JPH06296604A - X-ray computer tomography device - Google Patents

Abstract

PURPOSE:To execute a positioning operation without the intervention of an operator by providing a means for detecting that a photographing area comes to the scan surface, and a means for starting to photograph the photographing area in response to the detection of the detecting means. CONSTITUTION:When a photographing start instruction from an operator is received, a scan control part 1 outputs a control signal to a top board control part 6 so as to slide a top board 10. The top board 10 is driven by a top board driving device 9, allowed to slide toward an opening part of a gantry, and when the head top part of an examinee reaches the scan surface, the head top part is detected by an examinee position detector 12. The detecting signal is sent to the scan control part 1 through the top board control part 6, and the scan control part 1 instructs of a breathing-stop start by controlling a breathing-stop instructing device 7 and an X-ray generating part 2, and starts to charge up a high voltage by the X-ray generating part 2. Also, a rotation of a frame on which an X-ray tube and an X-ray detector are provided, is started by a frame control part 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray computer tomography apparatus having a predetermined scan plane and photographing a desired photographing region while inserting a subject placed on a top plate into the scan plane. Regarding

[0002]

2. Description of the Related Art In general, imaging by an X-ray computed tomography apparatus requires a positioning work performed in advance. This positioning refers to aligning a start surface of a desired cross-section of a subject or a scan surface within a gantry when three-dimensional scanning is performed, and various methods are adopted.

The main methods are a method using a light projector and a method using a scanogram. The former method is to actually project a beam of light, which defines the scan plane emitted from a projector provided in the gantry, onto the subject,
This is a method of sliding the top plate by manual operation. In the latter method, when the shooting direction is fixed and the above cross-section or 3D scan area is specified on the scanogram displayed on the monitor, the automatic slide mechanism that links this specification device and the bed is used. This is a method in which the top plate is automatically slid to perform alignment.

When the alignment is completed, the operator waits for a photographing start instruction, and the photographing is started in accordance with a predetermined sequence by the control unit for overall control of the apparatus. Ends.

By the way, in such a conventional X-ray computer tomography apparatus, it takes a long time for the entire inspection process including the above-mentioned positioning work, in other words, the number of persons inspected per unit time, that is, the inspection throughput is low. There is a problem that the operator has a large manual operation range and imposes a burden on the operator, and is not suitable for mass screening, which is often performed in lung cancer examinations, for example. Most of the causes of this problem are accounted for by the positioning work. That is, as described above, the positioning work requires that the top plate be manually slid or the scanogram be photographed in advance with reference to the beam light from the projector. Various proposals have been made for simplifying and labor saving this positioning work, but all of them require a lot of operator's intervention, though not so much as the above positioning work.

[0006]

SUMMARY OF THE INVENTION It is therefore an object of the present invention that the positioning operation can be performed without operator intervention, thereby reducing the overall inspection time.
A line computer tomography device is provided.

[0007]

According to the present invention, a desired imaging region of a subject is photographed while having a predetermined scan surface and inserting a subject placed on a top plate into the scan surface. An X-ray computer tomography apparatus, comprising: means for detecting that the imaging area is on the scan surface; and means for starting imaging of the imaging area in response to detection by the detection means. Characterize.

[0008]

According to the present invention, since it is detected that a desired imaging region of the subject is on the scan surface and imaging is started in response to this detection, the imaging process including alignment is manually operated by the operator. Shooting is started without the need for.

[0009]

Embodiments will be described below with reference to the drawings. FIG. 1 is a block diagram of an X-ray computer tomography apparatus according to an embodiment of the present invention. The X-ray computed tomography apparatus is one of apparatuses for obtaining a tomographic image of a subject, and for example, in the case of the third generation, an X-ray tube that irradiates a fan-shaped fan beam X-ray, and this X-ray. And a multi-channel type X-ray detector formed by arranging a plurality of X-ray detecting elements for detecting X-rays in parallel according to the spread width of the fan beam X-ray, and the X-ray tube and the X-ray tube face each other. The detector and the detector are rotated together at a predetermined angular velocity along the outer periphery of a predetermined scan surface, and X-ray exposure and X-ray detection are repeated at predetermined angles to collect multidirectional X-ray projection data of the subject. After that, it is a very useful apparatus for diagnosis that can obtain a tomographic image by performing image processing such as reconstruction processing on the basis of the multi-directional X-ray projection data.

In FIG. 1, reference numeral 1 denotes a scan control section for integrally controlling all the inspection steps from the positioning of the apparatus of this embodiment to the end of photographing to advance the inspection work.

On the output side of the scan controller 1, an X-ray generator 2 for supplying a high voltage to the X-ray tube, a data collector 3 for collecting data from the X-ray detector, and a gantry for controlling rotation of the gantry. A control unit 4, a bed up-and-down drive unit 5 for adjusting the height of the couch top, a couch control unit 6 for controlling a couch drive unit 9 for slidingly driving the couchtop 10, a sound and an indicator lamp for starting and releasing the breath-hold. A breath-hold instruction device 7 for instructing the subject by
A respiratory stop time display device 8 which is a display device for displaying the remaining time of the respiratory stop, and which is provided at a position in the gantry, the bed, or the imaging room where the subject can see. The top control section 6 and the imaging area input section 13 are connected to the input side of the scan control section 1. The photographing area input unit 13 will be described later.

On the input side of the top control unit 6, the top 1
A top position detector 11, which is arranged along a slide trajectory of 0 and detects the position of the top 10 at any time, and an object position detector 12 are connected.

The subject position detector 12 detects that the top of the subject placed on the top plate has reached the scan plane as the top plate 10 is inserted into the opening of the gantry. However, various structures can be adopted as long as this detection is achieved. Here, as the object position detector 12, an optical sensor including a light source that emits a beam of light and a detection unit that detects the reflected light is adopted. In this case, the object position detector 12 is shown in FIG.
As shown in the plan view of (a) and the side view of (b), the gantry is arranged so that the light source illuminates the vicinity of the center in the width direction on the top plate surface and the detection unit receives the reflected light from the top plate 10. It is arranged above the opening of 20. As a result, when the top 10 is inserted into the opening of the gantry, an output signal of a predetermined level is output from the detector until the top of the subject placed on the top reaches the scan surface. When the crown of the subject reaches the scan surface, the level of this output signal changes, usually to 0 level. Therefore, the subject position detector 12 detects that the crown of the subject has reached the scan plane. In addition, FIG.
In (b), reference numeral 21 is a bed main body that houses the bed up-and-down drive device 5 and the tabletop drive device 9.

The photographing area input unit 13 is an input device for inputting an area to be three-dimensionally scanned by a helical scan or the like. The hatched area in FIG. 2A is a three-dimensional scanning area (imaging area) for lung cancer screening. From the imaging area input unit 13, information that can specify this imaging area with reference to the crown of the subject, that is, the distance L ₀ from the crown of the subject to the imaging area and the total length L _{1 of the} imaging area are input. To be done. Note that this information is input before the inspection starts. Further, this information has individual differences depending on physical parameters such as the height of the subject P. At the time of group medical examination, enter this information in advance for each individual, or compare by making L ₀ short and L ₁ long so that people with relatively short height to people with relatively high height can be handled. Enter a wide shooting area. In the latter case, the trouble of inputting information for a large number of people individually is saved.

Next, the operation of this embodiment configured as described above will be described. FIG. 3 is a time chart for explaining this operation, and FIG. 4 is a side view showing the state of the apparatus at each main timing in the entire inspection process.

Before the inspection is started, the above-mentioned information for specifying the photographing area is input from the photographing area input unit 13. This information may be input in advance for each individual, or may be input in a relatively wide photographing area that can accommodate persons of relatively short height to persons of relatively high height.
This information is sent to the scan controller 1 and held there. At this time, general scanning conditions such as the scanning speed including the top slide speed and the X-ray exposure condition have already been input.

Then, the subject P is placed on the top plate 10 at an arbitrary position. In this state, the apparatus waits for an instruction to start shooting from the operator. When the operator gives an instruction to start image capturing, the scan control unit 1 advances all subsequent steps from alignment to the end of image capturing. That is, the operator can perform alignment work and
In addition, there is no need to perform the manual operation required during the shooting process.

When the scan control section 1 receives a photographing start instruction from the operator, the scan control section 1 outputs a control signal to the top control section 6 so as to slide the top 10 at a top slide speed input in advance. The top controller 6 controls the top driving device 9 according to this signal. The top plate 10 is driven by the top plate drive device 9, and as shown in FIG.
The slide is started toward the 0 opening. Top 10
The moving speed of the table is gradually increased, and then is kept constant at the above-mentioned table slide speed.

The subject is moved along with the slide of the tabletop 10, and when the top of the subject reaches the scan plane (two-dot chain line) as shown in FIG. 4 (b), the top of the subject reaches the scan plane. This is detected by the object position detector 12. This detection signal is sent to the scan controller 1 via the top controller 6.

The scan control unit 1 receives the detection signal and holds the breath-holding instruction device 7 and the X-ray generation unit 2.
Control and do the following: That is, the breath-hold instruction device 7 notifies the subject of an instruction to start breath-holding by voice or an indicator light. If it is a voice, a voice such as "take a big breath and hold your breath as it is" is issued. If it is an indicator light, it is turned on. Further, the X-ray generation unit 2 starts high voltage charge-up. Also,
Although not shown, the gantry control unit 4 starts rotation of the gantry on which the X-ray tube and the X-ray detector are provided. The gantry is maintained at a constant angular velocity over time.

Then, the top of the head passes through the scan plane,
As shown in FIG. 4C, when the tabletop 10 is slid by a distance L ₀ from the top of the head to the imaging region that is input in advance, the scan control unit 1 actually performs the imaging operation of irradiating X-rays. Start. The scan controller 1 recognizes that the tabletop 10 has slid the distance L ₀ as follows. Since the tabletop position detector 11 detects the tabletop position at any time, this position signal is supplied to the scan controller 1 via the tabletop controller 6 at any time. The scan control unit 1 compares the difference between the top plate position at the time of receiving the detection signal from the subject position detector 12 and the top plate position at each time with the distance L ₀ , and when both match. In addition, the top plate 10 has a distance L after the top of the head is detected.
Recognize that ₀ has been slid.

At this timing, the scan control unit 1 makes X
The line generator 2, the data collector 3, and the respiratory arrest time display device 8 are controlled to start imaging. The X-ray generation unit 2 ends the charge-up, supplies a high voltage to the X-ray tube, and starts X-ray irradiation from the X-ray tube. The data collection unit 3 starts a collection operation of projection data of the subject P detected by each detection element of the X-ray detector. The breath-hold time display device 8 calculates the remaining time until the breath-hold is released and displays it.

This photographing operation is continued from the state of FIG. 4C until the state of FIG. 4D in which the top plate 10 is further slid by the distance L ₁ . Therefore, the data collection of the entire planned imaging area is completed. At this time, the scan control unit 1 controls the X-ray generation unit 2, the data acquisition unit 3, the gantry control unit 4, the top control unit 6, and the breath-holding instruction device 7 to end the imaging. The X-ray generation unit 2 stops the supply of high voltage to the X-ray tube and stops the X-ray irradiation from the X-ray tube. The data collection unit 3 stops the data collection operation. The gantry control unit 4 stops the rotation drive of the gantry. Top control unit 6
Stops the slide drive of the top plate 10 and
The slide drive is started in the reverse direction, that is, in the direction of coming out of the opening of the gantry 20. The breath-hold instruction device 7 notifies the subject of an instruction to release the breath-hold by voice or an indicator light. If it is a voice, a voice such as "Please restart breathing" is issued. If it is an indicator light, it is turned off.

Finally, when the tabletop 10 is slid in a reverse direction to a predetermined position, usually to the end of the bed, the scan controller 1 controls the tabletop controller 6 and the table top / bottom drive device 5 to move the tabletop. The board 10 is stopped, and after the stop, the top board 1
When 0 is lowered, the subject P is prompted to descend from the top plate 10, and the entire inspection process is completed. When there is another patient, the above operation is repeated.

As described above, according to this embodiment, the object position detector detects that the parietal region has reached the scan plane, and the information for starting the detection and specifying the preliminarily input imaging region is obtained. According to the procedure, the data collection of the scheduled imaging area is executed, so that the operator inputs this information in advance and gives an instruction to start imaging, and the inspection proceeds without any intervention in the entire inspection process including alignment. be able to. Therefore, it is not necessary for the operator to perform manual alignment for each subject as in the past, so the time required for this alignment can be eliminated, the inspection time can be shortened, and the operator's burden is reduced. Is reduced.

Next, the second embodiment will be described. In the first embodiment described above, the subject position detector and the imaging region input unit are provided in order to automate the alignment. On the other hand, in the present embodiment, instead of these, an imaging area designation slit and a slit detector are provided to achieve automation of alignment. The rest of the configuration is the same as that of the first embodiment described above, so the description is omitted.

FIG. 5A is a plan view showing a mounting position of the photographing area designating slit and its planar structure. The imaging region designating slit 30 is a plate material having a black portion and a white portion 31 of variable length, and is located along the long axis direction of the top plate 10 at a position not covered by the subject P on one side of the top plate 10. It is installed.
The length and the position of the white portion 31 are adjusted so as to match the desired imaging region (hatched portion) of the subject P.

The slit detector 32 is provided with the photographing area designating slit 3 when the top plate 10 is inserted into the opening of the gantry.
It is for detecting the black and white state of 0, and various structures can be adopted as long as this detection is achieved. Here, as the slit detector 32, an optical sensor including a light source that emits a beam of light and a detection unit that detects the reflected light is adopted. In this case, in the slit detector 32, as shown in the plan view of FIG. 5A and the side surface of FIG.
It is arranged in the opening of the gantry 20 so as to illuminate 0, and so that the detection unit receives the reflected light from the photographing region designating slit 30. When the light from the light source is applied to the black portion of the photographing area designating slit 30, this light is not reflected and thus is not detected by the detection unit. On the other hand, when the light from the light source is applied to the white portion 31 of the photographing area designating slit 30, the light reflected here is detected by the detection unit.

When the white portion 31 is detected by the detection portion, the scan control portion detects the top of the subject P in the first embodiment, and the X-ray generation portion is the same as when the distance L _{0 is} slid. , The data collection unit and the like are controlled to proceed with photographing. Then, when the top plate is slid to change the portion illuminated by the light source from the white portion 31 to the black portion, the scan control unit ends the photographing operation as in the first embodiment, and ends the entire inspection process. As described above, according to this embodiment, the same effect as that of the first embodiment can be obtained.
The present invention is not limited to the above-described embodiments, but can be implemented with various modifications.

[0030]

As described above, according to the present invention, a desired imaging region of the subject is imaged while inserting the subject placed on the top plate into the scan surface having a predetermined scan surface. An X-ray computer tomography apparatus including: means for detecting that the imaging area is on the scan surface; and means for starting imaging of the imaging area in response to detection by the detection means. Is characterized in that a desired imaging region of the subject is detected on the scan surface, and the imaging operation is started in response to this detection, so the imaging process including alignment requires manual operation by the operator. Since the radiography is started without doing so, it is possible to provide an X-ray computer tomography apparatus that can shorten the total inspection time and reduce the burden on the operator.

[Brief description of drawings]

FIG. 1 is a block diagram of a first embodiment device of the present invention.

2A and 2B are a plan view and a side view showing an arrangement position of an object position detector of FIG.

FIG. 3 is a time chart for explaining the operation of the first embodiment device.

FIG. 4 is a side view showing the state of the apparatus at each main time during the entire inspection process of FIG.

5A and 5B are a plan view and a side view showing arrangement positions of an imaging region designating slit and a slit detector according to another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Scan control part, 2 ... X-ray generation part, 3 ... Data acquisition part, 4 ... Stand control part, 5 ... Bed up-and-down drive device, 6 ... Top control part, 7 ... Breath-holding instruction device, 8 ... Breath stop Time display device, 9 ... Top plate driving device, 10 ... Top plate, 11 ... Top plate position detector, 12 ... Subject position detector, 13 ... Imaging area entry part,
20 ... Gantry, 21 ... Sleeper body.

Claims (3)

[Claims] 1. An X-ray computer tomography apparatus for photographing a desired imaging region of the subject while inserting the subject placed on a top plate into the scan plane and having a predetermined scan plane, An X-ray computer tomography apparatus comprising: a unit that detects that the imaging region covers the scan surface; and a unit that starts imaging of the imaging region in response to the detection of the detection unit. 2. The detecting means includes means for detecting that an end of the subject touches the scan surface, and means for inputting a distance from the end to the imaging region. The X-ray computer tomography apparatus according to claim 1. 3. The X-ray computer tomography apparatus according to claim 1, further comprising means for notifying the subject of a breath-hold instruction in response to the detection by the detection means.