JPH09308626A - X-ray radiographing method and x-ray ct system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a reagent or an operator from being uselessly exposed with X-rays by controlling the irradiation of X-rays synchronously with the rotations of a gantry according to an X-ray ON signal from an operating console and the operation of an X-ray switch of a scan room. SOLUTION: First of all, a scan room control mode is set for starting scan by depressing an X-ray ON switch 22 for a scan room. Then, when a scan start switch 11 is depressed, an operating console 10 generates the X-ray ON signal and a changeover switch 42 supplies the output of a logic circuit 41 to an X-ray generator 32. When the X-ray ON switch 22 for the scan room is pushed down, the X-ray ON signal is outputted from a gantry rotation synchronizing controller 23 and this X-ray ON signal is outputted synchronously with the rotations of the gantry for a period required for generating one image. Next, a tube current increase switch 21 for the scan room is operated so that the amount of X-rays can be increased and the image can be provided with high picture quality.

Description

Detailed Description of the Invention

[0001]

The present invention relates to an X-ray CT (Computed
Tomography) for improving image reconstruction of the device,
The present invention relates to an X-ray imaging method and an X-ray CT apparatus that can be operated by an operator in a scan room.

[0002]

2. Description of the Related Art An X-ray CT apparatus is an apparatus that irradiates an X-ray over the entire circumference of a subject, detects the X-ray by a detector, reconstructs a tomographic image, and provides the image for diagnosis.

A schematic configuration of the X-ray CT apparatus is shown in FIG. In FIG. 6, reference numeral 10 is an operation console for performing various operations. In addition to various switches, the operation console 10 is provided with a scan start switch 11 for starting a scan.

Reference numeral 32 is an X-ray generator that generates a high voltage necessary for X-ray irradiation in synchronization with an X-ray ON signal according to a tube current / tube voltage setting signal from the console 10, and 33 is a gantry rotation control from the console 10. It is a gantry rotation control device that controls rotation of a gantry rotation unit according to a signal.

Reference numeral 50 denotes a gantry for irradiating and photographing a subject with X-rays, which is provided with a gantry rotating portion for rotating an X-ray tube and an X-ray detector described later. An X-ray tube 51 performs X-ray irradiation for performing X-ray tomography, and irradiates the subject within the image reconstruction area. Reference numeral 52 denotes an object to be irradiated with X-rays from the X-ray tube 51, which is placed on a table (not shown).

Reference numeral 53 is an object to be inspected 52 irradiated from the X-ray tube 51.
It is an X-ray detector that detects X-rays that have passed through and generates an electric signal proportional to X-ray energy, and is composed of a large number of detection elements.

Reference numeral 54 is a data collecting device (DAS) for collecting the electric signal generated by the X-ray detector 53, and a signal (raw data) proportional to the energy of the X-ray from the X-ray detector 53. ) Is to collect.

An image reconstructing device 60 reconstructs an image by subjecting raw data to backprojection processing, and generates image data from the reconstructed data. 8
Reference numeral 0 denotes an operation console image display device, which is an image display means for displaying the reconstructed image near the operation console 10. An image display device 90 for a scan room is an image display unit for displaying the reconstructed image in the scan room.

In such an X-ray CT apparatus, an X-ray tube 51 irradiates a subject 52 with a fan-shaped X-ray beam, and the transmitted X-rays are arranged according to the spread of the fan-shaped X-ray beam. The measurement is performed by an X-ray detector 53 which is a one-dimensional array composed of a plurality of detecting elements.

The transmitted X-rays are measured in a plurality of view directions while rotating the X-ray tube 51 and the X-ray detector 53 around the subject 52. Such a transparent X
The line measurement is called a scan, and one image is reconstructed in units of one rotation (360 °) or half rotation (180 °).

In the general X-ray CT apparatus as described above, a scan is performed to make about 100 revolutions.
Raw data of about 0 views is generated, and image reconstruction is performed.

Then, a tomographic image of the subject 52 is reconstructed in the image reconstructing device 60 based on the measurement data of a plurality of views obtained by the scan. Then, the reconstructed image data is displayed on the operation console image display device 80 and the scan room image display device 90.

In the above X-ray CT apparatus, the operation console 10 and the operation console image display device 80 are installed in the operation room, and the gantry 50 and the scan room image display device 90 are installed in the scan room. There is.

[0014]

Problems to be Solved by the Invention X-ray CT as described above
In the case of the device, the operation console 10 is previously
After setting the X-ray tube current and the tube voltage, the scan start switch 11 installed on the operation console 10 is pressed to rotate the rotating part in the gantry 50 so that X-rays are emitted. ing.

With such an X-ray CT apparatus, CT fluoroscopy (X-ray irradiation) is continuously performed using X-ray images of physiological movement in the subject, positional relationship of organs, morphological changes, etc. In view of the X-ray exposure to the subject 52 and the operator in the scan room, it is necessary to keep the X-ray tube current low. On the other hand, if the X-ray tube current is suppressed, there is a problem that the quality of an image obtained by reconstruction is deteriorated.

Further, since the control of X-ray irradiation is automatically performed in the operation console 10 in the operation room according to a preset scanning plan, X-rays can be emitted even when it is not necessary to emit X-rays. Can also happen.

Therefore, in the X-ray irradiation or the like in the case where the operator is performing the biological tissue examination on the subject 52, the control of the X-ray irradiation cannot be performed from the scan chamber, so that the subject 52 or the operation is performed. Will be uselessly exposed.

The present invention has been made in view of the above points, and an object thereof is to realize an X-ray imaging method and an X-ray CT apparatus which can be operated by an operator in a scan room.

[0019]

The present invention, which is a means for solving the problems, is as described in the following (1) to (5).

(1) The first aspect of the invention is characterized in that the X-ray irradiation is controlled at a timing synchronized with the rotation of the gantry according to the X-ray ON signal from the operation console and the operation of the X-ray switch in the scan chamber. X-ray imaging method.

In the X-ray imaging method of the first invention, when the X-ray ON signal is output from the operation console and the X-ray switch in the scan room is operated, X-rays are synchronized with the rotation of the gantry. The control is performed so as to perform the line irradiation.

As a result of the above operation, X
Since it becomes possible to control the irradiation of X-rays, X when the operator is performing a biopsy on the subject.
The subject and the operator will not be uselessly exposed to radiation such as irradiation.

(2) The second invention is an X-ray control means for controlling X-ray irradiation at a timing synchronized with the rotation of the gantry in accordance with an X-ray ON signal from the operation console and an operation of the X-ray switch in the scan room. An X-ray CT apparatus characterized by comprising:

In the X-ray CT apparatus of the second invention, when the X-ray ON signal from the operation console is output and the X-ray switch in the scan room is operated, the X-ray CT is synchronized with the rotation of the gantry. The control is performed so as to perform the line irradiation.

As a result of this, X from the scan room
Since it becomes possible to control the irradiation of X-rays, X when the operator is performing a biopsy on the subject.
The subject and the operator will not be uselessly exposed to radiation such as irradiation.

(3) The third aspect of the invention is the X of the second aspect of the invention.
The X-ray control means in the X-ray CT apparatus performs control such that the X-ray state does not change during a period required to reconstruct at least one image.

In the X-ray CT apparatus according to the third aspect of the present invention, when the X-ray ON signal is output from the operation console and the X-ray switch in the scan chamber is operated, the timing is synchronized with the rotation of the gantry. Therefore, control is performed so that X-ray irradiation is performed for a period necessary to reconstruct at least one image.

As a result, the X-ray irradiation can be controlled by a simple switch operation from the scan room, so that when the operator is inspecting the living body tissue, The subject and the operator will not be uselessly exposed to X-ray irradiation.

(4) A fourth invention is the X of the second invention.
The X-ray CT apparatus is provided with a tube current increasing switch for temporarily increasing the tube current supplied to the X-ray tube in the scan room or the operation room.

In the X-ray CT apparatus according to the fourth aspect of the present invention, it is possible to temporarily increase the tube current supplied to the X-ray from the scan room or the operation room, if necessary. As a result, the X-ray dose can be increased from the scan room or the operation room as needed.
It is possible to keep the usual X-ray dose low. For this reason, the subject and the operator will not be uselessly exposed to radiation even when X-ray irradiation is performed when the operator is performing a biological tissue examination on the subject.

(5) A fifth aspect of the invention is the X of the second aspect of the invention.
In the line CT apparatus, a control switch for performing control when displaying a reconstructed image is provided in the scan chamber.

In the X-ray CT apparatus according to the fifth aspect of the invention, various control operations can be performed when displaying an image from the scan room. As various controls in this case,
The window level, window width, etc. are applicable.

As a result, the window level and the window width of the image reconstructed from the scan room can be changed as necessary, so that the desired image can be displayed from the scan room. Therefore, it becomes possible to accurately grasp the state of the biological tissue inspection even when the operator is performing the biological tissue inspection on the subject, such as X-ray irradiation. Can be completed in a short time.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. <First Embodiment> FIG. 1 shows a configuration of an apparatus (X-ray CT apparatus) used in an X-ray imaging method according to an embodiment of the present invention and an X-ray CT apparatus according to an embodiment of the present invention. It is a block diagram showing.

Further, FIG. 2 shows X of an embodiment of the present invention.
4 is a flowchart showing a procedure of X-ray irradiation in the X-ray imaging method, and FIG. 3 is a time chart in the X-ray imaging method according to the embodiment of the present invention.

<Structure (1) of X-ray CT Apparatus> First, an X-ray CT apparatus used in an X-ray imaging method which is an embodiment of the present invention, and an embodiment of the present invention. X-ray C
The configuration of the T device will be described with reference to FIG.

In FIG. 1, 10 is an operation console for performing various operations. In addition to various switches, the operation console 10 is provided with a scan start switch 11 for starting a scan.

Reference numeral 21 denotes a tube current increasing switch which is arranged in the scan chamber and which temporarily increases the tube current of the X-ray tube. Although the tube current increase switch is shown as being arranged in the scan chamber here, it may be arranged in the scan chamber (on the operation console or the like) other than this, which is advantageous in terms of radiation exposure.

Reference numeral 22 denotes an X-ray ON switch for the scan chamber which is arranged in the scan chamber and generates an X-ray ON signal for starting X-ray irradiation. It is preferable that the tube current increasing switch 21 and the scan room X-ray on-switch 22 are formed of foot switches or the like for easy operation.

Reference numeral 23 is an X-ray on-switch 22 for the scan room.
It is a gantry rotation synchronization control device for generating an X-ray ON signal in a state synchronized with gantry rotation when is pressed.

Here, the X-ray ON signal in a state synchronized with the gantry rotation means that the X-ray ON signal starts to turn ON when the gantry rotating portion has a predetermined rotation angle, and at least 1
It means that X-ray irradiation is performed up to a predetermined rotation angle necessary for reconstructing one image.

Reference numeral 31 is a tube current increaser for instructing the X-ray generator 32 to increase the tube current when the tube current increase switch 21 is pressed.
This is achieved by changing the tube current setting signal.

Reference numeral 32 is an X-ray generator that generates a high voltage required for X-ray irradiation in synchronization with an X-ray ON signal according to a tube current / tube voltage setting signal from the console 10, and 33 is a gantry rotation control from the console 10. It is a gantry rotation control device that controls rotation of a gantry rotation unit according to a signal.

A mode switching unit 40 is for switching the X-ray ON signal between the operation console initiative mode and the scan room initiative mode, and includes a logic circuit 41 and a changeover switch 42. There is.

Here, the logic circuit 41 is the operation console 1
The logical sum (or the logical operation result equivalent to this) of the X-ray ON signal from 0 and the X-ray ON signal from the scan chamber is generated. Further, the changeover switch 42 is the operation console 10
The X-ray ON signal from the X-ray generator and the X-ray ON signal from the logic circuit 41 are selected and supplied to the X-ray generator 32 in an alternative manner.

Reference numeral 50 denotes a gantry for irradiating and photographing the subject with X-rays, which is provided with a gantry rotating unit for rotating an X-ray tube and an X-ray detector described later. An X-ray tube 51 performs X-ray irradiation for performing X-ray tomography, and irradiates the subject within the image reconstruction area. Reference numeral 52 denotes an object to be irradiated with X-rays from the X-ray tube 51, which is placed on a table (not shown).

53 is an object to be inspected 52 irradiated from the X-ray tube 51.
It is an X-ray detector that detects X-rays that have passed through and generates an electric signal proportional to X-ray energy, and is composed of a large number of detection elements.

Reference numeral 54 denotes a data acquisition device (DAS) for collecting the electric signal generated by the X-ray detector 53, and a signal proportional to the energy of the X-ray from the X-ray detector 53 (raw data). ) Is to collect.

An image reconstructing device 60 reconstructs an image by subjecting raw data to backprojection processing, and generates image data from the reconstructed data. 8
Reference numeral 0 denotes an operation console image display device, which is an image display means for displaying the reconstructed image near the operation console 10. An image display device 90 for a scan room is an image display unit for displaying the reconstructed image in the scan room.

In the above structure, the X-ray control means for controlling the X-ray irradiation at the timing synchronized with the rotation of the gantry is composed of the gantry rotation synchronization control device 23, the mode switching unit 40 and the X-ray generator 32. ing.

In such an X-ray CT apparatus, the subject 52 is irradiated with a fan-shaped X-ray beam from the X-ray tube 51, and the transmitted X-rays are arranged according to the spread of the fan-shaped X-ray beam. The measurement is performed by an X-ray detector 53 which is a one-dimensional array composed of a plurality of detecting elements.

The transmitted X-rays are measured in a plurality of view directions while rotating the X-ray tube 51 and the X-ray detector 53 around the subject 52. Such a transparent X
The line measurement is called a scan, and one image is reconstructed in units of one rotation (360 °) or half rotation (180 °).

Then, a tomographic image of the subject 52 is reconstructed in the image reconstructing apparatus 60 based on the measurement data of a plurality of views obtained by the scan. Then, the reconstructed image data is displayed on the operation console image display device 80 and the scan room image display device 90.

In the above X-ray CT apparatus, the operation console 10 and the operation console image display device 80 are installed in the operation room, and the tube current increasing switch 21, the scan room X-ray ON switch 22, and the gantry 50 are installed. The scan room image display device 90 is installed in the scan room.

<Processing Procedure (1) of X-ray Imaging Method> The procedure of the X-ray imaging method according to the embodiment of the present invention and the operation of the X-ray CT apparatus according to the embodiment of the present invention are largely. The process is divided into the following steps, as shown below.

Hereinafter, this procedure will be described step by step according to each step. Further, description will be given here with reference to the time chart shown in FIG. Note that FIG. 3 shows a case where X-ray irradiation is performed by the X-ray ON switch 22 for the scan room (scan room initiative mode).

Scan start: First, the operator sets the scan mode on the operation console 10 before starting the scan.

As the scan mode, the operation console initiative mode in which scanning is started by pressing the scan start switch 11 of the operation console 10 and the X-ray for the scan room with the start switch 11 of the operation console 10 being pressed A scan room initiative mode in which the on switch 22 is pressed to start scanning is prepared. The setting of the scan mode controls the switching state of the changeover switch 42 of the mode switching unit 40.

With the scan mode set in this way, the scan start switch 11 is turned on as shown in FIG.
When pressed as shown in FIG. 3, the operation console 10 generates an X-ray ON signal (FIG. 3 (b)).

X-ray irradiation: In this state, if the scan mode is the operation console initiative mode, the changeover switch 42
Receives the X-ray ON signal from the operation console 10 as is
Supply to the line generator 32. Therefore, as in the conventional normal operation, the X-ray tube 51 starts X-ray irradiation when the scan start switch 11 is pressed.

In this state, if the scan mode is the scan room initiative mode, the changeover switch 42 supplies the output of the logic circuit 41 to the X-ray generator 32.

When the X-ray on-switch 22 for the scan room is pressed, an X-ray on-signal is sent to the gantry rotation synchronization control device 2.
This X-ray ON signal is output from the device 3 in synchronization with the rotation of the gantry and is output for a period required to generate one image.

That is, the X-ray ON signal from the gantry rotation synchronization control device 23 based on the depression of the scan room X-ray ON switch 22 is logically summed with the X-ray ON signal of the operation console 10 side in the logic circuit 41 ( Or the logical result equivalent to it) is required.

Therefore, as for the X-ray ON signal from the scan room, as for FIG.
Since the line-on signal is not output, the output of the logic circuit 41 does not appear.

FIG. 3 shows the X-ray ON signal from the scan chamber.
As for (c), the X-ray ON signal on the side of the operation console is output, and the logic circuit 41 outputs the X-ray ON signal as the logical sum.

Here, the X-ray ON switch 2 for the scan room is used.
Although pressing of 2 is a short time (FIG. 3 (c)), the gantry rotation synchronization control device 23 needs a period (eg, gantry rotation) necessary for reconstructing at least one image in synchronization with gantry rotation. One rotation) generates an X-ray ON signal such that the X-ray state does not change. Therefore, X-ray irradiation is performed in synchronization with the gantry rotation (2) (FIG. 2S).
4, S5, S6: FIG. 3 (e)).

Further, the X-ray on-switch 22 for the scan room
Even when the button is pressed for a plurality of gantry rotation periods (FIG. 3C), the gantry rotation synchronization control device 23 synchronizes with the gantry rotation and reconstructs a plurality of images in the period. The X-ray ON signal is generated such that the X-ray state does not change during the period required for the. Therefore,
X-ray irradiation is performed in synchronization with gantry rotations (3) to (4) (FIGS. 2S4, S5, S6: FIG. 3E).

Then, by operating the tube current increasing switch 21 for the scan chamber, it is possible to temporarily increase the tube current supplied from the scan chamber to the X-rays as needed. The same is true by operating a tube current increase switch (not shown) arranged in the operation room.

As a result, the X-ray dose can be increased from the scan chamber as necessary to obtain a high-quality image, so that the normal X-ray dose can be kept low. Therefore, the operator is not exposed to unnecessary radiation even when X-ray irradiation or the like is performed when the operator is performing a biological tissue test on the subject.

Image reconstruction: Then, the image reconstruction device 60 performs image reconstruction based on the raw data obtained by the X-ray irradiation to generate image data (FIG. 3 (f) (2),
(4) to (5)). Then, the image display of the image data is performed on the operation console image display device 80 and the scan room image display device 90 under the control of the image display control device 70 (Fig. 3 (g) (2), (4) to (5). )).

Here, the image display control device 70 has a function of freezing the image display except when an effective image (image reconstructed by X-ray irradiation) comes. Therefore, the image data by the gantry rotation (2) is continuously displayed until the image data by the gantry rotation (4) is displayed.

<Effects Obtained by X-ray Imaging> As described above, the scan room-initiated mode is set and the scan room X-ray on-switch 22 installed in the scan room.
By performing X-ray irradiation by pressing, X-ray irradiation can be performed only when the operator in the scan room determines that X-ray irradiation is necessary. It is possible to suppress unnecessary radiation exposure.

Further, since the logic circuit 41 is provided to obtain the logical result of both X-ray ON signals, the X-ray ON switch 22 for the scan room is used when the X-ray ON signal from the operation console 10 side is not output. Even if is pressed, X-rays are not emitted. Therefore, it is possible to prevent X-ray irradiation due to a wrong operation.

<Operation Example (1)> Here, the above X
The radiography will be described with respect to a specific operation of the operator in the case of biopsy.

First, the operator makes a normal scan
Scan the area that seems to be a tumor,
Check the location etc. Then, the scan mode is set from the operation console 10. Here, the case where the scan room initiative mode is set is taken as an example. Also, X in the scan room initiative mode
Set the tube current to a low value. As a result, the changeover switch 42 of the mode changeover unit 40 is changed over to the logic circuit 41 side.

The operator presses the scan start switch 11 on the operation console 10. As a result, the gantry rotating part in the gantry 50 starts to rotate, and when X-rays are emitted, the X-ray detector 53 can acquire raw data. However, since the scan room X-ray on-switch 22 is not pressed, the X-ray is not emitted.

The operator depresses the scan chamber X-ray ON switch 22 at a desired timing such as confirming the tip of the needle while piercing the subject with the needle for biopsy.
Even if the X-ray on-switch 22 for the scan room is pressed for a short period of time, the gantry rotation synchronization control device 23 needs the X-rays for a period required to reconstruct at least one image in synchronization with the gantry rotation. X that does not change the state of
Generating line-on signal. Therefore, X-ray irradiation is performed in synchronization with the rotation of the gantry. With this X-ray irradiation, data collection and image reconstruction are performed, and the image data is converted into the image display device 80 for the operation console and the image for the scan room. It is displayed on the display device 90. The operator further sticks the needle while looking at the image display on the image display device 90 for the scan room.

If an image with high contrast and high resolution is required while X-rays are being irradiated, the operator depresses the tube current increase switch 21 to increase the X-ray tube current, resulting in a high quality image. Is obtained. Since the tube current increase switch 21 is provided in the scan chamber, it is possible to increase the tube current after the operator releases the scan surface (or the needle). Therefore, the operator can avoid exposure.

Then, when the X-ray on-switch 22 for the scan room is depressed and X-ray irradiation is performed for a predetermined period to turn it off, the image freeze function of the image display control device 70 operates to reconfigure. The last valid image remains displayed.

By repeating the above steps,
When the operator finally confirms that the needle has reached the target object, the user releases the needle and scans by increasing the tube current in the same manner as above. This makes it possible to obtain, as a higher quality image, an evidence image that the needle has surely reached the intended one.

Since the logic circuit 41 is provided to obtain the logical result of both X-ray ON signals, the X-ray ON switch 22 for the scan room is used when the X-ray ON signal from the operation console 10 side is not output. Even if is pressed by mistake, X-ray is not emitted.

<Example of Actual Layout> FIG. 4 is an actual layout showing the states of the operation room 100 and the scan room 200. Here, the operation console 10 of the operation room 100 and the scan room 2
The gantry 50 of 00 is mainly shown.

Then, the scan room 200 has a table 5
A foot switch 20 is arranged near the foot of No. 5.
The foot switch 20 constitutes a tube current increase switch 21 and a scan room X-ray on switch 22.

By providing the foot switch 20 in this manner, it is possible to instruct the irradiation of X-rays when necessary even while the operator is puncturing the needle. Further, the operation of the gantry rotation synchronization control device 23 does not matter even if the X-ray on-switch 22 for the scan chamber is pressed for a short period.
Operability is also good.

<Structure (2) of X-ray CT apparatus> Here, the X-ray CT apparatus used in the X-ray imaging method according to the second embodiment of the present invention, and the second embodiment of the present invention. The configuration of the X-ray CT apparatus, which is an example of the above embodiment, will be described with reference to FIG.

Here, in addition to the tube current increase switch 21 and the scan room X-ray ON switch 22 in the scan chamber 200, another switch is provided to further facilitate the operation X.
3 shows a line CT device.

In FIG. 5, the WL foot switch 2
4 and the WW foot switch 25 are provided, which is different from the above-described FIG. Further, the image display control device 70 is
The WL and WW of the image to be displayed can be controlled by receiving the operation of the L foot switch 24 and the WW foot switch 25.

Incidentally, this WL foot switch 24 and WW
The foot switch 25 is preferably a foot switch having an up pedal and a down pedal for easy operation.

Here, WL (window level), WW
(Window width) will be explained. In a medical diagnostic device such as an X-ray CT device, image data of a tomographic image of a subject is generated and displayed on an image display device such as a CRT display. In such a case, the pixel value of the image data (CT value in the case of an X-ray tomography apparatus) is determined by the X-ray transmittance, and generally air is -1000, water is 0, and bone is +2000. Has been set.

Then, the pixel value of such image data is converted into display data of about 256 gradations for image display. The number of gradations of the display data in this case differs depending on the circuit configuration of the image display circuit or the CRT display, but generally, the gradation number of about 256 gradations for processing the density data in 8 bits, The range of −1000 to +2000 of the pixel value of the image data is not displayed as it is.

Therefore, if the entire range of pixel values of the image data is assigned to the display data, -1 in the above example.
Since 000 to +2000 are assigned to 256 gradations, it becomes difficult to display fine gradation changes. For example, the pixel value of the organ of the subject to be noticed is -150 to +
Since it is distributed in 150, the whole organ is displayed in the same gradation, which causes a problem.

Therefore, the concept of the window width (WW) is introduced, image data within the range of the upper limit value and the lower limit value of the window width is converted into display data to display the image in shades, and the upper limit value is set. The part that exceeds the upper limit is displayed in white or black, and the part that does not reach the lower limit is displayed in black or white.
By doing so, it becomes possible to display the change in the range of the image data to be noticed.

The range of the image data to be converted into the display data when such a display is performed is defined by the window width (W
W) and the center value of the window width is called the window level (WL).

Therefore, the WL foot switch 24 and the WW
Image data converted according to a value input by the operator via the foot switch 25 is generated by the image display control device 70, and the image display is performed on the CRT display device 70. That is, the image data of the CT value in the range desired by the operator is displayed in shades.

With such a configuration, there is an advantage that even when such operation of WL and WW is repeatedly performed by changing the window level, the operation can be performed in the scan chamber 200.

That is, the state of the biopsy can be accurately grasped, and the biopsy or X-ray irradiation can be completed in a short time. Therefore, the result of X-ray irradiation can be effectively utilized.

In addition to the WL foot switch 24 and the WW foot switch 25, a cursor control switch is provided to move the cursor or enlarge the cursor.
It is also possible to give an instruction from 00. Also by doing so, various operations from the scan room can be performed easily, and the result of X-ray irradiation can be effectively utilized.

The foot switch 20 controls various image display-related controls other than the WW, WL, and cursor controls shown here.
It is also possible to carry out. By controlling various image display-related items in this manner, the operability in the scan chamber 200 when performing a biological tissue examination or the like is improved.

<Effects Obtained by Embodiments: Comparison with Prior Art> As described above, according to the X-ray ON signal from the operation console and the operation of the X-ray switch in the scan room, the rotation of the gantry is synchronized. According to the X-ray imaging method and the X-ray CT apparatus that control the X-ray irradiation at the timing, the effects described below can be obtained.

According to the X-ray ON signal from the operation console and the operation of the X-ray switch in the scan room, the X-ray irradiation is controlled at the timing synchronized with the rotation of the gantry. As a result, the X-ray irradiation is controlled from the scan room. Therefore, it is possible to prevent unnecessary exposure to the subject and the operator even when X-ray irradiation is performed when the operator is performing the biological tissue examination on the subject.

As a result of the above-mentioned X-ray control being performed such that the X-ray state does not change for a period necessary to reconstruct at least one image, a simple switch operation can be performed from within the scan room. Since it becomes possible to control the X-ray irradiation, it is possible to prevent the subject and the operator from being unnecessarily exposed to radiation even when the operator is performing a biopsy on the subject. become.

A tube current increasing switch for temporarily increasing the tube current supplied to the X-ray tube is provided in the scan chamber, and an operation for temporarily increasing the tube current supplied from the scan chamber to the X-rays can be performed if necessary. As a result, the X-ray dose can be increased from the scan room as needed,
It is possible to keep the usual X-ray dose low. For this reason, the subject and the operator will not be uselessly exposed to radiation even when X-ray irradiation is performed when the operator is performing a biological tissue examination on the subject.

As a result of providing various control operations (operation of window level and window width) when displaying an image from the scan room by providing a control switch for controlling the display of the reconstructed image in the scan room. The window level and window width of the image reconstructed from the scan room can be changed as necessary, so that a desired image can be displayed from the scan room. Therefore, even when X-ray irradiation is performed when the operator is performing a biological tissue test on the subject,
It is possible to accurately grasp the state of the biopsy, and it is possible to finish the biopsy and X-ray irradiation in a short time.

[0104]

The X-ray imaging method and the X-ray imaging method described in detail above
According to the line CT device, the following effects (1) to (5) can be obtained.

(1) In the X-ray imaging method of the first invention, when the X-ray ON signal is output from the operation console and the X-ray switch in the scan room is operated, the timing is synchronized with the rotation of the gantry. Control is performed so as to perform X-ray irradiation.

As a result of doing so, X from the scan chamber
Since it becomes possible to control the irradiation of X-rays, X when the operator is performing a biopsy on the subject.
The subject and the operator will not be uselessly exposed to radiation such as irradiation.

(2) In the X-ray CT apparatus of the second invention, when the X-ray ON signal from the operation console is output and the X-ray switch in the scan room is operated, the timing is synchronized with the rotation of the gantry. Control is performed so as to perform X-ray irradiation.

As a result of the above operation, X
Since it becomes possible to control the irradiation of X-rays, X when the operator is performing a biopsy on the subject.
The subject and the operator will not be uselessly exposed to radiation such as irradiation.

(3) In the X-ray CT apparatus of the third aspect of the invention, the X-ray control means in the X-ray CT apparatus of the second aspect of the invention causes the X-ray ON signal from the operation console to be output and the X-ray of the scan room to be detected. When the line switch is operated, control is performed so that X-ray irradiation is performed for a period necessary to reconstruct at least one image at a timing synchronized with the rotation of the gantry.

As a result, the X-ray irradiation can be controlled by a simple switch operation from the scan room, so that when the operator is inspecting the living body tissue, The subject and the operator will not be uselessly exposed to X-ray irradiation.

(4) In the X-ray CT apparatus of the fourth invention, in the X-ray CT apparatus of the second invention, a tube current increasing switch for temporarily increasing the tube current supplied to the X-ray tube is provided in the scan chamber or It is possible to perform an operation for temporarily increasing the tube current supplied to the X-ray from the scan room or the operation room, provided in the operation room.

As a result, the X-ray dose can be increased from the scan room or the operation room as required, and the normal X-ray dose can be kept low. For this reason, the subject and the operator will not be uselessly exposed to radiation even when X-ray irradiation is performed when the operator is performing a biological tissue examination on the subject.

(5) In the X-ray CT apparatus of the fifth invention, in the X-ray CT apparatus of the second invention, a control switch for performing control when displaying the reconstructed image is provided in the scan chamber, and the scan is performed. Various control operations are possible when displaying an image from the room. As various controls in this case, a window level, a window width, etc. are applicable.

As a result, the window level and the window width of the image reconstructed from the scan room can be changed as needed, so that the desired image can be displayed from the scan room. Therefore, it becomes possible to accurately grasp the state of the biological tissue inspection even when the operator is performing the biological tissue inspection on the subject, such as X-ray irradiation. Can be completed in a short time.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration example of an X-ray CT apparatus according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing a procedure of an X-ray imaging method according to the first embodiment of the present invention.

FIG. 3 is a time chart showing the procedure of the X-ray imaging method according to the first embodiment of the present invention.

FIG. 4 is an actual layout diagram showing states of an operation room and a scan room.

FIG. 5 is a configuration diagram showing a configuration example of an X-ray CT apparatus according to a second embodiment of the present invention.

FIG. 6 is a configuration diagram showing a configuration example of a main part of a conventional X-ray CT apparatus.

[Explanation of symbols]

 10 Operation Console 11 Scan Start Switch 20 Foot Switch 21 Tube Current Increasing Switch 22 Scan Room X-ray On Switch 23 Gantry Rotation Synchronous Control Device 31 Tube Current Increasing Device 32 X-ray Generator 33 Gantry Rotation Control Device 40 Mode Switching Section 41 Logic Circuit 42 changeover switch 50 gantry 51 X-ray tube 52 subject 53 X-ray detector 54 data acquisition device 60 image reconstruction device 70 image display control device 80 image display device for operation console 90 image display device for scan room

Claims (5)

[Claims] 1. An X-ray imaging method, wherein X-ray irradiation is controlled at a timing synchronized with rotation of a gantry according to an X-ray ON signal from an operation console and an operation of an X-ray switch in a scan room. 2. An X-ray control means for controlling the X-ray irradiation at a timing synchronized with the rotation of the gantry according to an X-ray ON signal from the operation console and an operation of the X-ray switch in the scan room. X-ray CT system. 3. The X-ray control means performs control such that the X-ray state does not change for a period required to reconstruct at least one image. The described X-ray CT apparatus. 4. The X-ray CT apparatus according to claim 2, further comprising a tube current increasing switch for temporarily increasing the tube current supplied to the X-ray tube in the scan room or the operation room. 5. The X-ray CT apparatus according to claim 2, further comprising a control switch provided in the scan chamber for performing control when displaying the reconstructed image.