JP3346441B2 - X-ray CT system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray CT apparatus, and more particularly, to a CR (Computed Radiograph) for making a slice plan for capturing a tomographic image by the X-ray CT apparatus.
y, also referred to as “scout view”).

[0002]

2. Description of the Related Art An X-ray CT apparatus of this type includes a gantry, a bed, and the like. The gantry is provided with a cylindrical opening for inserting a subject. An X-ray tube and an X-ray detector are attached to this opening so as to face each other. The X-ray tube and the X-ray detector are configured to rotate in the circumferential direction of the opening while maintaining the facing state. On the other hand, on the bed, a top plate on which the subject is placed is mounted on the top of a vertically movable base fixed to the floor near the gantry so that the subject can be moved horizontally, and the subject placed on the top plate can be moved. Insert and remove into the gantry opening.

[0003] To capture a tomographic image by such an X-ray CT apparatus, a subject is placed on a top plate, the height of the subject is adjusted, the top plate is moved horizontally, and the subject is moved to a gantry. The imaging position of the subject to be inserted into the opening of
The X-ray tube and the X-ray detector are rotated while emitting X-rays from the X-ray tube while being positioned at the center of imaging by the X-ray tube and the X-ray detector. This is performed by collecting line transmission data and reconstructing a tomographic image based on the collected data.

[0004] The imaging position at which the above-mentioned tomographic image is picked up is determined by an operator (doctor) by making a slice plan based on the CR image obtained before the tomographic image is picked up.

[0005] This CR image has been conventionally taken as follows. That is, the X-ray tube is arranged at a predetermined position (for example, above the subject on the top plate), and one end of a predetermined imaging region (for example, the head, the abdomen, or the whole body) is connected to the X-ray tube. The top plate is moved so as to be positioned at the center of imaging by the X-ray detector, and while irradiating X-rays from an X-ray tube arranged at a predetermined position, the position in the imaging region located at the imaging center is imaged. The top plate is moved so that the area is displaced from one end to the other end, and the CR of the imaging area is moved.
Capture an image.

[0006] The obtained CR image is displayed on, for example, a monitor. The surgeon observes the CR image displayed on the monitor,
A slice plan for specifying a tomographic image capturing position (a position of an affected part to be diagnosed in detail by capturing a tomographic image) is prepared.

[0007] The imaging region for capturing the CR image is set by a technician (an operator who operates a CR image capturing operation or the like). In addition, the arrangement position of the X-ray tube is also set by a technician, and this arrangement position is generally set to a position where it is easy to make a slice plan for the imaging region. For example, when the head is used as an imaging region, a slice plan of the head is generally made based on a CR image obtained by arranging an X-ray tube beside the subject and irradiating X-rays therefrom. And
When the region from the chest to the abdomen is set as the imaging region, generally, C is obtained by arranging the X-ray tube above the subject.
Based on the R image, a slice plan of the imaging region is made. Therefore, the technician sets the arrangement position of the X-ray tube according to the set imaging region.

[0008]

However, the prior art having such a structure has the following problems. For example, a subject (patient) having a disease at multiple locations
Therefore, in order to examine each disease in detail, it is necessary to capture a CR image of a region including each disease and determine an imaging position of a tomographic image based on each CR image.

In such a case, if the position of the X-ray tube at the time of capturing the CR image in each region is the same, for example, the whole body may be set as the imaging region and the CR image may be captured. For a subject having an affected part in the head and in the region from the chest to the abdomen, as described above, the C
Since the position of the X-ray tube at the time of capturing the R image is different, in the method of capturing a CR image in which the whole body is set as an imaging region,
A desired CR image cannot be obtained.

Therefore, in such a case, conventionally, a CR image of the head is first taken, a slice plan of the head is made, and then a C-region of the region from the chest to the abdomen is obtained.
A slice plan for each region is made by taking an R image and making a slice plan for that region.

[0011] However, in such a conventional procedure, the CR image must be captured twice.
There has been a problem that the examination time becomes longer, causing pain to the subject, and the technician's CR image imaging work becomes complicated.

The present invention has been made in view of such circumstances, and enables a desired CR image to be captured in a plurality of regions of the same subject in a short time, and a technician at that time. It is an object of the present invention to provide an X-ray CT apparatus capable of reducing the number of operations.

[0013]

The present invention has the following configuration to achieve the above object. That is, according to the present invention, (a) a cylindrical opening for inserting a subject is provided, and X is attached to face the opening.
A gantry for rotating the X-ray tube and the X-ray detector in the circumferential direction of the opening while maintaining a facing state; and (b) placing the subject, and placing the subject in the opening of the gantry. (C) a plurality of imaging areas of the same subject, and an arrangement angle of the X-ray tube with respect to each of the imaging areas (the X-ray tube with respect to the subject on the top plate) (D) moving the top plate so that one end of the set first imaging region is located at the center of imaging by the X-ray tube and the X-ray detector. Along with rotating the X-ray tube at the set angle of the X-ray tube in the set imaging area,
While irradiating X-rays from the X-ray tube arranged at the arrangement angle, the position in the first imaging region located at the imaging center is displaced from one end of the imaging region to the other end. The board is moved to take a CR (Scout View) image of the first imaging area, and then the top board is moved so that one end of the next set imaging area is located at the imaging center. At the same time, the X-ray tube is rotated so as to be arranged at the set angle of the X-ray tube in the set imaging region, and the next imaging is performed in the same operation as the CR image of the first imaging region. Control means for taking a CR image of the region, and thereafter similarly controlling to take a CR image of each of the set imaging regions while irradiating X-rays from the arrangement angle of the X-ray tube in each of the imaging regions. (E) obtained under the control of the control means. Is obtained and a display means for displaying the CR image of the imaging region.

[0014]

The operation of the present invention is as follows. The engineer
The setting means sets a plurality of imaging regions of the subject and an arrangement angle of the X-ray tube with respect to each imaging region (an arrangement position of the X-ray tube with respect to the subject on the top plate).

The control means controls the CR of each set imaging region.
Images (each CR image is obtained by arranging an X-ray tube at an X-ray tube arrangement angle set for each imaging region and irradiating X-rays therefrom) are continuously taken.

That is, the control means positions one end (the end on the top side of the imaging region) of the first imaging region (eg, head) set at the center of the imaging by the X-ray tube and the X-ray detector. The top plate on which the subject is mounted is moved as described above, and the set angle of the X-ray tube in the imaging region (head) (in a state where the X-ray tube is located on the side of the subject) is set. Rotate to position X-ray tube. At this time, since the X-ray detector is rotated while maintaining the state of facing the X-ray tube, it is arranged on the opposite side of the X-ray tube with respect to the subject. Then, while irradiating X-rays from the X-ray tube arranged at the arrangement angle, the first imaging region (head) located at the imaging center
Is moved from one end (top end) of the imaging region (head) to the other end (neck end) of the imaging region (head), and the imaging region (head) is displaced. X-ray data from one direction is detected by an X-ray detector to obtain a CR image of the first set imaging region (head).

Next, from the state where the other end side (end on the neck side) of the first imaging region (head) is located at the imaging center,
The top board is moved so that one end side (end on the head side) of the set next imaging region (for example, a region from the chest to the abdomen) is positioned at the imaging center, and the set imaging region ( The first imaging region (head) is rotated by rotating the X-ray tube at an arrangement angle of the X-ray tube in a region from the chest to the abdomen (in a state where the X-ray tube is positioned above the subject).
With the same operation as that for capturing the CR image, a CR image of the imaging region (the region from the chest to the abdomen) is captured. Thereafter, similarly, the set CR image of each imaging region is imaged while irradiating X-rays from the arrangement angle of the X-ray tube in each imaging region.

Each of the captured CR images is displayed on display means. The surgeon makes a slice plan for each imaging region based on each CR image displayed on the display means.

[0019]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an X-ray CT according to an embodiment of the present invention.
FIG. 2 is a front view showing a schematic configuration of the entire apparatus, FIG. 2 is a diagram showing a positional relationship between a subject on a top plate and a gantry (X-ray tube, X-ray detector), and FIG. FIG. 4 is a front view showing a state, and FIG. 4 is a diagram for explaining a configuration of a light projector for performing positioning between a specific part of a subject and an imaging center.

The apparatus of this embodiment includes a bed 1, a gantry 2, a setting panel 3, an image processing unit 4, a control unit 5, monitors 6, 7,
And the like.

The bed 1 is fixed on the floor, and is mounted on a base 11 which is moved up and down by an actuator (not shown).
A top plate 12 on which the subject M is placed is provided to be horizontally movable. The top plate 12 is configured to be horizontally moved in the left-right direction in FIG. 1 by the rotation of the motor 13 in the forward and reverse directions, so that the subject M on the top plate 12 can be inserted into and removed from the opening 23 of the gantry 2. . The rotation of the motor 13, ie, the top 1
The horizontal movement 2 is controlled by the control unit 5 as described later, but can also be performed (manually) by operating a button 14 provided on the base 11 by an engineer. Note that the base 11 can also be moved up and down with the button 14. Further, for example, data PD for recognizing the amount of movement of the top 12 obtained by detecting the number of rotations of the motor 13 with a rotary encoder (not shown) or the like.
Is provided to the control unit 5.

The gantry 2 is provided on an upper part of a gantry base 21 fixed to the floor so as to be tiltable as shown in FIG. The inclination of the gantry 2 is performed by the forward and reverse rotation of the motor 22, and the rotation of the motor 22 is controlled by the control unit 5.

The gantry 2 is provided with a cylindrical opening 23 for inserting a subject M, and a ring-shaped rotating frame 24 is rotatably provided inside the gantry 2. The X-ray tube 25 and the X-ray detector 26
Are mounted in a state where they face each other. Rotating frame 24
Is rotated in the forward and reverse directions around the center axis CJ of the opening 23 by the motor 27, whereby the X-ray tube 25 and the X-ray detector 26 are
Is configured to be rotated in the circumferential direction. Motor 2
Rotation in the forward and reverse directions of 7 is performed under the control of the control unit 5 as described later. Further, information relating to the arrangement angle of the X-ray tube 25 (the arrangement position of the X-ray tube 25 with respect to the subject M on the top plate 12) is recognized by an angle sensor (not shown) for detecting the rotation angle of the rotating frame 24. Is detected and supplied to the control unit 5.

The control of the start and stop of X-ray irradiation from the X-ray tube 25 is performed by the control unit 5 via a high-voltage generator (not shown). On the X-ray XR irradiation side of the X-ray tube 25, a collimator 28 for adjusting the spread angle α of the X-ray XR irradiated from the X-ray tube 25 and the irradiation X-ray thickness t is provided. I have. Further, a data acquisition unit (DAS) (not shown) is connected to the X-ray detector 26, and the transmitted X-ray data (acquisition data) detected by the X-ray detector 26 is acquired by the DAS, and the image processing unit 4 It is configured to give to.

As shown in FIG. 4A (a sectional view taken along the line AA in FIG. 2), X
A light projector 29 for irradiating light ML in a direction coinciding with the imaging center SC of the ray tube 25 and the X-ray detector 26 is provided. Then, as shown in FIG. 4B, while inserting the subject M into the opening 23 of the gantry 2, the technician observes the light ML emitted from the projector 29 to the subject M, and Is positioned at the imaging center SC.

The setting panel 3 includes a plurality of imaging regions of the same subject M, an arrangement angle of the X-ray tube 25 with respect to each imaging region (an arrangement position of the X-ray tube 25 with respect to the subject M on the top 12), In addition to setting the imaging position of the tomographic image determined by the slice plan based on the obtained CR image,
This is for setting an instruction to start capturing an image or a tomographic image. This setting panel 3 corresponds to the setting means in the present invention.

The image processing unit 4 is controlled by the control unit 5,
Reconstruction of a CR image or tomographic image is performed based on the collected data supplied from the DAS.

The control unit 5 controls each unit based on data set from the setting panel 3 as described later,
Control is performed such as capturing an image or a tomographic image and displaying the images reconstructed by the image processing unit 4 on the monitors 6 and 7. The control unit 5 corresponds to a control unit in the present invention, and is configured by, for example, a microcomputer.

The obtained CR image is displayed on the monitor 6 as described later, while the obtained tomographic image is displayed on the monitor 7 as described later.

Next, an operation of capturing a CR image by the apparatus having the above-described configuration will be described with reference to a flowchart shown in FIG.

First, the process waits for a technician's instruction to start capturing a CR image from the operation panel 3 (step S).
Before 1), the technician performs the following initial work before the CR image imaging start instruction is issued.

First, a plurality of imaging regions of the subject M are
An arrangement angle of the X-ray tube 25 with respect to each imaging region is set from the setting panel 3. As shown in FIG. 6, for example, it is assumed that two locations are set as the imaging region, that is, the head (imaging region SR1) and the region from the chest to the abdomen (imaging region SR2). The setting of the imaging region includes, for example, the length L1 between the top end P1 and the neck end P2 of the imaging region SR1, and the length of the neck end P2 of the imaging region SR1 and the length of the imaging region SR2. This is performed by setting a length L2 between the head-side end P3 and a length L3 between the head-side end P3 and the foot-side end P4 of the imaging region SR2.

The X-ray tube 25 for the imaging region SR1
Is set to “90 °” (as shown by the two-dot chain line in FIG. 2, the side of the subject M on the top 12), and the arrangement angle of the X-ray tube 25 with respect to the imaging region SR2 is “0”. ° ”(Fig. 2
(Above the subject M on the top 12) as shown by the solid line in FIG. In this setting method, for example, the state in which the X-ray tube 25 is arranged above the subject M on the top 12 shown by the solid line in FIG. 2 is set to “0 °”, and the clockwise direction in FIG. It is set at an absolute angle of “0 °” to “359 °”.

The technician places the subject M on the top 12 with the head thereof facing the gantry 1 and pushes the button 1.
4, the base 11 is moved up and down to move the body axis J of the subject M (see FIG. 1) and the center axis CJ of the opening 23 of the gantry 2.
(See FIG. 1), the height of the subject M is adjusted so as to match with that of FIG.
By operating the button 14, the table 12 is horizontally moved leftward in FIG. 1, and the subject M is inserted into the opening 23 of the gantry 2. Then, it is observed whether or not light from the projector 29 irradiates one end (the end P1 of the imaging region SR1 in the above setting) of the first imaging region (the above setting is the imaging region SR1). After irradiating the end P1 of the imaging region SR1,
The horizontal movement of the table 12 is stopped by operating the button 14.
At this time, the end P1 of the imaging region SR1 is located at the imaging center SC of the X-ray tube 25 and the X-ray detector 26.

When the above operations are completed, the technician gives an instruction from the operation panel 3 to start capturing a CR image. Thereby, the control unit 5 starts the operation after step S2 in FIG. The data set by the technician from the setting panel 3 is given to the control unit 5.

Steps S3 to S5 are operations for picking up a CR image of the i-th image pickup area. In this embodiment, the set image pickup areas are successively picked up sequentially from the gantry 2 (step S3). S2, S6, S7). In the above setting, i = 1 (imaging area SR1), i = 2
The operations of steps S3 to S5 are repeated for (imaging region SR2).

In step S3, the control unit 5
Is controlled so that one end of the i-th imaging area is in the X-ray tube 2.
The top board 12 is moved so as to be positioned at the center SC of the imaging by the X-ray detector 5 and the X-ray detector 26. In the case of i = 1, that is, in the case of the imaging region SR1 which is the first imaging region, the end P1 of the imaging region SR1 is already located at the imaging center SC as a result of the initial operation by the technician described above. Then, the top plate 12 is not moved. Also, i = 2,
That is, in the case of the imaging region SR2 which is the next imaging region,
As will be described later, when the imaging of the CR image in the imaging region SR1 with i = 1 ends, the end P2 of the imaging region SR1 is located at the imaging center SC.
The top plate 12 is moved to the left in FIG. 1 by L2 so that the end P3 of R2 is located at the imaging center SC.

The movement of the top 12 is controlled based on data PD provided to the control unit 5 for recognizing the movement of the top 12. For example, when the rotation speed of the motor 13 is given as the data PD, the moving amount of the top plate 12 per rotation of the motor 13 is known, and therefore, (the rotation speed of the motor 13) × (1 of the motor 13) The amount of movement of the top 12 can be known from the amount of movement of the top 12 per rotation).

At step S4, the control unit 5
To rotate the rotary frame 24 so that the X-ray tube 25 is arranged at the arrangement angle of the X-ray tube 25 in the i-th imaging area. In the above setting, the CR of the imaging region SR1 with i = 1
In the case of imaging an image, the arrangement angle of the X-ray tube 25 is arranged at “90 °”, and in the case of imaging a CR image in the imaging region SR2 of i = 2, the arrangement angle of the X-ray tube 25 is set to “0 °”. Be placed.

The rotation control of the rotating frame 24, that is,
The controller 5 recognizes the arrangement angle (arrangement position) of the X-ray tube 25.
Is performed based on the data KD for recognizing the information on the arrangement angle of the X-ray tube 25 (the arrangement position of the X-ray tube 25 with respect to the subject M on the top 12) given to the user. For example, a signal KD1 for detecting that the X-ray tube 25 is positioned above the subject M on the top 12 shown by a solid line in FIG. When kd1 is obtained, it is recognized as “0 °”, and by counting the number of pulses of kd2, the arrangement angle (arrangement position) of the X-ray tube is recognized. Can be. Note that the state in which the X-ray tube 25 is disposed above the subject M on the top 12 shown by the solid line in FIG.
° ”and“ 0 ° ”to“ 3 ”with the clockwise direction in FIG.
In order to recognize the arrangement angle of the X-ray tube 25 at an absolute angle of “59 °”, the rotation direction of the rotating frame 24 (forward / reverse direction of rotation of the motor 27) is added to the recognition based on kd1 and kd2. Good. That is, for example, from a state in which a signal of kd1 is given (a state in which the X-ray tube 25 is positioned at an absolute angle of “0 °”), the rotating frame 24 is rotated rightward in FIG.
When the count value of the kd2 pulse signal reaches 90, it can be known that the X-ray tube 25 has been positioned at "90 °" in absolute angle.

The X-ray detector 26 is disposed opposite the X-ray tube 25 across the subject M by the rotation of the rotating frame 24.

It should be noted that either of steps S3 and S4 may be performed first or may be operated simultaneously.

In step S5, the control unit 5 controls the X-ray tube 25
Of the i-th imaging region located at the imaging center SC while irradiating X-rays from the X-ray tube 25 arranged in step S4 while controlling the driving of the motor 13 while starting the X-ray irradiation. The top plate 12 is moved so that the position is displaced from one end to the other end of the imaging region, and a CR image of the i-th imaging region is captured. In the case of the imaging region SR1 where i = 1, the top plate 12 is moved from a state where the end P1 of the imaging region SR1 is located at the imaging center SC to a state where the end P2 of the imaging region SR1 is located at the imaging center SC. L1 only, FIG.
To the left, and in the case of the imaging region SR2 where i = 2,
From the state where the end P3 of the imaging region SR2 is located at the imaging center SC, the end P4 of the imaging region SR2 is shifted to the imaging center SC.
The top plate 12 is moved leftward in FIG. The control of the amount of movement of the top plate 12 is performed in the same manner as in step S3. When the top 12 is moved by a predetermined amount (L1 when i = 1, L3 when i = 2), the X-ray irradiation is stopped. Further, the CR image of the i-th imaging area is reconstructed by the image processing unit 4.

Thus, the CR images of the imaging regions at a plurality of locations of the same subject M having different arrangement angles (positions) of the X-ray tube 25 are not divided into two times as in the conventional example. , Can be performed by a series of operations.

In the above example, the case of capturing CR images of two imaging regions has been described. However, the same can be applied to CR imaging of three or more imaging regions. For example, as shown in FIG. 7, three imaging regions SR1, SR
2. When the CR image of SR3 is captured, it is performed as follows. Note that SR1 and SR2 are the same as the imaging region (including the arrangement angle of the X-ray tube 25) in FIG.

First, in setting the imaging region SR3, the length L4 of the foot end P4 of the imaging region SR2 and the head end P5 of the imaging region SR3, and the length of the head side of the imaging region SR3. The length L5 between the end P5 and the end P6 on the foot side of the imaging region SR3 is set. Further, since the slice planning based on the CR image of the imaging region SR3 is performed by observing the curved state of the spine, the arrangement angle of the X-ray tube 25 is “90 °” as in the imaging region SR1 (see FIG. 2). As shown by the two-dot chain line, it is set to the side of the subject M on the top 12).

In the operation shown in FIG. 5, after the CR images of the imaging regions SR1 and SR2 are captured by the same operation as the above-described example, the steps related to the operation of capturing the CR image of the imaging region SR3 where i = 3 are performed. In S3, when the imaging operation of the CR image of the imaging region SR of i = 2 ends, the end P of the imaging region SR2
4 is located at the imaging center SC, the motor 13 is rotated in the reverse direction to move the top plate 12 by L4 in order to position the end P5 of the imaging region SR3 at i = 3 at the imaging center SC.
In step S4, the rotating frame 24 is rotated so that the arrangement angle of the X-ray tube 25 becomes "90 °" in absolute angle. While irradiating X-rays from the X-ray tube 25 arranged on the side of the subject M, the motor 13 is rotated forward to move the top plate 12 to L5.
Only in the left direction in FIG.
Capture an image.

Returning to FIG. 5, in step S8, the obtained CR images are displayed on the monitor 6. This display method
For example, as shown in FIG. 8A, a CR image reduced to 1/4 may be divided into two and displayed on the monitor 6, or as shown in FIG. 8B. One CR image may be displayed on the monitor 6, and the display of the CR image to be displayed on the monitor 6 may be switched according to an instruction from the setting panel 3 by the operator.

For example, if the number of obtained CR images is three (or four) as set in FIG. 7, for example, FIG.
As shown in (1), a reduced CR image of each CR image may be displayed on the monitor 2 by dividing it into four. Furthermore, if the number of obtained CR images is five or more, each CR image reduced to 1/4 is divided into four and displayed on the monitor 2, and the display of the four divided screens is switched. Alternatively, an image obtained by reducing each CR image to 1/16 may be displayed on the monitor 2 by dividing it into 16 parts.

Next, the operator operates the CR displayed on the monitor 6.
The image is observed, a slice plan is made, the position where the tomographic image is captured is determined and set from the setting panel 3. At this time,
As shown in FIGS. 8 (a) and 8 (c), if the CR image is divided and displayed, the imaging position of the tomographic image can be determined while simultaneously observing the obtained CR image. It is convenient to make a slice plan while grasping the situation.

Next, the engineer sets the start of tomographic image capturing on the setting panel 3.
Is controlled by the control unit 5 to sequentially capture tomographic images at the imaging position determined by the operator. The outline of this operation is as follows.
C, the gantry 2 is tilted as necessary, and the rotating frame 24 is rotated while irradiating X-rays from the X-ray tube 25, so that the X-axis from the circumferential direction of the imaging position is obtained. The image processing unit 4 collects line transmission data, reconstructs a tomographic image of the imaging position based on the collected data,
Next, the top board 12 is moved so that the second imaging position is located at the imaging center SC, and a tomographic image at the imaging position is obtained in the same manner as described above. Thereafter, the same operation is repeated, and tomographic images at the imaging position determined by the operator are continuously and sequentially captured.

FIG. 9A shows an example of a tomographic image capturing position determined by a slice plan. FIG.
(A) shows the monitor 6 after the imaging position of the tomographic image is set.
The symbols SL1 to SL4 in the figure (in this example, four imaging positions are set) are lines indicating the imaging positions of the determined tomographic images. The lines SL1 to SL4 are set according to the settings from the setting panel 3.
The image is superimposed and displayed on the CR image on the monitor 6. FIG. 9B shows the relationship between the determined imaging position of the tomographic image and the actual subject M.

The length L11 in the figure can be calculated as follows. Both ends P1, P2 of the imaging region SR1
The length between them is L1, and the number of pixels of the CR image between them is known. Assuming that the number of pixels is G1, (L1 / G1)
Thus, the actual length of one pixel (referred to as gl1) is obtained. Therefore,
C between the end P1 of the imaging region SR1 and the imaging position SL1
L11 is determined by multiplying the above gl1 by the number of pixels (G11) on the R image. Similarly, L21 represents the length L3 between both ends P3 and P4 of the imaging region SR2 as the imaging region SR2.
2 is divided by the number of pixels (G2) between both ends P3 and P4 of the CR image to obtain the actual length gl2 of one pixel.
It can be obtained by multiplying the number of pixels on the CR image between the end P3 of R2 and the imaging position SL3. In addition, other L12,
L13, L22, and L23 can be calculated similarly.

Therefore, the above-described CR image capturing operation (for example,
When imaging of a tomographic image is to be continued from the state where the imaging operation for the setting in FIG. 6 is completed, the last imaging area (S
Since the end P4 of the imaging region SR2 is located at the imaging center SC upon completion of the imaging of the CR image of R2), the top plate 12
Is moved rightward in FIG. 1 by L23, and the imaging position S
L4 is positioned at the imaging center SC to capture a tomographic image,
Next, the top plate 12 is moved to the right in FIG. 1 by L22, and the imaging position SL3 is positioned at the imaging center SC, and a tomographic image is captured. Then, the top plate 12 is moved to (L21 + L2 + L
13), and moved to the right in FIG.
2 is positioned at the imaging center SC to capture a tomographic image, the top plate 12 is moved to the right in FIG. 1 by L12, and the imaging position SL1 is positioned at the imaging center SC to capture a tomographic image. .

The subject M is moved to the opening 23 of the gantry 2.
When starting with the action of inserting into the
4, the top plate 12 is moved horizontally, and the light from the projector 29 is moved to the top P1 of the top of the imaging region SR1 of the subject M.
When the top plate 12 is stopped, and then the start of tomographic image capture is instructed, the control unit 5 sets the top plate 12 to L
11 to the left in FIG.
Is positioned at the imaging center SC, and a tomographic image is captured. Next, the top plate 12 is moved to the left in FIG. 1 by L12, and the imaging position SL2 is positioned at the imaging center SC to capture the tomographic image. , And thereafter, the imaging of the tomographic images at the imaging positions SL3 and SL4 is similarly performed.

The lines SL1 and SL2 indicating the imaging position in the imaging region SR1 are inclined with respect to the body axis J. In this case, the gantry 2 is inclined by a predetermined angle to the right in FIG. The imaging center SC is connected to the lines SL1 and SL2.
The tomographic image may be taken in accordance with the time. This gantry 2
Is performed by the control unit 5 controlling the driving of the motor 22.

The CR of the imaging region SR3 set in FIG.
In the image, as shown in FIG. 10, when the imaging position of the tomographic image is determined along the curvature of the spine R as SL5 to SL7, the gantry is set in accordance with the inclination state of each line SL5 to SL7 with respect to the body axis J. 2 may be tilted in the left-right direction in FIG. 3 to capture each tomographic image.

The obtained tomographic image is displayed on the monitor 7. This display method may be configured such that one of the obtained tomographic images is displayed on the monitor 7 and display switching of each tomographic image is performed from the setting panel 3, or the obtained tomographic image is divided into 1 / 4 or 1
It may be reduced to / 16 and displayed in four divisions or sixteen divisions. Further, the imaging state of the tomographic image may be displayed by, for example, changing the color of the lines SL1 to SL4 displayed on the monitor 6 each time the imaging of the tomographic image at each imaging position is completed. At this time, if each CR image is divided and displayed on the monitor 6 and the obtained CR images are simultaneously displayed on the monitor 6, it is convenient to grasp the imaging state of the tomographic image as a whole.

In FIG. 9, four imaging positions are set. However, even when three or less or five or more imaging positions are set, the tomographic image is operated in the same manner as described above. Can be taken.

By the way, the projector 29 of the above-described embodiment is used.
Is configured to position a specific portion (one end P1 of the first imaging region SR1) of the subject M with the imaging center SC. For example, as shown in FIG. There is also a gantry 2 provided on the insertion port side of the subject M (at a position closer to the bed 1 side than the imaging center SC) in the opening 23 of the gantry 2. In such a configuration, the technician manually moves the top 12 while
The light from the projector 29 is applied to one end P of the first imaging region SR1.
When the irradiation of No. 1 is performed, if the movement of the top 12 is stopped and an instruction to start capturing a CR image is given in that state, the control unit 5
In the operation of S3 in the flowchart of FIG. 5 relating to the imaging of the CR image of the first imaging region SR1, the top plate 12 is
It will be moved to the left in FIG. 1 by 0. In addition,
This L30 is the length between the imaging center SC and the projector 29 and is known. In addition, the image pickup area S
After the position of one end P1 of R1 is adjusted, the photographing position S
When capturing the tomographic image of L1, the control unit 5 sets (L3
If the top plate 12 is moved to the left in FIG. 1 by (0 + L11), the imaging position SL1 can be positioned at the imaging center SC.

Further, as shown in FIG. 11B, when the light projectors 29 are individually provided outside the gantry 2, the movement of the top plate 12 of L30 in the case of FIG. If the length L40 between the imaging center SC and the projector 29 is changed, imaging of a CR image or the like can be performed in the above-described embodiment and FIG.
Can be performed in the same manner as the modified example.

[0062]

As is apparent from the above description, according to the present invention, for a plurality of imaging regions of the same subject, CR images obtained by arbitrarily setting the arrangement angle of the X-ray tube can be obtained. Since it is configured to be able to continuously capture images, the examination time is shortened compared to the conventional example, the pain of the subject can be reduced, and the CR image capturing work of the technician can be simplified, and the burden on the technician can be reduced. Can be.

[Brief description of the drawings]

FIG. 1 is a front view showing an overall schematic configuration of an X-ray CT apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a positional relationship between a subject on a top plate and a gantry (X-ray tube, X-ray detector).

FIG. 3 is a front view showing a tilted state of the gantry.

FIG. 4 is a diagram for explaining a configuration of a light projector for performing positioning between a specific portion of a subject and an imaging center.

FIG. 5 is a flowchart illustrating a CR image capturing operation performed by the embodiment apparatus.

FIG. 6 is a diagram illustrating an example of a set imaging region.

FIG. 7 is a diagram illustrating another example of a set imaging region.

FIG. 8 is a diagram for explaining a method of displaying an obtained CR image on a monitor.

FIG. 9 is a diagram illustrating an example of a slice plan.

FIG. 10 is a diagram showing another example of a slice plan.

FIG. 11 is a view for explaining a modification of the light projector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Bed 2 ... Gantry 3 ... Setting panel 5 ... Control part 6, 7 ... Monitor 12 ... Top plate 23 ... Gantry opening 25 ... X-ray tube 26 ... X-ray detector M ... Subject SR1-SR3 ... Imaging area SC ... imaging center

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-119137 (JP, A) JP-A-4-347143 (JP, A) JP-A-3-240169 (JP, A) JP-A-58-1983 94833 (JP, A) JP-A-6-98887 (JP, A) JP-A-7-194591 (JP, A) JP-A-4-259454 (JP, A) JP-A 2-156931 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) A61B 6/03

Claims (1)

(57) [Claims] (A) An X-ray tube and an X-ray detector which are provided with a cylindrical opening for inserting a subject and which are attached to face the opening are provided in a circumferential direction of the opening. A gantry that rotates while maintaining the facing state, (b) a bed provided with a subject on which a subject is placed and the subject is inserted into and removed from the opening of the gantry, and (c) a bed of the same subject. Setting means for setting a plurality of imaging regions and an arrangement angle of the X-ray tube with respect to each of the imaging regions (an arrangement position of the X-ray tube with respect to a subject on the top plate); The top plate is moved so that one end side of the first imaging region is positioned at the center of imaging by the X-ray tube and the X-ray detector, and the set angle of the X-ray tube in the set imaging region The X-ray tube is rotated so as to be arranged at While irradiating X-rays from the obtained X-ray tube, the top plate is moved so that a position in the first imaging region located at the imaging center is displaced from one end side to the other end side of the imaging region. Taking a CR (scout view) image of the first imaging region, and then moving the top plate so that one end side of the set next imaging region is located at the imaging center, and In addition, by rotating the X-ray tube so as to be arranged at the arrangement angle of the X-ray tube in the imaging region, the CR image of the next imaging region is formed in the same operation as the CR image of the first imaging region. (E) controlling means for controlling the imaging of the CR image of each of the set imaging regions while irradiating X-rays from the arrangement angles of the X-ray tubes in the respective imaging regions. The CR image of each imaging region obtained under the control of the control means X-ray CT apparatus characterized by comprising a Shimesuru display means.