JPH0678915A - Ct device - Google Patents

Abstract

PURPOSE:To hold down the shift amount of a CT value to the minimum at the time of photographing an X-ray sectional image of a subject and to remarkably reduce the trouble and time by aligning the center of an area to be photographed for the subject with the center of a photographing area automatically. CONSTITUTION:When a bed is inserted in a frame 2, a difference between the position of a subject 5 placed on the top plate 4 of the bed 1 and the center position of section photographing is detected by the frame 2, and according to the detection result, a control device 3 generates a control signal required for eliminating a difference between the position of the subject 5 and the center position of section photographing to control a driving mechanism 7 of the bed 1, whereby the position of the subject 5 placed on the top plate 4 is aligned with the center position of section photographing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CT apparatus for automatically recognizing a height position or a left and right position of a subject.

[0002]

2. Description of the Related Art X-ray CT used as a medical device
In the device, the subject is placed on the top plate, and the top plate is inserted into a frame-shaped mount having a hole formed in the central portion, and the observation target part of the subject matches the slice surface of the mount. At the same time, after adjusting the position of the subject so that the axis of the subject and the axis of the pedestal coincide with each other, X-rays are emitted from an X-ray tube provided in a part of the pedestal. While irradiating the subject, an X-ray cross section of the subject is detected by detecting an X-ray transmitted through the subject by a detector provided on the gantry and reconstructing the X-ray by an image reconstruction circuit. An image is generated and displayed on a CRT or the like.

[0003]

However, in the above-mentioned conventional CT apparatus, although the top panel height and the like can be operated and displayed by the operation panel provided on the gantry or bed, Even if the height is kept constant, the center of the part to be imaged of the subject and the center of the imaging area often do not match.

In such a case, in the conventional CT apparatus, the CT value is shifted and an X-ray sectional image is generated. However, in this method, when a doctor or the like interprets the X-ray sectional image, it is misread. There is a risk that

Therefore, when an X-ray cross-sectional image of the subject is taken, the technician repeatedly adjusts the height position and the left and right positions of the top plate to adjust the center of the subject to be imaged and the imaging area. Since it is made to coincide with the center of, there is a problem that it takes too much time and effort.

In view of the above circumstances, the present invention can automatically match the center of the portion of the subject to be imaged with the center of the image capturing area, thereby minimizing the shift amount of the CT value. Moreover, it is an object of the present invention to provide a CT apparatus that can significantly reduce the time and effort required to take an X-ray sectional image of a subject.

[0007]

In order to achieve the above-mentioned object, a CT apparatus according to the present invention comprises a bed having a drive mechanism for moving a top plate in vertical and horizontal directions, and when the bed is inserted, A gantry that detects a deviation between the position of the subject placed on the top of the bed and the center position of the cross-sectional imaging, and the position and cross-section of the subject based on the detection result obtained by the gantry. And a control device for controlling the drive mechanism of the bed by generating a control signal necessary for eliminating the deviation from the center position of photographing.

[0008]

In the above structure, when the bed is inserted through the gantry, the gantry detects a deviation between the position of the subject placed on the tabletop of the bed and the center position of the cross-sectional radiographing. , The control device generates a control signal necessary for eliminating the deviation between the position of the subject and the center position of the cross-section imaging based on the detection result, controls the drive mechanism of the bed, and controls the top plate. The position of the subject to be placed and the center position of the cross-sectional image are matched.

[0009]

1 is a block diagram showing an embodiment of a CT apparatus according to the present invention.

The CT apparatus shown in this figure has a bed 1 and a gantry 2
And a control device 3, the subject 5 is placed on a top plate 4 which constitutes the bed 1, and the top plate is mounted on a frame-shaped mount 2 having a hole (dome) formed in a central portion thereof. When 4 is inserted, the gantry 2 detects a deviation between the observation target portion of the subject 5 and the imaging center of the gantry 2, and the tabletop position of the bed 1 is adjusted so that the deviation becomes zero. After the automatic adjustment, X-ray from the X-ray tube 10 provided on a part of the gantry 2
While emitting a line and irradiating the subject 5 with the line, the detector 5 provided on the mount 2 causes the subject 5 to move.
X-rays that have passed through are detected and reconstructed by an image reconstruction circuit to generate an X-ray sectional image of the subject 5, which is displayed on a CRT or the like (not shown).

The bed 1 is a pedestal portion 6 which is movable.
And a top plate 4 which is arranged on the pedestal portion 6 and is movable in the vertical and horizontal directions with respect to the pedestal portion 6.
And a drive mechanism 7 that is disposed in the pedestal portion 6 and moves the top plate 4 in the up-down direction and the left-right direction based on a control signal output from the control device 3. When an X-ray cross-sectional image is taken, the subject 5 is placed on the top plate 4, and then the technician or the like moves the bed 1 to be inserted into the dome portion of the gantry 2. In this state, the control device The drive mechanism 7 operates based on the control signal output from the control unit 3 to move the top plate 4 in the vertical direction and the left-right direction, and the observation target of the subject 5 placed on the top plate 4 by this movement. The part and the photographing center of the gantry 2 are aligned.

Further, the pedestal 2 has a fixing portion 8 having a round hole formed in the central portion and a square outer shape, and the fixing portion 8
Rotating part 9 rotatably provided in the hole, an X-ray tube 10 arranged in the rotating part 9, and X-ray detection provided on the side of the rotating part 9 facing the X-ray tube 10. Bowl 1
1, inside the rotating unit 9 and at a position not far from the slice plane formed by the X-ray tube 10 and the X-ray detector 11 as shown in FIG. On the other hand, it is provided with a plurality of light emitting units 12 and light receiving units 13 which are arranged in a lattice so as to be each size unit.

When the position measurement command is supplied,
While causing each light emitting unit 12 to emit light, a signal (light receiving / light shielding signal) indicating whether or not the light from the corresponding light emitting unit 12 is being received by each light receiving unit 13 is generated and supplied to the control device 3. .

As shown in FIG. 4, the control device 3 has an input interface circuit 15 for receiving the light receiving / shading signals output from the gantry 2 and a CPU for processing the light receiving / shading signals received by the input interface circuit 15.
16 and a ROM 17 in which a program defining the operation of the CPU 16 and various constant data are stored, and various keys. When these keys are operated, a key signal is generated to generate the key signal. Keyboard 18 supplied to the CPU 16, a RAM 19 used as a work area of the CPU 16, a display interface circuit 20 that takes in display data output from the CPU 16 and creates screen data, and an output from the display interface circuit 20. CRT21 that displays the screen data
The communication interface circuit 22 which takes in the control data output from the CPU 16 to generate a control signal and transmits the control signal to the bed 1 is provided.

Then, as shown in FIG. 5, when the correlation position between the subject 5 placed on the bed 1 and the gantry 2 is measured, the light receiving / shading signals output from the gantry 2 are taken in ( In step ST1), the deviation between the center of the observation target portion of the subject 5 placed on the top plate 4 of the bed 1 and the imaging center of the gantry 2 is calculated (step ST1).
2) Generate a control signal required to match these and supply this to the bed 1.

As a result, the center of the portion of the subject 5 to be observed placed on the drive mechanism 7 of the bed 1,
The top plate 4 is moved vertically and horizontally so that the photographing center of the gantry 2 coincides (steps ST3, S).
T4).

After that, when an imaging command is supplied, X-rays are emitted from the X-ray tube 10 to irradiate the subject 5 placed on the top plate 4 with the X-ray detector. 1
An image processing unit (not shown) arranged outside the gantry 2 for detecting X-rays transmitted through the subject 5 by means of 1
Supply to.

As described above, in this embodiment, the subject 5 is placed on the table 4 which constitutes the bed 1, and the table 5 is mounted on the table 2.
When it is inserted into the dome, the position of the observation target portion of the subject 5 is detected by the plurality of light emitting units 12 and the plurality of light receiving units 13 provided on the gantry 2, and the control device 3 detects the position based on the detection result. A control signal necessary to match the center of the observation target portion of the subject 5 with the imaging center of the gantry 2 is generated to move the top plate 4 of the bed 1 vertically and horizontally. Therefore, the center of the part to be imaged of the subject 5 and the center of the imaging area can be automatically made to coincide with each other, whereby the CT value shift amount when the X-ray sectional image of the subject 5 is taken can be set. It can be kept to a minimum and the labor and time can be greatly reduced.

[0019]

As described above, according to the present invention, the center of the portion to be imaged of the subject and the center of the image capturing area can be automatically made to coincide with each other, whereby X-rays of the subject are obtained. The CT value shift amount when capturing a cross-sectional image can be minimized, and labor and time can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a CT apparatus according to the present invention.

FIG. 2 is a cross-sectional view of the mount shown in FIG.

FIG. 3 is a schematic diagram showing an arrangement example of each light emitting unit and each light receiving unit provided on the gantry shown in FIG.

FIG. 4 is a block diagram showing a circuit configuration example of the control device shown in FIG. 1.

5 is a flowchart showing an operation example of the CT apparatus shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bed 2 Stand 3 Control device 4 Top plate 5 Examinee 6 Pedestal part 7 Driving mechanism 8 Fixed part 9 Rotating part 10 X-ray tube 11 X-ray detector 12 Light emitting part 13 Light receiving part 15 Input interface circuit 16 CPU 17 ROM 18 Keyboard 19 RAM 20 Display interface circuit 21 CRT 22 Communication interface circuit

Claims (1)

[Claims] 1. A bed having a drive mechanism for moving the tabletop in the up-down direction and the left-right direction, and a position and a cross-sectional image of a subject placed on the tabletop of the bed when the bed is inserted. A pedestal that detects the deviation from the center position of the subject, and a control signal that is necessary to eliminate the deviation between the position of the subject and the center position of the cross-sectional image is generated based on the detection result obtained by this gantry. And a controller for controlling the drive mechanism of the bed.