JPH08299328A - X-ray ct device - Google Patents

Abstract

PURPOSE: To easily grasp the position of a needle inserted into a subject. CONSTITUTION: An X-ray tube 13 for collecting the X-ray CT image pickup data and an X-ray detector 14 are mounted on a rotary frame 12 in a gantry 10 and an X-ray tube 15 for performing a fluoroscopy, an image intensifier 16, and a TV camera 17 are mounted so that a fluoroscopic image containing a section of photographing an CT image is provided. And, an X-ray nontransmitting wire 18 is provided on the front face of the image intensifier 16 in compliance with its sectional position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray CT apparatus, and more particularly to an X-ray CT apparatus suitable for use in confirming a puncture position of a biopsy needle.

[0002]

2. Description of the Related Art A biopsy test (biopsy) is indispensable for the definite diagnosis of cancer such as lung cancer. In that case, it is necessary to insert a biopsy needle into a tissue suspected of being cancer, but it is difficult to accurately insert it into a minute affected area. Therefore, conventionally, an image near the affected area is displayed by using an X-ray fluoroscope based on an X-ray TV system in which an X-ray tube and an image intensifier are combined, and the needle insertion position is confirmed on the screen. There is. Alternatively, instead of the X-ray fluoroscope, an X-ray CT apparatus may be used to observe the needle insertion position.

In the observation with such an X-ray fluoroscopic apparatus or an X-ray CT apparatus, it is difficult to grasp the three-dimensional position of the needle in the living body in the former case, and only the image of a specific cross section is displayed in the latter case. It is difficult to know the positional relationship of needles in the whole body in real time.

Therefore, conventionally, the position of the needle has been confirmed by combining an X-ray fluoroscope and an X-ray CT apparatus. That is, an X-ray fluoroscopic apparatus and an X-ray CT apparatus, which are separately configured, are arranged side by side in the moving direction of the bed top, a subject is laid on the bed top, and the top is used as a visual field of the X-ray fluoroscope. A reciprocation is made between the region and the tunnel portion of the gantry of the X-ray CT apparatus. Then, while observing the position of the needle in real time on the screen of the X-ray fluoroscope, the needle is inserted, and then the top plate is sent into the tunnel part of the gantry of the X-ray CT apparatus to obtain a cross-sectional CT image of the subject. The confirmation of the position of the needle on the CT image is repeated.

[0005]

However, when the X-ray fluoroscopy apparatus and the X-ray CT apparatus, which are separately configured as in the prior art, are used in combination, it takes a lot of time and labor and a great burden is placed on the subject. There is a problem that compels you. That is, C
When it is found on the T-image that the needle has not reached the affected area, it is necessary to return the bed top again and perform X-ray fluoroscopic observation to correct the needle position, and then repeat the confirmation with the CT examination. Therefore, the subject must be moved frequently, and the moving distance becomes large. Therefore, the work efficiency is low and it is difficult to perform accurate biopsy quickly.

[0006] In view of the above, the present invention makes it possible to easily grasp the position of the needle to be inserted in the living body and to quickly insert the biopsy needle into the affected area accurately. It is an object of the present invention to provide an X-ray CT apparatus.

[0007]

In order to achieve the above object, in an X-ray CT apparatus according to the present invention, a high voltage is selectively applied to the first and second X-ray tubes and these two X-ray tubes. X-ray high-voltage device for supplying the X-ray from the first X-ray tube
An X-ray detector which receives the X-ray and obtains a signal regarding the X-ray absorption of a predetermined cross section relating to the object, and the X from the second X-ray tube.
An X-ray imaging device that receives an X-ray and captures an X-ray fluoroscopic image of a field of view including the cross section of the subject, and holds the first and second X-ray tubes, the X-ray detector, and the X-ray imaging device. A rotating device for rotating, a gantry in which the first and second X-ray tubes, an X-ray detector, an X-ray imaging device and a rotating device are housed, and a projection obtained from the output signal from the X-ray detector. An image reconstructing apparatus that reconstructs a CT image by processing data, a CT image of the reconstructed object in the cross section, and the cross section obtained by the X-ray imaging apparatus. An image display device for displaying an X-ray fluoroscopic image including the image shown is provided.

[0008]

With the first X-ray tube and the X-ray detector, the detection signal of the X-ray absorption for the cross section of the CT image is obtained,
From this, projection data for CT image reconstruction is obtained. Second
The X-ray tube and the X-ray imaging device can obtain an X-ray fluoroscopic image from the side surface of the subject, and the field of view of the X-ray fluoroscopic image is such that the CT image radiographing cross section is included. .
Therefore, the CT image displayed by the image display device and the X-ray
The line-transparent images are displayed in different formats for the same region, that is, one is a cross-sectional image and the other is a side-view transparent image. Since the fluoroscopic image includes an image showing a cross section, it is possible to know at which position the cross sectional CT image is obtained by observing the fluoroscopic image. Therefore, when the needle is inserted into the affected area, a CT image and an X-ray fluoroscopic image in the vicinity of the affected area are taken and the images are observed, so that the positional relationship of whether or not the needle has reached the affected area accurately. Can be easily grasped.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic view from the front of a gantry portion of an X-ray CT apparatus according to an embodiment of the present invention, and FIG. 2 is a schematic view from the side surface of the same portion. As shown in FIGS. 1 and 2, the gantry 10
A hollow tunnel portion 11 is provided in the center of the subject, and the subject 2 laid on a bed top plate 22 therein.
1 is to be inserted.

A rotary frame 12 having a hollow portion into which the tunnel portion 11 is inserted is rotatably held in the gantry 10, and is rotated by a rotary drive device (not shown in FIGS. 1 and 2). It is designed to be used. This rotating frame 12 has two X-ray tubes 13, 1
5 and an arc-shaped multi-channel X-ray detector 14
Image intensifier 16 and TV camera 1
7 and 7 are attached, and these are integrally rotated with the rotation of the rotary frame 12 around the tunnel portion 11 (that is, the subject 21).

As described above, the X-ray detector 14 has a large number of detection elements arranged in a line and formed in an arc shape, and is radiated from the X-ray tube 13 and formed into a fan shape in one plane. The divergent X-ray beam is detected. Therefore, this X
A signal for detecting the X-ray absorption of the subject 21 on the above-mentioned plane is obtained from the line detector 14. The absorption data obtained from this detection signal is later used as projection data for image reconstruction. As the rotating frame 12 rotates, the X-ray tube 13 and the X-ray detector 14 rotate around the subject 21, so that one rotation (or half rotation) reconstructs a CT image in one cross section. Projection data from each direction required to obtain is obtained.

The X-ray tube 15 is provided so that an X-ray fluoroscopic image of the field of view including the cross section for obtaining the X-ray absorption data is obtained.
The image intensifier 16 and the TV camera 17 are arranged. Here, as shown in the figure, the positional relationship is determined so that the X-rays traveling from the X-ray tube 13 to the X-ray detector 14 and the X-rays traveling from the X-ray tube 15 to the image intensifier 16 are substantially orthogonal to each other. However, if the X-rays of the two do not interfere with each other, it is not absolutely necessary to establish such an orthogonal positional relationship. A wire 18 made of a radiopaque material is stretched over the front surface of the image intensifier 16. The wire 18 is arranged on the same plane as the cross section for obtaining the X-ray absorption data.

FIG. 3 is a block diagram showing a signal processing system and a control system of the X-ray CT apparatus of the embodiment. This figure 3
As shown in, the signal from the X-ray detector 14 is input to the data acquisition device 31 and X-ray absorption data in each direction is acquired. The rotary frame 12 (FIGS. 1 and 2) to which the X-ray tubes 13 and 15, the X-ray detector 14, the image intensifier 16, and the TV camera 17 are attached is rotated by the rotary drive device 53. The rotation is controlled by the control device 51.
And a signal indicating the rotation angle is returned to the control device 51. Then, the control device 51 controls the X-ray high voltage device 52 according to the rotation angle signal,
For example, a high voltage is applied to the X-ray tube 13 in pulses so that X-rays are generated in pulses from the X-ray tube 13 at rotation angles of 1 °, and from the X-ray tube 15 at rotation angles of 30 °. The high voltage is applied to the X-ray tube 15 in a pulsed manner so that the X-ray is generated in a pulsed manner. These X-ray tubes 1
The pulsed high voltage to 3, 15 is applied alternately utilizing the respective dwell periods.

Under the control of the control device 51, the data collection device 31 collects data at the timing at which X-rays are emitted from the X-ray tube 13 (corresponding to each rotation angle of 1 °). It is sent to the image reconstruction device 32.
The image reconstructing device 32 also uses the angle information from the control device 51 to process the data from the data collecting device 31 by an algorithm such as backprojection to reconstruct the image.
The image memory 33 stores the images used and reconstructed for the processing. Thus, the rotating frame 12
Is rotated once (or a half rotation) to collect all the necessary data and the processing is completed, the reconstructed image is completed, displayed on the image display device 34, and recorded in the recording device 35 or the like. .

On the other hand, the X-ray tube 15 generates X-rays at every rotation angle of 30 °, and the TV camera 17 outputs the X-rays.
The video signal of the X-ray fluoroscopic image of the subject 21 in each direction is output. Under the control of the control device 51, the image processing device 41 takes in this video signal at every rotation angle of 30 °, performs necessary processing such as gradation conversion, temporarily stores each image in the image memory 42, and stores it. The data is read and sent to the image display device 43 and also sent to the recording device 35 for recording.

Therefore, a CT image of a predetermined cross section that crosses the subject 21 is displayed on one image display device 34, and an X-ray fluoroscopy from the side direction of the subject 21 including the cross section is displayed on the other image display device 43. Each image is displayed. The X-ray fluoroscopic image from the side surface direction is obtained at every 30 ° around the side surface of the subject 21 and stored in the image memory 42.
You can observe from any angle. An image of the wire 18 is projected on the screen of the X-ray fluoroscopic image from this side surface, and this wire image represents a cross section of the CT image.

Thus, according to this X-ray CT apparatus,
A CT image of a predetermined cross section of the subject 21 is captured and displayed, and an X-ray fluoroscopic image is obtained in a field of view including the cross section of the CT image, and the X-ray fluoroscopic image is displayed. can do. Therefore, for example, in a biopsy test for definitive diagnosis of cancer, when a biopsy needle is inserted into the affected area, the following operation is performed. First, the bed top plate 22 is moved to insert the subject 21 into the tunnel portion 11 of the gantry 10, and in this state,
A high voltage is supplied from the X-ray high voltage device 52 to the X-ray tube 15 to emit X-rays only from the X-ray tube 15, and an X-ray fluoroscopic image from the side surface of the subject 21 is obtained and displayed. The doctor adjusts the position of the subject 21 (adjusts the position of the bed top 22) so that the image of the wire 18 crosses the region to be biopsied while looking at the X-ray fluoroscopic image. At this time,
The rotating frame 12 is fixed. Next, while observing this X-ray fluoroscopic image, a biopsy needle is inserted into the subject 21.
When this needle can reach the affected area on the X-ray fluoroscopic image, the X-ray high-voltage device 52 is switched to the X-ray tube 13 this time.
Only the high voltage is supplied to the rotating frame 12
Of the obtained C
Display the T image. Since this CT image is a cross-section where the image of the wire 18 is located in the X-ray fluoroscopic image, a CT image of a cross-section that crosses the affected area is obtained.
By observing the image, it can be confirmed whether the needle has reached the affected area. If the needle is misaligned on this CT image, return to the observation by the X-ray fluoroscopic image, re-insert the needle while confirming the needle position on this X-ray fluoroscopic image, and further move the bed top 22 slightly. After adjusting the position of the subject 21, for example, the CT image is taken again, and the CT image is confirmed. Since the biopsy is performed in this manner, it is possible to prevent the subject 21 from being frequently moved or greatly moved, and thereby not burdening the subject 21. This also leads to improvement in operability, and the biopsy test can be performed quickly.

In the above embodiment, the image intensifier 16 and the TV camera 17 are used as the X-ray image pickup device.
Although a combination of and is used, it goes without saying that another X-ray imaging device such as one using a semiconductor can be adopted. Further, in order to represent the cross-sectional position of the CT image on the X-ray fluoroscopic image, the X-ray non-transparent wire 18 physically stretched at the cross-sectional position is used. The configuration for representing the above is not limited to this. For example,
The image processing device 41 can be configured to electrically generate an image (cursor) representing the cross-sectional position of the CT image and superimpose it on the X-ray fluoroscopic image. However, by using the wire 18 as in this embodiment, it is easy to physically and accurately correspond to the cross-sectional position of the CT image. Further, although two image display devices 34 and 43 are used,
It is also possible to provide two image display windows on one image display device and display each image on each of them. The angles at which X-rays are emitted from the X-ray tubes 13 and 15 are merely examples.

In the above description, the case of inserting a biopsy needle into the affected area in a biopsy test for the definite diagnosis of cancer is mainly described, but the application of the X-ray CT apparatus is not limited to this. For example, so-called IVR for performing diagnosis and treatment with a catheter or the like while fluoroscopy
(Interventional radiography)
The use of the T device is very effective.

[0020]

As described in the above embodiments, according to the X-ray CT apparatus of the present invention, the X-ray CT imaging and the X-ray fluoroscopy of the same region can be frequently moved or greatly moved. This can be performed without any inspection, the burden on the subject due to the inspection can be reduced, and the inspection efficiency can be improved. Further, since the X-ray CT imaging system and the X-ray fluoroscopy system are housed in the same gantry, the overall size is reduced and space saving can be achieved. In addition to this, since the X-ray high-voltage device can be shared by two X-ray tubes, it can be constructed at low cost.

[Brief description of drawings]

FIG. 1 is a schematic view of a gantry portion of an X-ray CT apparatus according to an embodiment of the present invention as viewed from the front.

FIG. 2 is a schematic view of the gantry portion of the X-ray CT apparatus according to the embodiment as viewed from the side surface.

FIG. 3 is a block diagram showing a signal processing system and a control system of the X-ray CT apparatus according to the embodiment.

[Explanation of symbols]

10 gantry 11 tunnel section 12 rotating frame 13, 15 X-ray tube 14 X-ray detector 16 image intensifier 17 TV camera 18 X-ray non-transmissive wire 21 subject 22 bed top 31 data acquisition device 32 image reconstruction Device 33, 42 Image memory 34, 43 Image display device 35 Recording device 51 Control device 52 X-ray high voltage device 53 Rotation drive device

Claims (1)

[Claims] 1. A first and a second X-ray tube and these two X-ray tubes.
An X-ray high voltage device for selectively supplying a high voltage to a X-ray tube, and an X-ray detector for receiving a X-ray from the first X-ray tube to obtain a signal regarding X-ray absorption of a predetermined cross section relating to a subject. And an X-ray imaging device that receives an X-ray from the second X-ray tube and captures an X-ray fluoroscopic image of a field of view including a cross section of the subject, the first and second X-ray tubes, and A rotation device that holds and rotates the line detector and the X-ray imaging device;
An image of a CT image is obtained by processing projection data obtained from a gantry in which a second X-ray tube, an X-ray detector, an X-ray imaging device, and a rotating device are housed, and projection signals obtained from the above X-ray detector. An image reconstructing device to be reconstructed, a CT image of the reconstructed subject at the cross section, and an X-ray fluoroscopic image including the image showing the cross section obtained by the X-ray imaging device are displayed. X-ray CT apparatus, comprising: