JP2008264519A - Radiographic imaging apparatus and method for controlling radiographic imaging apparatus - Google Patents

Abstract

A predetermined radiation dose measurement position as a region of interest is accurately selected from a plurality of radiation dose information measurement positions.
A mammography apparatus 10 that is a radiographic imaging apparatus includes a radiation source 20 that emits radiation, an AEC sensor 42 that detects radiation emitted from the radiation source 20 and acquires radiation dose information for exposure control, Based on the radiation dose information acquired by the AEC sensor 42, one or more AEC sensors 42 that output predetermined radiation dose information are selected to identify a breast position that is a region of interest of the subject. A weighting factor adding unit 60 that multiplies each output of each AEC sensor 42 before specifying the radiation dose measurement position by the mammary gland position specifying unit 56 by a weighting coefficient according to the installation position of each AEC sensor 42, and a radiation source. 20 to a radiation source control unit 54 for controlling the radiation dose irradiated at the specified breast position.
[Selection] Figure 4

Description

  The present invention relates to a radiographic image capturing apparatus and a radiographic image capturing apparatus control method for acquiring radiographic image information of a subject.

  2. Description of the Related Art In the medical field, a radiographic imaging apparatus that exposes radiation from a radiation source to a subject (patient), detects radiation transmitted through the subject with a solid state detector, and records radiation image information is widely used.

  In this type of radiographic imaging apparatus, it is necessary to ensure good radiographic image quality while minimizing the radiation dose of the subject. Therefore, in order to acquire appropriate radiological image information of the region of interest in the subject, it is necessary to set an exposure control condition so that a desired amount of radiation is exposed to the region of interest. In view of this, a radiographic imaging apparatus including an automatic exposure control (AEC) system that controls the radiation dose emitted from the radiation source based on the detection result of the radiation dose transmitted through the subject has been proposed.

  As one of such radiographic imaging devices, a mammography device used for breast cancer screening or the like is known. The mammography apparatus, for example, is equipped with a panel-shaped solid detector, supports a breast that is a photographing part of a subject, and a pressure table that is disposed opposite to the photographing base and presses the breast against the photographing base. A plate and a radiation source for exposing the breast to radiation through the compression plate.

  By the way, the breast has a mammary gland region and a fat region. The region of interest in breast cancer screening is a mammary gland region where the incidence of breast cancer is high. The mammary gland region has a large absorption coefficient of radiation, whereas the fat region has a small absorption coefficient and hardly absorbs radiation. Therefore, in order to acquire appropriate radiation image information of the mammary gland region, it is necessary to set appropriate exposure control conditions based on the mammary gland region so that a desired amount of radiation is exposed to the mammary gland region. . Here, the exposure control conditions are tube voltage, tube current, radiation exposure time, etc. set to the radiation source. Of these, the tube current and the exposure time determine the radiation dose to be irradiated to the subject. Is the most important condition to do.

  Therefore, in such a mammography apparatus, it is possible to have a radiation dose information detector for automatic exposure control in the imaging stand, and specify a region where the output value of the radiation dose information detector is small as a region having a high breast density. (See Patent Document 1 and Patent Document 2).

JP 2000-197624 A Japanese Patent Laid-Open No. 7-153592

  However, for example, in inside / outside oblique (MLO) imaging in a mammography apparatus, imaging is performed by exposing radiation X from an oblique direction of the subject, so that the pectoral muscle enters the radiation detection region. In general, the pectoral muscle tends to have a larger radiation absorption coefficient than the mammary gland region.

  Therefore, when specifying the region of high breast density, which is the region of interest, the output value of the AEC sensor tends to be smaller in the breast muscle than in the breast region. For this reason, the breast muscle is erroneously specified as the region of interest. There is a possibility that. If it does so, acquisition of the suitable radiographic image information of a mammary gland area | region will become difficult, and a desired radiographic image may not be produced | generated.

  The present invention has been made in order to solve the above-described problem, and a predetermined radiation dose measurement position serving as a region of interest can be accurately selected from a plurality of radiation dose information measurement positions. An object of the present invention is to provide a radiographic imaging apparatus capable of generating an image and a control method for the radiographic imaging apparatus.

  A control method for a radiographic image capturing apparatus according to the present invention is a control method for a radiographic image capturing apparatus for acquiring radiographic image information of a subject, the step of exposing radiation from a radiation source to an imaging region of the subject; Detecting a dose of the radiation transmitted through the imaging region at a plurality of measurement positions; multiplying each radiation dose information measured at the plurality of measurement positions by a weighting coefficient corresponding to the measurement position; Selecting one or more radiation dose measurement positions from a plurality of measurement positions; and determining radiation exposure control conditions by the radiation source based on the radiation dose information at the selected radiation dose measurement positions. It is characterized by having.

  In the case where the imaging region is the breast of the subject, in the step of selecting the radiation dose measurement position, the measurement is located closer to the center than the peripheral portion of the breast in the direction along the chest wall of the subject. Each radiation dose information can be multiplied by a weighting coefficient set for preferentially selecting a position.

  Still further, when the imaging region is the breast of the subject, in the step of selecting the radiation dose measurement position, in order to preferentially select the measurement position located on the nipple side rather than the breast wall side of the breast Each set of radiation dose information can be multiplied by the set weighting coefficient.

  The step of selecting one or a plurality of radiation dose measurement positions from the plurality of measurement positions is obtained by multiplying each radiation dose information measured at the plurality of measurement positions by a weighting coefficient corresponding to the measurement position, to obtain a predetermined radiation dose. Radiation for which radiation dose information in a predetermined range is obtained by comparing the radiation dose information before multiplying the weighting coefficient at the predetermined radiation dose measurement position selected in the first step with the first step of selecting the measurement position. A second step of selecting a dose measurement position, and determining a radiation exposure control condition by the radiation source at each of the radiation dose measurement positions selected in the first step and the second step. Based on each radiation dose information, the radiation exposure control condition by the radiation source may be determined. In this case, the predetermined range of the second step may be variable.

  A radiographic imaging apparatus according to the present invention detects a radiation source that irradiates radiation to an imaging region of a subject, and detects a dose of radiation that has passed through the imaging region at a plurality of measurement positions, and radiation dose information for exposure control A radiation dose information detector for acquiring the weight, a weighting factor applying means for multiplying the radiation dose information measured at the plurality of measurement positions by a weighting factor corresponding to the measurement position, and the respective weight coefficient multiplied Based on the radiation dose information, measurement position selection means for selecting one or more radiation dose measurement positions from the plurality of measurement positions, and based on the radiation dose information at the radiation dose measurement position selected by the measurement position selection means, Radiation source control means for controlling the radiation dose emitted from the radiation source.

  In addition, the radiographic imaging device is a mammography device in which the imaging part is a breast of a subject, and specifies an imaging table for storing the radiation dose information detector and a holding position of the breast on the imaging table. Holding position specifying means, and the weighting coefficient applying means follows the chest wall of the subject with a weighting coefficient by which each radiation dose information is multiplied according to the holding position of the breast specified by the holding position specifying means. Weighting coefficient shift means for shifting in the direction may be included.

  According to the present invention, when a predetermined radiation dose measurement position is selected from a plurality of measurement positions from which radiation dose information is detected, calculation processing is performed by multiplying each radiation dose information by a weighting coefficient corresponding to the measurement position. . Thus, for example, it is possible to effectively prevent the selection of a radiation dose measurement position corresponding to a part that hinders accurate identification of a region of interest, such as a pectoral muscle in MLO imaging with a mammography apparatus, and a predetermined radiation dose. The measurement position can be accurately selected, and a desired radiation image can be reliably acquired.

  Hereinafter, a control method of a radiographic image capturing apparatus according to the present invention will be described in detail with reference to the accompanying drawings by giving preferred embodiments in relation to the radiographic image capturing apparatus that performs the control method.

  FIG. 1 is a perspective explanatory view of a mammography apparatus 10 as a radiographic imaging apparatus according to an embodiment of the present invention, and is an inside / outside oblique (MLO) imaging that performs imaging by exposing radiation from an oblique direction of a subject. The state at is shown. In this embodiment, the mammography apparatus 10 is illustrated as an example to describe the radiographic image capturing apparatus according to the present invention, but the present invention is not limited to this.

  The mammography apparatus 10 includes a base 12 that is installed in an upright state, an arm member 16 that is fixed to a turning shaft 14 that is disposed at a substantially central portion of the base 12, and an imaging part (imaging part) of a subject 18. The radiation source 20 for exposing the breast to the radiation is housed, the radiation source housing portion 22 fixed to one end of the arm member 16, and the arm member 16 disposed opposite to the radiation source housing portion 22. An imaging table 24 fixed to the other end of the imaging table 24 and a compression plate (pressing plate) 26 that presses and holds the breast against the imaging table 24 are provided. The pivot shaft 14 is rotationally driven by a drive motor 28 built in the base 12, that is, the pivot shaft 14 and the drive motor 28 are configured as a rotation mechanism 30 that rotates the arm member 16.

  The arm member 16 to which the radiation source storage unit 22 and the imaging stand 24 are fixed is configured to be adjustable in the imaging direction with respect to the breast of the subject 18 by rotating in the direction of arrow A about the rotation axis 14 by the drive motor 28. The During this turning, the relative positional relationship between the radiation source 20 and the imaging table 24 is maintained. The compression plate 26 is disposed between the radiation source storage unit 22 and the imaging table 24 in a state of being connected to the arm member 16 and is configured to be displaceable in the arrow B direction.

  The base 12 displays photographing information of the subject 18 detected by the mammography apparatus 10, photographing information such as a photographing direction, ID information of the subject 18, and the like, and the information can be set as necessary. A display operation unit 32 is provided.

  FIG. 2 is a main part explanatory diagram showing an internal configuration of the imaging stand 24 in the mammography apparatus 10, and shows a state where a breast (mammo) 34 that is an imaging region of the subject 18 is arranged between the imaging stand 24 and the compression plate 26. . Reference numeral 36 indicates the chest wall of the subject 18.

  A solid-state detector (image sensor) that accumulates radiation image information captured based on the radiation X output from the radiation source 20 built in the radiation source storage unit 22 and outputs it as an electrical signal inside the imaging table 24. ) 38 and a reading light source unit 44 that irradiates the solid detector 38 with reading light in order to read the radiation image information stored and recorded in the solid detector 38. Further, a plurality of radiation dose information detectors for detecting the radiation dose of the radiation X that has passed through the breast 34 and the solid state detector 38 in order to determine the exposure (irradiation) control conditions of the radiation X in the imaging table 24. (Hereinafter referred to as the AEC sensor 42) and an erasing light source unit 40 that irradiates the solid detector 38 with erasing light in order to remove unnecessary charges accumulated in the solid detector 38 are housed.

  The solid state detector 38 is a direct conversion type and light readout type radiation solid state detector that accumulates radiation image information based on the radiation X transmitted through the breast 34 as an electrostatic latent image and reads it from the reading light source unit 44. By scanning with light, a current corresponding to the electrostatic latent image is generated.

  As the solid state detector 38, for example, one having a structure disclosed in Japanese Patent Application Laid-Open No. 2004-154409 can be used. Specifically, the solid state detector 38 is formed on a glass substrate and has a first conductive layer that transmits radiation X and The recording photoconductive layer that generates a charge when exposed to radiation X and the latent image polar charge charged in the first conductive layer act as an insulator while being opposite to the latent image polar charge. A charge transport layer that acts as a substantially conductive material for the polar transport polar charge, a read photoconductive layer that exhibits electrical conductivity when irradiated with read light, and a second that transmits radiation X A conductive layer is sequentially stacked. A power storage unit is formed at the interface between the recording photoconductive layer and the charge transport layer.

  The first conductive layer and the second conductive layer each constitute an electrode. The electrode of the first conductive layer is a two-dimensional flat plate electrode, and the electrode of the second conductive layer is a plurality of lines having a predetermined pixel pitch for detecting recorded radiographic image information as an image signal. Configured as an electrode. The arrangement direction of the linear electrodes corresponds to the main scanning direction, and the extending direction of the linear electrodes corresponds to the sub scanning direction.

  The reading light source unit 44 includes, for example, a line light source configured by arranging a plurality of LED chips in a row, and an optical system that linearly irradiates the reading light output from the line light source onto the solid state detector 38, The line light source in which the LED chips are arranged in a direction orthogonal to the extending direction of the linear electrode which is the second conductive layer of the solid state detector 38 is moved in the extending direction of the linear electrode (arrow C direction in FIG. 3). By doing so, the entire surface of the solid state detector 38 is exposed and scanned.

  As shown in FIG. 3, the erasing light source unit 40 is configured by arranging a large number of LED chips 46 on a panel 48 that emit and extinguish light in a short time and have very little afterglow. The panel 48 is housed in the imaging table 24 in a state of being arranged in parallel with the solid state detector 38.

  As shown in FIGS. 2 and 3, a plurality of AEC sensors 42 (16 in the case of the present embodiment) are arranged on the sensor substrate 50 and formed on the panel 48 constituting the erasing light source unit 40. The direction from the hole 41 toward the solid state detector 38 is directed. Each AEC sensor 42 is surrounded by a rectangular tubular member (not shown) extending from the hole 41 toward the AEC sensor 42 along the direction of the radiation X from the radiation source 20. Be placed.

  Such an AEC sensor 42 is arranged on the sensor substrate 50 so as to correspond to the breast 34 in a state where the breast 34 is positioned and fixed on the imaging table 24 (see FIG. 3).

  FIG. 4 is a block diagram of a control circuit constituting the mammography apparatus 10.

  The control circuit of the mammography apparatus 10 is stored in the radiation source storage unit 22, and a radiation source control unit (radiation source control means) 54 that controls the radiation source 20 that emits radiation X by the operation of the exposure switch 52, and the radiation dose. Based on the radiation dose of the radiation X detected by the AEC sensor 42 which is an information detector, a breast position specifying unit (measurement position selecting means) 56 for specifying a breast position (region of interest) of the breast 34 and the AEC sensor 42 are used. An exposure time calculation unit 58 that calculates an appropriate exposure time of the radiation X from the radiation source 20 based on the radiation dose per unit time of the radiation X and supplies the radiation X to the radiation source control unit 54 as an exposure control condition. .

  The control circuit of the mammography apparatus 10 includes a radiation image forming unit 59 that forms a radiation image based on the radiation image information detected by the solid state detector 38 and a display unit 61 that displays the radiation image. As described above, the solid state detector 38 functions as a radiation image generating unit that detects radiation exposed from the radiation source 20 and generates a radiation image. In the display unit 61, position information indicating the mammary gland position specified by the mammary gland position specifying unit 56, for example, an image representing the AEC sensor 42 is displayed superimposed on the radiation image.

  Further, the control circuit of the mammography apparatus 10 includes a weighting coefficient applying unit (weighting coefficient applying means) 60 that multiplies each output (radiation dose information) from each AEC sensor 42 by a predetermined weighting coefficient (weighting coefficient), and imaging. A holding position specifying unit (holding position specifying means) 62 that specifies (detects) the holding position (positioning) of the breast 34 on the table 24 and supplies the weighting coefficient to the weighting coefficient applying unit 60 is provided.

  As described above, the mammography apparatus 10 according to the present embodiment specifies the region of interest of the breast 34 by the breast position specifying unit 56 based on the radiation dose detected by the AEC sensor 42 that is a radiation dose information detector, The radiation source control unit 54 is configured as an automatic exposure control system that controls the radiation source 20.

  The mammography apparatus 10 of this embodiment is basically configured as described above, and the operation thereof will be described next.

  First, using a console (not shown), an ID card, or the like, ID information related to the subject 18, a photographing method, and the like are set. In this case, the ID information includes information such as the name, age, and sex of the subject 18 and can be acquired from an ID card possessed by the subject 18. In addition, when the mammography apparatus 10 is connected to a network, it can be acquired from another apparatus on the network. In addition, the imaging method includes information such as an imaging part and an imaging direction instructed by a doctor, which can be acquired from a higher-level device connected to the network or input by a radiologist from the console. These pieces of information can be displayed and confirmed on the display operation unit 32 of the mammography apparatus 10.

  Next, the radiologist sets the mammography apparatus 10 to a predetermined state according to the designated imaging method. For example, as the imaging direction of the breast 34, head-to-tail (CC) imaging in which radiation X is applied from the upper side, imaging in which side X (ML) imaging is performed by exposing the radiation X from the side, oblique There is an inside / outside oblique (MLO) imaging in which radiation X is emitted from the direction and imaging is performed, and the arm member 16 is turned around the turning axis 14 in accordance with these imaging directions.

  Hereinafter, the case where the inner / outer oblique position (MLO) photographing shown in FIG. 1 is performed will be described mainly based on FIGS.

  First, as shown in FIGS. 1 and 5, when performing right MLO imaging for imaging the right breast 34, the arm member 16 is pivoted by a predetermined angle about the pivot shaft 14 and set to a predetermined angular position. Next, the right breast 34 of the subject 18 is positioned with respect to the mammography apparatus 10. In this case, after the right breast 34 is placed on the placement surface of the imaging table 24, the compression plate 26 is pressed down to hold the breast 34 between the imaging table 24 and the compression plate 26 (see FIGS. 2 and 5). . That is, with the outer side (right arm side) of the right breast 34 being in contact with the imaging table 24, the compression plate 26 is pressed and held from the inner side (left breast 34 side).

  In such MLO imaging, normally, the breast 34 is held with the pectoral muscle 64 of the subject 18 entering between the imaging table 24 and the compression plate 26 (see FIG. 5).

  After the above preparatory work is completed, imaging of the breast 34 is started.

  First, after performing exposure (hereinafter referred to as pre-exposure) to determine the exposure control conditions in the mammary gland region that is the target site by setting the radiation dose of the radiation X to be exposed to the breast 34 to be small. A case will be described in which radiography X having a predetermined radiation dose is exposed to the breast 34 (hereinafter referred to as main exposure) in accordance with the determined exposure control conditions.

  Therefore, the radiation source control unit 54 controls the tube current supplied to the radiation source 20 and exposes the radiation X to the breast 34 in a state where the radiation dose per unit time is set to be small.

  On the other hand, the AEC sensor 42 detects the radiation dose of the radiation X that has passed through the compression plate 26, the breast 34, and the solid detector 38, and supplies it to the breast position specifying unit 56. The mammary gland position specifying unit 56 calculates the radiation dose per unit time from the radiation dose of the radiation X detected at predetermined sampling times by the AEC sensor 42, and specifies the mammary gland position based on the radiation dose. That is, the mammary gland position specifying unit 56 selects a sensor that outputs the minimum radiation dose from the plurality of AEC sensors 42 arranged on the sensor substrate 50 and specifies the mammary gland position, thereby measuring a predetermined radiation dose. A position having the highest breast density as a position can be detected as a breast position (region of interest).

  FIG. 6 is a plan view schematically showing a state where the breast 34 is held on the imaging table 24 in the right MLO imaging. In this state, not only the breast 34 but also the pectoral muscle 64 are located on the AEC sensor 42 that detects the radiation dose. In FIG. 6, the numbers described in the rectangular figures indicating the respective AEC sensors 42 indicate the channel numbers of the AEC sensors in the upper row, and the weights in the lower row are multiplied by the weighting coefficient assigning unit 60 on the outputs of the AEC sensors. An example of the weighting coefficient is shown. The channel numbers are given for convenience of explanation. In the following explanation, for example, the AEC sensor 42 with channel number 1 (ch1) is referred to as AEC sensor ch1, and the AEC sensor 42 with channel number 2 (ch2). Is referred to as AEC sensor ch2, and the same applies to others.

  In this case, the radiation X transmitted through the breast 34 is not so much absorbed in the fat region, but is greatly absorbed in the mammary gland region and the pectoral muscle 64, and in particular, tends to be absorbed most greatly in the pectoral muscle 64. Therefore, among the arranged AEC sensors 42, the radiation doses detected and output by the AEC sensors ch3 and ch8 located at the position overlapping the pectoral muscle 64 (the portion indicated by the region R1 in FIG. 6) are minimized. End up. For this reason, the mammary gland position specifying unit 56 erroneously specifies the position of the AEC sensor ch3 or ch8 that overlaps the pectoral muscle 64 as the mammary gland position, and the position where the mammary gland density is actually high (for example, the region R2 in FIG. 6). May not be identified as a mammary gland position (radiation dose measurement position).

  Therefore, in the case of the present embodiment, when specifying the mammary gland position in the mammary gland position specifying unit 56, first, the radiation dose information output from each AEC sensor 42 is introduced into the weighting coefficient adding unit 60. In the weighting coefficient assigning unit 60, a predetermined weighting coefficient set (stored) in advance based on the installation position (measurement position of radiation dose information) of each AEC sensor 42 is output to each output (radiation dose information) from each AEC sensor 42. ) Is multiplied. For example, as shown in FIG. 6, the output from the AEC sensor ch1 is multiplied by 2.0 as the weighting coefficient, the output from the AEC sensor ch11 is multiplied by 1.0 as the weighting coefficient, and the AEC sensors 42 of the other channels. The same applies to.

  In this case, as shown in FIG. 6, the weighting coefficient to be multiplied by each AEC sensor 42 is set on the center line CL <b> 1 that is the central portion (center side) of the breast 34 in the direction along the chest wall 36 (arrow C direction). The AEC sensor 42 (AEC sensors ch2, ch6, ch11, and ch15) is set to increase in a stepwise manner toward the periphery (outside). Furthermore, the weighting coefficient to be multiplied by each AEC sensor 42 is set so as to decrease stepwise in a direction (arrow D direction) from the chest wall 36 side toward the nipple side.

  That is, in the weighting coefficient assigning unit 60, among the radiation detection region R (see FIG. 6) where the radiation dose information is detected, the region R1 including the pectoral muscle 64 in MLO imaging (in the case of left MLO imaging, FIG. 9). The output of the adjacent AEC sensor 42 is multiplied by a large weighting coefficient, and the output of the adjacent AEC sensor 42 is multiplied by a small weighting coefficient, or the output of the adjacent AEC sensor 42 is likely to be included. Settings are made.

  For example, as shown in FIG. 7A, the output (for example, current value (mA)) of the radiation dose information detected by the AEC sensor ch11 located in the region R2 where the breast density is high is 100, and the surrounding AEC sensor ch6. And the radiation dose information detected by ch12 is 115 and 120, and the radiation dose information detected by the AEC sensors ch3 and ch8 located in the region R1 overlapping the pectoral muscle 64 is 75 and 70. . Then, each of these outputs is multiplied by a weighting coefficient set in accordance with the installation position of each AEC sensor 42 in the weighting coefficient assigning unit 60, and as shown in FIG. The output of the AEC sensor ch11 located is corrected as 100, the outputs of the surrounding AEC sensors ch6 and ch12 are 138 and 144, and the outputs of the AEC sensors ch3 and ch8 located in the region R1 overlapping the pectoral muscle 64 are corrected as 150 and 140 (calculation) Are supplied to the mammary gland position specifying unit 56.

  The mammary gland position specifying unit 56 selects the AEC sensor ch11 that is the AEC sensor 42 that outputs the minimum radiation dose among the outputs (radiation dose information) of each AEC sensor 42 corrected by the weighting coefficient assigning unit 60. To identify as mammary gland location. Accordingly, the mammary gland position specifying unit 56 can reliably select the AEC sensor ch11 located in the region R2 having a high mammary gland density shown in FIG. (Radiation dose measurement position) can be accurately detected.

  As described above, in the weighting coefficient assigning unit 60, among the AEC sensors 42, the AEC sensor 42 that is installed closer to the center than the periphery of the breast 34 and closer to the nipple than the chest wall 36 is used. A calculation process is performed to multiply the output of each AEC sensor 42 by a weighting coefficient set so that it can be preferentially selected by the specifying unit 56. For this reason, in the mammary gland position specifying unit 56, it is effectively prevented that the installation position of the AEC sensor 42 that overlaps the pectoral muscle 64 is erroneously selected as the mammary gland position (region of interest).

  The mammary gland position specifying unit 56 outputs an AEC sensor 42 (for example, the AEC sensor described above) that outputs a minimum radiation dose among the signals supplied from the weighting coefficient assigning unit 60 (the output of the corrected AEC sensor 42). In addition to selecting only one ch11) and specifying the position of the mammary gland, a plurality of AEC sensors 42 are selected and their average value (average output) or median number (median) (median number output) It is also possible to specify a region near the breast position.

  By selecting a plurality of AEC sensors 42 in the mammary gland position specifying unit 56 and specifying the area near the mammary gland position using the average value or the median number, an area having a high mammary gland density covers the plurality of AEC sensors 42. To meet various measurement needs due to individual differences of the breasts 34, etc., in a case where the breast density is large (see FIG. 8A), or where regions of high breast density are dispersed (see FIG. 8B). It becomes possible.

  For example, as shown in FIG. 8A, when the region R3 having a high mammary gland density is in a wide range, first, the AEC sensor ch11 that outputs the minimum radiation dose after correction by the weighting coefficient adding unit 60 is selected. Specifically, as understood from FIG. 8A, the AEC sensor ch11 has an actual output (actual output value before weighting) of 100, an output after correction of 100, and all of the AEC sensors 42. The output after correction is minimum.

  Next, for example, the AEC sensor 42 whose actual output is within plus or minus 20% (80 to 120) with respect to the actual output of the AEC sensor ch11 that outputs the minimum radiation dose selected as described above is selected. That is, in this case, since the actual output of the AEC sensor ch11 is 100, the AEC sensor ch5 (actual output 120), ch6 (actual output 110), and ch12 (actual output 105) are selected.

  Therefore, the mammary gland position specifying unit 56 averages the actual outputs of the AEC sensor ch11 and the AEC sensors ch5, ch6, and ch12 selected as described above, and calculates the calculated average value {108.75 = (100 + 120 + 110 + 105) / 4}. The final data is supplied to the exposure time calculation unit 58. Of course, as described above, the median number of the selected AEC sensor 42 may be used as the final data.

  As shown in FIG. 8B, even in the case where regions having high breast density are dispersed with regions R2, R4, and R5, as in the case shown in FIG. 8A, first, after the correction by the weighting coefficient assigning unit 60, The AEC sensor ch11 that outputs the minimum radiation dose is selected. Next, with respect to the actual output of the AEC sensor ch11, for example, AEC sensors ch5, ch6, ch7, and ch12 whose actual output is within ± 20% are selected, and the average value and the median number calculated from these are finally determined. What is necessary is just to supply to the exposure time calculation part 58 as data.

  In this way, by selecting a plurality of AEC sensors 42 in the mammary gland position specifying unit 56 and specifying the mammary gland position using the average value or the median number, the distribution of the region of interest (mammary gland position) is more accurately determined. It becomes possible to specify. Specifically, in the obtained radiographic image, the contrast in the mammary gland region (for example, the region R3 in FIG. 8A) or for each mammary gland region (for example, the regions R2, R4, and R5 in FIG. 8B) is further improved. A better radiation image can be acquired. Therefore, in the case shown in FIG. 8A, the contrast in one region R3 can be increased, and in the case shown in FIG. 8B, between one region R2 and its peripheral regions R4 and R5. As a result, the radiation image of the breast 34 as a whole can be made clearer.

  In the above description, the AEC sensor ch11 that outputs the minimum radiation dose after correction by the weighting coefficient assigning unit 60 is selected. However, the number of AEC sensors 42 that output the minimum radiation dose is not only one, There may be a plurality, and in this case, it is preferable to select a plurality of average values or those whose actual output is within ± 20% for each.

  Naturally, the range (threshold range) of the AEC sensor 42 selected for the actual output of the AEC sensor ch11 that outputs the minimum radiation dose is not within plus or minus 20%, for example, within plus or minus 15%. Alternatively, it may be configured such that the operator can appropriately change the setting via the display operation unit 32.

  When the mammary gland position is identified by the mammary gland position identifying unit 56 as described above, the exposure time calculating unit 58 determines the amount of the breast 34 based on the radiation dose per unit time detected by the AEC sensor 42 at the mammary gland position. An exposure time for exposing a radiation dose necessary for obtaining appropriate radiation image information of the mammary gland region is calculated as an exposure control condition.

  In this case, since the radiation X exposed to the AEC sensor 42 is partly absorbed by the solid state detector 38, the radiation per unit time detected by the AEC sensor 42 is taken into consideration in consideration of the influence of the attenuation. It is necessary to correct the dose to the radiation dose per unit time that reaches the detection surface of the solid state detector 38.

  The exposure time calculation unit 58 determines that the integrated value of the radiation dose per unit time and the exposure time on the detection surface of the solid state detector 38 corrected in consideration of the correction factors described above is appropriate radiation in the mammary gland region. The said exposure time of the radiation X is calculated so that it may become the required radiation dose which can obtain image information. The calculated exposure time is set in the radiation source control unit 54 as an exposure control condition.

  Next, the main exposure is started.

  The radiation source control unit 54 sets the tube current supplied to the radiation source 20 to a current that provides a radiation dose per unit time necessary for the main exposure. Next, when the radiologist operates the exposure switch 52, the radiation X is exposed to the breast 34 while the radiation source 20 is controlled by the current, and the exposure time set as the exposure control condition has elapsed. Thereafter, the exposure to the radiation X is stopped.

  Note that the radiation dose during the main exposure is detected by the AEC sensor 42 (for example, AEC sensor ch11), the integrated amount is calculated, and the radiation dose of the radiation X is reached before the set exposure time is reached. Exceeds the allowable amount, the radiation source controller 54 is controlled to forcibly stop the exposure of the radiation X by the radiation source 20, so that excessive radiation X is applied to the subject 18 due to a failure of the mammography apparatus 10 or the like. It is also possible to prevent exposure from occurring.

  When the radiation X transmitted through the breast 34 held between the compression plate 26 and the imaging table 24 reaches the solid state detector 38 accommodated in the imaging table 24, radiation image information is recorded. After the imaging of the breast 34 is completed, when the reading light source unit 44 moves along the solid detector 38 in the direction of arrow C in FIG. 3 and is irradiated with reading light, the radiation image information recorded on the solid detector 38 Is read out, a radiographic image is formed in the radiographic image forming unit 59, and displayed on the display unit 61. The solid state detector 38 from which the radiation image information has been read is irradiated with erasing light emitted from an erasing light source unit 40 to perform the next imaging, and accumulated unnecessary charges are removed.

  The display unit 61 displays the image of the AEC sensor 42 (for example, the AEC sensor ch11) superimposed on the breast gland position specified by the mammary gland position specifying unit 56 as necessary, so that the mammary gland position is displayed. It can be confirmed whether or not the position of the mammary gland specified by the specifying unit 56 is appropriate.

  Subsequently, when performing left MLO imaging, the arm member 16 is rotated about the turning shaft 14 and set to a predetermined angular position corresponding to the left MLO imaging. Next, in the state where the breast 34 on the left side of the subject is held by the imaging table 24 and the compression plate 26, imaging is performed in the same procedure as in the right MLO imaging.

  In the case of left MLO imaging, as shown in FIG. 9, the region R1 including the pectoral muscle 64 is located at a position that is substantially symmetrical with respect to the center line CL1 as compared with the case of right MLO imaging. Become. However, in the weighting coefficient assigning unit 60, among the AEC sensors 42, the AEC sensor 42 that is installed closer to the center than the periphery of the breast 34 and closer to the nipple side than the chest wall 36 is used as the breast position specifying unit. A calculation process is performed by multiplying the output of each AEC sensor 42 by a weighting coefficient preferentially selected at 56. For this reason, even in the left MLO imaging in which the position of the region R1 changes, correction that greatly increases the outputs of the AEC sensors ch3 and ch8 overlapping the region R1 including the pectoral muscle 64 is performed. Therefore, the mammary gland location specifying unit 56 prevents the AEC sensor 42 (AEC sensors ch3 and ch8 in FIG. 9) belonging to the region R1 including the pectoral muscle 64 from being erroneously selected as the mammary gland location (region of interest). Thus, the AEC sensor 42 (AEC sensor ch11 in FIG. 9) belonging to the region R2 having a high breast density is accurately detected. This makes it possible to perform imaging based on appropriate exposure control conditions even in left MLO imaging.

  Depending on the size of the breast 34, the central portion of the breast 34 may not be held on the center line CL1 shown in FIG. For example, in the case of a small-sized breast 34, as shown in FIG. 10, the center line CL2 at a position slightly deviated from the center line CL1 in the direction of the arrow C may be held as the center of the breast 34. is there.

  Therefore, in order to cope with such a situation, for example, a holding position selection switch (not shown) is provided in the display operation unit 32 configuring the mammography apparatus 10, and the technician uses the holding position selection switch to switch the imaging table 24. An input is made that the center of the breast 34 held above is on the center line CL2. The holding position specifying unit 62 (see FIG. 4) specifies the holding position (positioning) of the breast 34 on the imaging table 24 based on the selection result by the holding position selection switch, and the result (holding position) is used as a weighting coefficient. It supplies to the grant part 60.

  Next, the weighting coefficient assigning unit 60 sets the weighting coefficient based on the center line CL1 as shown in FIG. 6 based on the holding position information of the breast 34 from the holding position specifying unit 62 as shown in FIG. The center line CL2 is changed (shifted) to set the weighting coefficient. That is, when the center of the breast 34 is shifted on the center line CL2, the weighting coefficient to be multiplied by each AEC sensor 42 is shifted from the setting based on the center line CL1 to the setting based on the center line CL2. . Then, the setting is such that the AEC sensor 42 (AEC sensors ch3, ch7, ch12, and ch16) installed on the center line CL2 becomes larger stepwise in the direction toward the peripheral portion (outside) (arrow C direction). Become.

  As a result, even when the center of the breast 34 is shifted on the center line CL2, the mammary gland position specifying unit 56 outputs (radiation dose information) of each AEC sensor 42 calculated by the weighting coefficient adding unit 60. ), The AEC sensor ch12 that outputs the smallest radiation dose can be selected and reliably identified as the position of the mammary gland, and the position with the highest breast density is accurately detected as the mammary gland position (predetermined radiation dose measurement position) can do.

  Even when the center of the breast 34 is shifted in the direction of the other center line CL3 (see FIG. 10), the weighting coefficient based on the center line CL3 is the same as in the case of the shift in the direction of the center line CL2. Needless to say, it may be changed (shifted) to the setting.

  As described above, the weighting coefficient assigning unit 60 follows the chest wall 36 of the subject 18 with the weighting coefficient by which each output of each AEC sensor 42 is multiplied according to the holding position of the breast 34 specified by the holding position specifying unit 62. It is configured to include a function as a weighting coefficient shift means for shifting in the direction (arrow C direction).

  Incidentally, in the mammography apparatus 10 according to the present embodiment, the holding position specifying unit 62 specifies the holding position of the breast 34 based on the input from the holding position selection switch. It can be specified by the first to sixth specifying methods).

  Therefore, next, a method for specifying the holding position of the breast 34 in the holding position specifying unit 62 will be described with reference to FIGS.

  FIG. 11 is a block diagram for explaining a first specifying method of the holding position of the breast 34. In this case, the compression plate for fixing the breast 34 to the imaging table 24 is configured as a compression plate 26a movable in the direction of the arrow C, and the compression plate 26a is moved to an appropriate position according to the size of the breast 34, etc. By doing so, the breast 34 is securely fixed. Further, a compression plate position detector 70 for detecting the position (movement amount) of the compression plate 26a is provided, and the compression plate position information of the compression plate 26a is detected based on the compression plate position information detected by the compression plate position detector 70. A compression plate position specifying unit (compression plate position specifying means) 72 for specifying the position is provided.

  Thereby, the holding position specifying unit 62 specifies the holding position of the breast 34 based on the position of the compression plate 26 a specified by the compression plate position specifying unit 72, and supplies the result to the weighting coefficient applying unit 60. It becomes possible.

  FIG. 12 is a block diagram for explaining a second specifying method of the holding position of the breast 34. In this case, the compression plate for fixing the breast 34 to the imaging table 24 is a compression plate 26 b configured to be swingable by the center in the direction of arrow C being supported by the swing shaft 74. Furthermore, any one of the swinging direction, the swinging force (torque in the swinging direction when the breast 34 is fixed), or the swinging angle of the compression plate 26b with the breast 34 held on the imaging table 24. Alternatively, a compression plate rocking state detector 76 for detecting a rocking state composed of two or more is provided, and information regarding the rocking operation of the compression plate 26b detected by the compression plate rocking state detector 76 is provided. Based on the above, there is provided a compression plate rocking state specifying part (compression plate rocking state specifying means) 78 for specifying the rocking state of the compression plate 26b.

  Thereby, the holding position specifying unit 62 specifies the holding position of the breast 34 based on the swinging state of the compression plate 26b specified by the compression plate swinging state specifying unit 78, and the result is sent to the weighting coefficient applying unit 60. It becomes possible to supply. That is, for example, when the holding position of the breast 34 is shifted outward from the center portion of the compression plate 26b, the compression plate 26b swings according to the amount of the shift, so that the breast 34 is moved from the swinging state of the compression plate 26b. The holding position can be specified.

  FIG. 13 is a block diagram for explaining a third method for specifying the holding position of the breast 34. In this case, with the breast 34 fixed, a pressure detector 80 is provided on the imaging table 24 to which the pressing force from the compression plate 26 is applied, and the pressure applied from the compression plate 26 to the imaging table 24 is detected. For example, a pressure sensitive sheet is used as the pressure detector 80. Furthermore, based on the pressure information detected by the pressure detector 80, a pressure distribution specifying unit (pressure distribution specifying means) 82 for specifying the pressure distribution generated in the imaging table 24 is provided.

  Thereby, the holding position specifying unit 62 specifies the holding position of the breast 34 based on the pressure distribution of the imaging table 24 specified by the pressure distribution specifying unit 82, and supplies the result to the weighting coefficient applying unit 60. It becomes possible. That is, since the pressure distribution of the imaging table 24 is acquired corresponding to the holding position of the breast 34, the holding position of the breast 34 can be specified by specifying and analyzing such a pressure distribution. Even if the pressure detector 80 is provided on the compression plate 26 side, substantially the same effect can be obtained.

  FIG. 14 is a block diagram for explaining a fourth specifying method of the holding position of the breast 34. In this case, electrodes (transparent electrodes) 84a and 84b are provided on the compression plate 26 and the imaging stand 24 for fixing the breast 34, respectively, and a weak current from the power source 86 is passed between the electrodes 84a and 84b via the breast 34. Further, a potential difference distribution specifying unit (potential difference specifying means) 88 for detecting a potential difference (voltage) between the electrodes 84a and 84b and specifying the distribution of the potential difference is provided. When specifying the potential difference distribution, each of the electrodes 84a and 84b has a structure in which a plurality of electrodes extending in a direction orthogonal to the direction of the arrow C, which is the direction along the chest wall 36 of the subject 18, are arranged. It is also possible to obtain a potential difference distribution in the direction of arrow C by detecting a potential difference between each pair of electrodes facing each other across the electrode.

  Thereby, the holding position specifying unit 62 can specify the holding position of the breast 34 based on the distribution of the potential difference specified by the potential difference distribution specifying unit 88 and supply the result to the weighting coefficient applying unit 60. . That is, since a potential difference is generated between the electrodes 84a and 84b that are in contact with the breast 34 and no potential difference is generated between the electrodes 84a and 84b that are not in contact with the breast 34, the distribution of such potential differences should be specified. Thus, the holding position of the breast 34 can be specified.

  FIG. 15 is a block diagram for explaining a fifth specifying method of the holding position of the breast 34. In this case, the rotation angle θ and the rotation direction of the pivot shaft 14 of the arm member 16 are detected in the vicinity of the arm member 16 (the pivot shaft 14) provided with the compression plate 26 for fixing the breast 34 and the imaging table 24. A rotation angle detector 90 is provided, and based on the rotation angle and rotation direction of the arm member 16 detected by the rotation angle detector 90, the imaging posture of the breast 34 (the angular position of the arm member 16 and the imaging direction of the breast 34). ) To specify a shooting posture specifying unit (shooting posture specifying means) 92. As the rotation angle detector 90, for example, a potentiometer or an encoder is used.

  As a result, the holding position specifying unit 62, for example, stores various angular positions and various kinds of photographing stored in advance based on the photographing position composed of the angular position of the arm member 16 and the photographing direction of the breast 34 specified by the photographing posture specifying part 92. The holding position of the breast 34 can be specified (estimated) from the map data in the direction, and the result can be supplied to the weighting coefficient adding unit 60.

  FIG. 16 is a block diagram for explaining a fifth specifying method of the holding position of the breast 34. In this case, in specifying the holding position of the breast 34, the holding position specifying unit 62 first supplies a command to the weighting coefficient adding unit 60 to not multiply the output of the AEC sensor 42 by the weighting coefficient. Therefore, when radiation is exposed, the output of each AEC sensor 42 is supplied to the mammary gland position specifying unit 56 without being multiplied by the weighting coefficient. Here, the mammary gland position specifying unit 56 creates output distribution information of each AEC sensor 42 and supplies it to the holding position specifying unit 62. The holding position specifying unit 62 specifies the holding position by performing shape recognition of the breast 34 based on the output distribution information from the mammary gland position specifying unit 56, and supplies the result to the weighting coefficient adding unit 60. It becomes possible.

  In addition, this invention is not limited to embodiment mentioned above, Of course, it can change freely in the range which does not deviate from the main point of this invention.

  For example, in the above embodiment, the solid state detector 38 that is an image sensor and the AEC sensor 42 that is a radiation dose information detector are illustrated and described separately. In this case, a part of the image sensor can be used as a radiation dose information detector. In this case, the radiation dose information detector can be replaced by an image sensor.

  In the above-described embodiment, the case where the solid state detector 38 is used has been described. However, the radiation image capturing apparatus in which the stimulable phosphor panel is detachably attached to the imaging table 24, or the reading light source as described above. A radiation solid state detector capable of generating an image by direct conversion without using the unit 44 may be used.

  Needless to say, the radiographic image capturing apparatus according to the present invention is not limited to the mammography apparatus exemplified in the above embodiment, but may be applied to a radiographic image capturing apparatus that captures other parts of the subject.

  It goes without saying that the weighting coefficient described in the above embodiment (see FIG. 6) is appropriately changed according to the apparatus and method to which the present invention is applied, and of course, the number of installed AEC sensors can be changed.

  In the above embodiment, when the holding position of the breast 34 is shifted and the weighting coefficient is shifted, the maximum value (2.0 in the above embodiment) is fixed, that is, as shown in FIG. The weighting coefficients of both AEC sensors ch4 and ch5 are set to 2.0. However, the present invention is not limited to this. For example, the weighting coefficient of AEC sensor ch5 is set to 2.0, and the weighting coefficient of AEC sensor ch4 outside thereof is set to 2.5. It is also possible to set so as to.

It is a perspective explanatory view of a mammography device as a radiographic imaging device concerning one embodiment of the present invention. It is principal part explanatory drawing which shows the internal structure of the imaging stand in the mammography apparatus shown in FIG. FIG. 3 is a partially omitted perspective view showing an internal configuration of the photographing stand shown in FIG. 2. It is a block diagram of the control circuit which comprises the mammography apparatus shown in FIG. It is a partially omitted perspective view showing a state in which right MLO imaging is performed. It is a top view which shows typically the state by which the breast was hold | maintained on the imaging stand in right MLO imaging | photography. FIG. 7A is a schematic plan view showing the output of each AEC sensor before being multiplied by the weighting coefficient, and FIG. 7B is a schematic plan view showing the output of each AEC sensor after being multiplied by the weighting coefficient. FIG. 8A is a schematic plan view showing the output of each AEC sensor before multiplying the weighting coefficient when the region having a high mammary gland density covers a wide range, and FIG. 8B shows the case where the region having a high mammary gland density is dispersed. FIG. 2 is a schematic plan view showing the output of each AEC sensor before being multiplied by a weighting coefficient. It is a top view which shows typically the state by which the breast was hold | maintained on the imaging stand in left MLO imaging | photography. It is a top view which shows typically the state by which the breast was hold | maintained and shifted | deviated from the center of the imaging | photography stand. It is block explanatory drawing for demonstrating the 1st identification method of the holding | maintenance position of a breast. It is block explanatory drawing for demonstrating the 2nd identification method of the holding | maintenance position of a breast. It is block explanatory drawing for demonstrating the 3rd identification method of the holding | maintenance position of a breast. It is block explanatory drawing for demonstrating the 4th identification method of the holding | maintenance position of a breast. It is block explanatory drawing for demonstrating the 5th identification method of the holding | maintenance position of a breast. It is block explanatory drawing for demonstrating the 6th identification method of the holding | maintenance position of a breast.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Mammography apparatus 12 ... Base 14 ... Turning axis 16 ... Arm member 18 ... Subject 20 ... Radiation source 22 ... Radiation source storage part 24 ... Imaging stand 26, 26a, 26b ... Compression plate 32 ... Display operation part 34 ... Breast 36 ... Chest wall 38 ... Solid state detector 42 ... AEC sensor 52 ... Exposure switch 54 ... Radiation source control unit 56 ... Breast gland position specifying unit 58 ... Exposure time calculation unit 59 ... Radiation image forming unit 60 ... Weighting coefficient applying unit 61 ... Display 62: Holding position specifying unit 64 ... Pectoral muscle 72 ... Compression plate position specifying unit 78 ... Compression plate swinging state specifying unit 82 ... Pressure distribution specifying unit 88 ... Potential difference distribution specifying unit 92 ... Imaging posture specifying unit

Claims (14)

A method for controlling a radiographic imaging apparatus for acquiring radiographic image information of a subject,
Exposing radiation from a radiation source to the imaging region of the subject;
Detecting the radiation dose transmitted through the imaging region at a plurality of measurement positions;
Multiplying each radiation dose information measured at the plurality of measurement positions by a weighting coefficient corresponding to the measurement position, and selecting one or a plurality of radiation dose measurement positions from the plurality of measurement positions;
Determining radiation exposure control conditions by the radiation source based on the radiation dose information at the selected radiation dose measurement position;
A control method for a radiographic imaging apparatus, comprising: In the control method of the radiographic imaging device according to claim 1,
The imaging region is the subject's breast,
In the step of selecting the radiation dose measurement position, a weighting coefficient set to preferentially select the measurement position located on the center side of the breast in the direction along the chest wall of the subject is selected. A method for controlling a radiographic imaging apparatus, wherein the radiation dose information is multiplied. In the control method of the radiographic imaging device according to claim 1 or 2,
The imaging region is the subject's breast,
In the step of selecting the radiation dose measurement position, each radiation dose information is multiplied by a weighting coefficient set to preferentially select the measurement position located on the nipple side rather than the breast wall side of the breast. The control method of the radiographic imaging apparatus. In the control method of the radiographic imaging device according to claim 2 or 3,
A control method for a radiographic imaging apparatus, wherein a weighting coefficient to be multiplied by each radiation dose information is shifted in a direction along the chest wall in accordance with a holding position of the breast. In the control method of the radiographic imaging device according to claim 4,
A method for controlling a radiographic imaging apparatus, comprising: identifying a breast holding position by performing shape recognition of the breast based on each radiation dose information measured at the plurality of measurement positions. In the control method of the radiographic imaging apparatus of any one of Claims 1-5,
Selecting one or more radiation dose measurement positions from the plurality of measurement positions;
A first step of selecting a predetermined radiation dose measurement position by multiplying each radiation dose information measured at the plurality of measurement positions by a weighting coefficient corresponding to the measurement position;
A second step of selecting a radiation dose measurement position from which radiation dose information in a predetermined range is obtained, compared with radiation dose information before being multiplied by a weighting coefficient at the predetermined radiation dose measurement position selected in the first step; ,
Have
The step of determining the radiation exposure control condition by the radiation source is based on each radiation dose information at each radiation dose measurement position selected in the first step and the second step. A method for controlling a radiographic imaging apparatus, characterized by determining an irradiation control condition. In the control method of the radiographic imaging device according to claim 6,
The method of controlling a radiographic image capturing apparatus, wherein the predetermined range of the second step is variable. A radiation source that emits radiation to the imaging region of the subject;
A radiation dose information detector for detecting radiation dose transmitted through the imaging region at a plurality of measurement positions and acquiring radiation dose information for exposure control; and
Weighting coefficient giving means for multiplying each radiation dose information measured at the plurality of measurement positions by a weighting coefficient corresponding to the measurement position;
Measurement position selection means for selecting one or a plurality of radiation dose measurement positions from the plurality of measurement positions based on each radiation dose information multiplied by the weighting factor;
Radiation source control means for controlling the radiation dose exposed from the radiation source based on the radiation dose information at the radiation dose measurement position selected by the measurement position selection means;
A radiographic imaging apparatus comprising: The radiographic imaging apparatus according to claim 8, wherein
The radiographic imaging device is a mammography device in which the imaging part is a breast of a subject,
An imaging table for storing the radiation dose information detector;
Holding position specifying means for specifying a holding position of the breast on the imaging table;
With
The weighting coefficient assigning means shifts a weighting coefficient to be multiplied to each radiation dose information in a direction along the chest wall of the subject according to the breast holding position specified by the holding position specifying means. A radiographic imaging apparatus comprising: The radiographic imaging apparatus according to claim 9, wherein
A compression plate configured to compress and fix the breast to the imaging table and to be movable in a direction along at least the chest wall;
Compression plate position specifying means for specifying the position of the compression plate;
With
The radiographic imaging device characterized in that the holding position specifying means specifies the holding position of the breast on the imaging table based on the position of the compression plate specified by the compression plate position specifying means. The radiographic imaging apparatus according to claim 9, wherein
A compression plate configured to compress and fix the breast to the imaging table and swingable in a direction facing the imaging table;
A compression plate rocking state specifying means for specifying a rocking state consisting of at least one or more of the rocking direction, rocking force or rocking angle of the compression plate;
With
The radiographic imaging apparatus characterized in that the holding position specifying means specifies the holding position of the breast on the imaging table based on the rocking state of the compression plate specified by the compression plate rocking state specifying means. . The radiographic imaging apparatus according to claim 9, wherein
A compression plate for compressing and fixing the breast against the imaging table;
A pressure detector for detecting pressure from the compression plate to the imaging table;
Pressure distribution specifying means for specifying the distribution of pressure detected by the pressure detector;
With
The radiographic imaging apparatus characterized in that the holding position specifying means specifies the holding position of the breast on the imaging table based on the pressure distribution specified by the pressure distribution specifying means. The radiographic imaging apparatus according to claim 9, wherein
A compression plate for compressing and fixing the breast against the imaging table;
Electrodes provided on the imaging table and the compression plate,
A power source for passing current between the electrodes;
A potential difference distribution specifying means for specifying a distribution of a potential difference between the electrodes when a current is passed between the electrodes in a state where the breast is held between the imaging table and the compression plate;
With
The radiographic imaging apparatus characterized in that the holding position specifying means specifies the holding position of the breast on the imaging table based on the distribution of potential differences specified by the potential difference distribution specifying means. The radiographic imaging apparatus according to claim 9, wherein
The radiation source and the imaging table are fixed so as to face each other with the breast interposed therebetween, and an arm member configured to be rotatable,
An imaging posture specifying means for specifying the imaging posture of the breast based on a rotation angle or a rotation direction of the arm member;
With
The radiographic imaging apparatus characterized in that the holding position specifying means specifies the holding position of the breast on the imaging stand based on the imaging posture of the breast specified by the imaging posture specifying means.

Images