JP2011239915A - Radiographic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiographic apparatus obtaining an X-ray signal of a subject by irradiating the subject with X-rays output from an X-ray tube assembly, and detecting the X-rays transmitting the subject by an X-ray detector, and permitting the shape of the irradiation area of the X-rays made to fall on the X-ray detector to be trimmed into a rectangle or a square without complicating a movable mechanism of X-ray diaphragm blades even when the apparatus performs radiographing by making the X-rays obliquely fall on the X-ray detector.SOLUTION: When the X-ray tube assembly rotates in a direction maintained parallel with a detection face of the X-ray detector which detects the X-rays, it makes an X-ray opening face formed by the X-ray diaphragm blades installed in an X-ray diaphragm blade device parallel with the detection face of the X-ray detector.

Description

  The present invention relates to an X-ray imaging apparatus, and more particularly to attitude control of an X-ray diaphragm blade during imaging.

  The X-ray imaging apparatus irradiates the subject with X-rays output from the X-ray tube apparatus, and detects X-rays transmitted through the subject with an X-ray detector, thereby obtaining an X-ray signal of the subject. The X-ray imaging apparatus displays a fluoroscopic image on the display unit by processing the X-ray signal in the X-ray image processing unit.

  At the time of imaging, an operator who operates the X-ray imaging apparatus has a case where X-rays are incident perpendicularly to the X-ray detector and a case where the X-ray imaging is performed obliquely. In the latter case, the shape of the irradiation region of X-rays incident on the X-ray detector is a trapezoid.

  The trapezoidal shape is trimmed to a rectangle or square by changing the angle of two opposing X-ray diaphragm blades among the four X-ray diaphragm blades that form a rectangular opening that limits the X-ray irradiation area. There was technology (see Patent Document 1).

JP 2008-36314 A

  However, in Patent Document 1, with respect to the two X-ray diaphragm blades, a mechanism that operates in a rotational direction that changes the angle to each of the two X-ray diaphragm blades, and a mechanism that operates in a direction for changing the X-ray irradiation field size, Because it is necessary to prepare, the mechanism for controlling the X-ray diaphragm blades was complicated.

  For this reason, there existed the subject of the stability to the operation | movement of a X-ray aperture blade, and the weight increase by the said mechanism becoming complicated.

  Therefore, the object of the present invention is to make X-rays incident on the X-ray detector even when photographing with the X-rays obliquely inserted into the X-ray detector without complicating the movable mechanism of the X-ray diaphragm blades. It is an object to provide an X-ray imaging apparatus capable of trimming the irradiation area shape into a rectangle or a square.

In order to solve the above-described problems, the present invention is configured as follows.
An X-ray tube device that irradiates a subject with X-rays, an X-ray detector that is disposed at a position facing the X-ray tube device, detects X-rays transmitted through the subject, and the X-ray detector An X-ray image processing unit that performs image processing on the output X-ray signal, and an X-ray diaphragm blade that is joined to the X-ray tube device and shields X-rays generated from the X-ray tube device, An X-ray imaging apparatus comprising: an X-ray diaphragm apparatus that determines an X-ray irradiation area for the subject; wherein the X-ray tube apparatus is kept horizontal with respect to a detection surface for detecting X-rays of the X-ray detector When rotating in the direction, the X-ray aperture plane formed by the X-ray diaphragm blades installed in the X-ray diaphragm device is made parallel to the detection surface of the X-ray detector.

  According to the present invention, X-ray imaging that obtains an X-ray signal of a subject by irradiating the subject with X-rays output from the X-ray tube device and detecting the X-ray transmitted through the subject with an X-ray detector Even if the X-ray is imaged obliquely with respect to the X-ray detector in the apparatus, the irradiation region of the X-ray incident on the X-ray detector without complicating the movable mechanism of the X-ray diaphragm blades An X-ray imaging apparatus capable of trimming the shape into a rectangle or a square can be provided.

The figure which shows the structural example of the X-ray imaging apparatus of this invention The figure which shows the irradiation field shape of the X-ray which enters the X-ray detector when the conventional X-ray imaging device is used The figure which shows the irradiation area | region shape of the X-rays which inject into an X-ray detector at the time of using the X-ray imaging apparatus shown in FIG. 1 of this invention FIG. 1 is a diagram showing a detailed configuration of the X-ray diaphragm device 104 of the present invention shown in FIG. 1 and an X-ray detector 108 The figure explaining the movable mechanism of the X-ray aperture blade of this invention FIG. 6 is a diagram of the X-ray imaging apparatus of the present invention in a different imaging posture from that of FIG. An example of a flowchart for explaining the present invention The figure shown in detail about an example of the movable mechanism of the X-ray aperture base 402 shown in FIG.

  Hereinafter, the X-ray imaging apparatus of the present invention will be described in detail with reference to the accompanying drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiments of the invention, and the repetitive description thereof is omitted.

  FIG. 1 is a diagram showing a configuration example of an X-ray imaging apparatus of the present invention.

  In the X-ray imaging apparatus of the present invention, a top plate 102 on which a subject 101 is placed, an X-ray tube device 103 that irradiates the subject 101 with X-rays, and an X-ray tube device 103 are shown by arrows A1 (clock) shown in FIG. Rotation) or A2 (counterclockwise) direction (an X-ray detector 108 to be described later X-ray detector 108 detects the angle of rotation when rotating in the direction horizontal to the detection surface (hereinafter, the detection surface) to detect X-rays) An X-ray diaphragm control device 105 that controls the X-ray diaphragm device 104, an X-ray diaphragm device 104 that sets an X-ray irradiation region for the subject 101, an X-ray diaphragm controller 104 that controls the X-ray diaphragm device 104, The X-ray diaphragm blade 104a is controlled in the X-ray diaphragm controller 105a, and the X-ray diaphragm controller 105a is disposed in the X-ray diaphragm controller 105. Supports the X-ray diaphragm attitude maintenance control unit 105b that controls the attitude of 104a, the X-ray tube apparatus 103 and the X-ray diaphragm apparatus 104, and also supports the vertically movable support device 106, and supplies power to the X-ray tube apparatus 103. High voltage to perform An X-ray detector 108 that is disposed at a position facing the raw unit 107, the X-ray tube device 103, detects X-rays transmitted through the subject 101, and an X-ray signal output from the X-ray detector 108 An X-ray image processing unit 109 that performs image processing, an external storage unit 111 that stores an X-ray image (including a fluoroscopic image) output from the X-ray image processing unit 109, and an X-ray image (including a fluoroscopic image) , A control unit 112 that controls each of the above components, and an operation unit 113 that issues a command to the control unit 112.

  The X-ray tube device 103 has an X-ray tube that receives power supply from the high voltage generator 107 and generates X-rays. Further, the X-ray tube device 103 may have an X-ray filter that selectively transmits X-rays having specific energy.

  The X-ray diaphragm device 104 has a plurality of X-ray shielding lead plates that shield the X-rays generated from the X-ray tube device 103, and moves each of the plurality of X-ray shielding lead plates to the subject 101. Determine the X-ray irradiation area. Further, the X-ray diaphragm device 104 is joined to the X-ray tube device 103. For example, when the X-ray tube device 103 rotates in the direction of the arrow A1, the X-ray diaphragm device joined to the X-ray tube device 103 is used. 104 also follows.

  The X-ray detector 108 is configured by, for example, a plurality of detection elements that detect X-rays arranged in a two-dimensional array, and is irradiated from the X-ray tube device 103 and transmitted through the subject 101. This device detects X-ray signals according to the amount of incident light.

  The X-ray image processing unit 109 performs image processing on the X-ray signal output from the X-ray detector 108, and outputs an image-processed X-ray image. Image processing includes gamma conversion, gradation conversion processing, image enlargement / reduction, and the like.

The external storage unit 111 stores the X-ray image output from the X-ray image processing unit 109.
The display device 110 displays the X-ray image output from the X-ray image processing unit 109 or the X-ray image stored in the external storage unit 111.

Next, the main part of the present invention will be described with reference to FIGS.
FIG. 2 is a diagram showing the shape of an X-ray incident on an X-ray detector when a conventional X-ray imaging apparatus is used.

  FIG. 3 is a diagram showing the shape of X-rays incident on the X-ray detector when the X-ray imaging apparatus of the present invention shown in FIG. 1 is used.

  In FIG. 2 (a), X-rays generated from the X-ray tube device 203 are incident perpendicularly to the detection surface of the X-ray detector 108 through the X-ray diaphragm device 204. In this case, the X-ray detector 108 The shape of the irradiated region of X-rays that is incident on is rectangular or square. FIG. 2 (a) shows an X-ray irradiation region shape 200 when viewed from the X-ray irradiation surface. In this embodiment, the X-ray irradiation region shape 200 is a rectangle.

  Next, FIG. 2B shows an X-ray irradiation region shape 201 when X-rays generated from the X-ray tube device 203 are obliquely inserted into the X-ray detector 108 through the X-ray diaphragm device 204. Irradiation region shape 201 is a diagram showing the X-ray irradiation region shape when viewed from the X-ray irradiation surface in the same manner as irradiation region shape 200. In this case, the irradiation area shape 201 is not a rectangle or a square but a trapezoid. This is because the X-ray aperture surface 204b for allowing X-rays generated from the X-ray tube device 203 formed by the X-ray diaphragm blades 204a disposed in the X-ray diaphragm device 204 to pass through the X-ray detector 108. This is because it is not parallel to the detection surface.

  Therefore, in the X-ray imaging apparatus of the present invention, as shown in FIG. 3 (b), X-rays generated from the X-ray tube apparatus 103 are obliquely incident on the detection surface of the X-ray detector 108 through the X-ray diaphragm apparatus 104. In this case, the X-ray aperture surface 104b formed by the X-ray diaphragm blades 104a in the X-ray diaphragm device 104 is made parallel to the detection surface of the X-ray detector 108. Even when the X-ray generated from the X-ray tube device 103 is obliquely inserted into the detection surface of the X-ray detector 108 by making the X-ray aperture surface 104b parallel to the detection surface of the X-ray detector 108 The irradiation region shape of the X-rays incident on the X-ray detector 108 can be rectangular or square. In this embodiment, the X-ray irradiation region shape 301 is a rectangle. An irradiation region shape 301 indicates an X-ray irradiation region shape when viewed from the X-ray irradiation surface. In addition, as shown in FIG. 3 (a), the X-ray imaging apparatus of the present invention causes X-rays generated from the X-ray tube apparatus 103 to enter the X-ray detector 108 vertically through the X-ray diaphragm device 104. In this case, similarly to the conventional example shown in FIG. 2 (a), the shape of the irradiation region of X-rays incident on the X-ray detector 108 is rectangular or square. In FIG. 3 (a), the X-ray irradiation region shape 300 is a rectangle. The irradiation region shape 300 indicates the X-ray irradiation region shape when viewed from the X-ray irradiation surface.

  Next, with reference to FIGS. 1, 4, 6, and 8, even when X-rays generated from the X-ray tube device 103 are obliquely inserted into the X-ray detector 108 through the X-ray diaphragm device 104, A configuration in which the line opening surface 104b is parallel to the detection surface of the X-ray detector 108 will be described in detail.

  FIG. 4 is a diagram showing a detailed configuration of the X-ray diaphragm device 104 of the present invention shown in FIG. 1 and an X-ray detector 108.

  FIG. 6 is a view of the X-ray imaging apparatus of the present invention in a different imaging posture from that of FIG.

  FIG. 8 is a diagram showing in detail an example of the movable mechanism of the X-ray diaphragm base 402 shown in FIG.

  The X-ray diaphragm device 104 shown in FIG. 4 (a) includes an X-ray diaphragm housing 401, an X-ray diaphragm base 402, an X-ray diaphragm blade 104a, and an X-ray installed in the X-ray diaphragm housing 401. The X-ray diaphragm blade 104a is disposed on the X-ray diaphragm base 402, and the X-ray aperture surface 104b is formed by the X-ray diaphragm blade 104a. Further, the X-ray diaphragm base 402 can move along the X-ray diaphragm tilt rail 403. The X-ray aperture tilt rail 403 can be configured using a linear motor or the like. FIG. 4 (a) is a diagram in a case where X-rays generated from the X-ray tube device 103 shown in FIG. 1 are incident perpendicularly to the detection surface of the X-ray detector 108 through the X-ray diaphragm device 104. In this case, the X-ray aperture surface 104b is parallel to the detection surface of the X-ray detector 108. On the other hand, the X-ray diaphragm device 104 shown in FIG. 4B is a case where the X-rays generated from the X-ray tube device 103 are obliquely inserted into the detection surface of the X-ray detector 108 through the X-ray diaphragm device 104. FIG. In this case, the rotation angle of the X-ray tube device 103 is detected by the X-ray tube angle detection device 103a. Based on the detected rotation angle value, the X-ray aperture posture maintenance control unit 105b Is moved along the X-ray diaphragm tilt rail 403, the posture of the X-ray diaphragm blade 104a is controlled, and the X-ray aperture surface 104b formed by the X-ray diaphragm blade 104a is parallel to the detection surface of the X-ray detector 108. To maintain.

  Here, the configuration when a linear motor is used for the X-ray aperture tilt rail 403 shown in FIGS. 4 (a) and 4 (b) will be described with reference to FIG. The X-ray diaphragm tilt rail 403r shown in FIG. 8 is configured by a linear motor, and the X-ray diaphragm base 402 is fixed by an X-ray diaphragm base presser 104r. The X-ray aperture base presser 104r is configured by a linear motor, and the X-ray aperture base presser 104r is movable on the X-ray aperture tilt rail 403r. As a result, the X-ray aperture surface 104b formed by the X-ray aperture blades 104a disposed on the X-ray aperture base 402 is maintained parallel to the detection surface of the X-ray detector 108 shown in FIG. be able to.

  The imaging of the subject 101 shown in FIG. 1 is imaging in the supine position, and in this case, the detection surface of the X-ray detector 108 is installed in parallel to the floor surface 1. Here, the position of the X-ray tube device 103 when the X-ray generated from the X-ray tube device 103 with the reference value (0 degree) of the rotation angle is perpendicularly incident on the detection surface of the X-ray detector 108 and Then, for example, when the X-ray tube device 103 is rotated within the range of 45 degrees in the directions of arrows A1 or A2 shown in FIG. 1 by the operator, the X-ray aperture posture maintenance control unit 105b is placed on the floor surface 1. The attitude of the X-ray diaphragm blade 104a is controlled so as to keep the X-ray aperture surface 104b parallel to the detection surface of the X-ray detector 108 installed in parallel to the X-ray detector 108. When the direction is rotated more than 45 degrees, the X-ray aperture posture maintenance control unit 105b determines that the subject 101 is photographed in a standing position as shown in FIG. The posture of the X-ray diaphragm blade 104a is controlled so that the X-ray aperture surface 104b is maintained in parallel with the detection surface of the X-ray detector 108. By setting a threshold value for the detection value of the rotation angle of the X-ray tube device 103 detected by the X-ray tube angle detection device 103a, the X-ray aperture posture maintenance control unit 105b detects the X-ray detector 108 used for imaging. It is determined whether the surface is installed parallel or perpendicular to the floor surface 1, and based on this determination, the X-ray aperture surface 104b is made parallel to the detection surface of the X-ray detector 108. To maintain. The threshold can be arbitrarily changed by the operator using the operation unit 113.

Next, the movable mechanism of the X-ray diaphragm blade 104a according to the present invention will be described with reference to FIGS.
A total of four sets of X-ray diaphragm blades 104a are attached to each of four X-ray diaphragm blade rails 501 disposed on the X-ray diaphragm base 402 so as to face each other. The X-ray diaphragm blade rail 501 can be configured using a linear motor or the like. In FIG. 5, in order to make the movable mechanism of the X-ray diaphragm blade 104a of the present invention easier to understand, the illustration of the one X-ray diaphragm blade 104a facing each other is omitted.

  The X-ray imaging apparatus of the present invention makes the X-ray irradiation surface shape incident on the X-ray detector 108 rectangular or rectangular by making the X-ray aperture surface 104b parallel to the detection surface of the X-ray detector 108. Since it is square, there is no need to change the angle of two opposing X-ray aperture blades as in Patent Document 1. For this reason, the X-ray diaphragm blades 104a installed on four sides facing each other are each configured by a simple mechanism that moves linearly along the X-ray diaphragm blade rail 501 only in the same direction. This also makes it possible to stack and configure a plurality of X-ray diaphragm blades 104a per side, making it easy to save space. When multiple X-ray diaphragm blades 104a are stacked on one side and configured to increase the aperture ratio of the X-ray aperture surface 104b, the X-ray diaphragm blades 104a move while increasing the overlap of the multiple X-ray diaphragm blades 104a. In order to reduce the aperture ratio, the X-ray diaphragm blades 104a move while reducing the overlap. The amount of movement of the X-ray diaphragm blades 104a may be linked between the opposing X-ray diaphragm blades 104a or may be independent. Further, the X-ray diaphragm blades 104a on all four sides may be linked and may have the same movement amount. Further, in this embodiment, all four sides forming the X-ray aperture surface 104b are movable, but the X-ray aperture blade 104a is installed, but only one of the opposing sides, that is, orthogonal. The movable mechanism of the X-ray diaphragm blade 104a may be provided on only two sides, and the remaining two sides may be configured by one X-ray diaphragm blade 104a and fixed to the X-ray diaphragm base 402. By providing the movable mechanism of the X-ray diaphragm blade 104a only on two orthogonal sides, the weight of the X-ray diaphragm device 104 can be reduced. Further, in the present embodiment, the case where a plurality of X-ray diaphragm blades 104a are stacked and configured per side has been described, but may be configured by one per side. The aperture ratio of the X-ray aperture surface 104b is set by the operator using the operation unit 113, and the amount of movement of the X-ray aperture blade 104a is controlled by the X-ray aperture blade opening control unit 105a based on the setting. Is set.

Next, FIG. 7 is an example of a flowchart for explaining the present invention.
First, in step 701, the operator sets the imaging part of the subject 101 to be imaged using the operation panel 113. In step 702, the X-ray diaphragm blade opening controller 105a controls the amount of movement of the X-ray diaphragm blade 104a according to the set imaging region, and sets the aperture ratio of the X-ray aperture surface 104b. In step 703, the X-ray tube angle detection device 103a determines whether or not the operator has rotated the X-ray tube device 103. If there is a rotation operation, the process proceeds to step 704, and if there is no rotation operation, the process proceeds to step 705. In step 704, based on the rotation angle of the X-ray tube device 103 detected by the X-ray tube angle detection device 103a, the X-ray aperture posture maintenance control unit 105b determines that the X-ray aperture 104b is the detection surface of the X-ray detector 108. The posture of the X-ray aperture blade 104a is controlled so as to be parallel to the X-ray. In step 705, the operator is informed that the X-ray aperture surface 104b is parallel to the detection surface of the X-ray detector 108. Not). In step 706, the subject 101 is imaged using an exposure hand switch (not shown in particular) that generates a timing for generating X-rays from the X-ray tube apparatus 103 by the operator.

  As described above, the X-ray imaging apparatus of the present embodiment, when the X-ray generated from the X-ray tube apparatus 103 is obliquely inserted into the detection surface of the X-ray detector 108, the X-ray opening surface 104b, By making it parallel to the detection surface of the X-ray detector 108, the shape of the irradiation region of the X-rays incident on the X-ray detector 108 can be rectangular or square. Further, by providing a threshold value for the detected value of the rotation angle of the X-ray tube device 103 detected by the X-ray tube angle detection device 103a, the X-ray aperture posture maintenance control unit 105b allows the X-ray detector 108 used for imaging. Is determined to be parallel or perpendicular to the floor surface 1, and based on the determination, the X-ray aperture surface 104b is maintained parallel to the detection surface of the X-ray detector 108. And the operability of the operator can be improved. Further, the X-ray diaphragm blade 104a can be configured with a mechanism that moves linearly along the X-ray diaphragm blade rail 501 only in the same direction, and thus is configured with a simple mechanism. In addition, the X-ray diaphragm blades 104a are configured by laminating a plurality of X-ray aperture blades 104a per side, thereby facilitating space saving. Further, the X-ray diaphragm device 104 can be reduced in weight by providing a movable mechanism for the X-ray diaphragm blade 104a on either one of the opposing sides.

  1 Floor, 101 Subject, 102 Top plate, 103, 203 X-ray tube device, 103a X-ray tube angle detector, 104, 204 X-ray diaphragm device, 104a, 204a X-ray diaphragm blade, 104b, 204b X-ray aperture Surface, 104r X-ray diaphragm base holder, 105 X-ray diaphragm controller, 105a X-ray diaphragm blade opening controller, 105b X-ray diaphragm attitude maintenance controller, 106 supporter, 107 high voltage generator, 108 X-ray detector , 109 X-ray image processing unit, 110 display device, 111 external storage unit, 112 control unit, 113 operation unit, 200, 201, 300, 301 X-ray irradiation area shape, 401 X-ray diaphragm housing, 402 X-ray diaphragm Base, 403, 403r X-ray diaphragm tilt rail, 501 X-ray diaphragm blade rail

Claims (4)

An X-ray tube device that irradiates the subject with X-rays, an X-ray detector that is disposed at a position facing the X-ray tube device and detects X-rays transmitted through the subject, and the X-ray detector An X-ray image processing unit that performs image processing on the output X-ray signal, and an X-ray diaphragm blade that is joined to the X-ray tube device and shields X-rays generated from the X-ray tube device; An X-ray imaging apparatus comprising: an X-ray diaphragm device that determines an X-ray irradiation area for the subject;
An X-ray tube angle detection device for detecting a rotation angle of rotation of the X-ray tube device, and an X-ray diaphragm blade installed in the X-ray diaphragm device based on a detection value by the X-ray tube angle detection device An X-ray aperture attitude maintenance control unit that controls the attitude of the X-ray aperture blades so that the formed X-ray aperture surface is parallel to a detection surface for detecting X-rays of the X-ray detector; An X-ray imaging apparatus comprising:   A threshold value is provided for a detected value of the rotation angle of the X-ray tube device detected by the X-ray tube angle detection device, and the X-ray diaphragm posture maintenance control unit detects X-rays used for imaging based on the threshold value. It is determined whether the detection surface of the detector is installed parallel or perpendicular to the floor surface, and based on the determination, the X-ray aperture surface is controlled to be parallel to the detection surface of the X-ray detector. The X-ray imaging apparatus according to claim 1, wherein:   2. The X-ray diaphragm blade according to claim 1, wherein a movable mechanism for the X-ray diaphragm blade is provided only on at least one of the four sides facing each other. 2. The X-ray imaging apparatus according to 2.   The X-ray imaging apparatus according to claim 3, wherein a plurality of X-ray diaphragm blades provided with the movable mechanism are stacked per side.

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