JP2011098232A - X-ray tomographic imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an X-ray tomographic imaging apparatus capable of reducing the exposure of a subject while obtaining scanogram images with simple operation. <P>SOLUTION: The X-ray tomographic imaging apparatus includes a generating means 1 for generating X-rays; a detecting means 2 for detecting the X-rays; an image processing means 15 for creating the scanogram images based on the detected X-rays; a display means 17 for displaying the scanogram images; a setting means for setting a first range including one end of the photographing range of an X-ray tomographic image, and a second range including the other end of the photographing range; and a control means 6 controlling such that the X-rays generated in the first range have first intensity, that X-rays generated in the second range have second intensity and that X-rays generated outside the first and second ranges have intensity lower than the first and second intensity. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to an X-ray tomographic imaging apparatus that captures an X-ray tomographic image of a subject, and more particularly to an X-ray tomographic imaging apparatus capable of capturing a scanogram prior to the X-ray tomographic imaging.

An X-ray CT (X-ray CT) (X-ray CT) is used as an X-ray tomography apparatus for taking a tomogram of a subject such as a patient.
A computed tomography (hereinafter referred to as CT apparatus) apparatus is known. In this CT apparatus, scanning of a scanogram (hereinafter referred to as a scanogram) is often performed mainly for the purpose of determining the range of imaging prior to imaging of an X-ray tomographic image.

X-ray tomographic imaging is performed, for example, by rotating an X-ray tube and an X-ray detector provided in the CT apparatus around the body axis of the subject, whereas scanning imaging is performed without rotation. .

Since scanogram imaging includes the purpose of determining the X-ray tomographic imaging range, the scanogram imaging range is normally set wider than the X-ray tomographic imaging range. This scanogram is usually taken under the same conditions.

Accordingly, X-ray irradiation can be performed under the same conditions even on a portion where it is not desirable to perform X-ray irradiation or a portion that does not require scanogram imaging because of the purpose of determining the X-ray tomographic imaging range. As a result, there is a problem that the subject is exposed more than necessary. On the other hand, there is known an apparatus capable of taking an X-ray tomographic image without taking a scano image itself (see, for example, Patent Document 1). In some scanograms, X-ray irradiation is not performed on the part (for example, see Patent Document 2).

JP-A-7-1000012 Japanese Patent Application No. 2004-316684

The method shown in the above document is also preferable from the viewpoint of reducing exposure. However, on the other hand, in view of the fact that X-ray tomographic imaging is generally performed by irradiating X-rays stronger than those at the time of scanogram imaging, the X-ray tomographic imaging range is determined more accurately. In order not to unnecessarily widen the shooting range, shooting a scano image is still one useful method. In addition, it is possible to carry out scanogram imaging continuously within a certain range and to recognize predetermined object information by using the scanogram within the certain range. It is preferable for easy grasp.

The present invention has been made in view of the above problems, and an object thereof is to provide an X-ray tomography apparatus capable of reducing exposure of a subject while obtaining a scanogram by a simple operation.

In order to achieve the above object, an X-ray tomographic imaging apparatus according to the present invention is characterized in that an X-ray generating means, a detecting means for detecting the X-ray, and a scan based on the detected X-ray. An image processing unit for creating an image, a display unit for displaying the scanogram, a first range including one end of the imaging range of the X-ray tomographic image, and a second range including the other end of the imaging range are set Setting means to
In the first range, the generated X-ray has a first intensity, and in the second range, the generated X-ray has a second intensity, and the generated X-ray is outside the first and second ranges.
Control means for controlling the line to be lower than the first and second intensities.

  According to the present invention, exposure of a subject can be reduced by a simple operation while obtaining a scanogram.

The block diagram which shows an example of a structure of CT apparatus in one Example of this invention. The figure which shows an example of the external appearance schematic of a CT apparatus. The figure which shows an example of a dial knob. The figure which shows an example of a slide bar. The figure which shows an example of the button for the instruction input which concerns on light projection. The figure which shows the imaging | photography range of the X-ray tomogram in the state in which the subject was mounted in the table. The figure which shows the 1st example of the imaging | photography method of a scanogram. The figure which shows the 2nd example of the imaging | photography method of a scano image. The figure which shows the 3rd example of the imaging | photography method of a scano image. The figure which shows the 4th example of the imaging | photography method of a scano image. The figure which shows the 5th example of the imaging | photography method of a scanogram. The figure which shows the 6th example of the imaging | photography method of a scano image. The figure which shows the 7th example of the imaging | photography method of a scano image. The figure which shows the 8th example of the imaging | photography method of a scanogram. The figure which shows the 9th example of the imaging | photography method of a scanogram. The figure which shows the 10th example of the imaging | photography method of a scanogram. The figure which shows the 11th example of the imaging | photography method of a scanogram. The figure which shows the 12th example of the imaging | photography method of a scano image. The figure which shows an example of the external appearance schematic of the CT apparatus in another Example of this invention. The flowchart which shows an example of the flow of the operation | work for determining the position which controls the increase / decrease in X-ray in imaging | photography of a scanogram. The figure which shows an example of the external appearance schematic of the CT apparatus in another Example of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

Example 1
FIG. 1 is a block diagram showing an example of the configuration of a CT apparatus in one embodiment of the present invention. FIG. 2 is a diagram showing an example of a schematic external view of the CT apparatus. As shown in FIG. 1, X-ray CT
The apparatus includes, for example, a gantry / bed section 100, a scan control unit 10, and a system control unit 1.
1, an operation panel 12, a data collection unit 13, a memory 14, an image processing unit 15, and an image memory 16. Further, the X-ray CT apparatus includes the image display device 17 as a part thereof.

The gantry / bed section 100 captures a scanogram for the subject P such as a patient and X
This is for taking a line tomographic image. The gantry / bed section 100 includes an X-ray tube 1, an X-ray detector 2, an operation panel 3, a bed 4, a rotation control unit 5, an X-ray control unit 6, and a bed control unit 7.
A data collection control unit 8 and a gantry / bed control unit 9.

The X-ray tube 1 irradiates (generates) X-rays to the subject P lying on the table of the bed 4.
The X-ray detector 2 is composed of a plurality of detection elements arranged two-dimensionally. That is, X-ray detector 2
A plurality of detection elements along the body axis of the subject P (hereinafter referred to as the body axis direction)
A plurality of detection elements are also provided in a direction orthogonal to the body axis direction (hereinafter referred to as channel direction) to form a two-dimensional array. The X-ray detector 2 detects X-rays transmitted through the subject P as a result of being irradiated from the X-ray tube 1 to the subject P. The detected data is output from the X-ray detector 2.

Although not shown, the gantry / bed section 100 is provided with a rotation mechanism,
This rotation mechanism is provided so that the X-ray tube 1 and the X-ray detector 2 face each other on the opposite side of the subject P. The rotation mechanism rotates the X-ray tube 1 and the X-ray detector 2 around the subject P when capturing an X-ray tomographic image, but does not rotate when capturing a scanogram. Although the rotation mechanism is normally fixed at a predetermined position in relation to the bed 4, it may be movable in the body axis direction or the like as necessary.

The operation panel 3 is used for inputting an instruction or the like for the operation of the gantry / bed control section 100. For example, an operation for moving the table 40 of the bed 4 to an appropriate position can be performed.

The bed 4 has a table 40 on which the subject P can be placed, and the longitudinal direction of the table 40 usually coincides with the body axis direction. The bed 4 or its table 40 is movable in the body axis direction and the channel direction, and it is possible to position a predetermined part (examination part) of the subject P at an appropriate position in the examination. The bed 4 can move the table 40 in the vertical direction with respect to the floor surface on which the CT apparatus is installed. In photographing an X-ray tomogram or a scanogram, the subject P on the table 40 is inserted into the rotating mechanism of the gantry / bed section 100 and X-ray irradiation is performed by the X-ray tube 1.

The rotation control unit 5 controls the rotation mechanism to perform rotation and end of rotation. The X-ray control unit 6 performs power supply control on the X-ray tube 1 and controls to perform X-ray irradiation under predetermined conditions. The couch controller 7 controls the couch 4 or its table 40 so as to move in a three-dimensional direction based on an instruction input from the operation panel 3. The data collection control unit 8 controls the X-ray detector 2 so that data can be collected according to the imaging conditions. The gantry / bed control unit 9 controls the rotation control unit 5, the bed control unit 7, and the data collection control unit 8 based on the control by the scan control unit 10 and instructions input from the operation panel 3 so that they perform the above-described operations. Control.

The scan control unit 10 controls the gantry / bed control unit 9 and the data collection unit 13 based on control by the system control unit 11.

The system control unit 11 controls the entire CT apparatus. In particular, the system control unit 1
1 controls the scan control unit 10 and the image processing unit 15.

The console panel 12 enables input of information by its operation, and includes, for example, one or more of a switch, a button, a mouse, a touch panel, a dial knob, a slide bar, and the like.

In response to an instruction input from the console panel 12, the X-ray tube 1 is irradiated by changing the tube current of the X-ray tube 1.
An instruction to change the intensity of the line is included, and for example, the X-ray intensity can be changed depending on the degree of rotation (position) of the dial knob (see FIG. 3) and the degree of sliding (position) of the slide bar (see FIG. 4). . Moreover, the X-rays irradiated by the on / off of the switch or the X-ray reduction instruction button / increase instruction button may be switched between the first intensity X-ray and the second intensity X-ray. Such switching may be performed by selecting an icon displayed on an image display device (to be described later) using a mouse or selecting a button on the touch panel. Furthermore, in any case of switches, buttons, icons, buttons on the touch panel, and the like, a plurality of switches, buttons, and icons respectively assigned so as to selectively indicate a plurality of intensities of X-rays are provided. It may be.

In addition, when a later-described projector (not shown in FIG. 1) is provided in the CT apparatus, a predetermined instruction can be given from the console panel 12 to the projector. Furthermore, it is possible to enable an input to instruct the position of the table 40 determined by the projector as an X-ray reduction position and / or an enhancement position by a switch, a button, an icon, a button on the touch panel, or the like. An example of a button for inputting this instruction is shown in FIG.

The data collection unit 13 includes a plurality of data collection elements, and collects data detected by the X-ray detector 2 according to the connection state between the detection elements and the data collection elements. The data collection unit 13 outputs the collected data as projection data. The memory 14 is a data collection unit 13.
The projection data output from is saved.

The image processing unit 15 is controlled by the system control unit 11 and performs image reconstruction processing or scanogram generation processing based on projection data stored in the memory 14. An X-ray tomographic image is generated by this image reconstruction process. Processing by the image processing unit 15 is executed substantially in real time for data collection. The image memory 16 stores the X-ray tomographic image or scanogram obtained by the processing in the image processing unit 15, but the X-ray tomographic image or scanogram is substantially real-time with respect to the imaging in the image display device 17. Is displayed.

Next, FIG. 6 shows a case in which the intensity of X-rays irradiated from the X-ray tube 1 is changed by manual operation of the console panel 12 by a doctor, a radiologist, etc. (hereinafter referred to as an operator) without using a projector. This will be described with reference to FIG.

FIG. 6 is a diagram showing an imaging range of an X-ray tomographic image in a state where the subject P is placed on the table 40. The range that requires X-ray tomographic imaging performed by rotating the rotating mechanism is actually determined on the basis of the scanogram imaging result, but it is approximately the X-ray tomographic imaging range. It is possible to predetermine the position. Therefore, here, the positions at both ends of the range assumed in advance are referred to as position A and position B (the same applies hereinafter). As will be described below, the scanning image taken without rotating the rotating mechanism is performed in a range including the position A and the position B. Note that imaging is performed in a direction from the head of the subject P toward the toes. At that time, the table 40 may be moved toward the gantry by a driving device (not shown) provided on the bed 4, or the gantry itself may be moved toward the table 40. Moreover, both may move. By such movement, the relative positions of the X-rays irradiated by the X-ray tube 1 and the table 40 are changed. The same applies to photographing a scanogram.

FIG. 7 is a diagram illustrating a first example of a method for capturing a scanogram. As shown in the figure, scanning of a scanogram is started with, for example, low-intensity X-rays. The X-ray at this time has an intensity at which the imaging position of the subject P can be recognized at least to some extent, but is not enough to be used for determining the imaging range of the X-ray tomographic image. The scano image thus captured is the image display device 1.
7 is displayed substantially in real time, and the operator observes the displayed scanogram.

Scanning images are taken from position (1) to position (2) from position A to position B, which are both ends of the X-ray tomographic imaging range. This position (1) is determined by visual observation of the operator by observing the above-mentioned scanogram, and is a position that is an appropriate distance from the position where the operator himself is supposed to be position A. The operator turns on a predetermined switch provided on the console panel 12 at the position (1). The input information of the turned on switch is recognized by the system control unit 11. In response to this recognition, the system control unit 11 controls the scan control unit 10, the scan control unit 10 controls the X-ray control unit 6, and the X-ray control unit 6 controls the X-ray tube 1. As a result,
For example, the tube current of the X-ray tube 1 is increased, and the intensity of the irradiated X-ray is increased. X-ray at this time is X
This is the intensity at which a scanogram with sufficient image quality to be used for determining the imaging range of a line tomographic image can be obtained.

Instead of turning on a predetermined switch, a button, an icon, a button on the touch panel, or the like may be operated.

When the scanogram is taken with the X-rays after the switch is turned on and the operator who has been observing the image display device 17 determines that the position (2) is obtained by visual observation, the operator turns off the switch. This position (2) is a position that is a suitable distance away from the position that the operator considers to be position B. The system control unit 11 recognizes the input information of the turned off switch.

In response to this recognition, the system control unit 11 controls the scan control unit 10, the scan control unit 10 controls the X-ray control unit 6, and the X-ray control unit 6 controls the X-ray tube 1. As a result, for example, the tube current of the X-ray tube 1 is reduced, and the intensity of the irradiated X-ray is reduced. The X-ray at this time is the subject P
However, the intensity is not sufficient to be used for determining the imaging range of the X-ray tomographic image. For example, it is the same level as before switching on at position (1).

In this case as well, buttons, icons, buttons on the touch panel, etc. may be operated instead of turning off the predetermined switch.

As described above, since the operator can observe the scanogram until reaching an appropriate position (for example, position (1)), the operator can avoid the possibility of missing the imaging range of the X-ray tomogram. Thus, a scanogram can be acquired with sufficient X-ray intensity in this imaging range, and X-rays are reduced again after this imaging range, so that it is possible to reduce the exposure dose of the subject P outside the imaging range. It becomes.

FIG. 8 is a diagram showing a second example of a method for capturing a scanogram. Although the basic part is the same as that described with reference to FIG. 7, it is not necessary to turn off the switch in the example of FIG. Distance to a position sufficient to cover the X-ray tomographic imaging range (for example, a position corresponding to position (2)) [1
] Is input or set in advance, when the system control unit 11 recognizes that the switch is turned on, the distance [1] is compared with the actual movement distance of the table 40 obtained, for example, via the bed control unit 7. If it is determined that the table 40 has moved by the distance [1], the operation is the same as when the switch-off at the position (2) is recognized in FIG. This comparison may be performed in the bed control unit 7.

FIG. 9 is a diagram showing a third example of a scanogram imaging method. As shown in the figure, when the intensity of X-rays irradiated in FIG. 7 or FIG. 8 is reduced, the intensity of the X-rays may be lower than before switching on at position (1). . Conversely, the position before switching on at position (1) may be lower.

FIG. 10 is a diagram showing a fourth example of a scanogram imaging method. As shown in FIG. 7, when the intensity of X-rays irradiated in FIG. 7 or FIG. 8 is reduced, the X-ray intensity is reduced to zero, that is, X-ray irradiation is stopped. Good. In this case as well, the exposure of the subject can be further reduced without impairing the effect obtained in the case of FIG.

FIG. 11 is a diagram showing a fifth example of a scanano image capturing method. Here, unlike the above example, an instruction to change the X-ray intensity in scanning a scanogram using, for example, a dial knob as shown in FIG. 3 or a slide bar as shown in FIG. Shall be entered. The X-ray intensity can be changed stepwise in accordance with the degree of rotation of the dial knob and the degree of sliding of the slide bar, that is, the rotational position and slide position thereof. Hereinafter, the dial knob will be described as an example.

As shown in FIG. 11, scanogram imaging is started with, for example, low-intensity X-rays. As a result of observing the scanogram displayed on the image display device 17 at the start time, the operator can adjust the X-ray intensity by rotating the dial knob when it is determined that the X-ray intensity is insufficient or excessive. . When the system control unit 11 recognizes an input corresponding to the adjustment, the system control unit 11 controls the scan control unit 10 so that X-rays having an intensity corresponding to the recognized input are emitted from the X-ray tube 1. In any case, the X-ray at this stage has an intensity at which the imaging position of the subject P can be recognized at least to some extent, but is not sufficient to be used for determining the imaging range of the X-ray tomographic image.
Since the captured scanogram is displayed on the image display device 17 substantially in real time,
The operator continues to observe the displayed scanogram.

With respect to the position A to the position B which are both ends of the X-ray tomographic imaging range, the operator observes the above-mentioned scanogram and makes a dial knob from a position that is an appropriate distance from the position considered to be the position A by visual judgment. To increase the X-ray intensity. In the example of FIG. 4, this rotation is performed counterclockwise. The input corresponding to the rotational position of the dial knob is successively recognized by the system control unit 11 according to the rotation.

The system control unit 11 controls the scan control unit 10, the scan control unit 10 controls the X-ray control unit 6, and the X-ray control unit 6 controls the X-ray tube 1 for each recognition. As a result, for example, the tube current of the X-ray tube 1 is increased, and the intensity of irradiated X-rays is increased. As a result, the scanogram at the position A is taken by X-rays having such intensity that a scanogram having a sufficient image quality can be used for determining the radiographing range of the X-ray tomogram.

When the scanogram is taken with the X-ray and the operator observing the image display device 17 determines that the position B has been visually observed, the operator rotates the dial knob again. In the example of FIG. 4, this rotation is performed clockwise. The input corresponding to the rotational position of the dial knob is successively recognized by the system control unit 11 according to the rotation.

The system control unit 11 controls the scan control unit 10, the scan control unit 10 controls the X-ray control unit 6, and the X-ray control unit 6 controls the X-ray tube 1 for each recognition. As a result, for example, the tube current of the X-ray tube 1 is reduced, and the intensity of the irradiated X-ray is reduced. The X-ray at this time has an intensity at which the imaging position of the subject P can be recognized at least to some extent, but is not enough to be used for determining the imaging range of the X-ray tomographic image. The level may be the same as before the dial knob is rotated to increase the X-ray dose, or may be different.

In addition, when it is not necessary to confirm the scanogram after passing the position B, the dial knob is sufficiently rotated so that the intensity of the irradiated X-ray is reduced to zero, that is, the X-ray irradiation is stopped. May be.

As shown in this example, the operator can adjust the X-ray intensity using a dial knob or slide bar within the range of reducing the exposure of the subject while achieving the original purpose of scanning image acquisition. Can be adjusted to an arbitrary level at an arbitrary timing by self-judgement. Therefore, a more flexible operation for the operator can be realized.

FIG. 12 is a diagram showing a sixth example of a scanogram imaging method. The input for instructing the X-ray intensity may be performed by combining a dial knob or the like with a switch or the like. For example, as shown in the figure, using a dial knob, the X-rays are gradually increased (gradually), but after passing the position B, it is suddenly lowered to the above-mentioned predetermined intensity by a switch or the like. Good. Conversely, the X-rays may be enhanced by a switch or the like, and lowered to a predetermined intensity stepwise by a dial knob.

In this case, the operator can perform flexible operation, but can give an instruction to change the X-ray intensity instantaneously unlike the case of stepwise adjustment such as a dial knob. Compared with this case, the exposure of the subject can be further reduced.

FIG. 13 is a diagram showing a seventh example of a scanogram imaging method. As shown in the figure, the table 40 is provided with an identifiable mark. This mark is attached to a position corresponding to positions (1) and (2) in FIG. If the mark can be recognized by the operator during the scanogram image capture, the operator can implement the first to sixth examples with reference to the mark position.

In addition, if the operator cannot recognize the scan part while taking the scanogram because the part is moved into the gantry / bed section 100, for example, a mark is placed at a predetermined position of the table from the foot of the subject. The first to sixth examples can be implemented with reference to the relationship between the mark and the predetermined mark position.

FIG. 14 is a diagram showing an eighth example of a scanogram image capturing method. X-ray tomography is at position A
If it is sufficient that only the start position A and the end position B are obtained as a scanogram between the position B and the position B, the scanogram image as shown in FIG. 14 is taken in order to further reduce the exposure of the subject. It may be. That is, the scanogram is captured only between positions (1) and (2) and between positions (3) and (4).

In the case of FIG. 14 as well, scanning of a scanogram is started with, for example, low-intensity X-rays. The position (1) is determined by visual observation of the operator by observing the scanogram, and is a position that is an appropriate distance from the position considered by the operator himself / herself as the position A. At this time, the operator turns on a predetermined switch provided on the console panel 12 at the position (1). The input information of the turned on switch is recognized by the system control unit 11. In response to this recognition, the system control unit 11 controls the scan control unit 10, the scan control unit 10 controls the X-ray control unit 6, and the X-ray control unit 6 controls the X-ray tube 1. As a result, for example, the tube current of the X-ray tube 1 is increased, and the intensity of irradiated X-rays is increased. The X-rays at this time have such intensity that a scanogram with sufficient image quality can be obtained for use in determining the imaging range of the X-ray tomographic image.

As described above, buttons, icons, buttons on the touch panel, and the like may be operated instead of turning on a predetermined switch.

When the scanogram is taken with the X-rays after the switch is turned on and the operator who has been observing the image display device 17 visually determines that the position A has passed, for example, at the position (2), the operator presses the switch. Turn off. The system control unit 11 recognizes the input information of the turned off switch.

In response to this recognition, the system control unit 11 controls the scan control unit 10, the scan control unit 10 controls the X-ray control unit 6, and the X-ray control unit 6 controls the X-ray tube 1. As a result, for example, the tube current of the X-ray tube 1 is reduced, and the intensity of the irradiated X-ray is reduced. The X-ray at this time is the subject P
However, the intensity is not sufficient to be used for determining the imaging range of the X-ray tomographic image. For example, it is the same level as before switching on at position (1).

Also in this case, as described above, buttons, icons, buttons on the touch panel, and the like may be operated instead of turning off the predetermined switch.

Since the operator can recognize the imaging position of the subject P at least to some extent from the scanogram displayed on the image display device 17 as it is, when the operator determines that the position B has approached, the operator again provides the operator panel 12 at the position (3), for example. The specified switch is turned on. Thereafter, the operation of the operator and the operation of the CT apparatus are performed as in the case of the position A. Then, the X-ray intensity is reduced again at the position (4).

Thus, since the X-ray intensity is reduced between the position (2) and the position (3), the exposure of the subject can be further reduced. Also in this case, scan images around the positions A and B can be used to determine the imaging start position and end position of the X-ray tomographic image.

FIG. 15 is a diagram showing a ninth example of a scanogram imaging method. In the example shown in FIG.
X-rays were reduced based on the input instructed by the operator operating the switch or the like at 2) and at position (4). In the example shown in FIG. 15, instead of such an operator's operation, the system control unit 11 does not receive an instruction input by the operator after the system control unit 11 moves a predetermined distance as shown in FIG. 8. The X-ray is reduced by controlling the scan control unit 10.

A distance [1] from the position (1) to a position (for example, a position corresponding to the position (2)) covering the position A, which is one end of the X-ray tomographic imaging range, in an appropriate range is input or set in advance. In this case, when the system control unit 11 recognizes the switch-on, the distance [1] is sequentially compared with the actual movement distance of the table 40 obtained through the bed control unit 7, for example, and the distance [1] ], The system control unit 11 controls the scan control unit 10, and finally the X-ray tube 1 is controlled to reduce the X-ray intensity. The X-rays reduced here are intensities at which the imaging position of the subject P can be recognized at least to some extent, but are insufficient to be used for determining the imaging range of the X-ray tomographic image. It can be recognized that the position B approaches while observing the scanogram of the subject displayed substantially in real time. For example, the operator operates the switch or the like again at the position (2). Hereinafter, similarly to the operation at the position (1), when it is determined that the table 40 has moved by the distance [2], the scan control unit 10 is controlled to reduce the X-ray intensity. The distance comparison may be performed in the bed control unit 7.

As a tenth example of the scanogram imaging method, as shown in FIG. 16, the X-ray after moving a predetermined distance from the input at position (2) has a lower intensity than the X-ray before position (1). You may make it do. Although not shown in FIG. 16, in this case, X-ray irradiation may be stopped.

FIG. 17 is a diagram showing an eleventh example of a scanogram imaging method. Even when the operator inputs an instruction to change the X-ray intensity using a dial knob or a slide bar, the X-ray intensity is gradually increased in front of each position determined by the operator as position A and position B as shown in FIG. The dial knob and the slide bar may be operated so that the distance increases, and if it is determined that each position has passed, the dial knob and the slide bar may be operated so as to reduce the X-ray intensity stepwise. In this case, FIG.
As described above, the system control unit 11 sequentially recognizes input from the dial knob or the slide bar and controls the scan control unit 10 in accordance with this.

FIG. 18 is a diagram showing a twelfth example of a scanogram imaging method. In the above description, the case where the X-ray tomographic imaging range is between the position A and the position B has been described as an example. However, when there are a plurality of X-ray tomographic imaging ranges for the same subject P, scanogram imaging can be performed in a series of imaging.

For example, as shown in FIG. 18, there may be a case where a scanogram is taken from position C to position D in addition to the position A to position B described so far. In this case, any of the first to eleventh methods may be used to capture a scanogram from position C to position D. The method used for the position A to the position B may be the same or different. Further, the X-ray intensity at the time of reduction and / or increase may be set to an appropriate level according to the part, and as a result, the X-ray intensity at the time of reduction or increase may be different for each part. Good.

The first embodiment has been described based on the characteristic functions of the CT apparatus shown in FIG. In the embodiment described below, as shown in FIGS. 19 to 21, the same effects as in the above embodiment can be obtained regardless of the operation of the operator even during scanning of a scanogram by performing a predetermined preparation work in advance. Can be obtained.

(Example 2)
FIG. 19 is a diagram showing an example of a schematic external view of a CT apparatus according to another embodiment of the present invention. Since the block diagram shown in FIG. 1 can also be used in this embodiment, the following description will be given with reference to the configuration of FIG.

As shown in FIG. 19, the CT apparatus has a projector 190. The projector 190 may be provided in the gantry / bed section 100 or may be provided in another part of the CT apparatus. As a part of the CT apparatus, it may be provided at a position physically independent of the CT apparatus, such as a ceiling of an examination room where the CT apparatus is provided. That is, the table 4 in the vicinity of a part of the body of the subject P on which the beam irradiated from the projector 190 is placed on the table 40.
The installation position of the projector 190 is not limited as long as the irradiated position can be recognized by hitting a part of 0. Note that the beam irradiated from the projector is unnecessarily wide, and in order to irradiate a wide range, the irradiation position of the subject P or the table 40, particularly the position of the subject P in the body axis direction (longitudinal direction of the table 40) is set. Except for the case where it cannot be specified, it may be anything and is not necessarily limited to one that converges to a fine focus.

The preparatory work required for photographing a scanogram with the above CT apparatus will be described with reference to FIG. FIG. 20 is a flowchart showing an example of a work flow for determining a position for controlling increase / decrease in X-rays in scanogram imaging.

First, the projector 190 is turned on so that a predetermined beam is emitted from the projector 190 (step S21). When the operator operates the console panel 12 or the operation panel 3 here, the table 40 is moved in the longitudinal direction through the bed control unit 7. When the imaging range of the X-ray tomographic image is between the position A and the position B, the operator sets the table so that an appropriate position (1) before the position A, which is one end of the imaging range, is irradiated by the projector 190. An operation for adjusting the position of 40 is performed (step S22).

When the table 40 is moved according to this operation and the beam of the projector 190 irradiates the position (1), the operator presses a position determination button provided on the console panel 12 (step S2).
3). The position determination button may be a button for determining an X-ray increase position. Further, not only buttons but also switches and others may be the same as described above.

The input in step S23 is recognized by the system control unit 11. Further, the recognition information is transmitted to the bed control unit 7 via the scan control unit 10, so that the bed control unit 7.
Then, the position information of the table 40 at this time is determined. This position information is stored in the bed control unit 7, the gantry / bed control unit 9, the scan control unit 10, or the system control unit 11 (
Step S24). In particular, when the position determination button is a button for determining the X-ray increase position, the position determination button is stored as information on the increase position or in association with the information “increase”.

Next, the operator performs an operation to adjust the position of the table 40 again so that the appropriate position (2) past the position B which is the other end of the X-ray tomographic imaging range is irradiated by the projector 190. (Step S25). This operation is the operation of the console panel 12 or the operation panel 3 as in the above case, and the table 40 is moved in the longitudinal direction through the bed control unit 7.

When the beam of the projector 190 irradiates the position (2), the operator presses a position determination button provided on the console panel 12 (step S26). The position determination button here may be a button for determining the X-ray reduction position.

The input in step S26 is recognized by the system control unit 11. Further, the recognition information is transmitted to the bed control unit 7 via the scan control unit 10, so that the bed control unit 7.
Then, the position information of the table 40 at this time is determined. This position information is stored in the bed control unit 7, the gantry / bed control unit 9, the scan control unit 10, or the system control unit 11 (
Step S27). In particular, when the position determination button is a button for determining the X-ray reduction position, the position determination button is stored as information on the reduction position or in association with information “reducing”.

When setting a plurality of ranges as shown in FIGS. 14 and 18, the process returns to step S22 and the above operation is repeated for other ranges. If there is no other range to be set, the setting operation for determining the position ends (step S28).

7 to 10 and FIGS. 14 to 16 after the preparatory work described above is completed.
In addition, regarding each of the scanogram imaging methods shown in FIG. 18, it is possible to perform imaging that can obtain the same effect without any operation by the operator during the scanogram imaging.

For example, taking the case of FIG. 7 as an example, a method for photographing a scanogram using position information will be described.

First, the scanogram is captured with, for example, an X-ray with an intensity that can recognize at least some of the imaging region of the subject P, but is not sufficient to be used for determining the imaging range of the X-ray tomogram. Be started.

Although the table 40 is moved toward the gantry, the bed control unit 7 can recognize the position of the table 40, so that the position of the table 40 is indicated by the X-ray increase position information (1).
Until the position is reached, the position of the table 40 is monitored. Alternatively, the position information of the table 40 is transmitted to the successive gantry / bed control unit 9, the scan control unit 10, or the system control unit 11.

When it is determined that the table 40 has reached the position (1) indicated by the X-ray increase position information,
The intensity of X-rays emitted from the X-ray tube 1 via the line control unit 6 is enhanced. The X-rays at this time have such intensity that a scanogram with sufficient image quality can be obtained for use in determining the imaging range of the X-ray tomographic image.

Since the table 40 is continuously moved, the bed control unit 7 continues to monitor the position of the table 40. When it is determined that the table 40 has reached the position (2) indicated by the X-ray reduction position information, the intensity of X-rays emitted from the X-ray tube 1 via the X-ray control unit 6 is reduced. The X-ray at this time is, for example, intensity that can recognize at least to some extent the imaging region of the subject P,
The intensity can be set so as not to be sufficient for use in determining the imaging range of the X-ray tomographic image.

As described above, by using the projector 190, it is possible to reduce the operation burden on the operator during the scanogram shooting, and it is possible to perform more accurate shooting regardless of the operator's visual judgment.

In the above example, the relative position between the X-ray irradiated from the X-ray tube 1 and the table 40 is changed only by moving the table 40. However, the gantry is moved or both the table 40 and the gantry are moved. The present invention can also be applied to the case where the total position is changed.

Note that the projector 190 can be used even when the operator operates switches, dial knobs, and the like to increase and decrease X-rays for imaging. For example, if the position (1) and the position (2) are stored in advance using the projector 190 and the table 40 reaches each position, a predetermined notification is made by the control of the system control unit 11. The person can operate the switch and the like according to the notification.

In addition, the operator can operate the switch and the like based on his / her own judgment based on both information obtained by visual observation of the scanogram displayed on the image display device 17 and information on the notification.

The notification may be made to be a predetermined display on the image display device 17, or may be made to be notified by a beep sound, voice or other sound by separately providing a speaker or the like.

(Example 3)
The effect of the second embodiment can be obtained in the same manner by using a predetermined identification mark and sensor instead of the projector 190.

FIG. 21 is a diagram showing an example of a schematic external view of a CT apparatus in still another embodiment of the present invention. As shown in the figure, a mark 210 is attached in the longitudinal direction of the table 40. The attachment position may be anywhere along the longitudinal direction of the table 40. For example, the attachment position is attached to the side surface as shown in FIG. The mark 210 can identify the position (1) and the position (2) as described above, and may be anything as long as the sensor 220 can recognize the position.

Based on the position of the subject P placed on the table 40, the mark position is determined in advance by visual observation or the like before photographing the scanogram, and the mark 210 is attached to the determined position.

During photographing of a scanogram, the mark 210 is monitored by the sensor 220. When the mark 210 is recognized by the sensor 220, the projector performs the same operation as when the position reached using the projector 190 described above is reached. The same effect as when 190 is used can be obtained.

If the mark 210 is attached to the position shown in FIG. 21 in relation to the position where the sensor 220 is allowed to be installed, but the position is not directly recognized by the sensor 220 as the position to change the X-ray intensity, the position (1) or From the relationship between the position of the table 40 when the X-ray intensity is changed at the position (2) and the installation position of the sensor 220, another position of the table 40 (for example, in the case of FIG. You may make it attach | subject the mark 210 to the position near a step).

The embodiment of the present invention described above is merely an example described for facilitating the understanding of the present invention, and is not a description for limiting the present invention. Accordingly, each of the constituent elements and other elements disclosed in the above-described embodiment of the present invention can be changed in design or modified to equivalents thereof without departing from the gist of the present invention. Furthermore, any possible combination of the same components and other elements is included in the scope of the present invention as long as the same effects as those obtained in the embodiment of the present invention described above can be obtained.

DESCRIPTION OF SYMBOLS 1 ... X-ray tube 2 ... X-ray detector 3 ... Operation panel 4 ... Bed 5 ... Rotation control part 6 ... X-ray control part 7 ... Bed control part 8- ··· Data collection control unit 9 ··· Gantry / bed control unit 10 ··· Scan control unit 11 ··· System control unit 12 ··· Panel panel 13 ··· Data collection unit 14 · · · Memory 15 ..Image processing unit 16 ... Image memory 17 ... Image display device 40 ... Table 100 ... Gantry / bed section 190 ... Projector 210 ... Mark 220 ... Sensor

Claims (5)

Generating means for generating X-rays;
Detection means for detecting this X-ray;
Image processing means for creating a scanogram based on the detected X-ray;
Display means for displaying the scanogram,
Setting means for setting a first range including one end of the imaging range of the X-ray tomographic image and a second range including the other end of the imaging range;
In the first range, the generated X-ray has a first intensity, and in the second range, the generated X-ray has a second intensity, and the generated X-ray is outside the first and second ranges.
X-ray tomography apparatus, comprising: control means for controlling the line to be lower than the first and second intensities. A table on which the subject can be placed;
Irradiating means for irradiating the table with a beam;
Change means for changing the longitudinal direction of the table and the relative position of the irradiation beam;
The setting means sets the first position as one end of the first range when the relative position is at the first position by the changing means, and sets the first position as one end of the first range. 2 is set as the other end of the first range, and when the relative position is at the third position, the third position is set as one end of the second range, and the relative position is The X-ray tomography apparatus according to claim 1, wherein when the position is 4, the fourth position is set as the other end of the second range. A table on which the subject can be placed;
Irradiating means for irradiating the table with a beam;
Change means for changing the longitudinal direction of the table and the relative position of the irradiation beam;
The setting means sets the first position as one end of the first range when the relative position is at the first position by the changing means, and sets the first position along the longitudinal direction from the first position.
Is set as the other end of the first range, and when the relative position is at the second position, the second position is set as one end of the second range. 2. The X-ray tomographic imaging apparatus according to claim 1, wherein a position separated from the position by a second length along the longitudinal direction is set as the other end of the second range. A table on which the subject can be placed;
Identification means for identifying first to fourth positions along the longitudinal direction of the table;
Recognizing means for recognizing the first position to the fourth position,
The setting means sets the recognized first position as one end of the first range, sets the recognized second position as the other end of the first range, and sets the recognized third position. 2. The X-ray tomography apparatus according to claim 1, wherein the position is set as one end of the second range, and the recognized fourth position is set as the other end of the second range. . The X-ray tomography apparatus according to claim 1, wherein a plurality of sets of the first range and the second range are set as a set.

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