JP2012050518A - Radiation imaging apparatus - Google Patents

Abstract

A stereoscopic image suitable for stereoscopic viewing is acquired without causing an increase in cost, and a stereoscopic image excellent in stability and reproducibility is taken.
A radiation irradiating unit that irradiates a subject from two different imaging directions, and a radiation image detector that detects a radiation image for each imaging direction by irradiation of radiation from the radiation irradiating unit, In a mammography apparatus that acquires two radiographic images detected by a radiographic image detector as constituting a stereoscopic image, the first focal position of the first radiation source 17a and the second focus of the second radiation source 17b. It is assumed that radiations in two imaging directions are respectively emitted from two focal positions, and the first and second radiation sources 17a and 17b are a field emission electron source that generates electrons by applying an electric field, And an anode that emits radiation upon incidence.
[Selection] Figure 4

Description

  The present invention detects a radiation image for each imaging direction by irradiating the subject with radiation from two different imaging directions, and configures the two radiographic images as a stereoscopic image. The present invention relates to a radiographic imaging apparatus to be acquired.

  Conventionally, it is known that stereoscopic viewing can be performed using parallax by displaying a plurality of images in combination. Such a stereoscopically viewable image (hereinafter referred to as a stereoscopic image or a stereo image) is generated based on a plurality of images having parallax obtained by photographing the same subject from different directions.

  Such generation of stereoscopic images is used not only in the fields of digital cameras and televisions but also in the field of radiographic imaging. That is, the patient is irradiated with radiation from different directions, the radiation transmitted through the subject is detected by a radiation image detector, and a plurality of radiation images having parallax are obtained, and these radiations are acquired. A stereoscopic image is generated based on the image. And by generating a stereoscopic image in this way, a radiographic image with a sense of depth can be observed, and a radiographic image more suitable for diagnosis can be observed.

JP 2007-229201 A JP 2004-188200 A

  Here, as a radiographic imaging apparatus that generates a stereoscopic image as described above, a mammography imaging apparatus has been proposed, but in many existing mammography imaging apparatuses, the direction along the chest wall of the subject, that is, Since the radiation is irradiated from the imaging direction tilted to the left and right when viewed from the subject, the displayed stereoscopic image has a layout in which the chest wall extends along the horizontal direction (see, for example, Patent Document 1). .

  On the other hand, in the current 2D breast image interpretation protocol in the medical field, the breast image is displayed in a layout along the chest wall in the vertical direction, so it is compared with a stereoscopic image with the chest wall in the horizontal direction. There is a problem that observation is difficult.

  Thus, for example, in a mammography imaging apparatus, it is conceivable to acquire two radiation images by irradiating radiation from an imaging direction tilted back and forth when viewed from the subject.

  Further, it is generally said that the convergence angle suitable for stereoscopic viewing of a stereoscopic image is about 4 °, and as described above, radiation is irradiated from the imaging direction inclined forward and backward as viewed from the subject. The same applies when acquiring a single radiation image.

  However, for example, in a configuration in which the radiation source is moved using an arm or the like, it is mechanically difficult to control such a small angle movement, and a highly accurate moving mechanism is required. It also increases the cost.

  In addition, when the movement position of the radiation source varies, it is difficult to capture a stereoscopic image with stability and reproducibility.

  Note that Patent Document 2 proposes that in an X-ray tomosynthesis mammography imaging system, a radiation image is acquired by irradiating radiation from an imaging direction tilted back and forth when viewed from a subject. No proposal has been made regarding the problems in photographing such stereoscopic images.

  In view of the above circumstances, the present invention can acquire a stereoscopic image suitable for stereoscopic viewing without incurring a cost increase as described above, and is a stereoscopic image excellent in stability and reproducibility. An object of the present invention is to provide a radiographic imaging apparatus capable of performing the above imaging.

  The radiographic imaging device of the present invention detects a radiation irradiation unit that irradiates radiation from two different imaging directions with respect to a breast of a subject, and a radiographic image for each imaging direction by radiation irradiation of the radiation irradiation unit In the radiographic image capturing apparatus that acquires two radiographic images detected by the radiographic image detector as constituting a stereoscopic image, the radiation irradiating unit includes a first focal position and a first focal position. The first radiation source that irradiates radiation from the first focal position and the second radiation that irradiates radiation from the second focal position. A field emission electron source that generates electrons by applying an electric field, and an anode that emits radiation by the incidence of electrons. And characterized in that it was example.

  In the radiographic image capturing apparatus of the present invention, the radiation irradiating unit can irradiate the breast of the subject from two different imaging directions.

  Moreover, a radiation irradiation part can irradiate a radiation from the 1st focus position and 2nd focus position which were distant from the subject's chest wall about the front direction, respectively.

  In addition, the radiation irradiating unit can irradiate radiation perpendicularly to the breast from the direction in which the chest wall of the subject extends as one of the two imaging directions.

  In addition, a display unit that displays a stereoscopic image using two radiographic images is provided, and the display unit displays a stereoscopic image in which the extending direction of the chest wall of the subject in the two radiographic images is the vertical direction. I can do it.

  According to the mammography apparatus of the present invention, the first radiation source and the second radiation source that respectively irradiate the radiation in the two imaging directions from the first focal position and the second focal position are provided. Since the first and second radiation sources include a field emission type electron source that generates electrons when an electric field is applied and an anode that emits radiation upon incidence of electrons, two radiation sources are used. By reducing the size of the source, the distance between the two radiation sources can be sufficiently narrowed, and a radiographic image that can be easily viewed stereoscopically can be captured by capturing a radiographic image from an imaging direction that forms a relatively narrow angle of convergence. it can.

  In addition, since it is not necessary to move the radiation source as in the prior art, a structure for moving the radiation source becomes unnecessary, and the structure of the apparatus is simplified.

  Further, since the positions of the first and second radiation sources are fixed, the convergence angle can be reliably maintained constant, and a stable and reproducible stereoscopic image can be taken.

1 is a schematic configuration diagram of a breast image radiographing display system using an embodiment of a radiographic image radiographing apparatus of the present invention. Schematic configuration diagram of first and second radiation sources 1 is a block diagram showing a schematic configuration inside a computer of the breast image capturing and displaying system shown in FIG. The flowchart for demonstrating the effect | action of the mammography imaging display system using one Embodiment of the radiographic imaging apparatus of this invention. The figure which shows an example of the radiographic image for right eyes and the radiographic image for left eyes image | photographed so that a chest wall may follow an up-down direction

  Hereinafter, a breast image radiographing display system using an embodiment of a radiographic image radiographing apparatus of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of the entire breast image photographing display system of the present embodiment.

  As shown in FIG. 1, a breast image capturing and displaying system 1 according to the present embodiment includes a breast image capturing apparatus 10, a computer 2 connected to the breast image capturing apparatus 10, a monitor 3 connected to the computer 2, and an input unit. 4 is provided.

  As shown in FIG. 1, the mammography apparatus 10 includes a base 11 and an arm portion 13 supported so as to be movable in the vertical direction with respect to the base 11.

  The arm portion 13 has an alphabet C shape, and a radiation source unit 16 is attached to one end of the arm portion 13 so as to face the imaging table 14 at the other end. The movement of the arm unit 13 in the vertical direction is controlled by an arm controller 31 incorporated in the base 11.

  A radiographic image detector 15 such as a flat panel detector and a detector controller 33 that controls reading of a charge signal from the radiographic image detector 15 are provided inside the imaging table 14.

  Further, inside the imaging table 14, a charge amplifier that converts the charge signal read from the radiation image detector 15 into a voltage signal, a correlated double sampling circuit that samples the voltage signal output from the charge amplifier, A circuit board provided with an AD conversion unit for converting a voltage signal into a digital signal is also installed.

  The radiation image detector 15 can repeatedly perform recording and reading of a radiation image, and may use a so-called direct type radiation image detector that directly receives radiation and generates charges. Alternatively, a so-called indirect radiation image detector that converts radiation once into visible light and converts the visible light into a charge signal may be used. As a radiation image signal reading method, a radiation image signal is read by turning on / off a TFT (thin film transistor) switch, or by irradiating reading light. It is desirable to use a so-called optical readout system from which a radiation image signal is read out, but the present invention is not limited to this, and other systems may be used.

  In the radiation source unit 16, a first radiation source 17a, a second radiation source 17b, and a radiation source controller 32 are accommodated. The radiation source controller 32 determines the timing of irradiating radiation from the first and second radiation sources 17a and 17b, and the radiation generation conditions (tube current, time, tube current time product in the first and second radiation sources 17a and 17b). Etc.).

  As shown in FIG. 1, the first radiation source 17a and the second radiation source 17b are respectively arranged at positions away from the chest wall of the subject M in the forward direction, and the first radiation source 17a Radiation in two imaging directions is emitted from the first focal position and the second focal position of the second radiation source 17b. In the present embodiment, the first radiation source 17a emits radiation from the 0 ° direction to the breast, and the second radiation source 17b emits radiation from the 4 ° direction to the breast. The radiation source is arranged. Note that the angle in the photographing direction is not limited to this angle and may be other angles.

  FIG. 2 shows the detailed configuration of the first and second radiation sources 17a and 17b. In the first and second radiation sources 17a and 17b, a disk-shaped rotating anode 22 is attached to a rotating shaft 24 rotated by a rotating mechanism 25, and the surface of the rotating anode 22 contains a metal element such as Mo as a main component. An annular target layer 23 is formed. On the other hand, a cathode 21 is disposed to face the rotating anode 22, and a field emission electron source 20 is disposed on the cathode 21 so as to face the target layer 23.

  In the first and second radiation sources 17 a and 17 b, the rotating anode 25 is rotated by the rotating mechanism 25 rotating the rotating shaft 24 in accordance with control from the radiation source controller 32, and the field emission type is rotated by the power supply unit 27. A voltage (negative voltage) is applied to the electron source 20, and a voltage is applied between the rotating anode 22 and the cathode 21 by the power supply unit 26 (a positive voltage is applied to the rotating anode 22 and a negative voltage is applied to the cathode 21. Is applied).

  As a result, electrons are emitted from the field emission electron source 20, and the emitted electrons are accelerated by the voltage applied between the rotating anode 22 and the cathode 21 and collide with the target layer 23. Radiation corresponding to the collided electrons is emitted from the collision surface (focal point F) of the electrons in the target layer 23. Then, the radiation is irradiated toward the breast in a state where the irradiation range is narrowed by the collimator 28.

  Further, in the central portion of the arm portion 13, a compression plate 18 that is disposed above the imaging table 14 and presses against the breast, a support portion 35 that supports the compression plate 18, and a support portion 35 that extends in the vertical direction A moving mechanism 19 for moving is provided. The position of the compression plate 18 and the compression pressure are controlled by the compression plate controller 34.

  The computer 2 includes a central processing unit (CPU) and a storage device such as a semiconductor memory, a hard disk, and an SSD. The control unit 8a, the radiation image storage unit 8b, and the display shown in FIG. A control unit 8c is configured.

  The controller 8a outputs predetermined control signals to the various controllers 31 to 35 to control the entire system. A specific control method will be described in detail later.

  The radiation image storage unit 8b stores in advance two radiation image signals detected by the radiation image detector 15 by photographing from two different photographing directions.

  The display control unit 8c performs predetermined signal processing on the radiographic image signal read from the radiographic image storage unit 8b, and then displays a stereo image of the breast of the subject M on the monitor 3.

  The input unit 4 is configured by a pointing device such as a keyboard and a mouse, for example, and receives an input of shooting conditions, a shooting start instruction, and the like by a photographer.

  The monitor 3 is configured to be able to display a stereo image using two radiation image signals output from the computer 2. As a configuration for displaying a stereo image, for example, a radiographic image based on two radiographic image signals is displayed using two screens, and one of the radiographic images is observed by using a half mirror or a polarizing glass. It is possible to adopt a configuration in which a stereo image is displayed by being incident on the right eye of the observer and the other radiation image is incident on the left eye of the observer. Or, for example, two radiographic images may be displayed in a superimposed manner while being shifted by a predetermined amount of parallax, and this may be configured to generate a stereo image by observing with a polarizing glass, or a parallax barrier method and a lenticular method As described above, a stereo image may be generated by displaying two radiation images on a stereoscopically viewable 3D liquid crystal.

  Next, the operation of the mammography / display system of this embodiment will be described with reference to the flowchart shown in FIG.

  First, the breast of the subject M is placed on the imaging table 14, and the breast is compressed by the compression plate 18 with a predetermined pressure (S10).

  When the photographer gives an instruction to start photographing using the input unit 4, the first radiographic image of the two radiographic images constituting the stereo image is photographed (S12).

  The first radiographic image is taken using the first radiation source 17a disposed in front of the breast. In the present embodiment, the first radiation source 17 a has a straight line connecting the focal position of the first radiation source 17 a and the end surface 15 a of the radiation image detector 15 with respect to the detection surface of the radiation image detector 15. It is installed so that it is almost vertical.

  Specifically, the control unit 8a outputs a control signal to the radiation source controller 32 and the detector controller 33 so as to irradiate the radiation and read out the radiation image signal. In accordance with this control signal, radiation is emitted from the first radiation source 17a, radiation is irradiated perpendicularly to the breast from the direction in which the subject's chest wall extends, and a radiation image obtained by photographing the breast from 0 ° is obtained. It is detected by the radiation image detector 15. Then, the radiation image signal is read by the detector controller 33, subjected to predetermined signal processing on the radiation image signal, and stored in the radiation image storage unit 8b of the computer 2 (S14).

  Then, the second radiographic image of the two radiographic images constituting the stereo image is captured (S16).

  The second radiation image is taken using the second radiation source 17b. In the present embodiment, the second radiation source 17b has a straight line connecting the focal position of the second radiation source 17b and the end surface 15a of the radiation image detector 15 with respect to the detection surface of the radiation image detector 15. And is arranged so as to be inclined 4 ° from the vertical direction.

  Specifically, the control unit 8a outputs a control signal to the radiation source controller 32 and the detector controller 33 so as to irradiate the radiation and read out the radiation image signal. In response to this control signal, radiation is emitted from the second radiation source 17b, and a radiation image obtained by photographing the breast from the 4 ° direction is detected by the radiation image detector 15. Then, the radiation image signal is read by the detector controller 33, subjected to predetermined signal processing on the radiation image signal, and stored in the radiation image storage unit 8b of the computer 2 (S18).

  Then, the two radiographic image signals stored in the radiographic image storage unit 8b are output to the display control unit 8c, and the display control unit 8c performs predetermined processing on these radiographic image signals, and then the monitor 3 And a stereo image of the breast is displayed on the monitor 3 (S20).

  According to the mammography and display system of the present embodiment, since the first and second radiation sources 17a and 17b are provided with a field emission electron source and an anode, two radiation sources are used. By downsizing, the interval between the two radiation sources can be sufficiently narrowed, and a radiographic image that is easy to view stereoscopically can be taken by taking a radiographic image from an imaging direction having a relatively narrow convergence angle.

  In the breast image radiographing display system of the above embodiment, radiation images in two radiographing directions are respectively emitted from two focal positions separated from the subject's chest wall in the forward direction so as to take two radiographic images. Therefore, as shown in FIGS. 5A and 5B, it is possible to display a stereo image with the chest wall along the vertical direction. By displaying the stereo image in this way, it is possible to make the same orientation as the display at the time of interpretation of the conventional two-dimensional breast image, and these can be easily compared.

  Moreover, in the breast image radiographing display system of the above-described embodiment, radiation is irradiated from the 0 ° direction, that is, the direction perpendicular to the breast M, as one of the two radiation images constituting the stereo image. Since the radiographic image is taken, the radiographic image in the 0 ° direction can also be used for observation of a normal two-dimensional breast image.

  In the above embodiment, the radiographic imaging device of the present invention is applied to a mammography imaging display system. However, the subject is not limited to the breast, and so-called general imaging for breast imaging other than the breast. You may make it apply to the radiographic imaging apparatus for imaging | photography.

DESCRIPTION OF SYMBOLS 1 Mammography display system 2 Computer 3 Monitor 4 Input part 8a Control part 8b Radiation image memory | storage part 8c Display control part 10 Mammography apparatus 11 Base 13 Arm part 14 Imaging stand 15 Radiation image detector 16 Radiation source unit 17a 1st 1 radiation source 17 b second radiation source 18 compression plate 20 field emission electron source 21 cathode 22 rotating anode 23 target layer 24 rotating shaft 25 rotating mechanism 28 collimator

Claims (5)

A radiation irradiating unit that irradiates a subject with radiation from two different imaging directions, and a radiation image detector that detects a radiation image for each imaging direction by irradiation of the radiation of the radiation irradiating unit. In the radiographic imaging device for obtaining two radiographic images detected by the radiological image detector as constituting a stereoscopic image,
The radiation irradiating unit emits radiation in the two imaging directions from a first focal position and a second focal position,
A first radiation source that irradiates the radiation from the first focal position; and a second radiation source that irradiates the radiation from the second focal position;
Radiation characterized in that the first and second radiation sources include a field emission electron source that generates electrons when an electric field is applied, and an anode that emits radiation upon incidence of the electrons. Image shooting device.   The radiographic image capturing apparatus according to claim 1, wherein the radiation irradiating unit irradiates the breast of the subject with radiation from two different imaging directions.   3. The radiation irradiating unit irradiates the radiation from the first focal position and the second focal position, which are separated from the chest wall of the subject in the forward direction, respectively. The radiographic imaging apparatus described.   The radiation irradiation unit irradiates radiation perpendicularly to the breast from a direction in which the chest wall of the subject extends as one of the two imaging directions. Or the radiographic imaging apparatus of 3. A display unit for displaying a stereoscopic image using the two radiation images;
The radiographic imaging according to claim 3, wherein the display unit displays the stereoscopic image such that a direction in which the chest wall of the subject extends in the two radiographic images is a vertical direction. apparatus.

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