JP2010227372A - X-ray photography apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the time taken for shooting an elongated object without increasing costs and energy consumption. <P>SOLUTION: The X-ray photography apparatus is provided with an X-ray tube 2 and an X-ray detector 3 which are opposed to each other across a top plate 1. The X-ray tube 2 is supported by an X-ray tube moving mechanism 6 and oscillates during shooting of the elongated object. The X-ray detector 3 is supported by an X-ray detector moving mechanism 7 and moves in parallel to the top plate 1 following the X-ray tube 2. The X-ray tube 2 and the X-ray detector 3 are moved within a moving range corresponding to an elongated shooting range of a subject. In the meantime, the X-ray tube 2 irradiates the subject with X-ray in several shooting positions including shooting positions at both ends of the moving range. Several consecutive X-ray images are obtained. An elongated X-ray image is created from the X-ray images. X-ray images are obtained in an X-ray image acquisition area on a detection surface of the X-ray detector 3. The position of the X-ray image acquisition area on the detection surface is changed in the moving direction of the X-ray detector 3 for each shooting position. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an X-ray imaging apparatus, and more particularly to an X-ray imaging apparatus suitable for performing long imaging such as whole spine imaging and all lower limb imaging.

  This type of X-ray imaging apparatus includes an X-ray tube and an X-ray detector that are arranged to face each other with a subject taking a lying or standing position. The X-ray tube is supported by an X-ray tube moving mechanism, and is capable of swinging or translating along the body axis of the subject during long imaging. The X-ray detector detects X-rays. It is supported by an instrument moving mechanism, and can be translated along the body axis of the subject following the swinging motion or translation of the X-ray tube.

  The X-ray tube and the X-ray detector are moved from one end to the other end of the moving range corresponding to the long imaging range determined in advance along the body axis of the subject, The X-ray tube irradiates the subject with X-rays at a plurality of imaging positions including the imaging positions at both ends of the X-ray tube, and transmitted X-rays from the subject are detected by the X-ray detector each time. A plurality of continuous X-ray images are acquired.

In this case, the X-ray image acquisition area on the detection surface of the X-ray detector is usually smaller than the detection surface. Therefore, in order to simplify the correction process at the time of acquisition of each X-ray image, at each imaging position. The position of the X-ray detector is set so that the X-ray image acquisition area is always at the same position on the detection surface.
Then, the plurality of acquired X-ray images are connected to each other, and a long X-ray image of the subject is generated (see, for example, Patent Documents 1 and 2).

Thus, the physician can observe the entire region of interest based on the combined X-ray image having a total field of view wider than the field of view of the individual X-ray images, so that long imaging is an effective X-ray. It is one of the photography methods.
However, in the case of long imaging, X-ray imaging is performed while moving the X-ray tube and the X-ray detector within a certain range. Therefore, imaging is performed in proportion to the movement time of the X-ray tube and the X-ray detector. Time increases. In addition, the long X-ray image is formed by joining a series of X-ray images. Therefore, if a mismatch occurs between individual X-ray images, an accurate long image cannot be obtained. Usually, the subject is instructed not to move as much as possible during the long photographing, which is a heavy burden on the subject.

  In order to reduce the time required for long imaging, for example, it is conceivable to increase the size of the X-ray detector. However, a large X-ray detector is expensive, and a high output torque is required to move it. Motors are required, resulting in high costs and increased energy consumption.

JP 2007-135692 A JP 2007-222500 A

  Therefore, an object of the present invention is to reduce the time required for long shooting without increasing costs and without increasing energy consumption.

  In order to solve the above problems, the present invention provides an X-ray tube and an X-ray detector facing each other across a subject, and the X-ray tube is swung along the body axis of the subject. The X-ray detector is made to follow the X-ray tube and translated along the body axis of the subject so that the X-ray tube and the X-ray detector are photographed in a predetermined length. Move from one end of the moving range corresponding to the range toward the other end, while irradiating the subject with X-rays from the X-ray tube at a plurality of imaging positions including both ends of the moving range, By detecting transmitted X-rays from the subject by the X-ray detector, a plurality of continuous X-ray images are acquired, and the X-ray images of the subject are joined by joining them together. In an X-ray imaging apparatus that generates a line image, the X-ray tube is supported. And an X-ray tube moving mechanism that swings or translates along the body axis of the subject and an X-ray detector that supports the X-ray detector and translates along the body axis of the subject. An X-ray image on a detection surface of the X-ray detector, comprising: a X-ray detector moving mechanism; and a controller for controlling the X-ray tube, the X-ray tube moving mechanism, and the X-ray detector moving mechanism. The X-ray image is acquired in an acquisition area, and the control unit generates a control signal for changing the position of the X-ray image acquisition area on the detection surface in the moving direction of the X-ray detector for each imaging position. An X-ray imaging apparatus is configured to transmit to the X-ray detector moving mechanism.

In the above configuration, when the X-ray tube and the X-ray detector take imaging positions at both ends of the moving range, the control unit is arranged on the end side of the moving range on the detection surface of the X-ray detector. It is preferable that a control signal for causing the positioned edge to coincide with an edge positioned on the end side of the moving range in the X-ray image acquisition area is transmitted to the X-ray detector moving mechanism.
Further, when the X-ray tube and the X-ray detector take three or more imaging positions including the imaging positions at both ends within the movement range, the control unit detects the X-ray tube and the X-ray detection. A control signal for positioning the X-ray image acquisition area of the X-ray detector at the center of the detection surface is sent to the X-ray detector moving mechanism when the detector takes an imaging position excluding the imaging positions at both ends. Is preferred.

According to the present invention, in the long imaging apparatus, the X-ray detector moves during long imaging by changing the position of the X-ray image acquisition area on the detection surface of the X-ray detector for each imaging position. The distance to be performed can be made shorter than in the conventional example, whereby the imaging time can be greatly shortened, and the burden on the subject at the time of long imaging can be reduced.
This effect of the present invention is particularly remarkable when the X-ray tube is swung during long imaging. On the other hand, in the configuration in which the X-ray tube is translated in the body axis direction of the subject together with the X-ray detector during long imaging, this effect of the present invention is the output of the drive motor of the X-ray detector moving mechanism. However, this is significant when the output is smaller than the output of the drive motor of the X-ray tube moving mechanism.

1 is a block diagram of an X-ray imaging apparatus according to one embodiment of the present invention. (A) is a figure explaining the determination method of the imaging distance and long imaging | photography range in an X-ray imaging device, (B) is a figure explaining the determination method of the imaging position of an X-ray detector. It is a figure explaining the determination method of the imaging position of a X-ray tube. It is a figure which shows the relationship between each imaging position of an X-ray tube and an X-ray detector, and the position of the X-ray acquisition area on the detection surface of the X-ray detector in each imaging position. (A) is a side view explaining the state of movement of the X-ray tube and the X-ray detector during long imaging of the X-ray imaging apparatus of FIG. 1, and (B) is each imaging position of (A). It is a top view which shows the position of the X-ray image acquisition area on the detection surface of the X-ray detector in FIG. (A) is a side view explaining the state of movement of an X-ray tube and an X-ray detector during long imaging of a conventional X-ray imaging apparatus of the same type, and (B) is each imaging of (A). It is a top view which shows the position of the X-ray image acquisition area on the detection surface of the X-ray detector in a position. (A) is a side view explaining the state of movement of an X-ray tube and an X-ray detector during long imaging of an X-ray imaging apparatus according to another embodiment of the present invention, and (B) is a conventional view. It is a side view explaining the mode of a movement of the X-ray tube and X-ray detector at the time of long imaging | photography of the same kind of X-ray imaging apparatus.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a block diagram of an X-ray imaging apparatus according to one embodiment of the present invention.
With reference to FIG. 1, the X-ray imaging apparatus is formed of an X-ray transmitting material, and a top plate 1 on which a subject M is supported in a prone position, and is disposed above the top plate 1. X-ray tube 2 for irradiating X-rays, and an X-ray detector 3 disposed below the top plate 1 for detecting transmitted X-rays from the subject M.
In this embodiment, since the subject M taking the prone position is photographed long, the top plate 1 is provided. However, when the subject M taking the standing position is photographed long, the top plate 1 is not necessary. Instead, a partition made of an X-ray transmitting material is provided on the rear side of the subject M.

  The X-ray tube 2 includes a diaphragm 2a that limits the X-ray irradiation range. The X-ray detector 3 is a flat panel X-ray detector (FPD). As an X-ray detector, an image intensifier tube (II) and a TV camera can be used instead of the FPD.

The top plate 1 can be moved up and down by a top plate moving mechanism 4 and can be moved in the longitudinal direction and the width direction in a horizontal plane. The top plate moving mechanism 4 is provided with a position detector 15 that detects the height of the top plate 1 from the floor surface.
A high voltage power supply device 5 is connected to the X-ray tube 2, and the X-ray tube 2 is supported by an X-ray tube moving mechanism 6, and is movable in the vertical direction and the longitudinal direction of the top plate 1 to the initial position, and During long imaging, the head can swing around the body axis of the subject M around the focal point of the X-ray tube 2 at the initial position. The X-ray tube moving mechanism 6 includes a height of the X-ray tube 2 from the floor, a position in the longitudinal direction of the top plate, and a swing angle (the center of the X-ray irradiated from the X-ray tube 2 is perpendicular to the vertical line). A position detector 13 for detecting the angle formed by the operator is provided.

  The X-ray detector 3 is supported by an X-ray detector moving mechanism 7, follows the movement of the X-ray tube 2 during long imaging, and is parallel to the top plate 1 and the body of the subject M. It can move in the axial direction. The X-ray detector moving mechanism 7 is provided with a position detector 14 that detects the position of the X-ray detector 3 in the longitudinal direction of the top plate.

  The top plate moving mechanism 4, the X-ray tube 2, the high-voltage power supply device 5, the X-ray tube moving mechanism 6 and the X-ray detector moving mechanism 7 are controlled by the control unit 8. The control unit 8 controls these devices and mechanisms based on various commands and data input from the operation unit 9.

  The X-ray imaging apparatus also reads a detection signal from the X-ray detector 3, acquires a plurality of continuous X-ray images, and connects the X-ray images to form a long X-ray image of the subject. An image processing unit 10 to be generated, an image memory 11 for storing X-ray image data generated by the image processing unit 10, and a monitor 12 connected to the image memory 11 are provided.

2A is a diagram illustrating a method for determining an imaging distance and a long imaging range in the X-ray imaging apparatus, and FIG. 2B is a diagram illustrating a method for determining an imaging position of the X-ray detector. It is. FIG. 3 is a diagram for explaining a method for determining the imaging position of the X-ray tube. 2 and 3, the x axis is set in the longitudinal direction of the top plate.
With reference to FIG. 2 (A), the position of the top plate 1 is first set in the case of long photographing. At this time, the control unit 8 receives the detection signal of the position detector 15 and records the height of the top board 1 from the floor surface. Then, the subject M is laid on the top board 1 and the X-ray tube 2 is moved to the photographing distance setting position P (on a perpendicular line passing through an arbitrary point in the long photographing range) by the operator's manual operation. Then, an imaging distance setting button (not shown) of the X-ray tube 2 is pressed by the operator. At this time, the control unit 8 receives a detection signal of the position detector 13 records the position x ₂ in height and the top plate longitudinally from the floor of the X-ray tube 2, further comprising: a height from the floor surface The imaging distance D (the focal point of the X-ray tube 2 and the detector) based on the already recorded height from the floor surface of the top plate 1 and the preset distance d from the X-ray detector 3 to the top plate 1. 3) is calculated and recorded.

Then, a light beam g is irradiated from a projector for checking an X-ray irradiation range (not shown) built in the X-ray tube 2 (the light beam g passes through the center of the X-ray beam irradiated from the X-ray tube 2). The X-ray tube 2 is tilted manually by the operator, and one end A of the long imaging range of the subject M is illuminated (the position indicated by the broken line in FIG. 2A). The position determination button (not shown) is pressed by the operator. At this time, the control unit 8 receives the detection signal of the position detector 13, records the swing angle θ with respect to the perpendicular direction of the X-ray tube 2,
x ₁ = x ₂ − (D−d) × tan θ
x ₄ = x ₂ −D × tan θ
Accordingly, the position x _{1 of one} end A of the long photographing range and the position x ₄ of one end E in the longitudinal direction of the long photographing image are calculated and recorded.

Next, the X-ray tube 2 is tilted in the opposite direction to the front by the operator's manual operation, the other end of the long imaging range of the subject M is illuminated by the light beam from the projector, and the position determination button is displayed by the operator. Is pressed. Then, in the same manner as before, the control unit 8 obtains the position x ₃ of the other end B of the long photographing range and the position x ₅ of the other end F in the longitudinal direction of the long photographing image, and calculates them. Record.

Next, referring to FIG. 2B, the length s of the detection surface of the X-ray detector 3 and the length f of the overlapping portion when the X-ray images are joined are preset, and the control unit 8 From these setting values and the length EF (= x ₅ −x ₄ ) of the long shot image,
EF ≦ N × s− (N−1) × f
The minimum value of N that satisfies the above is obtained, and this is recorded as N. In the embodiment of FIG. 2, the number of shots N = 3.

Further, the control unit 8 divides the EF into N parts (in this embodiment, three equal parts), so that the length of the X-ray image acquired per imaging, and thus the X of the X-ray detector 3 for each imaging. The length of the line image acquisition area and the corresponding imaging position of the X-ray detector 3 are determined. In this case, the division of EF does not need to be equal.
For example, when the EF is divided into N equal parts, the length L of the X-ray image acquired per imaging is:
L = [EF + (N−1) × f] / N
It becomes.

  The control unit 8 determines the imaging position of the X-ray tube 2 corresponding to the X-ray irradiation range of the X-ray tube 2 for each imaging based on the length of the X-ray image acquired per imaging.

For example, referring to FIG. 3, one end of an X-ray image acquired per radiograph is now E (x ₄ ), the other end is J (x ₇ ), and the line segment EJ is the length of the X-ray image. Let L be
x ₇ = x ₄ + L
And the X-ray irradiation range is a line segment EJ, and the position of the X-ray on the incident line is point I (x ₆ ),
x ₆ = x ₄ + a
It is. Also, from the nature of the angle bisector,
a: b = √ [D ² + (x ₂ −x ₄ ) ² ]: √ [D ² + (x ₂ −x ₇ ) ² ]
Is established. Furthermore, from the proportional division of distance,
a = L × a / (a + b)
= L × √ [D ² + (x ₂ −x ₄ ) ² ] / [√ (D ² + (x ₂ −x ₄ ) ² ) + √ (D ² + (x ₂ −x ₇ ) ² )]
= L × √ [D ² + (x ₂ −x ₄ ) ² ] / [√ (D ² + (x ₂ −x ₄ ) ² ) + √ (D ² + (x ₂ −x ₄ −L) ² ) ]
So,
x ₆ = x ₄ + L × √ [D ² + (x ₂ −x ₄ ) ² ] / [√ (D ² + (x ₂ −x ₄ ) ² ) + √ (D ² + (x ₂ −x ₄ − L) ² )]
Is obtained. Therefore, the swing angle α (imaging position) of the X-ray tube 2 corresponding to the X-ray irradiation range EJ is:
α = tan ⁻¹ [(x ₂ −x ₆ ) / D]
It becomes.

  FIG. 4 is a diagram showing the relationship between the X-ray tube and X-ray detector imaging positions determined above and the position of the X-ray acquisition area on the detection surface of the X-ray detector at each imaging position. . In FIG. 4, the x axis is set along the moving direction of the X-ray detector 3. L represents the length of the X-ray image acquired per radiographing, f represents a predetermined value of the length of the overlapping portion when the X-ray images are joined, and (I), (II) and ( III) represents three imaging positions of the X-ray tube and the X-ray detector, respectively. W represents the center of the X-ray detector 3, and V represents the center of the X-ray image acquisition area 17.

  Referring to FIG. 4, the detection surface 16 of the X-ray detector 3 is limited to the moving direction of the X-ray detector 3 by two edges 16 a and 16 b, and on the detection surface 13 (per imaging) An X-ray image is acquired in an X-ray image acquisition area 17 (corresponding to the length of the X-ray image). Then, the control unit 8 sends a control signal for changing the position of the X-ray image acquisition area 17 on the detection surface 13 of the X-ray detector 3 to the moving direction of the X-ray detector 3 for each imaging position. Transmit to the moving mechanism 7.

A method of changing the position of the X-ray image acquisition area 17 on the detection surface 13 of the X-ray detector 3 by the control unit 8 will be described in detail.
Referring again to FIG. 4, the distance u from the center W of the X-ray detector 3 to both end edges 16 a and 16 b of the detection surface 16 is recorded in advance in the control unit 8. When the position W (x) of the line detector 13 is determined, the positions W (x) ± u of the edges 16a and 16b of the detection surface 16 at the position are also determined at the same time.

In FIG. 4, the center position V (x) of the X-ray image acquisition area 17 at each of the imaging positions (I), (II), and (III) is expressed as follows.
Shooting position (I): V (x) = x ₄ + L / 2
Shooting position (II): V (x) = x ₄ + L / 2 + (L−f)
Shooting position (III): V (x) = x ₄ + L / 2 + (L−f) × 2
Then, the control unit 8 sends a control signal to the X-ray detector 3, and when the X-ray detector 3 takes the imaging positions (I) and (III) at both ends of the moving range, The X-ray detector 3 is moved so that the edge located on the end side of the movement range on the detection surface 16 coincides with the edge located on the end side of the movement range in the X-ray image acquisition area 17.
For this reason, at the imaging positions (I) and (III), it is necessary to shift the center W of the X-ray detector 3 with respect to the center V of the X-ray image acquisition area 17. In this case, since the difference between the length in the x-axis direction of the detection surface 16 of the X-ray detector 3 and the length in the x-axis direction of the X-ray image acquisition area 17 is 2 × u−L, half the length thereof. You can shift it.
Therefore, the center position W (x) of the X-ray detector 3 at each imaging position (I), (II), (III) is determined as follows.
Shooting position (I): W (x) = V (x) + (2 × u−L) / 2 = x ₄ + u
Shooting position (II): W (x) = V (x) = x ₄ + L + (L / 2−f)
Shooting position (III): W (x) = V (x) − (2 × u−L) / 2 = x ₄ + 2 × (L−f) + (L−u)
The positions of the one end 17a and the other end 17b of the X-ray image acquisition area are determined as follows for each imaging position, where the center W of the X-ray detector at the imaging position is the coordinate origin.
Shooting position (I): position of one end 17a = −u, position of the other end 17b = L−u
Shooting position (II): position of one end 17a = −L / 2, position of the other end 17b = L / 2
Shooting position (III): position of one end 17a = u−L, position of the other end 17b = u
In this way, the control unit 8 controls the position of the X-ray detector 3 and the position of the X-ray tube 2 corresponding to the X-ray detector 3 and switches the positions of both ends 17a and 17b of the X-ray image acquisition area 17 for each imaging.

In the above description, the case where a total of three shootings are performed during the long shooting has been described, but this is generalized, and the case where the shooting is performed a total of N times during the long shooting will be described. At the imaging position, the position of the center V of the X-ray image acquisition area 17 is
V (x) = x ₄ + L / 2 + (L−f) × (n−1)
Further, the center position W (x) of the X-ray detector 3 is determined as follows.
(1) At the imaging position (n = 1) at one end of the movement range of the X-ray detector 3,
W (x) = V (x) + (2 × u−L) / 2
(2) At each imaging position (n ≠ 1, N) in the middle of the movement range of the X-ray detector 3,
W (x) = V (x) + (2 × u−L) / 2− (2 × u−L) × (n−1) / (N−1)
(3) At the imaging position (n = N) at the other end of the movement range of the X-ray detector 3,
W (x) = V (x) − (2 × u−L) / 2
Therefore, the positions of the one end 17a and the other end 17b of the X-ray image acquisition area 17 are determined for each imaging position as follows, where the center W of the X-ray detector at the imaging position is the coordinate origin.
(1) At the imaging position (n = 1) at one end of the movement range of the X-ray detector 3,
Position of one end 17a = −u, position of other end 17b = L−u
(2) At each imaging position (n ≠ 1, N) in the middle of the movement range of the X-ray detector 3,
Position of one end 17a = −u + (2 × u−L) × (n−1) / (N−1), position of the other end 17b = L−u + (2 × u−L) × (n−1) / (N-1)
(3) At the imaging position (n = N) at the other end of the movement range of the X-ray detector 3,
Position of one end 17a = u−L, position of the other end 17b = u

  In this way, the control unit 8 controls the position W (x) of the X-ray detector 3 corresponding to the imaging range (X-ray irradiation range) for each imaging position of the X-ray tube 2, and thus the X-ray image acquisition area on the detection surface 17. 17 is determined, and a control signal is transmitted to the X-ray detector moving mechanism 7 to move the position of the X-ray image acquisition area 17 on the detection surface 16 of the X-ray detector 3 to the X-ray detector 3. Change direction.

  In this embodiment, the position change of the X-ray image acquisition area 17 on the detection surface 16 of the X-ray detector 3 by the control unit 8 minimizes the distance that the X-ray detector 3 moves during long imaging. To be executed. This is because when the X-ray tube 2 and the X-ray detector 3 take the imaging positions at both ends of the movement range, the edge located on the end side of the movement range on the detection surface 16 of the X-ray detector 3 is This is executed by matching the edge located on the end side of the movement range in the line image acquisition area 17.

  That is, in this embodiment, with reference to FIG. 5 (A), during long imaging, the X-ray tube 2 and the X-ray detector 3 are separated from the head side end (I) indicated by the broken line. It moves between the foot side end (III) indicated by the chain line (swing motion), the first shooting position (I) at the head side end, the second shooting position (II) in the center, and the foot side X-ray images are acquired at three imaging positions, ie, the third imaging position (III) at the end.

  Then, as shown in FIG. 5B, when the X-ray tube 2 and the X-ray detector 3 take the first imaging position (I), the control unit 8 controls the head of the detection surface 16 of the X-ray detector 3. The position of the X-ray detector 3 is controlled so that the side edge 16a coincides with the head side edge of the X-ray image acquisition area 17 (FIGS. 5B and 5I), and the X-ray tube 2 and When the X-ray detector 3 takes the third imaging position (III), the control unit 8 determines that the foot side edge 16b of the detection surface 16 of the X-ray detector 3 is on the foot side of the X-ray image acquisition area 17. The position of the X-ray detector 3 is controlled so as to coincide with the edge (FIGS. 5B and III). Further, when the X-ray tube 2 and the X-ray detector 3 take the second imaging position (II), the control unit 8 positions the X-ray image acquisition area 14 at the center of the detection surface 13 of the X-ray detector 3. In this way, the position of the X-ray detector 3 is controlled (FIGS. 5B and II).

  In this way, as shown in FIGS. 5A and 5B, the X-ray tube 2 and the X-ray detector 3 are moved from one end of the moving range corresponding to the long imaging range to the other end. The subject M is irradiated with X-rays from the X-ray tube 2 at a plurality of imaging positions including the imaging positions at both ends of the moving range, and the transmitted X-rays from the subject M are transmitted by the X-ray detector 3 each time. Detected. Then, the detection signal of the X-ray detector 3 is read by the image processing unit 10, and the image processing unit 10 acquires a plurality of continuous X-ray images based on the detection signal, and sequentially connects these X-ray images. Thus, a long X-ray image of the subject M is generated. The generated long X-ray image data is stored in the image memory 11, and the long X-ray image data of the subject M is read out from the image memory 11 by the monitor 12. It is displayed on the monitor 11.

  FIG. 6A is a side view for explaining the movement of the X-ray tube and the X-ray detector at the time of long image capturing of this type of conventional X-ray imaging apparatus, and FIG. It is a top view which shows the position of the X-ray image acquisition area on the detection surface of the X-ray detector in each imaging position of FIG. In the conventional example of FIG. 6, the long imaging range of the subject M and the movement distance of the X-ray tube 2 are both the same as in the embodiment of FIG. 5, and the imaging position is also the same as in the embodiment of FIG. is there. However, in the conventional example, as is apparent from FIG. 6, the X-ray image acquisition area 17 of the X-ray detector 3 has the same position on the detection surface 13 (in this example, the center) in any of the three imaging positions. ), The position of the X-ray detector 3 is controlled.

Based on this difference in configuration, as is apparent from a comparison between FIG. 6A and FIG. 5A, in the X-ray imaging apparatus of the present invention, the X-ray detector moves during long imaging. The distance is shorter than the conventional example by the difference between the width of the detection surface 16 of the X-ray detector 3 and the width of the X-ray image acquisition area 17 in the moving direction. As a result, the movement time of the entire imaging system consisting of the X-ray tube and X-ray detector during long imaging is greatly shortened, so the imaging time is greatly reduced and the burden on the subject is greatly reduced. Is done.
Thus, according to the present invention, a long X-ray detector is required without using a large X-ray detector and a motor with a high output torque, and therefore without adding extra cost and increasing energy consumption. You can save time. In addition, according to the present invention, the X-ray detector can be moved in a shorter distance than before, so that the size of the X-ray imaging apparatus can be reduced, and at the same time, noise generated during operation of the apparatus can be reduced. it can.

  In addition, the position of the X-ray image acquisition area on the detection surface of the X-ray detector is the same as the moving distance for each imaging when imaging at each of the intermediate imaging positions other than the imaging positions at both ends in the long imaging range. If it changes so that it may become, it becomes easy for an operator to assume the timing of imaging | photography and the timing which all imaging | photography is completed, and the operativity of an apparatus improves.

Although one embodiment of the present invention has been described above, the configuration of the present invention is not limited to this embodiment. For example, in the above-described embodiment, the X-ray tube swings during long imaging, but the X-ray tube is parallel to the body axis direction of the subject M as shown in FIG. It is good also as a structure which switches a photographing position by moving and performs long photography. In this embodiment, as compared with the conventional X-ray imaging apparatus of the same type shown in FIG. 7B, the moving distance of the X-ray detector is shorter than that of the conventional example during long imaging, while X Since the X-ray tube moves in parallel with the top plate by the same distance as the conventional example, the rate at which the entire imaging system consisting of the X-ray tube and the X-ray detector is shortened is that the X-ray tube swings. It becomes smaller than the configuration. However, according to this embodiment, there is an additional effect that an imaging time comparable to that of the conventional example can be realized by using a smaller motor than the conventional one for moving the X-ray detector.
Further, in the above-described embodiment, the subject that is supported in the prone position by the top plate is configured to take a long image, but the subject that is standing can be configured to take a long image. In the case where the subject takes a standing position, the top plate is unnecessary, and instead, a screen formed of an X-ray transmitting material is provided on the rear side of the subject.

DESCRIPTION OF SYMBOLS 1 Top plate 2 X-ray tube 2a Aperture 3 X-ray detector 4 Top plate moving mechanism 5 High voltage power supply device 6 X-ray tube moving mechanism 7 X-ray detector moving mechanism 8 Control unit 9 Operation unit 10 Image processing unit 11 Image memory 12 Monitors 13 to 15 Position detector 16 Detection surfaces 16a and 16b Edge 17 X-ray image acquisition areas 17a and 17b Edge M Subject

Claims (3)

An X-ray tube and an X-ray detector are opposed to each other with the subject interposed therebetween, and the X-ray tube is swung or translated along the body axis of the subject. The X-ray tube and the X-ray detector are moved in parallel along the body axis of the subject following the X-ray tube, and the X-ray tube and the X-ray detector are moved from one end to the other end of the moving range corresponding to a predetermined long imaging range. The X-ray tube irradiates the subject with X-rays at a plurality of imaging positions including both ends of the moving range, and transmits X-rays from the subject to the X-rays. In an X-ray imaging apparatus that generates a long X-ray image of the subject by acquiring a plurality of continuous X-ray images by detecting by an X-ray detector and connecting the X-ray images.
An X-ray tube moving mechanism that supports the X-ray tube and swings or translates along the body axis of the subject;
An X-ray detector moving mechanism that supports the X-ray detector and translates along the body axis of the subject;
A control unit that controls the X-ray tube, the X-ray tube moving mechanism, and the X-ray detector moving mechanism;
The X-ray image is acquired in an X-ray image acquisition area on the detection surface of the X-ray detector, and the control unit determines the position of the X-ray image acquisition area on the detection surface for each imaging position. An X-ray imaging apparatus characterized by transmitting a control signal for changing in the moving direction of the X-ray detector to the X-ray detector moving mechanism.   When the X-ray tube and the X-ray detector take imaging positions at both ends of the moving range, the control unit is configured to detect an edge located on an end side of the moving range on the detection surface of the X-ray detector. 2. The X-ray imaging according to claim 1, wherein a control signal is transmitted to the X-ray detector moving mechanism so as to coincide with an edge located on an end side of the moving range in the X-ray image acquisition area. apparatus.   When the X-ray tube and the X-ray detector take three or more imaging positions including the imaging positions at both ends within the movement range, the control unit is configured so that the X-ray tube and the X-ray detector are When taking imaging positions excluding the imaging positions at both ends, a control signal for positioning the X-ray image acquisition area of the X-ray detector at the center of the detection surface is transmitted to the X-ray detector moving mechanism. The X-ray imaging apparatus according to claim 2.

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