JP2000126169A - Tomographic x-ray apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily obtain an X-ray tomographic image of a sectional plane to be photographed at various depth positions. SOLUTION: A control section 10 controls the driving of photographing drive systems 11-14 according to a drive data stored in a nonvolatile memory 30 to take a tomographic image of a sectional plane Ma to be photographed in a subject M. The memory 30 previously stores a plurality of drive data corresponding to the sectional plane Ma to be photographed at various depth positions. When the depth position of the sectional plane Ma to be photographed for shooting is set by an operator from a setting panel 31, the control section 10 reads the drive data out of the memory 30 corresponding to the set depth position of the sectional plane Ma to be photographed and controls the driving of the photographing drive systems 11, 14 according to the drive data to take a tomographic image for the section plane Ma to be photographed at the set depth position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-CT type (non-computer tomography type) X-ray tomography apparatus for obtaining an X-ray tomographic image of a tomographic plane to be imaged in a subject,
In particular, the present invention relates to an improved technique for obtaining X-ray tomographic images of a tomographic plane to be imaged at various depth positions.

[0002]

2. Description of the Related Art A non-CT type X-ray tomographic imaging apparatus installed in a medical institution such as a hospital, as shown in FIG. Fault plane Ma
X-rays are emitted toward the subject M while sequentially changing the incident direction of X-rays from the X-ray tube 2 to the X-ray tube 2, and the transmitted X-ray image of the tomographic plane Ma to be imaged inside the subject M is always image-in. Changing the direction of incidence of X-rays on the tomographic plane Ma to be imaged so that the X-rays are projected on the same position on the image receiving surface 3a of the imaging unit 3 such as an X-ray detector such as a tensifier or an imaging material such as a film (X-ray tube 2). The position of the image receiving surface 3a of the image capturing unit 3 is changed in conjunction with the operation of the imaging unit 3 to obtain an X-ray tomographic image of the imaging target tomographic surface Ma.

[0003] The principle of X-ray tomography by this X-ray tomography apparatus will now be described in more detail. That is, as shown in FIG. 9, for example, by changing the position of the X-ray tube 2 or the irradiation angle of the X-ray radiated from the X-ray tube 2, the X-ray with respect to the imaging target tomographic plane Ma in the subject M is changed. Even if the incident direction of the X-ray from the ray tube 2 is changed, the points A and B located in the tomographic plane Ma to be imaged are always projected on the same points a and b on the image receiving surface 3a of the imaging unit 3. In this way, the position of the image receiving surface 3a of the image receiving unit 3 is changed in conjunction with the change of the incident direction of the X-rays on the imaging target tomographic surface Ma. Then, as for the point C located outside the imaging target tomographic plane Ma, the projection position on the image receiving surface 3a changes rapidly as the incident direction of the X-rays on the imaging target tomographic plane Ma changes. For example, if the X-ray tube 1 is at the position P
When the X-ray tube 1 is moved to a position P2 different from the position P1 while the point C is projected on the point c1 on the image receiving surface 3a with respect to the incident direction of the X-ray to the imaging target tomographic plane Ma at 1 In the direction of incidence of X-rays on the imaging target tomographic plane Ma, the point C is projected on the point c2 on the image receiving surface 3a.

As described above, the X with respect to the tomographic plane Ma to be photographed is
When the transmission X-ray images received on the image receiving surface 3a of the imaging unit 3 are superimposed while changing the incident direction of the line, the transmission X-ray image of the point C is scattered throughout the image in the superimposed image. As a result, the point C appears as a point in an unclear blur state. The degree of blur at the point C increases as the point C moves away from the imaging target tomographic plane Ma. On the other hand, points A and B
Transmission X-ray image of the image is kept at one point of the image (concentrated)
As a result, points A and B appear as clear points in the superimposed image. Therefore, the direction of incidence of X-rays on the tomographic plane Ma to be imaged is changed in various ways, and
By superimposing a large number of transmitted X-ray images received at step S1 on the X-ray tomographic image, only the tomographic plane Ma to be imaged is clearly shown, that is, an X-ray tomographic plane obtained by extracting the tomographic plane Ma to be imaged within the subject M A photographed image can be obtained.

[0005] When the imaging section 3 is formed of an X-ray detector such as an image intensifier, the imaging target tomographic plane Ma sampled during the imaging operation of the X-ray tube 2 and the imaging section 3 is performed. A number of transmitted X-ray images having different X-ray incident directions are converted into digital images, and the images are integrated by digital image processing to obtain an X-ray tomographic image. In the case where the imaging unit 3 is formed of an imaging material such as a film, a large number of transmissions having different X-ray incidence directions with respect to the imaging target tomographic plane Ma during the imaging operation of the X-ray tube 2 and the imaging unit 3. The X-ray image is subjected to multiple exposure on the imaging material 3 to obtain an X-ray tomographic image.

A drive control system of an X-ray tomography apparatus for obtaining an X-ray tomographic image of a to-be-photographed tomographic plane Ma based on the above principle is conventionally configured as follows.

[First Conventional Example] Referring to FIG. In the first conventional example, an X-ray tube driving mechanism 11 such as a motor holds an X-ray tube 2 on an X-ray tube holding member 22 that moves horizontally along a rail 21 laid on a ceiling, for example.
The X-ray tube 2 is moved horizontally. X-ray tube 2
Is connected to an X-ray irradiation drive unit 12 including a high-voltage generator and the like, and the X-ray irradiation drive unit 12 drives X-ray irradiation from the X-ray tube 2. The irradiation angle driving mechanism 13 such as a motor causes the X-ray tube holding
The X-ray tube 2 is rotated with respect to the X-ray tube 2 to change the irradiation angle of the X-ray emitted from the X-ray tube 2.

The X-ray tube driving mechanism 11 and the X-ray irradiation driving unit 1
2. The drive control of the photographing drive system such as the irradiation angle drive mechanism 13 is performed by the control unit 10P1. Control unit 10P1
Controls the driving of the imaging drive systems 11, 12, and 13 to irradiate X-rays from the X-ray tube 2 while changing the irradiation angle of X-rays in accordance with the horizontal movement of the X-ray tube 2 as follows. To work. The X-ray irradiation angle is such that, at each position of the X-ray tube 2 during horizontal movement, the central axis XJ of the X-ray flux irradiated from the X-ray tube 2 is always the imaging target tomographic plane Ma within the subject M.
It is changed to pass through the middle shooting center GC. Thereby, the incident direction of the X-rays on the tomographic plane Ma (the middle imaging center GC) in the subject M mounted on and supported by the table 1 is changed in various directions.

[0009] X across the top plate 1 for mounting and supporting the subject M
The imaging unit 3 disposed on the opposite side of the X-ray tube 2 is connected to the X-ray tube 2 by a telescopic connecting member 100 so as to be horizontally movable integrally with the X-ray tube 2. A supporting point 101 is provided on the connecting member 100. Accordingly, when the X-ray tube 2 is moved horizontally, the connecting member 100 is swung around the fulcrum 101, and accordingly, the tomographic plane Ma to be imaged in the subject M
The position of the image receiving surface 3a of the imaging unit 3 is changed in conjunction with the operation of the X-ray tube 2 so that the transmitted X-ray image of the image capturing unit 3 is always projected at the same position on the image receiving surface 3a of the image capturing unit 3. The position of the fulcrum 101 can be changed.

With the above configuration, an X-ray tomographic image of a predetermined imaging range GH centered on the imaging center GC can be obtained from the imaging target tomographic plane Ma shown in FIG.

In the first conventional example, the control unit 1
0P1 is one imaging target tomographic plane M at a predetermined depth position as drive data for driving the imaging drive system.
It has only one type of drive data corresponding to a. When the depth position of the imaging target tomographic plane Ma is changed and imaging is performed, the position of the fulcrum 101 is changed to a position corresponding to the depth position of the imaging target tomographic plane Ma to be imaged, so that X-rays can be obtained. The interlocking operation between the tube 2 and the imaging unit 3
The operation is changed so that the operation according to the depth position of the tomographic plane Ma to be photographed can be performed.

[Second Conventional Example] Referring to FIG. In the first conventional example, an interlocking operation between the X-ray tube 2 and the imaging unit 3 necessary for obtaining an X-ray tomographic image of the imaging target tomographic plane Ma is performed by the X-ray tube 2 and the imaging unit 3. The connection is realized by a connecting member 100, but the second conventional example is an X-ray tube 2 and an imaging unit 3
An X-ray tube driving mechanism 11 for moving the X-ray tube 2 horizontally is provided with an imaging unit driving mechanism 14 such as a motor for moving the imaging unit 3 horizontally, without connecting the X-ray tube 2 and the imaging unit. 3 is configured to be horizontally movable independently of each other. The X-ray tube driving mechanism 11 and the X-ray tube driving mechanism 11 perform an interlocking operation between the X-ray tube 2 and the imaging unit 3 necessary for obtaining an X-ray tomographic image of the imaging target tomographic plane Ma. The drive of the imaging unit drive mechanism 14 is controlled. Other X-ray irradiation angle change control and X-ray irradiation drive control from the X-ray tube 2
This is the same as the first embodiment.

In the second conventional example, the control unit 10P2 also includes:
As drive data for driving the imaging drive system, only one type of drive data corresponding to one imaging target tomographic plane Ma at a predetermined depth position is provided. Then, when changing the depth position of the tomographic plane Ma to be imaged and performing imaging, the top 1 is moved up and down by the top driving mechanism 15 that moves up and down the top 1 to move the subject M to the X-ray tube 2. (In the near and far directions with respect to the image receiving surface 3a of the imaging unit 3), thereby changing the positional relationship of the one tomographic plane Ma in the subject M in the depth direction.

[0014]

However, the prior art having such a structure has the following problems. Usually, in a series of tomographic examinations, imaging is performed by changing the depth position of the imaging target tomographic plane Ma by several points in order to specify the position of the lesioned part. Each time imaging is performed with the depth position of the tomographic plane Ma changed,
It is necessary to change the position of the fulcrum 101 of the connecting member 100. Since the operation of changing the fulcrum 101 of the connecting member 100 includes the manual operation of the operator, there is a problem that the operation of changing the fulcrum 101 of the connecting member 100 is troublesome and burdens the operator.

In the second conventional example, it is possible to perform imaging while changing the depth position of the to-be-photographed tomographic plane Ma only by moving the top 1 up and down, and the elevation of the top 1 is usually performed by button operation or the like. Therefore, the problem of the first conventional example is solved. However, as the top 1 is moved up and down,
Above, body movement of the subject M is likely to occur, and as a result, an X-ray tomographic image of the imaging target tomographic plane Ma at a desired depth position may not be accurately obtained. In particular, in order to identify the position of the lesion, the depth position of the imaging target tomographic plane Ma may be changed in (mm) units, and the depth position of the imaging target tomographic plane Ma due to the body movement of the subject M may be changed. (M
m) Each X-ray tomographic image for the imaging target tomographic plane Ma at each depth position changed in units of m) may not be accurately obtained, which may hinder a series of tomographic inspections. In addition, if the table 1 is frequently moved up and down finely during the tomography inspection, there is a problem that the subject M may be psychologically anxious.

The present invention has been made in view of such circumstances, and solves the above-mentioned disadvantages of the prior art to easily obtain X-ray tomographic images of tomographic planes to be imaged at various depth positions. It is an object of the present invention to provide an X-ray tomography apparatus capable of performing the above.

[0017]

The present invention has the following configuration to achieve the above object. That is, the present invention relates to an X-ray tomography apparatus for obtaining an X-ray tomographic image of a tomographic plane to be imaged in a subject, wherein (a) a supporting means for supporting the subject; (C) X-ray irradiating means for irradiating the supported object with X-rays, and (c) X-ray irradiating means arranged on the opposite side of the X-ray irradiating means with the object supported by the supporting means interposed therebetween. Imaging means for receiving a line transmission image on an image receiving surface and imaging the image; and (d) driving for changing the incident direction of X-rays from the X-ray irradiating means on a tomographic plane to be imaged in the subject supported by the supporting means. X to do
X-ray incident direction changing driving means, and X-rays from the X-ray irradiating means.
X-ray irradiation driving means for driving irradiation of X-rays, imaging driving means including image receiving position changing driving means for changing the position of the image receiving surface of the imaging means, and (e) an object supported by the supporting means X-rays are radiated toward the subject while sequentially changing the incident direction of the X-rays from the X-ray irradiating means on the tomographic plane in the inside, and the transmitted X-ray image of the tomographic plane to be imaged is always obtained by the imaging. The photographing driving means is operated in accordance with drive data to change the position of the image receiving surface of the image pickup means in conjunction with a change in the direction of incidence of X-rays on the tomographic plane to be imaged so as to be projected at the same position on the image receiving surface of the means. Control means for controlling the driving, when performing imaging while changing the depth position of the imaging target tomographic plane, the control means, according to the depth position of the imaging target tomographic plane to be imaged, the depth position Shooting target The imaging driving means according to the positional relationship between the surface and the X-ray irradiating means and the depth position of the imaging target tomographic plane determined by the positional relationship between the imaging target tomographic plane at the depth position and the image receiving surface of the imaging means The driving of the photographing driving means is controlled according to the driving data.

[Operation] The operation of the present invention is as follows. When the subject is supported by the supporting means and the subject is positioned at a predetermined imaging position between the X-ray irradiating means and the imaging means, the control means controls the imaging target in the subject supported by the supporting means. X-rays are emitted while sequentially changing the direction of incidence of X-rays from the X-ray irradiator on the tomographic plane, and a transmitted X-ray image of the tomographic plane to be imaged is always projected on the same position on the image receiving surface of the imaging means. X-ray incident direction changing driving means, X-ray irradiation driving means, image receiving position changing driving means so as to change the position of the image receiving surface of the imaging means in conjunction with the change of the X-ray incident direction on the tomographic plane to be imaged. Is driven in accordance with the drive data to obtain an X-ray tomographic image of the tomographic plane to be imaged.

When changing the depth position of the tomographic plane to be photographed, the control means controls the depth of the tomographic plane to be photographed in accordance with the depth position of the tomographic plane to be photographed. And the X-ray irradiating means, and the driving data of the imaging driving means corresponding to the depth position of the imaging target tomographic plane determined by the positional relation between the imaging target tomographic plane at the depth position and the image receiving surface of the imaging means. The driving of the imaging driving means is controlled to obtain an X-ray tomographic image for the imaging target tomographic plane at the depth position.

The positional relationship between the tomographic plane to be imaged and the X-ray irradiating means and the positional relation between the tomographic plane to be imaged and the image receiving surface of the imaging means can be replaced by a geometrical positional relation.

To change the depth position of the tomographic plane to be photographed means to make the tomographic plane to be photographed farther from the X-ray irradiating means (closer to the image receiving surface of the imaging means).

Accordingly, the positional relationship between the tomographic plane to be imaged at the depth position to be imaged and the X-ray irradiating means and the positional relation between the tomographic plane to be imaged at that depth position and the image receiving surface of the imaging means are geometrical. Can be grasped biologically.

Based on this, in order to obtain an X-ray tomographic image on the tomographic plane to be photographed at the depth position, the X-ray irradiating means for changing the incident direction of X-rays on the tomographic plane to be photographed is changed. The drive data for the X-ray incident direction changing drive means such as the operation range and the operation speed, and the drive data for the image receiving position change drive means such as the operation range and the operation speed for changing the position of the image receiving surface of the imaging means in conjunction with the drive data. It can be obtained by a typical operation. Also, X
Once the operating range and operating speed of the X-ray irradiating unit and the operating range and operating speed for changing the position of the image receiving surface of the imaging unit are determined, the timing of X-ray irradiation and the like are also determined. The drive data of the means is also determined. By controlling the driving of the imaging drive means in accordance with the drive data determined for each imaging target tomographic plane at a depth position in this manner, X-ray tomographic images for the imaging target tomographic planes at various depth positions can be automatically obtained. it can.

[0024]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of an X-ray tomography apparatus according to one embodiment of the present invention. In the following embodiment, to simplify the description, the X-ray tube 2 is moved horizontally, and the irradiation angle of the X-ray from the X-ray tube 2 is changed, so that the tomographic plane to be imaged in the subject M is changed. An example of an apparatus that changes the incident direction of X-rays from the X-ray tube 2 to Ma and follows the direction to horizontally move the image receiving surface 3a of the imaging unit 3 to obtain an X-ray tomographic image of the tomographic surface Ma to be imaged It will be explained. In addition, in the embodiments, portions denoted by the same reference numerals as those used in the description of the related art are basically the same as those in the related art, and thus unnecessary duplicate description will be omitted.

The imaging drive system of the X-ray tomography apparatus according to this embodiment is basically the same as that of the second conventional example.
That is, the X-ray tube driving mechanism 11 holds the X-ray tube 2 on the X-ray tube holding member 22 that is horizontally moved along the rail 21 laid on the ceiling, for example, and the X-ray tube 2 is horizontally moved. It has become. An X-ray irradiation drive unit 12 including a high voltage generator and the like is connected to the X-ray tube 2, and the X-ray irradiation drive unit 12 drives X-ray irradiation from the X-ray tube 2. Further, an irradiation angle driving mechanism 13 such as a motor
Thus, for example, the X-ray tube 2 is rotated with respect to the X-ray tube holding member 22 so that the irradiation angle of the X-ray emitted from the X-ray tube 2 is changed.

On the other hand, an image receiving surface 3 of an image pickup unit 3 arranged on the opposite side of the X-ray tube 2 with respect to the top plate 1 on which the subject M is placed and supported.
“a” is horizontally moved by the imaging unit driving mechanism 14.

In this embodiment, the top 1 is used as the support means, the X-ray tube 2 is used as the X-ray irradiating means, the imaging section 3 is used as the imaging means, and the X-ray tube driving mechanism 11 and the irradiation angle driving mechanism 13 are used. The X-ray incident direction changing drive unit, the X-ray irradiation drive unit 12 as the X-ray irradiation drive unit, the imaging unit drive mechanism 14 as the image receiving position changing drive unit, the X-ray tube drive mechanism 11 and the X-ray irradiation drive unit 12, A photographing drive system including the irradiation angle drive mechanism 13 and the imaging unit drive mechanism 14 corresponds to a photographing drive unit.

X-ray tube driving mechanism 11 and X-ray irradiation driving unit 1
2. The drive control of the photographing drive system including the irradiation angle drive mechanism 13 and the imaging unit drive mechanism 14 is performed by the control unit 1 corresponding to a control unit.
Performed by 0. The control unit 10 controls the photographing drive system 1 according to the drive data stored in the nonvolatile memory 30.
Drive control of 1, 12, 13, and 14 is performed to capture an X-ray tomographic image of the tomographic plane Ma to be imaged in the subject M.

The memory 30 stores a tomographic plane M to be imaged at various depth positions determined by a determination method described later.
A plurality of drive data corresponding to a is stored in advance. When the operator sets the depth position of the to-be-photographed tomographic plane Ma to be photographed from the setting panel 31, the control unit 10 drives the drive data according to the set depth position of the to-be-photographed tomographic plane Ma. Is read out from the memory 30, and the imaging drive systems 11 to 14 are drive-controlled in accordance with the drive data to capture an X-ray tomographic image on the tomographic plane Ma to be imaged at the set depth position.

Therefore, according to the configuration of this embodiment, the first
The photographing drive is performed without changing the fulcrum 101 of the connecting member 100 connecting the X-ray tube 2 and the imaging unit 3 as in the conventional example, or without moving the top plate 1 up and down as in the second conventional example. Only by changing the driving of the systems 11 to 14, an X-ray tomographic image in which the depth position of the imaging target tomographic plane Ma is changed can be captured. Therefore, each X-ray tomographic image can be accurately obtained with respect to the tomographic plane to be imaged at various depth positions without burdening the operator and burden on the operator and reducing the body movement of the subject M during imaging. The first and the second, such as being able to reduce psychological anxiety about the subject M during imaging,
The disadvantages of the conventional example can be eliminated.

The photographing drive system of the apparatus is basically the same as that of the second conventional example, and only the contents of the drive control of the photographing drive system are changed. The contents of the PROM storing computer programs and data are simply rewritten so as to include drive data according to the tomographic plane Ma to be photographed at various depths and to selectively use the drive data to drive and control the photographing drive system. Thus, it is possible to use the device resources of the second conventional example without performing significant remodeling. Therefore, when the device of the second conventional example is already installed in a medical institution or the like, the resources can be effectively used without wasting.

The above embodiment is provided with a top driving mechanism for moving the top 1 in the horizontal direction such as front and rear, left and right, and elevating, so as to change the depth position of the tomographic plane Ma to be photographed. For example, the top 1 (subject M) is moved between a position where the subject M gets on and off the top 1 and an imaging position between the X-ray tube 2 and the imaging unit 3. The top board 1 may be configured to be movable, for example, for movement.

As will be described in detail later in a method of determining drive data, a tomographic plane Ma to be photographed at a certain depth position will be described.
Is the reference imaging target tomographic plane MaS, and the driving data of the imaging drive systems 11 to 14 corresponding to the reference imaging target tomographic plane MaS is the reference driving data, the depth position of the reference imaging target tomographic plane MaS In some cases, the drive data according to the imaging target tomographic plane MaN at a different depth position need only be multiplied by the reference drive data by a coefficient corresponding to the imaging target tomographic plane MaN at that depth position. In such a case, all the drive data corresponding to the imaging target tomographic plane Ma at each depth position is not stored in the memory 30, and the reference driving data and the imaging target tomographic plane MaN at each depth position are not stored. Is stored in the memory 30, and when an X-ray tomographic image of the imaging target tomographic plane MaN at each depth position is taken, the reference driving data contains the imaging target tomographic plane MaN at that depth position. May be multiplied by a coefficient corresponding to the driving data corresponding to the imaging target tomographic plane MaN at the depth position. With this configuration, the amount of storage in the memory 30 can be reduced.

The tomographic plane M to be photographed at each depth position
The drive data according to a, the reference drive data, and the coefficient corresponding to the imaging target tomographic plane MaN at each depth position are not stored in the memory 30. Program it, and from the setting panel 31,
Each time the depth position of the imaging target tomographic plane Ma to be imaged is set, the control unit 10 calculates drive data according to the set depth position of the imaging target tomographic plane Ma before imaging, In accordance with the driving data obtained as a result of the calculation, the driving of the imaging drive systems 11 to 14 is controlled to perform X-ray tomographic imaging on the imaging target tomographic plane Ma at the set depth position. Good.

Next, the tomographic plane M to be photographed at different depth positions
A method of determining drive data according to a will be described.

<First Determination Method> Referring to FIG. FIG.
As shown in the figure, the positional relationship between the imaging target tomographic planes MaS and MaN and the X-ray tube 2 and the positional relation between the imaging target tomographic planes MaS and MaN and the image receiving surface 3a of the imaging unit 3 are geometrically related. Can be replaced by

In FIG. 2, one predetermined tomographic plane to be photographed is defined as a reference tomographic plane MaS to be photographed, and the tomographic plane MaN to be photographed has a depth different from the depth position of the reference tomographic plane MaS to be photographed. 3 shows the tomographic plane to be imaged at the position. A point GCS in FIG. 2 is a photographing center when photographing an X-ray tomographic image in the reference photographing target tomographic plane MaS, GCN
Denotes a photographing center when photographing an X-ray tomographic image in the photographing target tomographic plane MaN.

Here, the imaging in which the depth position of the tomographic plane to be imaged is changed basically means that when an X-ray tomographic image is photographed with a point GCS in a certain tomographic plane MaS as the imaging center. In the tomographic plane MaN at another depth position, the tomographic plane Ma to be photographed is changed without changing the position in the horizontal direction (the left-right direction in FIG. 2 and the direction perpendicular to the plane of FIG. 2).
This means that an X-ray tomographic image is taken with the point GCN obtained by shifting the imaging center GCS of S in the depth direction (the vertical direction in FIG. 2) as the imaging center. That is, in FIG. 2, the respective photographing centers GNS and GCN are plotted on the photographing central axis CJ extending in the depth direction.

In FIG. 2, a point XF indicates the position of the focal point of the X-ray tube 2, and a point IF indicates the center position of the image receiving surface 3a of the imaging unit 3. The point XC is a reference position of the focal point XF of the X-ray tube 2, while the point IC is a reference position of the image receiving surface 3a.
The photographing center axis CJ described above corresponds to the reference position XC, IC
Is the axis connecting.

That is, when an X-ray tomographic image of the tomographic planes MaS and MaN to be photographed is taken with the points GCS and GCN as the photographing centers, the photographing centers GCS and GCN are aligned on the photographing central axis CJ. The top plate 1 and the subject M are positioned at the position.

The depth position of the reference tomographic plane MaS to be photographed is determined, for example, by the distance XHS of the focal point XF of the X-ray tube 2 from the reference position XC. That is, the points GCS, G
When the X-ray tomographic image of the imaging target tomographic planes MaS and MaN is taken with the CN as the imaging center, the imaging position is such that the reference imaging target tomographic plane MaS is a distance XHS from the reference position XC of the focal point XF of the X-ray tube 2. And the imaging centers CGS and CGN coincide with each other on the imaging center axis CJ, and imaging is performed with the top plate 1 and the subject M positioned at such imaging positions. Imaging is performed with the depth position of the tomographic plane changed.

Now, one tomographic plane MaS to be photographed by the driving data of the photographing drive systems 11 to 14 held by the control unit 10P2 of the conventional example 2 is set as a reference tomographic plane MaS to be photographed, and the driving data is used as the reference. It is assumed that the imaging of the reference imaging target tomographic plane MaS is performed.

In the photographing data, the focal point XF of the X-ray tube 2
Is set as the center of the movement range of the focal point XF of the X-ray tube 2 during imaging. That is, the imaging of the reference imaging target tomographic plane MaS is performed by setting a position away from the reference position XC by a predetermined distance XWS in the leftward direction in FIG. 2 as the movement start position XSS of the focal point XF of the X-ray tube 2, and from the reference position XC. 2 is defined as a movement end position XES of the focal point XF of the X-ray tube 2 at the same distance XWS in the right direction in FIG. 2, and a movement range (2 × XWS) between the movement start position XSS and the movement end position XES.
The X-ray tube 2 is horizontally moved so that the focal point XF of the X-ray tube 2 horizontally moves from left to right in FIG.

The irradiation angle of X-rays from the X-ray tube 2 during the movement of the X-ray tube 2 within the above-mentioned movement range is irradiated from the X-ray tube 2 at each position during the horizontal movement of the X-ray tube 2. The center axis XJ of the X-ray flux is changed so as to always pass through the imaging center GCS in the reference imaging target tomographic plane MaS. That is, the rotation range from the state in which the angle is inclined θS to the right with respect to the depth direction to the state in which the angle is inclined θS to the left with respect to the depth direction is adjusted to the horizontal movement of the X-ray tube 2. Then, the X-ray tube 2 is rotated clockwise around the horizontal axis with respect to the X-ray tube holding member 22.

As described above, the horizontal movement of the X-ray tube 2 and the change of the X-ray irradiation angle change the reference tomographic plane MaS (middle) in the subject M mounted and supported on the top 1. The incident direction of X-rays with respect to the imaging center GCS is changed in various directions.

On the other hand, the image receiving surface 3a of the imaging unit 3 is
At each position during the horizontal movement of the X-ray tube 2, the center axis XJ of the X-ray flux emitted from the X-ray tube 2 is always opposite to the X-ray tube 2 so as to be incident on the center IF of the image receiving surface 3 a (from the right in FIG. 2). Move horizontally to the left). Thereby, the transmission X-ray image of the reference imaging target tomographic plane MaS is always displayed on the image receiving surface 3a of the imaging unit 3.
To be projected at the same position of
The position of the image receiving surface 3a of the imaging unit 3 can be changed in conjunction with the change in the direction of incidence of X-rays on the aS (the middle imaging center GCS) (operation on the X-ray tube 2 side).

In FIG. 2, the image receiving surface 3 of the image pickup unit 3 is shown.
The movement start position of the horizontal movement a is ISS, the movement end position is IES, the reference position IC of the image receiving surface 3a and the movement start position IS.
The distance between S and the distance between the reference position IC on the image receiving surface 3a and the movement end position IES is indicated by IWS. The distance XIH between the reference position XC of the focal point XF of the X-ray tube 2 and the reference position IC of the image receiving surface 3a is determined when the X-ray tube 2 and the imaging unit 3 are installed. If the distance XHS between the reference position XC of the focal point XF and the reference imaging target tomographic plane MaS is determined, the distance IHS between the reference position IC of the image receiving surface 3a and the reference imaging target tomographic plane MaS is determined.

The driving data of the X-ray tube driving mechanism 11 for horizontally moving the X-ray tube 2 includes the moving speed of the X-ray tube 2 in addition to the moving range of the X-ray tube 2. In addition, the drive data of the irradiation angle drive mechanism 13 that changes and drives the X-ray irradiation angle includes the rotation speed when rotating the X-ray tube 2 in addition to the rotation range of the X-ray tube 2 described above. Further, the image receiving surface 3 of the imaging unit 3
The drive data of the imaging unit driving mechanism 14 that horizontally moves the a includes the moving range of the imaging surface 3a of the imaging unit 3 in addition to the movement range of the imaging surface 3a of the imaging unit 3.

FIGS. 3A to 3C show examples of the moving speed VXS (t) and the rotational speed WXS (t) of the X-ray tube 2 and the moving speed VIS (t) of the image receiving surface 3a of the image pickup unit 3. Shown by solid lines. In this example, the moving speed VXS (t) of the X-ray tube 2 is
The camera is accelerated from the start of photographing t0 to t1 to a predetermined speed VX1.
Is reached, a constant speed VX1 is set from t1 to t2, and t2
, The movement of the X-ray tube 2 is stopped at t3, and t
Shooting is performed at the time S. Note that t0 to t
For example, the time between 1 and the time between t2 and t3 is set to be the same. Rotation speed WXS (t) of X-ray tube 2 and imaging unit 3
The moving speed XIS (t) of the image receiving surface 3a corresponds to the moving speed VXS (t) of the X-ray tube 2 from the start of imaging t0 to t.
Acceleration to 1 and constant speed from t1 to t2, t
The rotation of the X-ray tube 2 and the movement of the image receiving surface 3a of the imaging unit 3 are stopped at t3 at t3, and the imaging ends at time tS.

The X-ray irradiation drive unit 2 is, for example, as shown in FIG.
As shown in (d) and (e), X-rays are constantly emitted from the X-ray tube 2 during t0 to t3 (or t1 to t2 if necessary), or pulsed at regular intervals. Is controlled to irradiate the laser beam.

Next, a case will be considered in which a tomographic image plane MaN at a depth different from the depth position of the reference tomographic image plane MaS is photographed.

Here, the change range of the X-ray irradiation angle (the change range of the X-ray incidence direction with respect to the imaging target tomographic planes MaS and MaN), which is the rotation range of the X-ray tube 2, is used as a reference. Consider the case of making the same (2 × θS) as at the time of shooting.

The rotation range of the X-ray tube 2 is determined by the tomographic plane Ma to be photographed.
S (2 × θS) and the tomographic plane M to be imaged
In order to image aN, as shown in FIG.
The range of (2 × XWN) where XSN is the movement start position and XEN is the movement end position is the movement range of the X-ray tube 2, while the movement start position of the image receiving surface 3a of the imaging unit 3 is ISN and the movement end is It can be geometrically derived that the range of (2 × IWN) where the position is IEN must be set as the movement range of the image receiving surface 3a of the imaging unit 3. Further, the distances XHS, IH in FIG.
The distance XHN between the reference position XC of the focal point XF of the X-ray tube 2 and the depth position of the tomographic plane MaN to be imaged, and the reference position IC of the image receiving surface 3a of the imaging unit 3 by S and SNH (both are known). A distance IHN between the image and the depth position of the imaging target tomographic plane MaN is obtained.

The point at which the focal point XF of the X-ray tube 2 is located at the movement start position XSS at the time of imaging of the reference tomographic plane MaS, the point at which the focal point XF of the X-ray tube 2 is located at the reference position XC, A triangle having three vertices with respect to the imaging center GCS of the imaging target tomographic plane MaS, a point where the focal point XF of the X-ray tube 2 is located at the movement start position XSN at the time of imaging the imaging target tomographic plane MaN, and an X-ray (3) the point where the focus XF of the tube 2 is located at the reference position XC and the imaging center GCN of the imaging target tomographic plane MaN
A triangle having a point as a vertex is a similar shape. In addition, a point where the image receiving surface 3a of the imaging unit 3 is located at the movement start position ISS at the time of imaging the reference imaging target tomographic surface MaS, a point where the image receiving surface 3a of the imaging unit 3 is located at the reference position IC, and A triangle having three vertexes at the photographing center GCSN of the photographing target tomographic surface MaS, and the image receiving surface 3a of the imaging unit 3 are represented by the photographing target tomographic surface MaN.
A point located at the movement start position ISN at the time of imaging, a point at which the image receiving surface 3a of the imaging unit 3 is located at the reference position IC, and a triangle having vertices of the three points of the imaging center GCN of the imaging target tomographic plane MaN. Is similar.

Therefore, the distance XWN that determines the moving range of the X-ray tube 2 when imaging the tomographic plane MaN to be imaged and the distance IWN that determines the moving range of the image receiving surface 3a when imaging the tomographic plane MaN to be imaged are known. XWS, XHS, XHN
And IWS, IHS, and IHN, and can be obtained by the following equations (1) and (2).

XWN = KXN × XWS (1) where KXN = XHN / XHS IWN = KIN × XIS (2) where KIN = IHN / IHS

Also, from a similar relationship, the following equation (3):
(4) and the moving speed VXN (t) of the X-ray tube 2 at the time of imaging of the imaging target tomographic plane MaN as shown by the two-dot chain line in FIGS. The moving speed VXS (t) of the X-ray tube 2 at the time of imaging of the surface MaS is multiplied by the coefficient KXN of the above equation (1), and the image receiving unit 3 receives an image of the imaging target tomographic surface MaN. The moving speed VIN (t) of the surface 3a is set to the moving speed VIS (t) of the image receiving surface 3a of the imaging unit 3 at the time of photographing the reference tomographic surface MaS.
When the driving speed is multiplied by the coefficient KIN of the above equation (2), the same time t during the imaging of the reference imaging target tomographic plane MaS in the imaging of the imaging target tomographic plane MaN is obtained.
Angle of X-rays at the time of imaging (tomography plane MaS, Ma
The angle of the X-ray incidence direction with respect to N) can always be the same. Therefore, the rotation speed WXS of the X-ray tube 2 at the time of imaging the imaging target tomographic plane MaS based on the rotation speed of the X-ray tube 2
(T) It can be driven by the same drive data as in FIG. 3 (c).

VXN (t) = KXN × VXS (t) (3) VIN (t) = KIN × VIS (t) (4)

Further, when the horizontal movement of the X-ray tube 2, the irradiation angle of the X-ray, and the horizontal movement of the image receiving surface 3a of the imaging unit 3 are controlled by the above-described drive data, the imaging of the tomographic plane MaN to be imaged takes tS. It will be completed in time. Therefore, the X-ray irradiation drive can be performed using the same drive data (FIGS. 3D and 3E) as when the reference imaging target tomographic plane MaS is captured.

The coefficients KXN and KIN indicate that the imaging target tomographic plane MaN is farther from the X-ray tube 2 than the reference imaging target tomographic plane MaS, as shown in FIG. 2 (on the image receiving surface 3a of the imaging unit 3). KXN> 1 and 0 <KIN <1 when they approach each other, and conversely, the imaging target tomographic plane MaN comes closer to the X-ray tube 2 than the reference imaging target tomographic plane MaS (away from the image receiving surface 3a of the imaging unit 3). And 0 <KXN <1, KIN> 1.

The image receiving surface 3 at the time of photographing the tomographic plane MaS as the reference and at the time of photographing the tomographic plane MaN to be photographed.
In FIG. 2, the image receiving surface 3a of the reference imaging target tomographic surface MaS at the time of imaging and the image receiving surface 3a of the imaging target tomographic surface MaN at the time of imaging are slightly shifted up and down in FIG. Actually move on the same axis. Also,
Similarly, in the figures and graphs in FIG. 4 and subsequent figures, even in the case of the actual overlapping portion, a slight difference is required for distinguishing between the image of the reference imaging target tomographic plane MaS and the imaging target tomographic plane MaN. In some cases, they are shifted.

<Second Determination Method> First, the movement range of the X-ray tube 2 and the movement range of the image receiving surface 3a of the imaging section 3 are determined by the same determination method as the first determination method (see FIG. 2). . In other words, the moving range of the X-ray tube 2 during imaging of the imaging target tomographic plane MaN is defined as a range of (2 × XWN) from the movement start position XSN to the movement end position XEN, and the movement range of the image receiving surface 3a of the imaging unit 3 is set. , From the movement start position ISN to the movement end position IEN (2 × IWN).

Next, the moving speed VXN (t) of the X-ray tube 2
Is determined so that the speed at the time of moving at a constant speed becomes VX1 which is the same as that at the time of imaging the reference imaging target tomographic plane MaS. That is, as shown by the two-dot chain line in FIG. 4A, the imaging is accelerated from t0 to t1, and when the predetermined speed VX1 is reached, the speed is set to a constant speed VX1 from t1 to t4, and then reduced from t4 to X-ray at t5. The movement of the tube 2 is stopped and tN
Shoot at the time. The time between t4 and t5 is, for example, the same as the time between t2 and t3. The moving speed VXS (t) of the X-ray tube 2 at the time of imaging the reference imaging target tomographic plane MaS is shown by a solid line in FIG.

In order to match the moving speed VXN (t) of the X-ray tube 2, the moving speed VI of the image receiving surface 3a of the image pickup unit 3 is required.
N (t) is as shown by the two-dot chain line in FIG.
The solid line in FIG. 4B shows the moving speed VIS (t) of the image receiving surface 3a of the imaging unit 3 when the reference imaging target tomographic plane MaS is imaged.

As shown in FIGS. 4A and 4B, in this case, the time tN required for photographing the tomographic plane MaN to be photographed.
Is the time t required for imaging the reference imaging target tomographic plane MaS
It is longer than S. Note that, contrary to FIG.
When aN is closer to the X-ray tube 2 than the reference imaging target tomographic plane MaS (away from the image receiving surface 3a of the imaging unit 3), the time tN required for imaging of the imaging target tomographic plane MaN is:
The time is shorter than the time tS required for imaging the reference imaging target tomographic plane MaS.

In any case, when the imaging time fluctuates, the change rate of the X-ray irradiation angle (X
It is necessary to newly determine the rotation speed of the wire tube 2). That is, in order to match the moving speed of the X-ray tube 2,
Of the rotation speed WXN (t) is as shown by a two-dot chain line in FIG. The solid line in FIG. 4C shows the rotation speed WXS (t) of the X-ray tube 2 at the time of imaging the reference imaging target tomographic plane MaS.

Here, the speed WX2 at a constant time shown in FIG.
Is an unknown, but the speed WX2 can be determined, for example, as follows. First, as shown in FIG. 5, when a position at which the focal point XF of the X-ray tube 2 reaches the reference position XC after a predetermined time (for example, one second) is defined as XC1,
Distance from reference position XC to position XC1 (movement amount)
WC1 is the moving speed VXN (t) of the X-ray tube 2 (VX1)
Can be determined by: This position XC1 is plotted on the movement locus of the focal point XF of the X-ray tube 2. At this time,
The change angle of the X-ray irradiation angle per unit time at the constant speed WX2 is θ1 in FIG. In FIG. 5, three points of a point where the focal point XF of the X-ray tube 2 is located at the reference position XC, a point where the focal point XF of the X-ray tube 2 is located at the position XC1, and the photographing center GCN of the photographed tomographic plane MaN are shown. Focusing on the triangle as the vertex, θ1 is the known distance XHN and X
It can be obtained from C1 by a trigonometric function. Therefore, if the change angle θ1 per unit time of the X-ray irradiation angle at the constant speed VX2 is determined, the constant speed WX2 is determined.

If the speed WX2 at the constant time is obtained, the speed is changed from "0" to WX in the time (known) between t0 and t1.
It is sufficient to accelerate to 2 so that t of WXN (t)
The gradient of the speed at the time of acceleration from 0 to t1 is determined.
The gradient of the speed at the time of deceleration from t5 to t5 is also determined.

As described above, the rotation speed WXN (t) of the X-ray tube 2 at the time of photographing the tomographic plane MaN to be photographed can be determined. Note that the rotation range of the X-ray tube 2 is the same (2 × θS) as in the first determination method. Therefore, the irradiation angle driving mechanism 13
Can be determined.

With the change of the imaging time, the X-ray irradiation is performed in the same manner as that shown in FIGS.
5 (or t1 to t4 as necessary).

<Third Determining Method> Here, as shown in FIG. 6, the moving range of the X-ray tube 2 is determined for each tomographic plane Ma to be imaged.
Consider the case where the same is set when shooting S and MaN.

At this time, the moving speed of the X-ray tube 2 can be the same at the time of photographing each of the tomographic planes MaS and MaN to be photographed. That is, the drive data of the X-ray tube drive mechanism 11 can be the same at the time of imaging each of the imaging target tomographic planes MaS and MaN. As a result, each imaging tomographic plane Ma
Since the time required for shooting S and MaN is the same, X
The driving data of the X-ray irradiation drive unit 12 is also used for each imaging target tomographic plane Ma.
The same can be applied when shooting S and MaN.

However, as shown in FIG. 6, in this drive control, the change range of the X-ray irradiation angle (the change range of the X-ray incidence direction with respect to the tomographic planes MaS and MaN to be imaged) of the X-ray tube 2 is determined. The rotation range differs between when the tomographic plane MaS is photographed (2 × θS) and when the tomographic plane MaN is photographed (2 × θN).

The θN is the movement start position XS when the focal point XF of the X-ray tube 2 is at the time of photographing each of the tomographic planes MaS and MaN to be photographed.
S and the focal point XF of the X-ray tube 2 are at the reference position XC
And the imaging center GC of the imaging target tomographic plane MaN
If attention is paid to a triangle having three points N as vertices, it can be obtained from the known distances XWS and XHN by a trigonometric function.

In the photographing of the tomographic planes MaS and MaN to be photographed, the photographing time is the same (tS) and the rotation range of the X-ray tube 2 is changed. It is necessary to newly determine the change speed (the rotation speed of the X-ray tube 2). In order to adjust to the movement of the X-ray tube 2, the rotation speed WXN (t) of the X-ray tube 2 becomes as shown by a two-dot chain line in FIG. The solid line in FIG. 7A shows the rotation speed WXS (t) of the X-ray tube 2 at the time of imaging the reference imaging target tomographic plane MaS.

The speed WX3 at a constant time in FIG. 7A can be obtained by the same determination method as that of WX2 described in the second determination method described above. Therefore, drive data of the irradiation angle drive mechanism 13 can be determined.

Further, as shown in FIG. 6, the moving range of the X-ray tube 2 is the same at the time of photographing each of the tomographic planes MaS and MaN to be photographed (the rotation angle of the X-ray tube 2 has been changed). The moving range of the image receiving surface 3a of the imaging unit 3 is changed. The distance IWN2 that determines the moving range of the image receiving surface 3a of the imaging unit 3 when capturing the to-be-photographed surface MaN can be obtained as follows. That is, in FIG.
a is the movement start position IS at the time of imaging of the imaging target tomographic plane MaN.
N and the image receiving surface 3a of the imaging unit 3 are positioned at the reference position I.
C and the imaging center G of the imaging target tomographic plane MaN
Focusing on a triangle having three vertices with CN, a distance IWN2 is obtained by a trigonometric function from the known values of the distance IHN and the angle θN.

In photographing the tomographic planes MaS and MaN to be photographed, the photographing time is the same (tS), and the moving range of the image receiving surface 3a of the photographing unit 3 is changed. It is also necessary to newly determine the moving speed of the image receiving surface 3a. In order to match the movement of the X-ray tube 2, the moving speed VIN (t) of the image receiving surface 3 a of the imaging unit 3 is set as shown in FIG.
As indicated by the two-dot chain line. Reference imaging target tomographic plane M
The moving speed VIS of the image receiving surface 3a of the imaging unit 3 during the photographing of aS
(T) is shown by a solid line in FIG.

Here, the speed VI2 at a constant time shown in FIG.
Is an unknown number, but this speed VI2 can be determined, for example, as follows. That is, the third method is used in the same manner as in the case where the change angle per unit time of the X-ray irradiation angle at a constant speed among the rotation speeds of the X-ray tube 2 described in the above-described second determination method is obtained. Of the X-ray irradiation angle per unit time at the constant speed WX3 during the rotation speed of the X-ray tube 2 in the method of determining
Is drawn including the image receiving surface 3a of the imaging unit 3 as shown in FIG. Note that the position XC2 in FIG.
Is determined, the focal point XF of the X-ray tube 2 is set at the reference position X.
The distance WC2 indicates a position reached after a predetermined time (for example, one second) from C, and the distance WC2 indicates a movement amount from the reference position XC to the position XC2. As is clear from FIG.
Of the image receiving surface 3 at a constant speed V in the moving speed VIN (t)
Movement amount WC of image receiving surface 3a per unit time at I2
3 can be obtained by a trigonometric function from the known distance IHN and the angle θ2, and the moving speed VIN of the image receiving surface 3 of the imaging unit 3 is obtained.
The speed VI2 at a certain time during (t) is obtained. Therefore,
The moving speed VIN (t) of the image receiving surface 3 of the imaging unit 3 is determined,
The driving data of the imaging unit driving mechanism 14 is determined.

In addition, the drive data of the photographing drive systems 11 to 14 is determined so that the moving range and the moving speed of the image receiving surface 3a of the image pickup unit 3 are the same at the time of photographing each of the tomographic planes MaS and MaN to be photographed. Can also. In this case, the moving range and moving speed of the X-ray tube 2 at the time of photographing the tomographic plane MaN to be photographed,
It is necessary to newly determine the rotation range and rotation speed,
These drive data can also be obtained geometrically as described above.

In the above-described first to third determination methods, determination of drive data of the imaging drive systems 11 to 14 at the time of imaging of the imaging tomographic plane MaN has been described as an example, but imaging at other depth positions has been described. Imaging drive systems 11 to 14 at the time of imaging the target tomographic plane Ma
Can be determined in a similar manner.

In the first to third determining methods, the photographing drive systems 11 to 14 at the time of photographing the reference photographing tomographic plane MaS with reference to one predetermined photographing tomographic plane MaS. Using the driving data, the imaging drive system 11 at the time of imaging the imaging target tomographic plane MaN at other depth positions
Although the drive data of No. to No. 14 are determined, the present invention is not limited to this, and the drive data of the imaging drive systems 11 to 14 at the time of imaging the imaging target tomographic plane Ma at an arbitrary depth position can also be individually determined. .

That is, as is apparent from the above description, when imaging the tomographic plane Ma to be imaged at a certain depth position, the moving range of the X-ray tube 2, the rotation range of the X-ray tube 2, the imaging unit 3 If any one of the moving ranges of the image receiving surface 3a is determined, the rest is also determined. In addition, if any one of the moving speed of the X-ray tube 2, the rotating speed of the X-ray tube 2, and the moving speed of the image receiving surface 3a of the imaging unit 3 is determined, the rest is also determined. Therefore, drive data of the X-ray tube driving mechanism 11, the irradiation angle driving mechanism 13, and the imaging unit driving mechanism 14 can be determined. When the driving data of the X-ray tube driving mechanism 11, the irradiation angle driving mechanism 13, and the imaging unit driving mechanism 14 are determined, the imaging time is determined. Therefore, it is also determined when to perform X-ray irradiation. The drive data of the unit 12 is also determined. Such a method of determining the drive data of the photographing drive systems 11 to 14 is the same even if the depth position of the photographing target tomographic plane Ma changes, so that the photographing is performed for each photographing target tomographic plane Ma at an arbitrary depth position. The drive data of the photographing drive systems 11 to 14 at the time can also be determined individually.

By the way, when X-rays are always radiated during imaging or when X-rays are always radiated in the same cycle in a pulse form,
If the imaging time varies for each imaging of the imaging target tomographic plane Ma, the amount of X-ray exposure to the subject M varies for each imaging of the imaging target tomographic plane Ma, which is not preferable. Therefore, it is preferable to determine the drive data of the imaging drive systems 11 to 14 so that the imaging time for each imaging of the imaging target tomographic plane Ma is always the same, but the imaging time of each imaging of the imaging tomographic plane Ma varies. Even when the drive data of the imaging drive systems 11 to 14 is determined so as to perform, for example, X-rays are radiated in a pulse shape and the pulse cycle is set to the imaging target tomographic plane Ma.
May be changed according to the shooting time for each shooting.

The tomographic plane Ma to be photographed at the same depth position
When changing the shooting center (shooting range) within
The subject M may be moved in the horizontal direction on the top 1, or the top 1 on which the subject M is placed and supported may be moved in the horizontal direction, but may be configured as follows.

The maximum movable range of the horizontal movement of each of the X-ray tube 2 and the image receiving surface 3a of the image pickup unit 3 is made sufficiently long, and the reference position XC of the focal point XF of the X-ray tube 2 and the image receiving surface of the image pickup unit 3 are set. When the reference position IC (imaging center axis CJ) of 3a is moved in the longitudinal direction of the top board 1 (the body axis direction of the subject M), the imaging center (imaging range) in the imaging target tomographic plane Ma at the same depth position )
Can be changed in the longitudinal direction of the top 1 (the body axis direction of the subject M). The X-ray tube 2 including the rail 21 and the like
A drive mechanism is provided for moving the entire unit for performing the horizontal movement in the lateral direction of the top board 1 (horizontal direction orthogonal to the body axis direction of the subject M), and the image receiving surface 3a of the imaging unit 3 is provided.
A drive mechanism for moving the entire unit for performing the horizontal movement in the same horizontal direction is provided.
Is horizontally moved in the lateral direction of the table 1, the photographing center (photographing range) in the photographing tomographic plane Ma at the same depth position is moved to the top 1
Lateral direction (horizontal direction perpendicular to the body axis direction of subject M)
Can be changed. With such a configuration, an X-ray tomographic image whose imaging center (imaging range) has been changed can be imaged within the imaging target tomographic plane Ma at the same depth position without moving the top 1 or the subject M. Can also.

In the above-described embodiment, the case where the X-ray tube 2 and the image receiving surface 3a of the imaging section 3 are moved only in the horizontal one axis direction to perform imaging of the imaging tomographic plane Ma has been described.
The X-ray tube 2 and the image receiving surface 3a of the imaging unit 3 are moved in an arc shape, or circular or elliptical or radial orbits in a horizontal plane.
The present invention is similarly applicable to a configuration in which the imaging target tomographic plane Ma is imaged in a well-known movement mode such as moving along a spiral orbit, a hypocyclo (registered trademark) id orbit, or the like. can do. Note that, for example, the X-ray tube 2 and the image receiving surface 3a of the
In the configuration in which the imaging target tomographic plane Ma is imaged by moving along the two circular orbits, the irradiation angle of the X-ray is usually fixed. The driving mechanism for moving along one circular orbit corresponds to the X-ray incident direction changing driving means in the present invention.

The present invention is not limited to the case where an X-ray tomographic image of the tomographic plane Ma to be imaged is taken in a state where the subject M is laid down, but also in a state where the subject M is supported in an oblique state or supported upright. The present invention can be similarly applied to a case where the X-ray tube 2 and the image receiving surface 3a of the imaging unit 3 are arranged with the subject M interposed therebetween to capture an X-ray tomographic image of the imaging target tomographic surface Ma. Can be.

[0089]

As is apparent from the above description, according to the present invention, X-ray tomography for each of the tomographic planes to be imaged at various depths only by changing the driving data for driving the imaging driving means. Since the configuration is such that an image is taken, it is possible to take an image while changing the depth position of the tomographic plane to be taken, without burdening the operator or burden on the operator. Further, the depth of the tomographic plane to be imaged can be increased without raising and lowering the supporting means (object) such as a top plate so as to move the object near and far from the X-ray irradiating means (near and far from the image receiving surface of the imaging means). Since the imaging with the changed position can be performed, the body movement of the subject during the imaging can be reduced, and each X-ray tomographic image can be accurately obtained with respect to the imaging target tomographic plane at various depth positions. Psychological anxiety can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an X-ray tomography apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram in a case where drive data of a photographing drive system when photographing while changing the depth direction of a photographing target tomographic plane is determined by first and second determination methods.

FIG. 3 shows a moving speed of an X-ray tube and a moving speed of an image receiving surface of an imaging unit when drive data of an imaging drive system is determined by a first determination method when imaging is performed by changing the depth direction of an imaging target tomographic plane. It is a figure which shows a moving speed, the rotation speed of an X-ray tube, etc.

FIG. 4 is a diagram illustrating a moving speed of an X-ray tube and a moving speed of an image receiving surface of an imaging unit when drive data of an imaging drive system is determined by a second determination method when imaging is performed by changing the depth direction of an imaging target tomographic plane. It is a figure which shows a moving speed and the rotation speed of an X-ray tube.

FIG. 5 is a view for explaining a method of determining a rotation speed of an X-ray tube when drive data of an imaging drive system is determined by a second determination method when imaging is performed by changing the depth direction of an imaging target tomographic plane. FIG.

FIG. 6 is an explanatory diagram of a case where drive data of a photographing drive system when photographing while changing the depth direction of the tomographic plane to be photographed is determined by a third determining method.

FIG. 7 shows the rotation speed of the X-ray tube and the rotation speed of the X-ray tube when the drive data of the imaging drive system is determined by the third determination method when imaging is performed by changing the depth direction of the imaging target tomographic plane. It is a figure showing a moving speed.

FIG. 8 illustrates a method of determining a moving speed of an image receiving surface of an imaging unit when driving data of an imaging drive system is determined by a third determination method when imaging is performed by changing the depth direction of an imaging target tomographic plane. FIG.

FIG. 9 is a diagram for explaining the principle of imaging of an X-ray tomographic image of an imaging target tomographic plane.

FIG. 10 is a schematic configuration diagram of a drive control system of an X-ray tomography apparatus according to a first conventional example.

FIG. 11 is a schematic configuration diagram of a drive control system of an X-ray tomography apparatus according to a second conventional example.

[Explanation of symbols]

 1: Top plate 2: X-ray tube 3: Imaging unit 3a: Image receiving surface of the imaging unit 10: Control unit 11: X-ray tube driving mechanism 12: X-ray irradiation driving unit 13: Irradiation angle driving mechanism 14: Imaging unit driving mechanism M: subject Ma, MaS, MaN: tomographic plane to be imaged

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hirotaka Isono 1 Shiwazu Works Sanjo Plant, Nakagyo-ku, Kyoto, Japan F-term (reference) 4C093 AA11 CA16 EA02 EB02 EC03 EC23 EC26 EC33 FA15 FA34 FA36 FA44 FA53

Claims (1)

[Claims] 1. An X-ray tomography apparatus for obtaining an X-ray tomographic image of a tomographic plane to be imaged in a subject, comprising: (a) supporting means for supporting the subject; and (b) supporting means for supporting the subject. X-ray irradiating means for irradiating the irradiated subject with X-rays; and (c) X-rays arranged on the opposite side of the X-ray irradiating means with respect to the subject supported by the supporting means, and transmitted through the subject. Imaging means for receiving and transmitting a transmission image on an image receiving surface; and (d) changing and driving the incident direction of X-rays from the X-ray irradiating means on a tomographic plane to be imaged in the subject supported by the supporting means. X-ray incident direction changing driving means, X-ray irradiation driving means for driving X-ray irradiation from the X-ray irradiation means, and image receiving position changing driving means for changing and driving the position of the image receiving surface of the imaging means. Imaging drive means; and (e) an imaging object in the subject supported by the support means While sequentially changing the incident direction of the X-rays from the X-ray irradiating means on the tomographic plane, X-rays are radiated toward the subject, and the transmitted X-ray image of the tomographic plane to be imaged is always displayed on the image receiving surface of the imaging means. Control for driving and controlling the photographing drive means in accordance with drive data so as to change the position of the image receiving surface of the image pickup means in conjunction with the change in the direction of incidence of X-rays on the tomographic plane to be photographed so as to be projected at the same position Means for changing the depth position of the tomographic plane to be imaged, and the control means, in accordance with the depth position of the tomographic plane to be imaged, the tomographic plane at that depth position The imaging driving means according to the positional relationship between the surface and the X-ray irradiating means and the depth position of the imaging target tomographic plane determined by the positional relationship between the imaging target tomographic plane at the depth position and the image receiving surface of the imaging means No drive X-ray tomographic apparatus, characterized by driving and controlling the imaging drive unit according to the data.