JPH11128214A - X-ray diagnosis equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable to eliminate peripheral image and complexity of mechanical structure under a top plate and to execute high speed X-ray image picking-up all at once. SOLUTION: This X-ray diagnosis equipment detects an X-ray fluoroscopy image of a subject M not by an image intensifier but by a flat panel X-ray sensor 3 and is composed to shorten the time required for one frame scanning by partially or collectively reading out a signal from an X-ray detecting element. As a result, the peripheral image distortion and complexity of the mechanical structure can be eliminated by adopting the small and light flat panel X-ray sensor 3 without image distortion and, further, the number of X-ray detecting elements to be read out can be reduced and the frame scanning speed can be increased to execute high speed X-ray image picking-up by switching a visual field to smaller one.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention reads an X-ray detection signal from a two-dimensional array type X-ray sensor for detecting an X-ray fluoroscopic image of a subject (patient) generated by X-ray irradiation, and detects X-rays. The present invention relates to an X-ray diagnostic apparatus that displays an X-ray image of a subject based on a signal, and more particularly to a technique for increasing a frame scanning speed of an X-ray image (the number of frames per unit time).

[0002]

2. Description of the Related Art In the case of a conventional X-ray diagnostic apparatus, FIG.
As shown in FIG. 2, an X-ray tube 52 for irradiating the subject (patient) M placed on the top 51 with X-rays, and an X-ray fluoroscopic image detection device disposed opposite to the top 51 with the X-ray tube 52 interposed therebetween. And a monitor 54 for displaying an X-ray image. The subject detected by the image intensifier 53 when the subject M is irradiated with X-rays from the X-ray tube 52. X-ray fluoroscopic image of M is image intensifier 5
3, after being imaged by a TV camera (not shown) installed at the subsequent stage, undergoing AD conversion, image processing, and the like, and finally projected and displayed as an X-ray image on the screen of the monitor 54. Has become. An X-ray image obtained by the X-ray diagnostic apparatus is provided to a doctor, and the doctor can make an accurate diagnosis based on the X-ray image. Therefore, it can be said that the X-ray diagnostic apparatus is a very useful apparatus. it can.

[0003]

However, in the case of the conventional X-ray diagnostic apparatus using the image intensifier, there are problems that the peripheral image distortion is large and the mechanical structure below the top plate is complicated. is there. That is, when an X-ray fluoroscopic image is detected by using the image intensifier 53, all the bars are straight as shown in FIG. 13A due to peripheral image distortion caused by the structure of the image intensifier. When the grid 55 running vertically and horizontally is used as the subject, as shown in FIG. 13B, the beam around the grid 55 becomes a bent X-ray image, and the shape of the subject cannot be correctly captured. Is invited. Since the situation of the peripheral image distortion in the image intensifier 53 is complicated, it is also difficult to obtain an X-ray image with no peripheral image distortion by correction by image processing.

Further, an image intensifier 53
Is a heavy vacuum tube with a large volume, which is difficult to handle, and the accompanying equipment of the image intensifier becomes considerable. As a result, the mechanical structure on the lower side of the top plate to which the image intensifier 53 is attached is inevitably complicated. This leads to inconveniences such as large design restrictions.

An X-ray sensor of a type that can eliminate the distortion of the peripheral image of the image intensifier and the complication of the mechanical structure should be changed. There are few X-ray sensors suitable for high-speed imaging. Recently, there is a high need for X-ray imaging with movement of the subject, such as cardiac imaging and angiography, and it is indispensable as a useful device to be able to perform high-speed X-ray imaging suitable for this. It's not too much to say.

The present invention has been made in view of the above circumstances, and provides an X-ray diagnostic apparatus capable of eliminating peripheral image distortion and complication of a mechanical structure below a top plate and performing high-speed X-ray imaging. That is the task.

[0007]

To achieve the above object, an X-ray diagnostic apparatus according to the first aspect of the present invention comprises: (a) irradiating an X-ray to a subject placed on a top plate; An X-ray tube and (b) a flat panel type for X-ray fluoroscopic image detection of a two-dimensional array type in which a large number of X-ray detection elements are arranged vertically and horizontally with a top plate interposed therebetween. X-ray sensor and (c) readout of X-ray detection signals from the X-ray detection elements of the flat panel X-ray sensor by full-read scanning in which the X-ray detection signals are extracted from each X-ray detection element without fail. The scanning means and (d) reading of the X-ray detection signal from the X-ray detection element of the flat panel type X-ray sensor can be performed by using only one element in each element block composed of a plurality of adjacent elements. Thinning out the line detection signal A thinning readout scanning means for performing a scan out seen, and read the designated scanning means for Run select the thinning readout scanning (e), (f)
Image display means for displaying an X-ray image of the subject based on the X-ray detection signal read from the flat panel X-ray sensor.

Further, in order to achieve the above object, an X-ray diagnostic apparatus according to a second aspect of the present invention includes: (a) an X-ray tube for irradiating an object mounted on a top plate with X-rays; (B) a two-dimensional array type flat panel X-ray sensor for X-ray fluoroscopic image detection, which is arranged to face the X-ray tube with the top plate interposed therebetween and has a number of X-ray detection elements arranged vertically and horizontally. ,
(C) full-read scanning means for reading the X-ray detection signals from the X-ray detection elements of the flat panel X-ray sensor by full-read scanning for extracting the X-ray detection signals from each X-ray detection element one by one without omission; d) The reading of the X-ray detection signals from the X-ray detection elements of the flat panel X-ray sensor is performed by combining the X-ray detection signals of all the elements in each block composed of a plurality of adjacent elements. (E) read-out scan designating means for designating and executing the collective read-out scan as a block signal from the X-ray sensor taken out of the X-ray sensor; and (f) read-out from the flat panel X-ray sensor. Image display means for displaying an X-ray image of the subject based on the output X-ray detection signal.

Next, various operations of the flat panel X-ray sensor for detecting an X-ray fluoroscopic image at the time of X-ray imaging by the X-ray diagnostic apparatus of the present invention will be described. In the case of X-ray imaging by the X-ray diagnostic apparatus of the present invention, an X-ray fluoroscopic image of the subject is formed by a two-dimensional array type flat panel X-ray sensor with X-ray irradiation on the subject on the tabletop. At the same time as the detection, the reading of the X-ray detection signal is normally performed without any omission from each X-ray detecting element flat of the flat panel X-ray sensor by the full reading scanning of the full reading scanning means. The image display means is a flat panel type X
An X-ray image is displayed based on the X-ray detection signal read from the line sensor.

In the case of the two-dimensional array type flat panel type X-ray sensor used in the present invention, unlike an image intensifier, the proportionality between the dimension on the X-ray fluoroscopic image and the dimension on the subject is different. Since the relationship is maintained over the entire surface, peripheral image distortion does not occur. In addition, since the X-ray sensor is a light and thin panel, the mechanical structure on the lower side of the top plate is not complicated.

Further, when high-speed X-ray imaging is performed in the X-ray diagnostic apparatus according to the first aspect of the present invention, thinning-out reading scanning is designated by the reading-out scanning designating means, and the thinning-out reading scanning means is used for the flat panel X-ray sensor. X
The reading of the X-ray detection signal from the X-ray detection element is performed by performing thinning-out scanning for extracting the X-ray detection signal from only one element in each element block that is assumed to include a plurality of adjacent elements. An X-ray image is displayed based on the detected X-ray detection signal.

In the case of the above-mentioned full reading scan, the number of times of reading the X-ray detection signal during one frame scan (one screen scan) is the total number of X-ray detection elements. The number of times the X-ray detection signal is read during frame scanning is the total number of element blocks. Because, in each element block, the reading of the X-ray detection signal is performed only for one X-ray detection element, and the reading of the X-ray detection signal is not performed for the other X-ray detection elements in the element block. It is. Therefore, in the thinning-out reading scan, the number of times of reading the X-ray detection signal during one frame scan is significantly reduced as compared with the case of the full reading scan. For example, if the number of elements in the element block is 4, the number of times of reading is 1/4.
Becomes In addition, since the time required for reading one X-ray detection signal does not substantially change, in the case of thinning-out scanning in which the number of times of reading the X-ray detection signal is reduced, the time required for scanning one frame is also reduced. Read count is 1 /
If it is 4, the time required for one frame scanning is also reduced to 1/4, and the frame scanning speed is increased. As a result, high-speed X-ray imaging can be realized.

Further, when high-speed X-ray imaging is performed in the X-ray diagnostic apparatus according to the second aspect of the present invention, collective read scanning is specified by the read scan specifying means, and the collective read scanning means controls the flat panel X-ray sensor. The reading of the X-ray detection signal from the X-ray detection element is taken out from the X-ray sensor as a single block signal by combining the X-ray detection signals of all the elements in each block composed of a plurality of adjacent elements. Collective read scanning is performed, and an X-ray image is displayed based on the read X-ray detection signal.

In the case of the collective readout scan as well, as in the case of the thinning-out readout scan, X during one frame scan is used.
The number of times the line detection signal is read is the total number of element blocks. This is because, in each element block, the signals of all the X-ray detection elements are combined into one and extracted as a block signal, and reading is performed only once for each element block.

Therefore, even in the collective read scan, the number of times of reading the X-ray detection signal during one frame scan is greatly reduced as compared with the case of the full read scan, and the time required for one signal read is substantially reduced. Therefore, even in the case of collective read scanning in which the number of times of reading the X-ray detection signal is reduced, the frame scanning speed is increased, so that high-speed X-ray imaging can be realized. Further, in the case of collective readout scanning, since the X-ray detection signals of all the X-ray detection elements are reflected on the X-ray image, the image quality of the X-ray image can be expected to be improved as compared with the case of the thinned-out readout scan, and the subject is not wasted. In other words, an unnecessary X-ray irradiation area is eliminated.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an overall configuration of an X-ray diagnostic apparatus according to a first embodiment of the present invention, and FIG. 2 is a diagram showing a flat panel X-ray sensor (hereinafter abbreviated as “X-ray sensor” as appropriate). FIG. 3 is a plan view showing an arrangement of X-ray detection elements, FIG. 3 is a perspective view showing a schematic configuration of the X-ray sensor, FIG. 4 is a cross-sectional view showing a layer structure of the X-ray sensor, and FIG.
Is a plan view showing an element block assumed in the X-ray sensor, and FIG. 6 is a block diagram showing a circuit configuration of the X-ray sensor.

As shown in FIG. 1, the X-ray diagnostic apparatus according to the first embodiment applies X-rays to a top 1 on which a subject M is placed and to the subject M placed on the top 1. X-ray tube 2 for irradiation and top plate 1
A flat panel type X-ray sensor 3 for two-dimensional array type X-ray fluoroscopic image detection, which is opposed to the monitor, and displays an X-ray fluoroscopic image detected by the X-ray sensor 3 (image display means) 4 and the like, and the X-ray fluoroscopic image of the subject M is detected by the X-ray sensor 3 with the X-ray irradiation from the X-ray tube 2, and the X-ray detection signal is read from the X-ray sensor 3. Thereafter, it is configured to be finally displayed as an X-ray image on the screen of the monitor 4 through AD conversion and image processing. In addition, the X-ray diagnostic apparatus according to the first embodiment also includes a cassette-type rapid imaging mechanism (not shown) that captures an X-ray image of the subject M on a film. The apparatus has a fluoroscopic imaging apparatus configuration. Hereinafter, each unit of the first embodiment will be described more specifically.

The top board 1 is configured to be moved up and down in addition to front and rear and left and right under the control of the drive control unit 5 while the subject M is placed thereon. This drive control unit 5
Controls the movement of the top 1 based on a command signal sent from the photographing control unit 8 in accordance with an operation input from the keyboard 6 or the mouse 7. Further, the X-ray tube 2
The flat panel X-ray sensor 3 having a rectangular planar shape is also moved in conjunction with the control of the drive control unit 5 while maintaining the opposed arrangement state, or the X-ray tube 2 In order to change the distance (distance) between the X-ray sensor 3 and the flat panel type X-ray sensor 3, it can be moved up and down. The movements of the X-ray tube 2 and the X-ray sensor 3 are also controlled based on a command signal sent from the imaging control unit 8.

On the other hand, the X-ray tube 2 is configured to emit X-rays according to the set imaging conditions under the control of an irradiation control unit 9 including a high voltage generator and the like. The irradiation control unit 9 controls the operation of the irradiation control unit 9 based on a command signal transmitted from the imaging control unit 8 in accordance with an operation input from the keyboard 6 or the mouse 7.

On the other hand, the flat panel type X-ray sensor 3
A sensor configured to detect an X-ray fluoroscopic image of the subject M generated by X-ray irradiation by the X-ray tube 2, convert the X-ray fluoroscopic image into an electric signal as an X-ray detection signal, and output the signal. As shown in FIG. This is a so-called two-dimensional array type sensor in which many X-ray detection elements XD are arranged vertically and horizontally. X of the first embodiment
The array of the X-ray detection elements XD in the X-ray sensor 3 is horizontal (X).
This is a regular matrix in a direction 1024 and a vertical (Y) direction 1024. Flat panel type X having a rectangular planar shape
The X-ray sensor 3 is a useful X-ray sensor also in that, unlike an image intensifier whose detection surface is limited to a circular shape, a square detection surface suitable for photographing a large part such as the chest and abdomen is possible. .

As shown in FIG. 3, the flat panel X-ray sensor 3 detects an X-ray conversion layer 12 for converting incident X-rays into electric charges or light, and detects electric charges or light generated in the X-ray conversion layer 12. The device has a laminated structure with a detection array layer 13 in which elements are arranged vertically and horizontally in a matrix. The plane dimension of the X-ray conversion layer 12 of the flat panel X-ray sensor 3 is, for example, about 30 cm in length and width.

This flat panel type X-ray sensor 3 includes:
The direct conversion type sensor shown in FIG.
There is an indirect conversion type sensor shown in FIG. In the case of the former direct conversion type, the X-ray conversion layer 12 is composed of a selenium layer or a CdZnTe layer that directly converts incident X-rays into charges, and faces the surface electrode 15 as a charge detection element 14 on the surface of the detection array layer 13. Each of the charge detection elements 14 and a part of the X-ray conversion layer 12 thereon form one X-ray. The detection element XD is formed. In the latter case of the indirect conversion type, the X-ray conversion layer 12 is composed of a scintillator layer for converting incident X-rays into light, and light is detected by a photodiode group formed as a light detection element 16 on the surface of the detection array layer 13. Is performed to transmit an X-ray detection signal, and one X-ray detection element XD is formed by each light detection element 16 and a part of the X-ray conversion layer 12 thereon.

In the flat panel X-ray sensor 3, as shown in FIG. 6, each of the X-ray detection elements XD,.
Are connected to read wirings 18 and 19 running vertically and horizontally, respectively, via a TFT (Thin Film Transister) 17, and the read wirings 18 and 19 are respectively connected to an X (horizontal) read drive unit 20 or Y (vertical). The X / Y full scan signal for full read scan is normally sent from the read scan signal generator 26 to the X, Y read drive 21. As a readout voltage is applied to the readout wirings 18 and 19 from the X readout drive unit 20 or the Y readout drive unit 21 in accordance with the X and Y full scan signals, all the detection elements XD,.
An X-ray detection signal is extracted from the XD in order from the TFT 17 through the readout wiring 19, further through each preamplifier 22 and the multiplexer 23, and taken out as an X-ray detection signal. That is, the reading of the X-ray detection signal from the flat panel type X-ray sensor 3 has substantially the same configuration as that of an ordinary video detector such as a TV camera.

On the other hand, the configuration of the read scan signal generator 26 for supplying the full read scan signal to the X, Y read driver 21 is as follows. Since the identification of each X-ray detection element XD of the X-ray sensor 3 is performed based on the addresses 0 to 1023 sequentially assigned to each X-ray detection element XD along the array in the X direction and the Y direction, The X and Y full scanning signals for read scanning are signals indicating addresses in the X and Y directions.

As shown in FIG. 7, the scanning signal generator 26 inputs a clock pulse having a constant period, and when one clock pulse is received, the count value becomes 1 (starting from 0).
The number of the X address counter 27, the end address in the X direction (1023 in the case of full scan) and the count value of the X address counter 27 are input, and the count value of the X address counter 27 reaches the end address in the X direction. Then, an X comparator 28 that outputs one pulse, and X
The pulse of the comparator 28 is input, and the X comparator 2
When one pulse of 8 enters (starts from 0), the Y address counter 29 whose count value increases by one, and the end address in the Y direction (1023 in the case of full scanning)
And the count value of the Y address counter 29, the count value of the Y address counter 29 is set to 1 as the end address.
And a Y comparator 30 that outputs one pulse when the value reaches the value obtained by adding.

The count value of the X address counter 27 is sent to the X read drive unit 20 as an X full scan signal, and the count value of the Y address counter 29 is sent to the Y read drive unit 21 as a Y full scan signal. The X full scan signal sequentially supplies each address from 0 to 1023 to the X readout drive unit 20, and the Y full scan signal also outputs 0 to 1023.
Needless to say, the respective addresses of No. 3 are sequentially applied to the Y read drive unit 21 to execute full read scanning. In addition,
The pulse of the X comparator 28 is sent as a one-line scanning end signal, and the pulse of the Y comparator 30 is sent as a one-frame scanning end signal to necessary parts such as the image processing unit 24.

The reset terminal of the X address counter 27 is connected to the X, Y comparator 2 via the OR element 31.
8, 30 pulses are input and the Y address counter 29
The pulse of the Y comparator 30 is input to the reset terminal of. Reset terminals of the X and Y address counters 27 and 29 are connected to X and Y comparators 28, which are scanning end signals.
When 30 pulses are input, the count values of both counters 27 and 29 return to 0 at the start. Thereafter, as long as there is no scan stop command, the readout scan signal generator 26 outputs X,
The generation of the Y scanning signal is repeated.

In the case of the X-ray sensor 3 of the first embodiment, both read-out drive units 20 and 21, the preamplifier 22 and the multiplexer 23 are installed on the periphery of the surface of the detection array layer 13 and have an integrated configuration. . And the X-ray sensor 3
An X-ray detection signal taken out of the X-ray detector 3 is digitized by an AD converter 10 and then stored in a frame memory type image memory 11 having an XY matrix configuration corresponding to the XY matrix configuration of the X-ray detection elements in the X-ray sensor 3. Is stored as an image signal. The image signal stored in the image memory 11 is taken out by the image processing unit 24 in a timely manner, and after signal processing such as filtering is performed as necessary, the image signal is sent to the monitor 4 and projected on the screen as an X-ray image. Is displayed.

The storage unit 25 is a disk-type storage device, and is used for loading necessary execution programs and recording X-ray images. In the case of the first embodiment, the drive control unit 5, the photographing control unit 8, and the irradiation control unit 9 are used.
And the image processing unit 24 are each a computer (C
PU) and its execution program.

Further, in the X-ray diagnostic apparatus of the first embodiment,
As the readout scan for reading out the X-ray detection signal from the X-ray sensor 3, as described above, in addition to the full-reading scan for extracting the X-ray detection signals from all the X-ray detection elements one by one without omission, a plurality of adjacent elements are used. The configuration is characterized in that thinning-out reading scanning for extracting an X-ray detection signal from only one element in each of the assumed element blocks can be executed at any time. That is, although the full reading scan is normally performed, the point that the thinning read scanning is designated by the keyboard 6 and the mouse 7 and executed at any time is a remarkable feature. The configuration related to the above will be specifically described.

In the case of thinning-out reading scanning, 1024 ×
For the entire array of 1024 X-ray detection elements XD, FIG.
As shown in (2), an element block XB is assumed by a total of four X-ray detection elements XD, two in the X (horizontal) direction and two in the Y (vertical) direction. The assumed arrangement of the element blocks XB is 512 × 512. Then, when performing the thinning-out reading scan, the X-ray detection signal is extracted from only one of the four X-ray detection elements XD1 to XD4 of each element block XB. Normally, an X-ray detecting element (for example, the upper left X-ray detecting element XD1) which is a common position on each matrix among all the element blocks XB is selected as an element to be read.

In the case of the device of the first embodiment, the X-ray detecting element XD1 at the upper left of each element block XB is selected as the X-ray detecting element to be read out in the thinning-out reading scan. If the numerical value of Y is an address, (X: 0, Y: 0) → (X: 2, Y: 0) →.
(X: 1022), Y: 0) → (X: 0, Y2) →
(X: 2, Y: 2) → 1 in both the X and Y directions
An X-ray detection signal is extracted from every other X-ray detection element. Therefore, in the case of the thinning-out reading scanning, the reading-out scanning signal generating section 26 generates X and Y thinning-out scanning signals for sequentially giving one-by-one addresses, and outputs the X and Y thinning-out scanning signals.
The data is sent to the read drive units 20 and 21, respectively.

That is, the keyboard 6 or the mouse 7
As the thinning-out scan is designated in the above, the read-out scan signal generator 26 sets the same 511 as the end address in the X and Y directions in accordance with the command signal sent from the scan mode switching unit 35, and also sets the switch 34. _X , 3
4 _Y is switched to the alternate long and short dash line. Switch 3
4 _X, 34 when _Y is switched toward the dashed line, X,
The count value of Y address counters 27 and 29 is X and Y
After being converted into doubled values by the multiple units 32 and 33, they are output as X and Y thinned-out scanning signals, respectively. The count values of the X and Y address counters 27 and 29 are converted into double values by the X and Y multiple units 32 and 33, thereby giving necessary one-by-one addresses. Y
As the multiple units 32 and 33, for example, a register that shifts the binary count value by one bit to the upper bit side can be used.

It should be noted that the X and Y address pointers 27 and 2
9 is 511, and the position of the read scan reaches the final element block XB. Therefore, it is necessary to terminate the one-line scan and the one-frame scan with the count value of 511, respectively. 511 is set as the end address in the Y direction. vice versa,
In the case of full read scanning, the X, Y address
Since the reading value reaches the final X-ray detection element XD when the count values of 7, 29 are 1023, the end address in the X and Y directions is set to 1023 in accordance with the command signal sent from the scanning mode switching unit 35. It has become.

Further, since both the full scan and the thinning read scan are based on the same clock pulse, the scanning speed is equal and the time required for reading one element is the same. Is a quarter of the time of full read scan,
The frame scanning speed increases four times. If the frame rate in the full-read scan is 15 frames / sec, the frame rate in the thinning-out scan is 60 frames / sec. Therefore, high-speed X-ray imaging can be realized.

Subsequently, in the X-ray diagnostic apparatus of the first embodiment having the above configuration, high-speed X
The operation of the apparatus when the line imaging is performed will be described with reference to the flowchart of FIG. In the case of imaging by the embodiment apparatus, the subject M is placed on the top 1 and then the top 1 is moved to the imaging position together with the subject M.

[Step S1] The operator uses the keyboard 6 or the mouse 7 to specify thinning-out reading scanning.

[Step S2] In response to the designation of the thinning-out reading scan, a command signal is sent from the scanning mode switching unit 27 to the read-out scanning signal generating unit 26, and the X, Y comparator 2
The X and Y end addresses given to the registers 8 and 30 are changed to 511, and as shown in FIG.
7, 29 are reset.

[Step S3] Then, the X and Y address counters 27 and 29 stand by in a reset state until a photographing start command is issued.

[Step S4] The operator inputs a command to start X-ray photography from the keyboard 6 or the mouse 7.

[Step S5] The counting operation of the X and Y address counters 27 and 29 starts, and as the thinning-out reading scan proceeds, the X-ray detection signals are sequentially extracted from the X-ray detection elements XD1 of each element block XB. At the same time, the X-ray image is displayed on the screen of the monitor 4 at a high frame scanning speed, so that high-speed X-ray imaging is executed.

[Step S6] When the photographing for the amount specified by the operator is completed, a photographing stop command is automatically issued.

[Step S7] In response to the instruction to stop the imaging, the X-ray irradiation and the reading scan of the X-ray detection signal are stopped, and the X-ray imaging is completed.

The X-ray diagnostic apparatus of the first embodiment is a flat panel type X-ray apparatus of a two-dimensional array system in which the proportional relationship between the dimension on the X-ray fluoroscopic image and the dimension on the subject is maintained over the entire surface. Since a line sensor is used, peripheral image distortion can be eliminated and the mechanical structure beneath the tabletop can be eliminated.In addition, by specifying and executing thinning-out reading scanning,
Projects X-ray images at a high frame scanning speed,
Since the X-ray imaging can be performed, the X-ray diagnostic apparatus of the first embodiment is an extremely useful apparatus.

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 9 is a plan view showing element blocks set by collective readout scanning in the second embodiment, and FIG. 10 is a block diagram showing a circuit configuration of the X-ray sensor 3 provided in the X-ray diagnostic apparatus of the second embodiment. FIG. The X-ray diagnostic apparatus of the second embodiment reads out the X-ray detection signal from the X-ray detection element of the X-ray sensor instead of the thinning-out readout scanning of the first embodiment described above. Is substantially the same as the first embodiment except that the collective readout scan is performed in which the X-ray detection signals of all the elements in each block are combined and taken out from the X-ray sensor as a single block signal. Because of the structure and effect of
To avoid duplication, only different parts will be described, and description of the same parts will be omitted.

That is, in the case of the collective readout scanning of the apparatus of the second embodiment, as shown in FIG. 9, the entire array of 1024.times.1024 X-ray detecting elements XD is arranged in the X (horizontal) direction as shown in FIG. An element block Xb is set by a total of four X-ray detection elements XD1 to XD4, two in the Y (vertical) direction. This element block Xb is equivalent to the element block XB assumed in the previous thinning-out reading scan, and the set arrangement of the element blocks Xb is also 512 × 512. Then, when performing the collective reading scan, the X-ray detection signals of the four X-ray detection elements XD1 to XD4 of each element block Xb are all summed together and read out at once.

Therefore, the number of times of reading for each element block Xb is also one, and the number of times of reading a signal in one frame scan is １ ／ of the number of full reading scans as in the case of thinning-out scanning.
On the other hand, the X and Y collective scanning signals for collective read scanning require a signal indicating an address corresponding to each element block Xb. In the second embodiment, the X-ray detection element XD1 at the upper left of each element block Xb is required. Allocate an address. As a result, since the X and Y combined scanning signals can use the X and Y thinning-out scanning signals of the first embodiment generated by the read-out scanning signal generator 26 in FIG. 7 as they are, the overall configuration of the device of the second embodiment is also improved. As shown in FIG.

However, in the case of collective read scanning, it is necessary to sum the signals of the four X-ray detection elements XD1 to XD4 of the element block Xb and read them at once. for that reason,
In the case of the device of the second embodiment, as shown in FIG. 10, in the X-ray sensor 3, the readout wirings 18,
, A switch SWa for connecting the switch 18 and readout wirings 19 and 19.
And an element switch SWc for making the preamplifier 22 the same as each other in each element block X.
b, and when the collective reading scan is designated, the switches SWa to SWc can be switched from the state shown by the solid line to the state shown by the dashed line by the command signal from the scanning mode switching unit 35. ing.

When each of the switches SWa to SWc is in a state shown by a dashed line, the currents of the four X-ray detection elements XD1 to XD4 of each element block Xb are all one preamplifier 2
2, the signals of the X-ray detection elements XD1 to XD4 are summed and extracted at one time. When the signals of the X-ray detection elements XD1 to XD4 are summed up, the signal strength becomes four times the normal value. Therefore, when the gain of the preamplifier is reduced to 1/4 or when the AD converter 10 converts the signal into a digital signal, 1
An average is obtained by setting the value to / 4, or performing processing to reduce the pixel value to １ ／ in the image processing unit.

Next, the operation of the X-ray diagnostic apparatus of the second embodiment having the above configuration when high-speed X-ray imaging by collective read scanning is executed will be described with reference to the flowchart of FIG. Also in the case of imaging by the apparatus of the second embodiment, of course, after placing the subject M on the top 1, the top 1 together with the subject M is moved to the imaging position. [Step F1] The operator uses the keyboard 6 or the mouse 7 to specify collective read scanning.

[Step F2] At the same time that the collective reading scan is designated, a command signal is sent from the scanning mode switching unit 27 to the reading scan signal generating unit 26, and the X and Y ends to be given to the X and Y comparators 28 and 30 are sent. Address is 511
7, the switch 34 is switched to the dashed line state as shown in FIG. 7, and at the same time, the switches SWa to SWc are also switched to the dashed line state as shown in FIG.
The X and Y address counters 27 and 29 are reset.

[Step F3] Then, the X and Y address counters 27 and 29 stand by in a reset state until a photographing start command is issued.

[Step F4] The operator inputs an X-ray imaging start command from the keyboard 6 or the mouse 7.

[Step F5] As the count operation of the X and Y address counters 27 and 29 starts and the collective reading scan progresses, the X-ray detectors XD1 to XD4 of each element block Xb collectively collect the X-rays. At the same time that the detection signal is taken out, an X-ray image is displayed on the screen of the monitor 4 at a high frame scanning speed.
High-speed X-ray imaging will be performed.

[Step F6] When the photographing for the amount specified by the operator is completed, a photographing stop command is automatically issued.

[Step F7] In response to the instruction to stop the imaging, the X-ray irradiation and the reading scan of the X-ray detection signal are stopped, and the X-ray imaging is completed.

In the case of the first embodiment, only the X-ray detection signal of the X-ray detection element XD1 is reflected on the X-ray image.
In the case of the embodiment, the X-ray detection signals of all the X-ray detection elements XD are reflected in the X-ray image, and the image quality of the X-ray image can be improved. Since the device disappears, the utility of the device is high.

The present invention is not limited to the above embodiment, but can be modified as follows. (1) In the example device, the element configuration in the element block is X
Although it was a 2 × 2 array with two directions and two Y directions,
The element block is 2 × 1 with two in the X direction and one in the Y direction.
Or a 4 × 1 array with four in the X direction and one in the Y direction,
Alternatively, an array other than 2 × 2, such as a 3 × 3 array of three in the X direction and three in the Y direction, may be used.

(2) Embodiment In the thinning-out reading scan and the collective reading scan of the apparatus, the element configuration in the element block is X
Only a 2 × 2 array having two directions and two Y directions can be designated. However, a 2 × 1 array having two X directions and one Y direction, four X directions, and one Y direction can be specified. 4 ×
An array of 1, or 3 in the X direction and 3 in the Y direction
An array other than 2 × 2, such as a × 3 array, can also be selected and specified, and a configuration may be used in which there are a plurality of element arrays that can be specified by thinning-out scanning or collective scanning.

(3) In the apparatus of the embodiment, the X-ray sensor 3 is a square panel. However, the X-ray sensor 3 is not limited to a square panel, and may be, for example, a rectangular panel.

(4) Embodiment The apparatus has a cassette-type quick-shooting mechanism for copying an X-ray image on a film. No.

[0062]

According to the X-ray diagnostic apparatus of the present invention, the X-ray sensor for detecting the X-ray fluoroscopic image is a two-dimensional array type flat panel X-ray sensor, Since the proportional relationship between the above dimensions and the dimensions on the subject is maintained over the entire surface, peripheral image distortion in the X-ray image does not occur, and the thin and thin plate-shaped sensor is lightweight. The complication of the mechanical structure under the top plate is also eliminated. In addition, in the thinning-out scanning, the number of X-ray detection elements to be read out is reduced, so that the number of times of reading out the X-ray detection signals during one frame scanning is significantly reduced as compared with the case of the full scanning. Since the speed is increased, high-speed X-ray imaging suitable for imaging when the subject is moving can be performed.

According to the X-ray diagnostic apparatus according to the second aspect of the present invention, the X-ray sensor for X-ray fluoroscopic image detection is
A flat panel X-ray sensor of a two-dimensional array type, wherein a proportional relationship between a dimension on an X-ray fluoroscopic image and a dimension on a subject is maintained over the entire surface, so that a peripheral image in an X-ray image is provided. Since the sensor does not cause distortion and is a small and lightweight thin plate-shaped sensor, the mechanical structure on the lower side of the top plate is not complicated. In addition, in addition to the above, in the collective reading scan, a plurality of X-ray detection elements are collectively read at once, so that the number of times of reading the X-ray detection signal during one frame scan is significantly larger than in the case of full reading scan. Decrease to
Since the frame scanning speed is increased, high-speed X-ray imaging suitable for imaging when the subject is moving can be performed. In addition, in the case of collective read scanning, since the X-ray detection signals of all the X-ray detection elements are reflected in the X-ray image, the image quality of the X-ray image can be expected to be improved as compared with the case of the thinning-out read scan, and the subject is wasteful. There is also an effect that an unnecessary X-ray irradiation area is eliminated.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an overall configuration of an X-ray diagnostic apparatus according to a first embodiment.

FIG. 2 is a plan view showing an arrangement of X-ray detection elements in a flat panel X-ray sensor.

FIG. 3 is a perspective view showing a schematic configuration of a flat panel X-ray sensor.

FIG. 4 is a sectional view showing a layer structure of a flat panel X-ray sensor.

FIG. 5 is a plan view showing an element block assumed in the thinning-out scanning.

FIG. 6 is a block diagram illustrating a circuit configuration of a flat panel X-ray sensor.

FIG. 7 is a block diagram showing a circuit configuration of a read-out scanning signal generator of the device of the embodiment.

FIG. 8 is a flowchart showing a flow of high-speed X-ray imaging by thinning-out reading scanning.

FIG. 9 is a plan view showing element blocks set in collective read scanning according to the second embodiment.

FIG. 10 is a block diagram illustrating a circuit configuration of a flat panel X-ray sensor according to a second embodiment.

FIG. 11 is a flowchart showing a flow of high-speed X-ray imaging by collective reading scanning.

FIG. 12 is a block diagram showing a schematic configuration of a conventional X-ray diagnostic apparatus.

FIG. 13 is a schematic diagram illustrating a distortion state of a peripheral portion of an X-ray fluoroscopic image of a conventional apparatus.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 top plate 2 X-ray tube 3 flat panel X-ray sensor 4 monitor 6 keyboard 7 mouse 20 X read drive 21 Y read drive M subject 26 read scan signal generator 35 ... Scanning mode switching unit XD ... X-ray detection elements XD1 to XD4 ... X-ray detection elements XB ... Element block Xb ... Element block

Claims (2)

[Claims] 1. An X-ray tube for irradiating an X-ray to a subject mounted on a top plate, and (b) a plurality of X-ray tubes arranged opposite to the X-ray tube with the top plate interposed therebetween. A two-dimensional array type X-ray fluoroscopic image detection flat panel X-ray sensor in which X-ray detection elements are arranged vertically and horizontally, and (c) an X-ray detection signal for the X-ray detection element of the flat panel X-ray sensor (D) reading all the X-ray detection signals from the X-ray detection elements of the flat panel type X-ray sensor by performing full-reading scanning for extracting the X-ray detection signals from each X-ray detection element without fail. Thinning-out scanning means for performing reading-out by thinning-out scanning for extracting an X-ray detection signal from only one of the element blocks assumed to be composed of a plurality of adjacent elements; and (e) the thinning-out scanning. (F) image reading means for displaying an X-ray image of a subject based on an X-ray detection signal read from a flat panel X-ray sensor An X-ray diagnostic apparatus comprising: 2. An (a) X-ray tube for irradiating an X-ray to a subject mounted on a top plate, and (b) a plurality of X-ray tubes arranged opposite to the X-ray tube with the top plate interposed therebetween. A two-dimensional array type X-ray fluoroscopic image detection flat panel X-ray sensor in which X-ray detection elements are arranged vertically and horizontally, and (c) an X-ray detection signal for the X-ray detection element of the flat panel X-ray sensor (D) reading all the X-ray detection signals from the X-ray detection elements of the flat panel type X-ray sensor by performing full-reading scanning for extracting the X-ray detection signals from each X-ray detection element without fail. Collective read scanning means for performing readout by collective read scanning in which the X-ray detection signals of all the elements in each block composed of a plurality of adjacent elements are combined and taken out from the X-ray sensor as a single block signal; , e) read-scan designating means for designating and executing the collective read-scan, and (f) image display means for displaying an X-ray image of the subject based on the X-ray detection signal read from the flat panel X-ray sensor. An X-ray diagnostic apparatus comprising: