section may further generate a combined sectional image corresponding to a slice position between a predetermined plural slice positions corresponding to the one sectional image. 
     In a seventh aspect of the present invention, in the above aspects, after the reception section has received a successive change instruction for a slice position from a first slice position to a second slice position, in cases in which the reception section further receives a successive change instruction for a third slice position during a period in which successive switching of the combined sectional image is being performed by the controller according to the successive change instruction, the controller may effect control to stop the successive switching of display of the other sectional image and, after displaying the other sectional image at a slice position close to the second slice position in a successive switching direction, to successively switch from the sectional image being displayed to the combined sectional image corresponding to the third slice position. 
     In an eighth aspect of the present invention, in the first to sixth aspects, after the reception section has received a successive change instruction for a slice position from a first slice position to a second slice position, in cases in which the reception section further receives a successive change instruction for a third slice position during a period during a period in which successive switching of the combined sectional image is being performed by the controller according to the successive change instruction, for display of the other sectional image, the generation section may generate a new combined sectional image combined from the combined sectional image being displayed and the other sectional image, at a combination proportion according to a slice position corresponding to the combined sectional image being displayed and the third slice position, and the controller may effect control to stop the successive switching of display of the other sectional image and to successively switch to the new combined sectional image. 
     A ninth aspect is an image displaying device, including: a display section that displays a pair of mutually related sectional images; a reception section that, for one sectional image of the pair of sectional images being displayed at the display section, receives a successive change instruction for a slice position; a generation section that generates a combined sectional image, corresponding to a slice position between slice positions of the one sectional image, from the other sectional image of the pair of sectional images; and a controller that, in cases in which the reception section has received the successive change instruction, effects control so as to switch display of the one sectional image from the one sectional image being displayed to the one sectional image that corresponds to the slice position indicated in the successive change instruction, and, in conjunction with the switching, so as to successively switch display of the other sectional image from the other sectional image that is being displayed to the combined sectional image or to a sectional image. 
     A tenth aspect of the present invention is an image processing device, including: a reception section that receives a successive change instruction for a slice position for one sectional image of a pair of mutually related sectional images being displayed at a display section that displays the pair of sectional images; a generation section that generates a combined sectional image, corresponding to the slice position of the one sectional image, from the other sectional image of the pair of sectional images; and a controller that, in cases in which the reception section has received the successive change instruction, effects control so as to switch display of the one sectional image from the one sectional image being displayed to the one sectional image that corresponds to the slice position indicated in the successive change instruction, and, in conjunction with the switching, so as to successively switch display of the other sectional image from the other sectional image that is being displayed to the combined sectional image. 
     An eleventh aspect of the present invention is a radiographic imaging system, including: a radiographic imaging device that images a radiographic image of an imaging target; and the image displaying device of the first aspect, which displays a sectional image generated based on the radiographic image imaged by the radiographic imaging device. 
     A twelfth aspect of the present invention is a radiographic imaging system, including: a radiographic imaging device that images a radiographic image of an imaging target; a display section that displays a sectional image generated based on the radiographic image imaged by the radiographic imaging device; and the image processing device of the tenth aspect, which performs image processing of the sectional image for display at the display section. 
     A thirteenth aspect of the present invention is a sectional image displaying method, including: by a reception section, receiving a successive change instruction for a slice position for one sectional image of a pair of mutually related sectional images being displayed at a display section that displays the pair of sectional images; by a generation section, generating a combined sectional image, corresponding to the slice position of the one sectional image, from the other sectional image of the pair of sectional images; and in cases in which the successive change instruction has been received by the reception section, by a controller, effecting control so as to switch display of the one sectional image from the one sectional image being displayed to the one sectional image that corresponds to the slice position indicated in the successive change instruction, and, in conjunction with the switching, so as to successively switch display of the other sectional image from the other sectional image that is being displayed to the combined sectional image. 
     A fourteenth aspect of the present invention is a non-transitory computer readable medium storing a sectional image display program that causes execution of processing, the processing including: receiving a successive change instruction for a slice position for one sectional image of a pair of mutually related sectional images being displayed at a display section that displays the pair of sectional images; generating a combined sectional image, corresponding to the slice position of the one sectional image, from the other sectional image of the pair of sectional images; and in cases in which the successive change instruction has been received, effecting control so as to switch display of the one sectional image from the one sectional image being displayed to the one sectional image that corresponds to the slice position indicated in the successive change instruction, and, in conjunction with the switching, so as to successively switch display of the other sectional image from the other sectional image that is being displayed to the combined sectional image. 
     As explained above, the above aspects of the present invention are capable of providing an image displaying device, an image processing device, a radiographic imaging system, a sectional image displaying method, and a non-transitory computer readable medium storing a sectional image displaying program, that are, in cases in which a pair of related sectional images are displayed, coupled to switching slice position of the one sectional image, capable of smoothly switching display of the other sectional image. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiments of the present invention will be described in detail based on the following figures, wherein: 
         FIG. 1  is a schematic configuration diagram illustrating a schematic overall configuration of a radiographic imaging system of a first exemplary embodiment; 
         FIG. 2  is a functional block diagram illustrating a schematic configuration to explain the function of a console and a portable data terminal device in a radiographic imaging system of the first exemplary embodiment; 
         FIG. 3  is an explanatory diagram to explain tomosynthesis imaging in a radiographic imaging device of the first exemplary embodiment; 
         FIG. 4  is a flowchart of sectional image display processing executed by a controller of a portable data terminal device of a first exemplary embodiment; 
         FIG. 5  is an explanatory diagram to explain sectional image of a right breast; 
         FIG. 6  is a diagram illustrating a specific state in which a sectional image of a left breast, and a sectional image of a right breast, are displayed on a display section of a mobile data terminal device; 
         FIG. 7  is an explanatory diagram to explain generation of a combined sectional image by a controller of a portable data terminal device of the first exemplary embodiment; 
         FIG. 8  is an explanatory diagram to explain generation of a combined sectional image by a controller of a portable data terminal device of the first exemplary embodiment; 
         FIG. 9  is an explanatory diagram to explain a specific example in which a left breast is displayed by a sectional image, and a right breast is displayed by switching between a combined sectional image and a sectional image, on a display section of a portable data terminal device; 
         FIG. 10  is an explanatory diagram to explain generation of a combined sectional image by a controller of a portable data terminal device of a first exemplary embodiment; 
         FIG. 11  is an explanatory diagram to explain an example of switching of the other sectional image in a case in which a change in slice position is instructed during fading; 
         FIG. 12  is a flowchart of sectional image display processing of the other sectional image in a case in which a change in slice position is instructed during fading; 
         FIG. 13  is an explanatory diagram to explain another example of switching of the other sectional image in a case in which a change in slice position is instructed during fading; 
         FIG. 14  is a flowchart of another example of sectional image display processing of the other sectional image in a case in which a change in slice position is instructed during fading; 
         FIG. 15  is an explanatory diagram to explain a specific example of generating a combined sectional image; 
         FIG. 16  is an explanatory diagram to explain a specific example of generating a combined sectional image; 
         FIG. 17  is an explanatory diagram to explain a specific example of generating a combined sectional image; 
         FIG. 18  is a schematic configuration diagram illustrating an outline overall configuration of a radiographic imaging system in a case in which a viewer is provided as a radiographic image reading device instead of a portable data terminal device; and 
         FIG. 19  is a schematic configuration diagram illustrating an outline overall configuration of a radiographic imaging system in a case in which a device equivalent to a personal computer is provided instead of a portable data terminal device. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     First Exemplary Embodiment 
     Detailed explanation follows regarding exemplary embodiments of the present invention, with reference to the drawings. Note that the exemplary embodiments do not limit the invention. 
     Explanation first follows regarding a schematic configuration of an overall radiographic imaging system  10  of the present exemplary embodiment.  FIG. 1  illustrates a schematic configuration of an overall configuration of the radiographic imaging system  10  of the present exemplary embodiment.  FIG. 2  is a functional block diagram illustrating a schematic configuration to explain the function of a console  16  and a portable data terminal device  20  in the radiographic imaging system  10  of the present exemplary embodiment. 
     A radiographic imaging system  10  of the present exemplary embodiment includes a function to image radiographic images based on instructions (an imaging menu) input from an external system (for example a Radiology Information System (RIS)) through the console  16  by operation of a user, such as a doctor or radiographer. 
     The radiographic imaging system  10  of the present exemplary embodiment includes a radiographic imaging device  12 , the console  16 , and the portable data terminal device  20 . 
     Explanation follows regarding of a case in the radiographic imaging system  10  of the present exemplary embodiment in which the console  16  generates sectional images based on radiographic images imaged by tomosynthesis imaging by the radiographic imaging device  12 , and the generated sectional images are, for example, viewed and read by a user using the portable data terminal device  20 . 
     The radiographic imaging device  12  of the present exemplary embodiment is a device that images radiographic images of the breasts of examinees in, for example, what is referred to as, mammography. The radiographic imaging device  12  may be a device that images the breast of the examinee with the examinee in a seated state, such as sat on a chair (including a wheelchair), and is a device at least capable of imaging the left and right breasts of an examinee separately with the upper body of the examinee in an upright state. 
     The radiographic imaging device  12  includes a radiation source  24 , such as an x-ray tube, that is provided facing toward an imaging face  27  of an imaging table  26 , and irradiates X-rays from the radiation source  24  toward the imaging face  27 . 
     To image a radiographic image of the breast of the examinee, the breast on one side, this being the imaging target, is immobilized by being compressed between a press plate (see  FIG. 3 ) and the imaging face  27  of the imaging table  26 , and X-rays are irradiated from the radiation source  24  onto the immobilized breast. 
     The radiographic imaging device  12  of the present exemplary embodiment is device capable of at least performing imaging of a breast as the imaging target from plural directions, in which is referred to as tomosynthesis imaging.  FIG. 3  is an explanatory diagram to explain tomosynthesis imaging in the radiographic imaging device  12  of the present exemplary embodiment. In the radiographic imaging device  12 , as illustrated in  FIG. 3 , in a case in which imaging is performed of a breast from plural directions (tomosynthesis imaging), the radiation source  24  moves in a circular arc shape. In the present exemplary embodiment, the imaging position is moved from an angle α by steps of a specific angle θ, as illustrated in  FIG. 3 , and imaging is performed with the position of the radiation source  24  at N locations, P 1  to PN. 
     A radiation detector  22 , installed inside the imaging table  26 , is irradiated with X-rays that have passed through the breast that is the imaging target and through the imaging face  27 , and detects the X-rays. The X-rays detected by the radiation detector  22  are visualized by generating a radiographic image. The radiation detector  22  is irradiated by the X-rays carrying the image data, records image data expressing a radiographic image, and outputs the recorded image data. Charges are generated for each pixel according to the dose of X-rays irradiated, and detected as image data. The radiation detector  22  according to the present exemplary embodiment is an electronic cassette, and is, for example, a digital radiography (DR) cassette provided with a radiosensitive layer that converts the radiation into digital data, and outputs the digital data. 
     In the present exemplary embodiment, the image data expressing the radiographic images output from the radiation detector  22  of the radiographic imaging device  12  is transmitted to the console  16 . The console  16  according to the present exemplary embodiment controls the radiographic imaging device  12  by using an imaging menu, various data, and the like acquired from external systems and the like through a wireless Local Area Network (LAN) or the like. The console  16  of the present exemplary embodiment performs transmission and reception of various data with the radiation detector  22  of the radiographic imaging device  12 . The console  16  of the present exemplary embodiment generates a sectional image based on the radiographic images acquired from the radiation detector  22 , and transmits the generated sectional image to the portable data terminal device  20 . 
     The console  16  of the present exemplary embodiment is a server/computer that serves as an example of an image processing device. As illustrated in  FIG. 2 , the console  16  includes a controller  30 , a storage section  32 , a display drive section  34 , a display section  36 , an operation input detection section  38 , an operation section  40 , an input/output (I/O) section  42 , and an interface (I/F) section  44 . The controller  30 , the storage section  32 , the display drive section  34 , the operation input detection section  38 , and the I/O section  42  are connected together so as to enable exchange of data and the like with each other through a bus  45 , such as a system bus or a control bus. 
     The controller  30   i  controls the overall operation of the console  16 . The controller  30  generates a sectional image based on radiographic images obtained by tomosynthesis imaging. The controller  30  of the present exemplary embodiment includes a Central Processing Unit (CPU), Read Only Memory (ROM), Random Access Memory (RAM), and a Hard Disk Drive (HDD). The CPU has functionality to control the overall operation of the console  16 . Various programs and the like for use by the CPU are pre-stored in the ROM. The RAM temporarily stores various data. The HDD stores and retains various data. The HDD may be a Solid State Drive (SSD), and may be commonly employed as the storage section  32 . 
     The display drive section  34  controls display of various data on the display section  36 . The display section  36  of the present exemplary embodiment displays an imaging menu, radiographic images, sectional images, etc. The operation input detection section  38  detects the operation status and processing operations of the operation section  40 . The operation section  40  is employed for a user to perform instructions related to imaging radiographic images, generating sectional images, etc. The operation section  40  may, for example, be embodied by a keyboard and mouse, and may be integrated together with the display section  36  and embodied by a touch panel. The operation section  40  may include a camera, and be embodied such that various instructions are input by the camera recognizing gestures of the user. 
     The I/O section  42  and the I/F section  44  performs wired or wireless communication for transmission and reception of various data with the radiographic imaging device  12  (the radiation source  24 , the radiation detector  22 , etc.), the portable data terminal device  20 , an external system such as a RIS, and an external system such as a picture archiving and communication system (PACS). 
     The storage section  32  stores various data, such as image data of the radiographic images, and image data of the sectional images (described in detail below). 
     The portable data terminal device  20 , which is an example of an image displaying device, receives sectional images from the console  16 , and to present (display) to the user the received radiographic images, and sectional images (described in detail below) generated based on the radiographic images. The portable data terminal device  20  of the present exemplary embodiment is what is referred to as a Personal Digital Assistant (PDA) that is capable of being driven by an internal battery, with specific examples thereof including a tablet terminal and a smartphone. 
     As illustrated in  FIG. 2 , the portable data terminal device  20  according to the present exemplary embodiment includes a controller  50 , a storage section  52 , a display drive section  54 , a display section  56 , an operation input detection section  58 , an operation section  60 , an I/O section  62 , and an I/F section  64 . The controller  50 , the storage section  52 , the display drive section  54 , the operation input detection section  58 , and the I/O section  62  are connected together so as to be capable of exchanging data etc. through a bus  65 , such as a system bus or a control bus. 
     The controller  50  is an example of a generation section and a controller, and includes functionality to control the overall operation of the portable data terminal device  20 . The controller  50  includes a CPU, ROM, and RAM. The CPU controls the overall operation of the portable data terminal device  20 . Various processing programs and the like for use by the CPU are pre-stored in the ROM. The RAM temporarily stores various data. 
     The display drive section  54  controls display of various data, including various types of image data, on the display section  56 . The operation input detection section  58  detects the operation status and processing operations of the operation section  60 . In the present exemplary embodiment, the operation section  60  is employed for a user to perform instructions such as to instruct the slice position of a sectional image to display on the display section  56 . In the present exemplary embodiment, the operation section  60  may include, for example, a touch panel, a touch pen, plural keys, or a mouse. In cases in which the operation section  60  is embodied by a touch panel then it may also serve as the display section  56 . 
     The I/O section  62  and the I/F section  64  are an example of a reception section, and performs wireless communication, optical communication using light, or the like, for the transmission of various data to and from the console  16  and a PACS. 
     The storage section  52  stores sectional images acquired from the console  16 . More specifically, the storage section  52  stores sectional images generated by the console  16  and corresponding to plural respective slice positions. Specific examples of the storage section  52  include non-volatile memory. 
     In the present exemplary embodiment, various programs stored in the controller  30  of the console  16  and in the controller  50  of the portable data terminal device  20  are pre-stored in ROM of the controller  30  and the controller  50 , however there is no limitation thereto, and configuration may be made such that programs are stored on a recording medium such as a Compact Disk Read Only Memory (CD-ROM) or removable disk, and then installed from the recording medium onto ROM or the like. Configuration may be made such that the programs are installed on ROM or the like from an external device, via a communication line such as the internet. 
     Explanation follows regarding operation of the radiographic imaging system  10  of the present exemplary embodiment, with reference to the drawings. 
     Explanation first follows regarding imaging radiographic images in the radiographic imaging device  12  of the present exemplary embodiment. In such case, imaging radiographic images is executed in the radiographic imaging device  12  according to an imaging menu. 
     The examinee places the breast on one side that is the imaging target in contact with the imaging face  27  of the radiographic imaging device  12 . The radiographic imaging device  12  moves a press plate (see  FIG. 3 ) toward the imaging face  27 , and immobilizes the breast. 
     In the radiographic imaging device  12  according to the present exemplary embodiment, from this state, in cases in which an instruction has been input to perform tomosynthesis imaging by imaging the breast from plural directions, the radiation source  24  is moved in a circular arc shape without moving the imaging table  26 . The imaging position is moved from an angle α by steps of a specific angle θ, as illustrated in  FIG. 3 , and X-rays are irradiated based on each of the imaging conditions with the position of the radiation source  24  at N locations, P 1  to PN. X-rays, separately irradiated from the radiation source  24 , reach the radiation detector  22  after passing through the respective breasts. 
     On irradiation with X-rays, the radiation detector  22  outputs image data representing the respective irradiated radiographic images to the console  16 . Image data for N frames of radiographic images are output to the console  16  in cases in which, as described above, X-rays are irradiated with the radiation source  24  positioned in N locations, P 1  to PN. 
     Thus, in a case in which plural radiographic images are imaged by tomosynthesis imaging in the radiographic imaging device  12 , the console  16  acquires image data of the plural imaged radiographic images, and generates a sectional image of the breast of the examinee. 
     The controller  30  of the console  16 , as described above, reconstructs a sectional image from plural radiographic images obtained by tomosynthesis imaging, and generates a sectional image parallel to the imaging face  27 . In the present exemplary embodiment, “parallel” includes substantially parallel. The position in the depth direction of the section in the present exemplary embodiment is referred to as the slice position. The slice position is defined with reference to the imaging face  27 , with the slice position of the imaging face  27  set as “0”, and with the slice position becoming shallower (higher) (see  FIG. 5 ) on approaching the radiation source  24  (on progression upward in  FIG. 1  and  FIG. 2 ). 
     The controller  30  generates sectional images from plural radiographic images imaged at positions P 1 , P 2 , P 3 , and so on to PN, illustrated in  FIG. 3 . Thus, in the console  16  of the present exemplary embodiment, the radiographic images received from the radiation detector  22  and obtained by tomosynthesis imaging are stored in the storage section  32 . The radiographic images obtained by tomosynthesis imaging may be deleted after the sectional images have been generated; however, they are preferably left stored in preparation for cases in which, for example, a further sectional image is generated with a slice position different to the generated sectional images. 
     The imaging position of the object of interest on the radiographic images differs according to the imaging angle at which X-rays are irradiated from each of the positions of the radiation source  24 . In the controller  30 , the moved amount is calculated for the object of interest between the plural radiographic images based on the imaging angle at which the radiographic images were imaged, and a sectional image is reconstructed corresponding to the desired slice position according to a known reconstruction method. The imaging angle maybe acquired from the radiographic imaging device  12  (the radiation detector  22 ), and may be acquired from an imaging menu or the like. The slice position (or the slice interval) may be acquired by a user instructing the slice position (or slice interval) using the operation section  40  or the like, or may be acquired from an imaging menu or the like. 
     The sectional image generated by the console  16  may be displayed on the display section  36 . 
     The sectional image generated in the console  16  is associated with the slice position and transmitted to the portable data terminal device  20 . 
     The controller  50  of the portable data terminal device  20  displays sectional images received through the I/F section  64  and the I/O section  62  on the display section  56 . In the portable data terminal device  20  of the present exemplary embodiment, the sectional images received from the console  16  are stored in the storage section  52 . 
     Explanation follows regarding sectional image display processing executed by the controller  50  of the portable data terminal device  20  of the present exemplary embodiment.  FIG. 4  illustrates a flowchart of one example of sectional image display processing executed in the controller  50  of the portable data terminal device  20  of the present exemplary embodiment. Explanation follows regarding a case in the present exemplary embodiment of a specific example in which the portable data terminal device  20  is a tablet terminal including a touch panel in which the display section  56  and the operation section  60  have been integrated together. 
     At step S 100 , the controller  50  of the portable data terminal device  20  displays a pair of mutually related sectional images on the display section  56 . Explanation follows regarding a case that employs, as a specific example of pairs of mutually related sectional images, sectional images corresponding to respective plural slice positions of the right breast, and sectional images corresponding to respective plural slice positions of the left breast of the examinee.  FIG. 5  is an explanatory diagram to explain a specific example of the sectional images of the left and right breasts. In the specific example illustrated in  FIG. 5 , left breast sectional images  70 L include 7 frames of the left breast sectional images  70 L taken with a slice position of the imaging face  27  as 0, at slice thicknesses of 10 mm up to a slice position of 60 mm. The right breast sectional images  70 R include 6 frames of the right breast sectional images  70 R taken with a slice position of the imaging face  27  as 0, at slice thicknesses of 10 mm up to a slice position of 50 mm. Thus in the specific example of the present exemplary embodiment, there are less frames of sectional images  70  for the right breast sectional images  70 R than for the left breast sectional image  70 L. There are cases in which the number of frames of the left and right breast sectional images  70  (pairs of the sectional images  70 ) differ from each other due to, for example, the sizes of the breasts, the manner in which pressing was performed, or due to employing different slice thicknesses on the left and right. 
     In the present exemplary embodiment, explanation follows regarding of a case in which the right breast sectional image and the left breast sectional image are to be displayed on the display section  56  of the portable data terminal device  20 .  FIG. 6  illustrates a specific example of a state in which the left breast sectional image  70 L and the right breast sectional image  70 R are displayed on the display section  56  of the portable data terminal device  20 .  FIG. 6  illustrates a specific example in which a user touches the left breast sectional image  70 L displayed on the display section  56  with a finger. In the following, left breast sectional images of the examinee are referred to as “sectional images  70 L” irrespective of the slice position, and similarly right breast sectional images of the examinee are referred to as “sectional images  70 R”. In cases in which discrimination is not made between the sectional images of the left and right breasts, sectional images are referred to collectively as “sectional images  70 ”. 
     In the processing of step S 100 , as a specific example in the portable data terminal device  20  of the present exemplary embodiment, the slice positions of the sectional images  70  displayed on the display section  56  are slice positions “0 mm” where the slice positions have the smallest values of slice position for both the sectional images, namely the left and right breast sectional images  70  having slice positions corresponding to the imaging face  27  are displayed on the display section  56 , however they are not particularly limited. The slice position of the sectional images  70  displayed is preferably the same in the left and right breasts, or corresponding positions (described in detail below). For example, the sectional image  70 L with slice position of “60 mm” for the left breast and the sectional image  70 R of the slice position “50 mm” for the right breast may be displayed on the display section  56  such that both slice positions are at maximum values. 
     In the next step S 102 , determination is made as to whether or not the controller  50  of the portable data terminal device  20  has instructed the slice position of the sectional images  70  to be changed successively. 
     In the present exemplary embodiment, in a case in which a user desires to successively change the slice position of the sectional images  70  of the left and right breast being displayed on the display section  56  (namely, desires to successively change the sectional images  70 ), the user touches either the left or right breast sectional image  70 , and moves so as to slide (move) the sectional image  70  to instruct the slice position so as to be changed successively. Whether to successively change the slice position in the direction such that the sectional image becomes deeper, namely, to successively change in the direction that the slice position becomes deeper (smaller), or to successively change in the direction such that the section image becomes shallower (higher), may be predetermined according to the direction in which the sectional image  70  was slid. In the present exemplary embodiment, as a specific example, in cases of sliding (the finger of the user) upward and toward the left from the state of the sectional images  70  indicated in  FIG. 6 , the slice position is successively changed in the direction that makes the slice position shallower (higher), and in cases of sliding downward and toward the right, the slice position is successively changed in the direction to become deeper (smaller). 
     A standby state is adopted in cases in which there is no successive change in slice position instructed, and the sectional images  70  continue to be displayed as they are. In cases in which the operation input detection section  58  detects the above movement (sliding), the controller  50  of the portable data terminal device  20  transitions to step S 104 . 
     At step S 104 , the slice position of the sectional images  70  being displayed on the display section  56  is changed successively, however, in the portable data terminal device  20  according to the present exemplary embodiment, the slice position of the one sectional images  70  on which successive slice position change was instructed (as a specific example, the sectional image  70 L) is successively changed (the sectional image  70 L is switched), and coupled to this, the display of the other sectional image  70  (as a specific example, the sectional image  70 R) is switched to a combined sectional image (described in detail below). 
     Thus in the controller  50  according to the present exemplary embodiment, processing is performed to switch display of the one sectional image  70  ( 70 L) that was instructed to be changed successively, and parallel processing is performed of processing for switching display of the other sectional image  70  ( 70 R) and the combined sectional image. 
     In cases in which successive change of the one sectional image  70 L has been instructed, at step S 104 A, the controller  50  successively switches the slice position of the sectional images  70 L and displays the sectional images  70 L. For example, in cases in which the slice position has been instructed to successively change in the direction to become shallower (higher) from the sectional image  70 L with slice position 0 mm, the controller  50  reads out the sectional image  70 L at the corresponding slice position from the sectional images  70 L stored in the storage section  52 , and sequentially switches the sectional image  70 L being displayed on the display section  56  according to the successive change instruction, from the sectional image  70 L with slice position 0 mm, through the sectional image  70 L with slice position at 10 mm, to the sectional image  70 L with slice position 20 mm. 
     However, for the other sectional image  70 R, at step S 104 B, the controller  50  generates a combined sectional image according to the slice position of the sectional image  70 L, and, coupled to the switching of the sectional image  70 L, switches display of the combined sectional image that has been combined. 
     Explanation follows regarding the combined sectional image of the present exemplary embodiment, and generation of the combined sectional image. As described above, in cases in which the number of frames of the sectional images  70  of the left and the right breasts are different from each other, the switching timings of the sectional images  70  falls out of synchronization with each other. For example, in sectional images  70  illustrated in  FIG. 5 , since there are more frames of the sectional images  70 L, in order to match the display of the sectional images  70 R to the display (slice positions) of the sectional images  70 L, there are cases in which the numbers of frames of the sectional images  70 L and the sectional images sectional images  70 R are made to align with each other during display by repeating display of the sectional image  70 R having a particular slice thickness. For example, there is a case in which the sectional image  70 R having a slice thickness of 30 mm is displayed twice, coupled to the sectional image  70 L having a slice thickness of 30 mm and the sectional image  70 L having a slice thickness of 40 mm. In the opposite scenario, in cases in which the sectional image  70 L is to be displayed matched to display of the sectional image  70 R (slice position), then the number of frames of the sectional images  70 L and the sectional images  70 R can be aligned by skipping (not displaying) the sectional image  70 L having one particular slice thickness. There is, for example, a case in which display is performed while skipping the sectional image  70 L at the slice thickness of 40 mm. In such circumstances, display of the sectional images  70  being switched becomes intermittent display, and sometimes display ceases to be viewed smoothly, such as in a case in which the speed of display change ceases to be constant. 
     In contrast thereto, in the controller  50  of the portable data terminal device  20  of the present exemplary embodiment, control is performed to make the display appear smooth as seen by a user by generating and displaying a combined sectional image of the other sectional image  70  ( 70 R) to correspond to the slice position of the one sectional image  70  ( 70 L) for which successive change in slice position has been instructed. 
       FIG. 7  is an explanatory diagram to explain generation of the combined sectional image in the controller  50  of the portable data terminal device  20  of the present exemplary embodiment. In the controller  50  of the present exemplary embodiment, in order to make display smooth, the number of frames of the one sectional image  70 L is made to effectively match the number of frames of the other sectional image  70 R, by generating a combined sectional image  72 R of the sectional images  70 R corresponding to the slice position of the one sectional image  70 L that was instructed to change successively. 
     In the controller  50  of the present exemplary embodiment, the pairs of sectional images  70  are pairs that have corresponding maximum values and minimum values of slice thickness. Thus there is no generation of a combined sectional image  72 R corresponding to a maximum value or a minimum value of slice thickness. 
     As illustrated in  FIG. 7 , in cases in which the slice position displayed on the display section  56  is currently successively changing from the sectional image  70  of the slice position 0 mm in the direction in which the slice position becomes shallower (higher), the controller  50  generates combined sectional images  72 R corresponding to each of the slice positions of the sectional image  70 L, at 10 mm, 20 mm, 30 mm, 40 mm, and 50 mm. 
     The method of generation is combination from 2 frames of sectional image  70 R close to the slice position of the sectional image  70 L (namely positioned in the depth direction above/below the slice position of the sectional image  70 L), at a proportion according to the slice positions of the 2 frames. Namely, generation is a combination from 2 frames of sectional image  70 R, according to a weighted average according to the slice positions of the 2 frames. 
     In the specific example illustrated in  FIG. 7 , the sectional image  70 R with slice position at 10 mm and the sectional image  70 R with slice position at 0 mm are combined at a ratio of 1:5, to effectively generate a combined sectional image  72 R with slice position at 50×⅙ mm corresponding to the sectional image  70 L with slice position at 10 mm. Similarly, the sectional image  70 R with slice position at 20 mm and the sectional image  70 R with slice position at 10 mm are combined at a ratio of 2:4, to effectively generate a combined sectional image  72 R with slice position at 50× 2/6 mm corresponding to the sectional image  70 L with slice position at 20 mm. The sectional image  70 R with slice position at 30 mm and the sectional image  70 R with slice position at 20 mm are combined at a ratio of 3:3, to effectively generate a combined sectional image  72 R with slice position at 50× 3/6 mm corresponding to the sectional image  70 L with slice position at 30 mm. The sectional image  70 R with slice position at 40 mm and the sectional image  70 R with slice position at 30 mm are combined at a ratio of 4:2, to effectively generate a combined sectional image  72 R with slice position at 50× 4/6 mm corresponding to the sectional image  70 L with slice position at 40 mm. Moreover, the sectional image  70 R with slice position at 50 mm and the sectional image  70 R with slice position at 40 mm are combined at a ratio of 5:1, to effectively generate a combined sectional image  72 R with slice position at 50×⅚ mm corresponding to the sectional image  70 L with slice position at 50 mm. 
     On receipt of an instruction to successively change the slice position of the one sectional image  70 L, the controller  50  of the present exemplary embodiment generates the combined sectional images  72 R as described above for the other sectional images  70 R. In cases in which there is a continuous instruction to successively change, such as cases in which the user continues sliding the sectional images  70 L displayed on the display section  56 , due to it being unclear which is the slice position of the sectional image  70 L to finally be displayed, the controller  50  preferably generates (including sequentially generates) combined sectional images  72 R corresponding to all conceivable slice positions as the change destination from the slice position of the currently displayed sectional image  70 L.  FIG. 8  is an explanatory diagram to explain generation of combined sectional images in the controller  50  of the portable data terminal device  20  of the present exemplary embodiment. The specific example illustrated in  FIG. 8  illustrates a case in which, in the state in which the sectional images  70  with slice positions at 20 mm are being displayed, instruction is made to successively change the slice position in the direction in which the slice thickness of the sectional image  70 L becomes shallower (higher). In a case in which the controller  50  has recognized that there is a successive change in the direction in which the slice position successively changes (the direction making the slice position shallower/higher), then the controller  50  generates the combined sectional images  72 R corresponding to each of the sectional images  70 L at the slice positions 30 mm, 40 mm, and 50 mm. In the specific example illustrated in  FIG. 8 , the sectional image  70 R with slice position at 30 mm and the sectional image  70 R with slice position at 20 mm are combined at a ratio of 1:3, to effectively generate a combined sectional image  72 R with slice position at 20+30×¼ mm corresponding to the sectional image  70 L with slice position at 30 mm. Similarly, the sectional image  70 R with slice position at 40 mm and the sectional image  70 R with slice position at 30 mm are combined at a ratio of 2:2, to effectively generate a combined sectional image  72 R with slice position at 20+30× 2/4 mm corresponding to the sectional image  70 L with slice position at 40 mm. Moreover, the sectional image  70 R with slice position at 50 mm and the sectional image  70 R with slice position at 40 mm are combined at a ratio of 3:1, to effectively generate a combined sectional image  72 R with slice position at 20+30×¾ mm corresponding to the sectional image  70 L with slice position at 50 mm. 
     Namely, the controller  50  generates the combined sectional images  72 R by combining 2 frames of sectional image  70 R, at combination proportions corresponding to the slice position of the sectional image  70 R currently being displayed, the final slice position in the change direction (having the highest value of lowest value), and the number of the combined sectional images  72 R to be generated. 
     Thus the controller  50  generates the combined sectional images  72 R, and then switches to displaying the combined sectional image  72 R corresponding to the slice position of the sectional image  70 L coupled to switching of display of the one sectional image  70 L. 
     At the next step S 106 , the controller  50  determines whether or not instruction to successively change the slice position has ended. For example, in cases in which successive change continues to be instructed, such as by a user continuing sliding on the sectional image  70 L, the processing of step  104  (S 104 A, S 104 B) is repeated. However, for example, in cases in which there is no sliding (movement) on the sectional image  70 L for a fixed period of time or longer, or the user is not touching the display section  56 , determination is made that the instruction to successively change has ended, and processing proceeds to step S 108 . 
     At step S 108 , the controller  50  switches display of the other sectional image  70 R to displaying the sectional image  70 R having a slice position that is closest in the depth direction to the slice position of the one sectional image  70 L after the change. In a state in which instruction to change the slice position successively has ended, for example in the specific case illustrated in  FIG. 7  in which the slice position of the one sectional image  70 L has changed to 40 mm, the left breast is displayed on the display section  56  in a state in which the one sectional image  70 L with slice position at 40 mm is displayed. Whereas, the right breast is displayed in a state in which the combined sectional image  72 R combined from the sectional image  70 R with slice position at 40 mm and the sectional image  70 R having the slice position at 30 mm, at the ratio 4:2. Thus, at the present step, as illustrated in the specific example of  FIG. 9 , the controller  50  switches display of the right breast from the combined sectional image  72 R to the sectional image  70 R having the slice position at 40 mm. 
     Thus by switching display on the other side from the combined sectional image  72 R to the sectional image  70 R, the left and right breasts are displayed on the display section  56  in a state in which the sectional images  70  have corresponding slice positions. 
     At the next step S 110 , determination is made as to whether or not to end the current processing. For example, in cases such as those in which display of the sectional images  70  on the display section  56  continues to be performed, determination is made to not end the processing, processing returns to step S 102 , and the current processing is repeated. However, for example, in a case in which an instruction to end display of the sectional image  70  has been received by the operation input detection section  58 , the current processing is ended. 
     As described above, explanation has been given of a case in which there are more frames of the sectional images  70 L than of the sectional images  70 R. However, similarly in cases in which there are fewer frames of the sectional images  70 L than of the sectional images  70 R, the controller  50  may generate the combined sectional image  72 R and switch display coupled to switching the slice position of the one sectional image  70 L.  FIG. 10  is an explanatory diagram to explain generation of combined sectional images  72 R by the controller  50  in such a case. The specific example illustrated in  FIG. 10 , similarly to the specific example illustrated in  FIG. 7 , illustrates a case in which instruction has been made to successively change the slice position, from the slice position at 0 mm, in the direction becoming shallower (higher). 
     In the specific example illustrated in  FIG. 10 , the sectional image  70 R with slice position at 20 mm and the sectional image  70 R with slice position at 10 mm are combined at a ratio of 4:1, to effectively generate a combined sectional image  72 R with slice position at 60×⅕ mm corresponding to the sectional image  70 L with slice position at 10 mm. Similarly, the sectional image  70 R with slice position at 30 mm and the sectional image  70 R with slice position at 20 mm are combined at a ratio of 3:2, to effectively generate a combined sectional image  72 R with slice position at 60×⅖ mm corresponding to the sectional image  70 L with slice position at 20 mm. The sectional image  70 R with slice position at 40 mm and the sectional image  70 R with slice position at 30 mm are combined at a ratio of 2:3, to effectively generate a combined sectional image  72 R with slice position at 60×⅗ mm corresponding to the sectional image  70 L with slice position at 30 mm. Moreover, the sectional image  70 R with slice position at 50 mm and the sectional image  70 R with slice position at 40 mm may be combined at a ratio of 1:4, to effectively generate a combined sectional image  72 R with slice position at 60×⅘ mm corresponding to the sectional image  70 L with slice position at 40 mm. 
     Second Exemplary Embodiment 
     In the first exemplary embodiment, in cases in which the controller  50  of the portable data terminal device  20  has received an instruction to successively change the slice position of the one sectional image  70 L, the one sectional image  70 L is switched according to successive changes to the slice position, and coupled to this switching, switching is performed to switch to displaying the combined sectional image  72 R of the other sectional image  70 R corresponding to the slice position of the one sectional image  70 L. In the present exemplary embodiment, switching of the combined sectional image  72 R will be referred to as “fading”. 
     Explanation follows regarding of the present exemplary embodiment in which, in addition to fading as explained with respect to the first exemplary embodiment, the controller  50  has also been instructed to successively change the slice position with respect to the one sectional image  70 L. 
     For the one sectional image  70 L, the controller  50  of the portable data terminal device  20  may, similarly to step S 104 A of the first exemplary embodiment, successively switch the slice position of the sectional image  70 L and display the switched-slice-position sectional image  70 L. 
     For the other sectional image  70 R, the controller  50  of the portable data terminal device  20  performs different processing in the present exemplary embodiment to that of the first exemplary embodiment.  FIG. 11  is an explanatory diagram to explain an example of switching the other sectional image  70 R in cases in which successive change to the slice position has been instructed during fading.  FIG. 11  illustrates a case in which an N th  frame (an example of a sectional image in a first slice position) of the sectional images  70 R is being displayed, successive change of the slice position to change to an N+2 th  frame (an example of a sectional image of a third slice position) is instructed during fading to an N+1 th  frame (an example of a sectional image in the second slice position) instructed for a successive change of the slice position. For transition from the N th  frame sectional image  70 R to the N+1 th  frame sectional image  70 R, the controller  50  generates a combined sectional image  72 R combined from the N th  frame and the N+1 th  frame, and displays the combined sectional image  72 R. During generation of the combined sectional image  72 R or the like, in cases in which successive change to the slice position is instructed during fading, the current fading is stopped. The controller  50  then first displays the sectional image  70 R corresponding to the previous change destination slice position (the final change position) on the display section  56  (the N+1 th  frame sectional image  70 R in the case illustrated in  FIG. 11 ). Then, the controller  50  generates a combined sectional image  72 R from the N+1 th  frame slice position according to the newly instructed change destination slice position, similarly to step S 104 B of the first exemplary embodiment, and displays the combined sectional image  72 R. The controller  50  accordingly fades to a combination of the N+1 th  frame sectional image  70 R and the N+2 th  frame sectional image  70 R. 
       FIG. 12  is a flowchart illustrating an example of sectional image display processing for the other sectional image  70 R in cases in which successive change of the slice position is instructed during fading. 
     At step S 200 B, the controller  50  switches to the combined sectional image  72 R, namely ends fading. Then at step S 202 B, the controller  50  first displays the sectional image  70 R corresponding to the slice position of the previous change destination on the display section  56 . In the specific example illustrated in  FIG. 7 , in a case in which successive change to the slice position of 60 mm is instructed during fading from the slice position 0 mm to the slice position at 20 mm, at step S 202 B, the controller  50  first displays the sectional image  70 R at the slice position of 20 mm on the display section  56 . 
     Then at the next step S 204 B, the controller  50  generates a combined sectional image  72 R, similarly to at step S 104 B of the first exemplary embodiment, and ends the current processing after displaying the combined sectional image  72 R. In the above example, as illustrated in  FIG. 8 , the controller  50  generates the combined sectional image  72 R, and performs switching to display the combined sectional image  72 R. 
     In this manner, in cases in which new instruction is made to successively change the slice position of the one sectional image  70 L during fading of the other sectional image  70 R, the fading is temporarily interrupted, the new combined sectional image  72 R is generated, and switching is performed to display the new combined sectional image  72 R. Thereby misalignment between the left and right slice positions is suppressed, and the sectional images  70  of the left and right breasts being displayed on the display section  56  are coupled together for switching. 
     The sectional image display processing of the sectional image  70 R in cases in which successive change to the slice position is additionally instructed for the one sectional image  70 L during fading is not limited to the specific examples illustrated in  FIG. 11  and  FIG. 12 . Explanation follows regarding other specific examples. 
       FIG. 13  is an explanatory diagram to explain another example of switching the other sectional image  70 R in cases in which successive change to the slice position is instructed during fading.  FIG. 13  illustrates a case in which the N th  frame (an example of a sectional image in a first slice position) sectional image  70 R is being displayed, successive change of the slice position to change to an N+2 th  frame (an example of a sectional image of a third slice position) is instructed during fading to an N+1 th  frame (an example of a sectional image in the second slice position) instructed for a successive change of the slice position. During transition from the N th  frame sectional image  70 R to the N+1 th  frame sectional image  70 R, the controller  50  generates and displays a combined sectional image  72 R combined from the N th  frame and the N+1 th  frame. In cases in which during fading, such as during generation of the combined sectional image  72 R, successive change to the slice position is instructed, the current fading is stopped. The controller  50  then, similarly to at step S 104 B of the first exemplary embodiment, generates and displays a new combined sectional image  72 L according to the slice position corresponding to the combined sectional image  72 R currently being displayed, or being generated, and the newly instructed slice position. The controller  50  accordingly generates a new combined sectional image  72 R by combining the combined sectional image  72 R, combined using the N th  frame sectional image  70 R and the N+1 th  frame sectional image  70 R, and the N+2 th  frame sectional image  70 R, and starts the fading. 
     Moreover,  FIG. 14  illustrates a flowchart of another example of sectional image display processing for the other sectional image  70 R in cases in which successive change to the slice position is instructed during fading. 
     At step S 250 B, the controller  50  switches to the combined sectional image  72 R, namely stops fading. 
     Then at step S 252 B, similarly to at step S 104 B of the first exemplary embodiment, the controller  50  generates and displays a new combined sectional image  72 L according to the slice position corresponding to the combined sectional image  72 R and the newly instructed slice position, and then ends the current processing. In the specific example illustrated in  FIG. 7 , in cases in which successive change is instructed during fading from the combined sectional image  72 R corresponding to the slice position at 0 mm to the combined sectional image  72 R corresponding to the slice position at 20 mm, the controller  50  calculates a new combination proportion between the current slice position at 20 mm and the newly instructed slice position, generates a new combined sectional image  72 R combined from the combined sectional image  72 R of the slice position at 20 mm, and the sectional image  70 R at the calculated combination proportion, and displays the new combined sectional image  72 R on the display section  56 . The controller  50  then sequentially a combines the combined sectional images  72 R that were combined from the sectional image  70 R at the new combination proportion, and switches to displaying the combined sectional image  72 R coupled to switching of the sectional image  70 L. 
     In this manner, in cases in which a new instruction is given to successively change the slice position of the one sectional image  70 L during fading of the other sectional image  70 R, the new combination proportion is calculated according to the slice position of the combined sectional image  72 R during fading, and the combined sectional image  72 R is generated according to the calculated combination proportion. Thereby the sectional images  70  of the left and right breasts are displayed on the display section  56  while suppressing misalignment between the left and right slice positions, and coupled switching is performed of the left and right sectional images  70 . 
     In the above, in the radiographic imaging system  10  of each of the exemplary embodiments explained above, the controller  30  of the console  16  generates the left and right pair of sectional images  70  of the breasts from the radiographic images imaged by the radiation detector  22  of the radiographic imaging device  12 , and transmits the generated sectional images  70  to the portable data terminal device  20 . The controller  50  of the portable data terminal device  20  displays the pair of sectional images  70  on the display section  56 . The controller  50  switches the one sectional image  70 L according to successive change to the slice position in cases in which instruction is received to successively change the slice position of the one sectional image  70 L, and coupled to this switching, the combined sectional image  72 R of the other sectional image  70 R is generated according to the slice position of the one sectional image  70 L, and switching is performed to display the generated combined sectional image  72 R. The combined sectional image  72 R is generated by combining from the two frames of the sectional image  70 R close to the slice position in the depth direction (namely, positioned above/below in the depth direction). 
     In cases in which pairs of mutually related sectional images  70  are displayed due to the controller  50  generating the combined sectional image  72 R in this manner, and switching display coupled to switching the sectional image  70 L, display of the other sectional image  70 R can be switched smoothly, as if animated, coupled to switching of the slice position of the one sectional image  70 L. 
     Explanation has been given in each of the above exemplary embodiments of cases in which the controller  50  generates the combined sectional image  72  according to the other slice positions, except for the greatest value and the smallest value of slice thickness of the one sectional image  70 L, however the combined sectional images  72  are not necessarily combined so as to correspond to all the slice positions. A specific example of combined sectional images  72  in such a case is illustrated in  FIG. 15 . In the controller  50  of each of the above exemplary embodiments, the number of frames of the sectional image  70 L and the number of frames of the sectional images  70 R (including the combined sectional images  72 ) match each other. Thus configuration may be made such that combined sectional images  72 R are only generated to correspond to the missing number of frames. The specific example illustrated in  FIG. 15  illustrates an example in which only the combined sectional image  72 R is generated corresponding to the sectional image  70 L with slice position at 30 mm by combining the sectional image  70 R at the slice position at 30 mm and the sectional image  70 R at the slice position at 20 mm at a combination proportion of 3:3, and for the other sectional images switching is performed to display using the sectional images  70 R. 
     Explanation has been given in each of the above exemplary embodiments of cases in which the number of frames of the sectional images  70  of the left and right breasts are made to substantially match. However, the number of frames of the sectional images  70  of the left and right breasts need not necessarily match, and in particular the effective number of frames of the other sectional image  70 R may be made greater than the one sectional image  70 L. In such cases, a new slice position may be provided between the existing slice positions of the sectional image  70 L, and a combined sectional image  72 R corresponding to the provided slice positions may be generated and displayed. In this manner, display of the other sectional image  70 R can be made to change smoothly, gradually as if animated, by making the effective number of frames of the other sectional image  70 R greater than the sectional image  70 L. 
     Moreover, although in each of the above exemplary embodiments cases have been explained in which the number of frames of the sectional images  70  of the left and right breasts are different from each other, similarly, even there are the same number of frames, as in a specific example, the effective number of frames generated of the combined sectional images  72 R for the other sectional image  70 R may be greater than those of the one sectional image  70 L. In the specific example illustrated in  FIG. 16 , a new slice position is provided between the existing slice positions of the sectional image  70 R, and a combined sectional image  72 R corresponding to the provided slice position may be generated and displayed. In a specific example illustrated in  FIG. 16 , this results in display on the other side being performed by switching alternately between display of the combined sectional image  72 R, or the sectional image  70 R, according to the slice position. 
     Explanation has been given in each of the above exemplary embodiments of cases in which successive change of the slice position is instructed by a user operating (sliding etc.) on the sectional image  70  being displayed on the display section  36  of the portable data terminal device  20 , however the method of instructing successive change to the slice position is not limited thereto. For example, as illustrated in  FIG. 17 , in cases in which a bar  80  or the like has been displayed on the display section  36  as a display to represent the slice position (depth), the controller  50  may instruct successive change to the slice position by a user operating the bar  80  with a finger, or operating the operation section  60 . 
     Moreover, although explanation has been given of cases in each of the above exemplary embodiments in which the controller  50  of the portable data terminal device  20  generates the combined sectional image  72  after receiving an instruction to perform successive change of the slice position, there is no limitation to the timing to generate the combined sectional image  72 . In advance, combined sectional images  72  of both breasts may be generated according to slice positions (number of frames) of the sectional images  70  of both breasts, and stored in the storage section  52 . 
     Moreover, although explanation has been given in each of the above exemplary embodiments of cases in which the portable data terminal device  20  is a tablet terminal, the portable data terminal device  20  is not limited to being a tablet terminal. Moreover, there is no limitation to the portable data terminal device  20 , and another radiographic image reading device may be employed, such as a viewer.  FIG. 18  illustrates a schematic configuration diagram illustrating an overall schematic configuration of an example of a radiographic imaging system for a case in which a radiographic image reading device  90  is employed as a viewer instead of the portable data terminal device  20 . Moreover, for example, another device may be employed instead of the portable data terminal device  20 , such as an ordinary personal computer.  FIG. 19  is a schematic configuration diagram illustrating an overall schematic configuration of an example of a radiographic imaging system for a case in which a device equivalent to a personal computer is provided instead of the portable data terminal device  20 . 
     Explanation has been given in each of the above exemplary embodiments of cases in which the sectional images  70  are generated in the console  16 , however the sectional images  70  may be generated in the portable data terminal device  20 . Explanation has been given in each of the above exemplary embodiments of cases in which the controller  50  of the portable data terminal device  20  includes functionality of a generation section to generate the combined sectional images  72 R, and includes functionality of a controller to switch the other combined sectional image  72 R coupled to switching display of the one sectional image  70 L, however there is no limitation thereto. For example, the controller  30  of the console  16  may include each of these functional sections, and then the portable data terminal device  20  may be dispensed with in cases in which the sectional images  70  are only displayed on the display section  36  of the console  16 . Moreover, the controller  30  of the console  16  may include some of these functional sections, and the other functional sections may be included in the controller  50  of the portable data terminal device  20 . 
     Moreover, explanation has been given in each of the above exemplary embodiments of case in which the sectional images  70  of the left and right breasts serve as an example of a pair of mutually related sectional images, however the pair of mutually related sectional images is not particularly limited. For example, the sectional images  70  may be of either the left or right breast, taken at different imaging times. 
     Moreover, explanation has been given of cases of the radiographic imaging system  10  of each of the above exemplary embodiments in which the radiographic imaging device  12  is a mammography device; however another radiographic imaging device may be employed. Moreover, the imaging target is also not limited to a breast, and may be another site, without particular limitation. 
     Moreover, explanation has been given in each of the above exemplary embodiments of cases in which successive change to the slice position of the left breast sectional image  70 L was instructed as the one sectional image  70 , however it is obvious that successive change to the slice position of the right breast sectional images  70 R may be similarly instructed as the one sectional image  70 . 
     Moreover, the radiation employed for imaging the radiographic images is not particularly limited, and X-rays, gamma-rays or the like may be suitably employed. 
     Configuration and operation of the radiographic imaging system  10 , the radiographic imaging device  12 , the console  16 , and the portable data terminal device  20  as explained in each of the above exemplary embodiments are merely examples thereof, and obviously modifications may be made according to the circumstances, within a range not departing from the spirit of the present invention. Moreover, the flow of sectional image display processing explained in each of the above exemplary embodiments is merely an example, and obviously modifications may be made according to the circumstances, within a range not departing from the spirit of the present invention.