JPS639427A - Positioning apparatus of ct apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides a position tomograph for a radiation tomography apparatus that allows anyone to easily perform positioning.
(Computeriz@d Tomography
There is a device called a CT rack device (hereinafter abbreviated as a CT rack device).

As shown in FIG. 5, this device includes an X-ray source 1 that pulses 7-am beam X-rays FX1 that spread out in a flat fan shape, and a plurality of radiation detection cells DI-1 that detect the X-rays.
The X-ray source 1 and the radiation detector 2, which are arranged in parallel, face each other with the subject 3 interposed therebetween, and the X-ray source 1 and the radiation detector 2 are rotated synchronously in the same direction with respect to the subject 3. and collect X-ray absorption data in various directions of the cross section of the object 3.

After collecting sufficient data, this data is analyzed by a computer to calculate the X-ray absorption rate for each position on the tomographic plane of the subject, and the gradation level corresponding to the absorption rate is Since it is designed to reconstruct and analyze in as many as 4,000 gradation levels depending on one composition, clear tomographic images can be obtained from soft tissues to hard tissues.

In this sophisticated CT system, it is first necessary to set the tomographic plane of the patient's observation area within the imaging region (within the area where fan beam X-rays from all directions overlap among rotating fan beam X-rays). However, since the shooting area cannot be seen with the naked eye, it is difficult to accurately enter this area.

Furthermore, in order to obtain a good image, it is necessary to set the tomographic plane of the patient's observation target region in the center of this area, but this is even more difficult.

Particularly, among the data collected by the detector, the data of the part that is outside the tomographic plane is wasted, so the relative positions of the radiation source and the detector with respect to the subject are moved to change the imaging area.
It is even more difficult to make the area (target area) variable in width depending on the size of the fault plane.

In order to perform this positioning, conventionally, a projector is provided on the front side of the gantry to project a positioning spot across the imaging hole.

That is, as shown in Fig. 6, the CT apparatus has a mechanism for supporting the X-ray tube 1 and the detector 2t and rotating them around the tomographic plane of the subject. That's what I say. The gantry 4 is provided with an imaging hole 4a in the center for placing the patient, and the X-ray tube 1 and the detector 2 face each other through the imaging hole 4&.

Therefore, the bed top 5t in a horizontal state is inserted into the photographing hole 4a to photograph the tomographic plane of the subject 3 on the bed top 5. However, when photographing a tilted cross section, The gantry itself will be tilted.

Therefore, in order to know the degree of inclination of the gantry with respect to the subject 3, the gantry is equipped with optical positioning that projects a spot 6h near the imaging hole 4a in a direction parallel to the plane of the fan beam XR of the X-rays. A floodlight 6 is provided for use.

Therefore, when positioning, the bed top 5t is moved to locate the target area of the subject 3 on the bed top 5 (spora of the projector 6).
After adjusting to the 5 m position, the height of the bed top 5 is adjusted, and the bed top 5 is sent by a predetermined amount to the gantry 4 side to align the target region with the imaging area. fan beam x
The thickness S of H becomes the slice thickness, and X-ray absorption data within this slice thickness S can be collected.

Since the slice thickness S is normally on the order of several millimeters, the pitch is shifted by 8 slice thicknesses to obtain 07 images of multiple cross-sections and used for diagnosis.

Therefore, unless the position is set correctly, images that can be used for diagnosis cannot be obtained. and.

One of the conditions for correctly setting the position is to operate the bed top 5 so that the target region falls within the imaging area. However, the bed top plate 5 has operation buttons for upward, downward, forward and backward movement, etc., and these must be selected and operated as appropriate, making this task difficult to perform unless you are familiar with the operation. Therefore, positioning and imaging of the subject must rely on the hands of a person who is familiar with operating the OCT apparatus, and an inexperienced person cannot satisfactorily image the target region.

(Problems to be Solved by the Invention) Conventionally, when photographing a target region of a patient (subject) using a CT device, the patient (subject) has to place the target region within the imaging area of the CT device. It is necessary to set the specimen, but the positioning work is extremely troublesome unless you are an experienced person, as the imaging area is located in a space where no landmarks can be placed. The problem is not solved by detecting the size of the subject and automatically adjusting the height of the bed top so that the subject is at the optimal position in the imaging area.

By the way, in general, on holidays, Saturday afternoons, and at night, the staff who handle the CT apparatus often go home and are not present.

On the other hand, it is not known when an emergency case will occur, and a situation may arise in which a patient wants to perform CT imaging for diagnosis even if there is no staff to handle the CT device.

However, as mentioned above, it is difficult for amateurs to position the CT apparatus, so it is difficult to satisfy such a requirement.

By the way, in the case of emergency treatment, it is usually sufficient to approximate the location where CT imaging is desired. This is because it is sufficient to grasp the situation of the part that is considered to be the affected area.

Therefore, an object of the present invention is to make it possible to reliably perform CT imaging of that region by placing the patient in a fixed position on the bed top of a CT device and specifying the target region. It is an object of the present invention to provide a positioning device for a CT device which allows even a person who is inexperienced in handling the CT device to handle it.

[Configuration of the Invention (Means for Solving Problems) To achieve the above object, the present invention is configured as follows. That is, a bed top plate has a mark in advance indicating the placement position of the body part to be imaged at a predetermined position on the top plate, switches for selecting the body part to be imaged are provided corresponding to the marks, and switches corresponding to these switches are provided. an imaging area determining means for determining the size of the imaging area of the CT apparatus; a selection means for selecting a top plate movement position and a height position to the imaging position of the CT apparatus in correspondence with the switch; and a top plate position. a detection means for detecting, a control means for comparing the detection value of the detection means with reference to the selected position of the melodic selection means and generating a control amount necessary for the detection value to reach a reference value; and a driving means for adjusting the position of the top plate according to the position of the top plate.

(Function) In this configuration, the operator first places the subject on the top plate by aligning the target part of the subject with the mark attached to the corresponding position on the top plate, and then places the subject on the top plate. Press the switch corresponding to that part. As a result, the imaging area is selected, and the selection means selects the top plate movement position and height position of the CT apparatus to the imaging position, and the detection means outputs the selected value as a reference value. The positions of the top plates are compared. The control means generates a control amount necessary for the detected value to reach the reference value, and drives the drive means in accordance with this control amount,
Adjust the position of the top plate.

As a result, the position that the top plate should reach is the position where the mark on the top plate matches the slice position of the CT device, and the position that the top plate should reach in the vertical direction is the bottom of the subject. The headrest and top plate are automatically adjusted so that they are located at the bottom of the imaging area, so the subject is placed on the top plate so that the target area is at the position of the mark corresponding to the area on the top plate. Then, by simply selecting the positioning switch, the optimal imaging area size for imaging is selected and set, and the top plate is positioned so that the mark position corresponding to the selection switch matches the slice position of the CT device. The height is automatically set so that the headrest or top plate, which is the lowest part of the subject, is at the lowest position in the imaging area, ensuring that the target area is within the imaging area.

Therefore, anyone can easily and reliably image a target region by simply arranging the subject so that the target region is located at the position of the mark corresponding to the region on the top plate.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of this apparatus, and FIG. 2 is a plan view showing the configuration of the bed top plate.

In this apparatus, the bed top plate portion 10t is constructed as shown in FIG. That is, in the figure, 1oa is a bed section, and a top plate section 10b is provided on the top of the bed section 1oa so as to be movable in the longitudinal direction thereof. The bed section 10m allows the top plate section 10b to be raised and lowered by a built-in drive mechanism. In addition, in order to designate the place where the subject is placed on the top plate part 10b, for example, "
Characters such as ``Head'', ``Lungs'', and ``Liver'' and their placement areas are marked.

In FIG. 1, 11 is a positioning switch, and the third
As shown in the figure, align it with the above marks on the top plate,
Push methane switch with words such as ``lung'' and ``liver'' °1
There are 1m, Ilb, and lla.

Reference numeral 12 designates an imaging area determination circuit. When one of the push methane switches 11&+11bll16 is selected and pressed, the imaging area determination circuit 12 selects the imaging area PER or B corresponding to the part of the subject to be imaged. (See Figure 4).

For example, if the switch 11a labeled "Head" is pressed, a small imaging area suitable for imaging the head is selected. Which area to select is determined in advance.

Reference numeral 13 & is a destination position selection circuit for selecting the destination position of the top plate in the vertical direction, and reference numeral I3b is a destination position selection circuit for selecting the destination position of the top plate in the advancing/retracting direction with respect to the gantry. Each of these selects a preset top reach position in the area selected by the switch 11 in response to input from the positioning switch 11 and input from the imaging area determining circuit 12.

14a is a comparison circuit for the vertical direction of the top board, and 14b is a comparison circuit for the forward/backward direction of the top board with respect to the gantry, and the corresponding arrival position selection circuits 13m+13b obtain the arrival position information and respond based on this. Position detector 17 m
The detected position information from +17b is compared to detect whether or not they match.

15& is a drive control circuit for the top plate in the vertical direction, 16b is a drive control circuit for the top plate in the forward and backward direction with respect to the gun l,
Drive to move the position of the top until the top reaches the position and height determined by the destination position selection circuits 13* and 13b according to the outputs of the corresponding comparison circuits 14m* and 14b. A driving unit 16* for moving and operating.

16bt-controlling. That is, the driving unit of the top plate is controlled to drive until the current position and the desired position match. At this time, a sequencer 18 is provided to control the vertical position first and then the horizontal movement (reverse direction movement). The position detector 17
17b detects the current position of the top plate, the position detector 17a detects the height position of the top plate, and the position detector 27aK detects the position of the top plate in the forward/backward direction.

As the position detectors 17h and 17b, a detector that outputs an absolute position, such as a potentiometer 1 meter, is used.

The position that the bed top should reach is the position where the mark position made on the bed top matches the slice position S of the CT apparatus.

Further, the position to be reached in the vertical direction of the bed top is determined so that the headrest and the bed top, which are the lowest part of the subject, are at the position shown in FIG. t, b, When using a shift-type CT device in which the X-ray tube 1 and the detector 20 rotation center O can be moved to select the imaging area A or B, when the head is selected. is a small shooting area A
is selected, and when the lungs and liver are selected, the large imaging area B
The center of rotation 0 of the X-ray tube 1 and the detector 2 is moved so that the image capturing area is selected. Therefore, when the head is specified, the height is set such that the headrest 10c is placed at the lowest position of the photographic area size selected at that time.

Further, when the lungs or liver are specified, a large imaging area B is selected, so the height is set so that the entire top plate is at the lowest position within the imaging area B.

Next, the operation of this device having the above configuration will be explained.

First, the operator places the subject on the top plate 10b so that the part of the subject to be imaged is located at the corresponding marking position. At this time, since the X-ray CT apparatus moves the slice position of the subject and takes a number of images, the first slice is aligned with the mark.

After setting the subject, press switch 1 for automatic positioning of the part you want to photograph. This switch 11 is marked with a mark corresponding to the mark shown in FIG. 2, as shown in FIG. When this switch is pressed, the photographing area determination circuit 12
The imaging area is determined in accordance with the part of the subject to be imaged (see FIG. 4).

For example, if the user presses the switch "One head", a small imaging area A suitable for photographing the head is selected. Which area to select is determined in advance.

That is, for each of the six switches 11a to 11ie in FIG. 3, it is determined which of the photographing areas A and B in FIG. 4 is selected.

Once the imaging area is determined, the reached position selection circuit 13
The position and height to be reached by the top plate 10b are determined by m and 13b, and the drive units 16h and 16b are operated under the control of drive control circuits 11m and 17b until the current position and the position to be reached coincide. Operate. At this time, the sequencer 18 controls the top plate so that it is first positioned vertically and then horizontally. Position detector 7 detects the current position.
7 a * Z 7 b, and the comparator circuit 141
At 14b, the current position and the position to be reached are compared and the drive movement of the top board by the drive units 16g and 11b continues until they match.The position detector may be a detector that outputs an absolute position, for example, A 4-tensile meter or the like is used, but even if the current position is not known, it is sufficient to have a sensor that can tell which direction to move and detect the position to be reached.

In this case, when setting the subject on the top plate, the initial state is always set, for example, the top plate is lowered to the lowest position on the bed and is at the farthest position from the gantry, so the positioning operation begins. It is only necessary to make sure that the top plate always moves in the upward direction and in the f-entry direction. Alternatively, only a detector whose state changes depending on the position to be reached may be used. In this case, if there is a detector that outputs rOJ if it has not arrived, and "1" if it has arrived, you can check its status and know whether to move it up or down or in the direction of advance or retreat with respect to the gantry. The movement operation may be controlled to stop at the position where the output is switched.

As a result, the position to be reached by the top plate 10b is the position where the mark made on the top plate 10b coincides with the slice position S of the CT apparatus. In addition, the position to be reached in the vertical direction of the top plate 10b is such that the headrest, which is the lowest part of the subject, and the top plate are at the fourth position.
The position will be as shown in the figure. Therefore, by simply selecting the positioning switch 11, the optimal imaging area size for imaging is selected, and the top plate is positioned so that the mark position corresponding to the selection switch matches the slice position S of the CT device. The height is also set so that the headrest or top plate, which is the lowest part of the subject, is at the lowest position of the imaging area, so that the target part is reliably placed within the imaging area.

As described above, the present invention attaches a mark in advance to a predetermined position on the top plate of a CT apparatus to indicate the placement position of the region to be imaged, and
Switches for selecting the imaging region are provided corresponding to these marks, and an imaging area determining means is provided for determining the size of the imaging region of the CT apparatus in correspondence with these switches, and an imaging area determining means for determining the size of the imaging area of the CT apparatus in correspondence with the switches. A selection means for selecting a top plate movement position and a height position to a photographing position, a detection means for detecting a position of the top plate, and a detection value by comparing the detection value of the detection means with reference to the selected position of the selection means, and detection. a control means for generating a control amount necessary for the value to reach the reference value;
The apparatus is constructed with a driving means for adjusting the position of the top plate according to this control amount. Then, place the subject on the top plate by aligning the target area of the subject with the mark attached to the corresponding position on the top plate, and press the switch corresponding to that area to select the imaging area. , also, depending on the selection means
The top movement position and height position of the T device to the photographing position are selected, and the top position output from the detection means is compared with the selected value as a reference value. Then, the control means generates a control amount necessary for the detected value to reach a reference value, and drives the drive means in accordance with this control amount to adjust the position of the top plate.

As a result, the position that the top plate should reach is the position where the mark made on the top plate matches the slice position of the CT device9, and the position that the top plate should reach in the vertical direction is the bottom of the subject. The headrest and top plate are automatically adjusted so that they are located at the bottom of the imaging area, so the subject is placed on the top plate so that the target area is at the position of the mark corresponding to the area on the top plate. Then, by simply selecting the positioning switch, the optimal imaging area size for imaging is selected and set, and the top plate is positioned so that the mark position corresponding to the selection switch matches the slice position of the CT device. The height is automatically set so that the headrest or top plate, which is the lowest part of the subject, is at the lowest position in the imaging area, ensuring that the target area is within the imaging area.

Therefore, anyone can easily and reliably image a target region by simply arranging the subject so that the target region is located at the position of the mark corresponding to the region on the top plate.

It should be noted that the present invention is not limited to the embodiments described above and shown in the drawings, but can be implemented with appropriate modifications within the scope without changing the gist thereof.

[Effects of the Invention] As detailed above, according to the present invention, anyone can easily and reliably simply place the subject so that the target region is located at the position of the mark corresponding to the region on the top plate. C, which has characteristics such as being able to perform imaging of the target area
A positioning device for a T device can be provided.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a plan view showing the configuration of a bed top plate used in the invention, Fig. 3 is a diagram showing an example of a positioning switch, and Fig. 4 is a diagram showing a selection switch. FIG. 5 is a diagram illustrating the principle of the CT apparatus, and FIG. 6 is a diagram illustrating its appearance. 10... Bed top plate part, 10a... Bed part, 10b.
...Top plate part, 10C...Headrest part, 11...
Positioning switch, 11 m + 1 l b + 1
1 e... Push-♂ button switch, 12... Imaging area determination circuit, 13a. JJb... Arrival position selection circuit, 14h, 14b...
Comparison circuit, 15m, 15b... Drive control circuit, 16a. 16 b--Drive unit, 17*, 17b- Position detector, 18 Sequencer. Applicant's representative Patent attorney Takeshi Suzue Syllable 1 Figure 0a 0b Suspension 2 Figure 4 Figure 5

Claims (1)

[Claims] A bed top plate has a mark attached to a predetermined position on the top plate to indicate the placement position of the region to be imaged, a switch for selecting the region to be imaged is provided corresponding to each mark, and a CT a photographing area determining means for determining the size of the photographing area of the device; and C corresponding to the switch.
A selection means for selecting a top plate movement position and a height position to the photographing position of the T device, a detection means for detecting the position of the top plate, and a comparison of detected values of the detection means with reference to the selected position of the selection means. A positioning device for a CT apparatus, comprising: a control means for generating a control amount necessary for a detected value to reach a reference value; and a drive means for adjusting the position of the top plate in accordance with the control amount.