JP2015100641A - X-ray equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide X-ray equipment which can appropriately obtain the opening amount of a collimator.SOLUTION: X-ray equipment has a reference height input setting section 12a as magnification parameter input setting means for inputting and setting parameters on magnification of an X-ray image. Therefore, a parameter (reference height) on the magnification can be freely set, and a controller obtains the opening width of a collimator so that a slot width may be constant. Accordingly, the parameter (reference height) on the magnification can be appropriately set in each examination from the physique of a subject and medical cases, and, on the basis of them, the opening amount of the collimator can be appropriately obtained.

Description

  The present invention relates to an X-ray imaging apparatus that performs X-ray imaging, and more particularly to a technique for creating a long image by connecting a plurality of X-ray images.

  Conventionally, as an apparatus of this type, an X-ray tube (X-ray irradiating means) and an X-ray detector (X-ray detecting means) are operated synchronously to move along the body axis direction of a subject to obtain an X-ray image. Each is acquired and an X-ray image is connected in the body axis direction to create a long image. In particular, long shooting (hereinafter referred to as “slot shooting”) is performed by connecting X-ray images obtained by adjusting the X-ray opening amount with a collimator to narrow the illumination field into a slit shape in the body axis direction. (Refer to Patent Document 1).

  The opening amount of the X-ray can be adjusted by setting the opening width of the collimator. The collimator opening width is “the slot width to be collected (the width of the X-ray image along the connecting direction)”, “the height from the top of the X-ray tube (ie, between the X-ray tube and the X-ray detector). Distance between the X-ray tube and the top plate obtained by subtracting the height from the X-ray detector of the top plate from the distance SID (Source Image Distance) ”and“ the height of the subject to be imaged from the top plate ” (Ie, the reference height) ”is automatically determined. The opening width of the collimator affects the exposure amount of the subject and the image quality of the final X-ray image obtained by slot imaging.

JP 2004-236929 A

  However, among the factors that determine the opening amount of the collimator, the “height of the subject to be imaged from the top (reference height)” is the target site to be observed, the body thickness of the subject (patient), etc. Because of this, there is a problem that it differs for each shooting. Further, even if the target region to be observed (for example, the spine) is the same, it differs depending on the imaging posture such as the supine position or the lateral position. Conventionally, the reference height corresponding to the target region to be observed and the body thickness of the subject (patient) is stored in a table, the reference height is selected according to the imaging, and the selected reference height is selected. Was used to determine the opening of the collimator. Therefore, the user of the X-ray fluoroscopic imaging apparatus clearly determines the height (reference height) of the subject to be observed from the top plate from the result of the fluoroscopic image and the captured image (for example, the physique and case of the subject). Even if it was confirmed, the height of the collimator could not be adjusted by specifying its height.

  This invention is made in view of such a situation, and it aims at providing the X-ray imaging apparatus which can obtain | require the opening amount of a collimator appropriately.

In order to achieve such an object, the present invention has the following configuration.
That is, an X-ray imaging apparatus according to the present invention is an X-ray imaging apparatus that performs X-ray imaging, and includes an X-ray irradiation unit that irradiates an X-ray toward a subject, and an X-ray that has passed through the subject. X-ray detection means for detection, image connection means for connecting a plurality of X-ray images obtained by the X-ray detection means to create a long image, and opening of X-rays irradiated from the X-ray irradiation means A collimator that adjusts the amount; an enlargement factor parameter input setting unit that inputs and sets a parameter relating to an enlargement factor of the X-ray image; and An opening width calculating means for determining an opening width of the collimator for determining an opening amount of the X-ray based on a parameter relating to the enlargement factor input and set by a rate parameter input setting means. .

  [Operation / Effect] The X-ray imaging apparatus according to the present invention includes an enlargement factor parameter input setting means for inputting and setting parameters relating to the enlargement factor of the X-ray image. As a result, the parameter relating to the enlargement ratio can be freely set, and the opening width calculating means obtains the opening width of the collimator so that the slot width becomes constant. Thereby, the parameter regarding the enlargement ratio can be appropriately set in each examination based on the physique and case of the subject, and the opening amount of the collimator can be appropriately determined based on the parameter. In addition, by appropriately determining the opening amount of the collimator, it is possible to perform slot imaging with an optimal opening amount of the collimator, to suppress exposure of the subject, and to obtain a high-quality X-ray image. Also play.

  In the above-described X-ray imaging apparatus according to the present invention, an example of the parameter relating to the enlargement ratio is the height of the subject to be imaged from the placement means for placing the subject. Therefore, by inputting and setting the height of the subject from the placement means to the enlargement ratio parameter input setting means, the height of the subject from the placement means can be freely set, and the slot width is constant. As described above, the opening width calculation means obtains the opening width of the collimator. Accordingly, the height of the subject from the placement means can be appropriately set in each examination based on the physique and case of the subject, and the opening amount of the collimator can be appropriately obtained based on the height.

  The X-ray imaging apparatus according to the present invention includes an enlargement factor parameter input setting unit that inputs and sets parameters relating to the enlargement factor of the X-ray image. As a result, the parameter relating to the enlargement ratio can be freely set, and the opening width calculating means obtains the opening width of the collimator so that the slot width becomes constant. Thereby, the parameter regarding the enlargement ratio can be appropriately set in each examination based on the physique and case of the subject, and the opening amount of the collimator can be appropriately determined based on the parameter.

1 is a schematic perspective view of an X-ray imaging apparatus according to an embodiment. 1 is a schematic front view of an X-ray imaging apparatus according to an embodiment. It is the schematic side view and block diagram of the X-ray imaging apparatus which concern on an Example. 2 is an equivalent circuit of a flat panel X-ray detector (FPD) viewed from the side. 2 is an equivalent circuit of a flat panel X-ray detector (FPD) in plan view. It is the schematic which showed the relationship between reference | standard height, slot width, and the opening width of a collimator. It is a figure of the one aspect | mode of a reference | standard height input setting part (interface).

Embodiments of the present invention will be described below with reference to the drawings.
1 is a schematic perspective view of an X-ray imaging apparatus according to an embodiment, FIG. 2 is a schematic front view of the X-ray imaging apparatus according to the embodiment, and FIG. 3 is an X-ray imaging apparatus according to the embodiment. FIG. 2 is a schematic side view and a block diagram of FIG. In FIG. 3, illustration of the top plate holding part and the like is omitted.

  As shown in FIGS. 1 to 3, the X-ray imaging apparatus includes a top plate 1 on which a subject M is placed, an X-ray tube 2 that emits X-rays toward the subject M, and a subject M. A flat panel X-ray detector (FPD) (hereinafter abbreviated as “FPD”) 3 for detecting transmitted X-rays is provided. The FPD 3 is accommodated in the top plate 1. The top plate 1 corresponds to the mounting means in the present invention, the X-ray tube 2 corresponds to the X-ray irradiation means in the present invention, and the flat panel X-ray detector (FPD) 3 corresponds to the X-ray in the present invention. It corresponds to detection means.

  The X-ray imaging apparatus includes a support column 21 that supports the X-ray tube 2 and a main column 31 that supports the top plate 1. On the irradiation side of the X-ray tube 2, a collimator 22 that controls the irradiation field by adjusting the opening amount of the X-rays irradiated from the X-ray tube 2 is disposed. In this embodiment, one end of the main support 31 supports the X-ray tube 2 as described above, and the other end supports the FPD 3 accommodated in the top plate 1 so that the X-ray tube 2 and the FPD 3 are inspected. Parallel to the top plate 1 in the same direction along the longitudinal direction of M (see FIG. 3). The collimator 22 narrows the irradiation field narrower than the irradiation field projected onto the FPD 3 (see FIG. 3), and the X-ray tube 2 and the FPD 3 are aligned in the same direction along the longitudinal direction of the subject M. The X-ray tube 2 irradiates slit-shaped X-rays while moving in parallel, and the FPD 3 detects the X-rays to perform X-ray imaging. The collimator 22 corresponds to the collimator in the present invention.

  The main column 31 is erected on a base 32 installed on the floor surface, and a top plate holding portion 33 for holding the top plate 1 so that it can be tilted (tilted) is disposed. The main column 31 is erected on the base 32 installed on the floor, and the top plate holding part 33 for holding the top plate 1 is disposed, so that the top plate 1 is held in the state where the top plate 1 is held. The FPD 3 accommodated in the FPD 3, the support 21 that supports the FPD 3 at the other end, the X-ray tube 2 supported at one end of the support 21, and the collimator 22 disposed on the irradiation side of the X-ray tube 2 are also supported.

  Within the top plate holding portion 33, a fan-shaped rack 34 that rotates and tilts the top plate 1 around the axis of the horizontal axis, a support shaft 35 that is inserted into the fan-shaped rack 34 and the main column 31, and a fan-shaped rack 34. A pinion 36 to be fitted, a rotating shaft 37 having the pinion 36 disposed at one end, and a motor 38 for rotating the rotating shaft 37 are accommodated. When the motor 38 rotates the rotating shaft 37, the pinion 36 disposed at one end of the rotating shaft 37 rotates, and the fan rack 34 fitted to the pinion 36 rotates the supporting shaft 35 in conjunction with the rotation of the pinion 36. It rotates around the support shaft 35 as a fulcrum. By rotating the sector rack 34 around the support shaft 35, the top plate 1 is rotated around the axis of the horizontal axis to be inclined.

  As described above, when the top plate 1 rotates and tilts around the horizontal axis, the top plate 1 can be tilted to a standing posture, a tilted posture, or a horizontal posture (an upright posture). In conjunction with the inclination of the top plate 1, the X-ray tube 2 and the FPD 3 are inclined and the support column 21 that supports the X-ray tube 2 is also inclined. When the top plate 1 is tilted to the upright posture, the distance from the rotational position around the horizontal axis of the top plate 1 to the lower portion of the top plate 1 is the height from the support shaft 35 of the support column 31 to the lower portion of the support column 31. If it is longer than this, the standing posture cannot be realized. In this case, the standing posture can be realized by moving the top plate 1 upward.

  In addition, as shown in FIG. 3, the X-ray imaging apparatus includes a support column 21 and an X-ray tube 2 and a collimator 22 supported on the column 21 along the longitudinal direction that is the body axis of the subject M. A column driving mechanism 4 that drives a motor (not shown) for translation, and an FPD driving mechanism that drives a motor (not shown) to translate the FPD 3 relative to the top plate 1 along the longitudinal direction. 5 or the top plate rotation mechanism 6 for driving the motor 38 (see FIG. 2) to tilt (tilt) the top plate 1 described above, or the axis of the connecting shaft (ie, the axis orthogonal to the body axis). An X-ray tube rotating mechanism 7 that drives a motor (not shown) to rotate the X-ray tube 2 around, and an A / D converter 8 that digitizes and extracts an X-ray detection signal that is a charge signal from the FPD 3 Or output from the A / D converter 8 An image processing unit 9 that performs various processes based on the detected X-ray detection signal, a controller 10 that controls these components, a memory unit 11 that stores processed X-ray images, etc., and an operator input An input unit 12 for setting, a monitor 13 for displaying a processed X-ray image, and the like are provided. In addition, since the high voltage generation part etc. which generate | occur | produce the tube voltage and tube current of the X-ray tube 2 are not related to the characteristic part, illustration and description are abbreviate | omitted. The controller 10 corresponds to the opening width calculation means in this invention. Specific calculation of the controller 10 will be described later with reference to FIGS.

  The image processing unit 9 includes an image connecting unit 9a that connects a plurality of X-ray images obtained by the FPD 3 to create a long image. When a long image is created by connecting a plurality of X-ray images by the image connecting unit 9a, the FPD 3 is moved in parallel with a data line 49 (see FIGS. 4 and 5) to be described later. A plurality of X-ray images are acquired and connected. The image connecting portion 9a corresponds to the image connecting means in this invention.

  The controller 10 is configured by a central processing unit (CPU) and the like, and the memory unit 11 is configured by a storage medium represented by ROM (Read-only Memory), RAM (Random-Access Memory), and the like. Yes. The input unit 12 includes a pointing device represented by a mouse, a keyboard, a joystick, a trackball, a touch panel, and the like. In the X-ray imaging apparatus, the FPD 3 detects X-rays that have passed through the subject M, and the image processing unit 9 performs image processing based on the detected X-rays to create an X-ray image. Perform X-ray imaging.

  In the present embodiment, the input unit 12 includes a reference height input setting unit 12a that inputs and sets the height of the subject M from the top 1 (that is, the reference height). The reference height input setting unit 12a corresponds to the enlargement ratio parameter input setting means in this invention. Specific functions of the reference height input setting unit 12a will also be described later with reference to FIGS.

  Next, the structure of the flat panel X-ray detector (FPD) 3 will be described with reference to FIGS. 4 is an equivalent circuit of a flat panel X-ray detector (FPD) viewed from the side, and FIG. 5 is an equivalent circuit of the flat panel X-ray detector (FPD) viewed from above.

  As shown in FIG. 4, the FPD 3 includes a glass substrate 41 and a thin film transistor TFT formed on the glass substrate 41. As shown in FIGS. 4 and 5, the thin film transistor TFT includes a plurality of switching elements 42 (for example, 1024 × 1024) formed in a vertical / horizontal two-dimensional matrix arrangement. The switching elements 42 are formed separately from each other. That is, the FPD 3 is also a two-dimensional array radiation detector.

  As shown in FIG. 4, an X-ray sensitive semiconductor 44 is laminated on the carrier collection electrode 43, and the carrier collection electrode 43 is connected to the source S of the switching element 42 as shown in FIGS. 4 and 5. Has been. A plurality of gate lines 46 are connected from the gate driver 45, and each gate line 46 is connected to the gate G of the switching element 42. On the other hand, as shown in FIG. 5, a plurality of data lines 49 are connected via an amplifier 48 to a multiplexer 47 that collects charge signals and outputs them as one, as shown in FIGS. Each data line 49 is connected to the drain D of the switching element 42.

  With the bias voltage applied to the common electrode (not shown), the gate of the switching element 42 is turned on by applying the voltage of the gate line 46 (or 0 V), and the carrier collecting electrode 43 is located on the detection surface side. The charge signal (carrier) converted from the incident X-ray through the X-ray sensitive semiconductor 44 is read out to the data line 49 through the source S and drain D of the switching element 42. Until the switching element is turned on, the charge signal is temporarily accumulated and stored in a capacitor (not shown). The charge signals read out to the respective data lines 49 are amplified by the amplifiers 48 and are collectively output as one charge signal by the multiplexer 47. The output charge signal is digitized by the A / D converter 8 and output as an X-ray detection signal.

  Next, a specific calculation of the controller 10 and a specific mechanism of the reference height input setting unit 12a will be described with reference to FIGS. FIG. 6 is a schematic diagram showing the relationship among the reference height, the slot width, and the collimator opening width, and FIG. 7 is a diagram of one mode of the reference height input setting unit (interface).

As shown in FIG. 6, the longitudinal direction (body axis direction) of the top plate (not shown in FIG. 6) is V, and the direction orthogonal to the V (short direction) is H. The collimator 22 includes a V leaf (illustrated by a dotted line in the collimator 22) that sets an opening width in the V direction and an H leaf (not shown) that sets an opening width in the H direction. The opening width of the V direction of the collimator and d _1, the slot width is the width of the X-ray image along the connecting direction and d _2. Although overlapping the adjacent X-ray image, the overlapping portion (margin) is also included in the slot width d _2. The distance between the X-ray tube 2 and the FPD 3 is SID, the distance between the X-ray tube 2 and the V leaf is h _1, and the height of the top plate from the FPD 3 is h _2. height from the top plate of FIG At 6 not shown) (i.e. reference height) and h _3.

In the configuration of FIGS. 1 to 3, a reference height h ₃ variable, so that the slot width d ₂ is computed width d ₁ of opening of the V direction of the collimator to be constant. The other heights h ₁ and h ₂ are fixed. Each relational expression is expressed as the following expression (1).

d ₁ = h ₁ × d ₂ / (SID−h ₂ −h ₃ ) (1)
The reference height input setting unit 12a shown in FIG. 7, when the input set the height (the reference height) h ₃ from the top plate of the object to be photographed subject, as the slot width d ₂ becomes constant, the controller 10 (see FIG. 3) calculates the width _{d 1} of opening of the V-direction collimator from the equation (1).

  The reference height input setting unit 12a is provided with a button 12A for setting the reference height to a high value and a button 12B for setting the reference height to a low value as shown in FIG. By pressing the buttons 12A and 12B, an arbitrary reference height can be input and set. The input reference height is displayed in the window 12C.

  The X-ray imaging apparatus according to the present embodiment includes the reference height input setting unit 12a as an enlargement factor parameter input setting unit that inputs and sets parameters relating to the enlargement factor of the X-ray image. As a result, the parameter relating to the enlargement ratio (the reference height in this embodiment) can be freely set, and the controller 10 obtains the opening width of the collimator so that the slot width becomes constant. Thereby, the parameter (reference height) regarding the enlargement ratio can be appropriately set in each examination based on the physique or case of the subject M, and the opening amount of the collimator can be appropriately obtained based on the parameter. Further, by appropriately determining the opening amount of the collimator, it is possible to perform slot imaging with the optimal opening amount of the collimator, to suppress the exposure of the subject M, and to obtain a high-quality X-ray image. There is also an effect.

  In the present embodiment, the parameter relating to the enlargement ratio is the height (reference height) from the top 1 of the subject M to be imaged. Therefore, the height (reference height) of the subject M from the top 1 is set by inputting and setting the height (reference height) of the subject M from the top 1 to the reference height input setting unit 12a. The controller 10 determines the opening width of the collimator so that the slot width can be set freely. Thereby, the height (reference height) of the subject M from the top plate 1 can be appropriately set in each examination based on the physique and case of the subject M, and the opening amount of the collimator is appropriately set based on the height. Can be sought.

  The present invention is not limited to the above-described embodiment, and can be modified as follows.

  (1) In long shooting, it may be performed in a horizontal posture (a standing posture), a standing posture, or an inclined posture.

  (2) In the above-described embodiment, the flat panel X-ray detector (FPD) has been described as an example of the X-ray detection means. However, as in the image intensifier (I.I), it is normally used. If it is a X-ray detection means, it will not specifically limit.

(3) In the above-described embodiment, the parameter related to the enlargement ratio is the height (reference height) of the subject M from the top 1, but the height h from the FPD 3 of the SID or the top of FIG. If it is a parameter regarding an enlargement ratio as illustrated in ₂ , it is not particularly limited. For example, when the SID is variable, the SID may be input and set.

DESCRIPTION OF SYMBOLS 1 ... Top plate 2 ... X-ray tube 3 ... Flat panel type X-ray detector (FPD)
9a ... image connecting section 10 ... controller 12a ... reference height input setting unit 22 ... collimator h ₃ ... reference height d ₁ ... V width d ₂ ... slot width M ... subject opening of the collimator

Claims (2)

An X-ray imaging apparatus that performs X-ray imaging,
X-ray irradiation means for irradiating the subject with X-rays;
X-ray detection means for detecting X-rays transmitted through the subject;
An image connecting means for connecting a plurality of X-ray images obtained by the X-ray detecting means to create a long image;
A collimator for adjusting the opening amount of the X-rays irradiated from the X-ray irradiation means;
An enlargement ratio parameter input setting means for inputting and setting parameters relating to the enlargement ratio of the X-ray image;
The opening amount of the X-ray is determined based on the parameter relating to the enlargement factor input and set by the enlargement factor parameter input setting means so that the slot width which is the width of the X-ray image along the connecting direction is constant. An X-ray imaging apparatus comprising: an opening width calculating means for determining an opening width of the collimator. The X-ray imaging apparatus according to claim 1,
The parameter relating to the enlargement ratio is the height of the subject to be imaged from the placement means for placing the subject,
Input and set the height of the subject from the above-mentioned placing means to the enlargement ratio parameter input setting means,
The opening width calculating means calculates the opening width of the collimator based on the height from the placement means of the subject input and set by the enlargement ratio parameter input setting means so that the slot width is constant. An X-ray imaging apparatus characterized by being obtained.

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