JP2003038473A - X-ray machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform a high-speed CT radiographing of high quality and an oblique-incidence fluoroscopic radiographing of a large tilt angle by use of a single device. SOLUTION: Two arm members 10 and 11 having an X-ray tube 1 and a panel type detector 2 at the tips are arranged in such a manner as to be capable of advancing and retreating in a direction parallel to the axis Z of a subject M. At the time of high-speed CT radiographing, the X-ray tube 1 and the detector 2 are laid in a state where they are mutual opposed in the vicinity of a ring-like rotary base 4 by adjusting the advance and retreat of the two arm members 10 and 11, and the rigidity of the arm members 10 and 11 is ensured to prevent the X-ray tube 1 and detector 2 from being unstable by the high-speed rotation, whereby the high-speed CT radiographing of high quality is realized. At the time of oblique-incidence fluoroscopic radiographing, the X-ray tube 1 and the detector 2 are laid in a stat where they are opposed with a large space, and the inclination is increased, thereby, the oblique-incidence fluoroscopic radiographing of a large inclination is realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray imaging apparatus capable of performing X-ray tomography [X-ray CT (Computer Tomography) imaging] and X-ray fluoroscopy. The present invention relates to a technique for performing high-speed X-ray CT imaging with high image quality and oblique-incidence X-ray fluoroscopic imaging with a large inclination angle by one device.

[0002]

2. Description of the Related Art FIG. 10 is a diagram showing a conventional X-ray CT apparatus. The gantry 51 includes an X-ray tube 52 and an X-ray detector 53.
And are arranged opposite to each other with the subject M interposed therebetween. This X-ray C
During the X-ray CT imaging, the T apparatus keeps the X-ray tube 52 and the X-ray detector 53 facing each other while maintaining the body axis Z of the subject M.
While rotating around, the subject M is irradiated with X-rays from the X-ray tube 52, and the X-ray detector 5 is detected as the transmitted X-rays are detected.
3 is configured to perform reconstructed image signal processing for obtaining reconstructed image data on the basis of the X-ray detection signal output from No. 3 in the subsequent stage of the X-ray detector 53, and finally create and display an X-ray CT image. Has been done.

FIG. 11 is a view showing a conventional C-arm type X-ray fluoroscope. This X-ray fluoroscope has a C-arm 6
An X-ray tube 62 for X-ray irradiation attached to one end of 1.
An image intensifier (II tube) 63 for X-ray detection, which is attached to the other end of the C-arm 61, is in an opposing state with the subject M sandwiched therebetween. The X-ray tube 62 and the I / I tube 63 are immovable and irradiates the subject M with X-rays from the X-ray tube 62, and at the same time transmits X-rays.
X-ray fluoroscopic image data is obtained based on the X-ray detection signal output from the I / I tube 63 in accordance with the detection of the X-ray, and the X-ray fluoroscopic image signal processing is performed in the subsequent stage of the I / I tube 63 to finally perform X-ray It is configured to create and display a fluoroscopic image.

[0004]

However, in both of the above-mentioned conventional apparatuses, high-quality X-ray CT imaging with high image quality and oblique-entry X-ray fluoroscopic imaging with a large inclination angle cannot be performed with a single apparatus. There is a problem. That is, in the conventional X-ray CT apparatus, high-quality high-speed X-ray CT imaging is possible, but oblique oblique X-ray fluoroscopic imaging with a large inclination angle is difficult. That is, conventional X-ray C
In the case of the T apparatus, the X-ray tube 52 and the X-ray detector 53 are firmly attached, and even if the rotation speed of the X-ray tube 52 and the X-ray detector 53 is increased to perform high-speed X-ray CT imaging, The positions of the X-ray detector 52 and the X-ray tube 53 are stable, and the image quality is not deteriorated. However, as shown by the alternate long and short dash line in FIG. Since the tilt angle (tilt angle) of the fluoroscopic imaging is about 15 ° at the most, oblique oblique X-ray fluoroscopic imaging with a large inclination angle is impossible.

On the contrary, with the conventional X-ray fluoroscopic apparatus, although high-angle X-ray CT imaging is possible, it is difficult to perform high-quality high-speed X-ray CT imaging. That is, in the case of the conventional X-ray fluoroscopic apparatus, the C-arm 61 can be largely tilted to perform oblique-entry X-ray fluoroscopic imaging with a large inclination angle, as shown by the alternate long and short dash line in FIG. When attempting to perform high-speed X-ray CT imaging by rotating the I and I tubes 63 around the body axis Z of the subject M at high speed, the rigidity of the C arm 61 is insufficient, and
Since the positions of the X-ray tube 62 and the X-ray detector 63 become unstable and the image quality deteriorates, high-speed X-ray CT imaging is impossible.

When the heart is the target of X-ray photography among the circulatory organs, high-speed high-speed X-ray CT photography is performed and a three-dimensional reconstructed image clearly showing blood vessels and a large inclination angle are obtained. It is often the case that both X-ray fluoroscopic images obtained by oblique-entry X-ray fluoroscopy are required. To deal with this, two devices, an X-ray CT system and an X-ray fluoroscopy system, are used separately. It is necessary to take an image, the image taking becomes complicated, and the burden on the subject M is not small.

The present invention has been made in view of such circumstances, and high-speed high-speed X-ray CT imaging and oblique-incidence X-ray fluoroscopic imaging with a large inclination angle can be performed by one apparatus. An object is to provide an X-ray imaging apparatus.

[0008]

The present invention has the following constitution in order to achieve such an object. That is, in the X-ray imaging apparatus according to claim 1, (A) an X-ray source for irradiating X-rays and an X-ray detector having a two-dimensional X-ray detection surface are arranged so as to face each other with the subject in between. And a ring-shaped rotary base arranged so as to be rotatable around the body axis of the subject, and (B) the X-ray source and the X-ray detector are attached to the respective tips, And (2) two arm members installed on the ring-shaped rotary base so as to be able to advance and retreat in a direction parallel to the body axis of (1), (C) the X-ray source and the X-ray by adjusting the advancing and retracting of the arm members. The setting of the non-diagonal imaging mode arrangement state in which both detectors face each other in the vicinity of the ring-shaped rotary base and the oblique incidence imaging mode arrangement state in which the X-ray source and the X-ray detector diagonally face each other are set. And (D) an X-ray detector is provided after the X-ray detector. Reconstructed image signal processing for obtaining reconstructed image data based on the X-ray detection signal output from the X-ray detector during tomography, and X-ray output from the X-ray detector during X-ray fluoroscopy It is characterized in that a signal processing unit for performing fluoroscopic image signal processing for obtaining X-ray fluoroscopic image data based on a detection signal is provided.

Further, in the X-ray imaging apparatus according to a second aspect of the present invention, (a) an X-ray source for irradiating X-rays and an X-ray detector having a two-dimensional X-ray detection surface face each other with a subject being sandwiched therebetween. A ring-shaped rotation base that is arranged so as to be rotatable around the body axis of the subject, and (b) either the X-ray source or the X-ray detector is attached to the tip. A single arm member attached to the ring-shaped rotary base so that it can be moved back and forth in a direction parallel to the body axis of the subject; and (c) the X-ray is adjusted by moving the arm member forward and backward. Source and the X-ray detector both face each other in the vicinity of the ring-shaped rotary base, and a non-diagonal imaging mode arrangement state, and the X-ray source and the X-ray detector diagonally oppose each other in the oblique incidence imaging mode arrangement It is configured to be able to set the state and
(D) In the subsequent stage of the X-ray detector, reconstructed image signal processing for obtaining reconstructed image data based on the X-ray detection signal output from the X-ray detector during X-ray tomography, and X A signal processing unit is provided for performing fluoroscopic image signal processing for obtaining X-ray fluoroscopic image data based on an X-ray detection signal output from the X-ray detector during fluoroscopic radiography. .

An X-ray imaging apparatus according to a third aspect is
The X-ray imaging apparatus according to claim 1 or 2, further comprising a facing direction moving unit that moves at least one of the X-ray source and the X-ray detector in a facing direction thereof. It has a feature.

An X-ray imaging apparatus according to a fourth aspect is
The X-ray imaging apparatus according to any one of claims 1 to 3, wherein the X-rays emitted from the X-ray source during X-ray tomography are cone-beam X-rays, and reconstruction performed by the signal processing unit. The image signal processing is for three-dimensional reconstructed images.

[Operation] Next, the operation of the present invention will be described. That is, according to the invention of claim 1, the high speed X
When performing X-ray CT imaging, the two arm members having the X-ray source and the X-ray detector attached to the distal ends are largely retracted in a direction parallel to the body axis of the subject, whereby the X-ray source and the X-ray are detected. Both of the detectors are set in a non-oblique imaging mode arrangement state in which they face each other in the vicinity of the ring-shaped rotary base, and the ring-shaped rotary base is rotated around the body axis of the subject. Then, as the ring-shaped rotating base rotates, the X-ray source and the X-ray detector rotate around the body axis of the subject, and the X-ray source irradiates the subject with X-rays and transmits the subject. The X-ray detector detects the X-rays (transmitted X-rays). Then, in the subsequent stage of the X-ray detector, the signal processing unit performs signal processing for the reconstructed image on the basis of the X-ray detection signal output from the X-ray detector in association with the detection of the transmitted X-ray, and reconstructed image Data is obtained.

According to the first aspect of the invention, when performing oblique-incidence X-ray fluoroscopic imaging with a large inclination angle, the X-ray source and the X-ray detector are attached to the two arm members. By setting one side to a large extent and the other side to a large extent, the X-ray source and the X-ray detector are set in the oblique-incidence shooting mode arrangement with a large inclination angle in which the X-ray source and the X-ray detector are opposed to each other at a large angle.
X-rays are emitted from an X-ray source and transmitted X-rays are detected by an X-ray detector. Then, in the subsequent stage of the X-ray detector, the signal processing unit performs the signal processing for the fluoroscopic image based on the X-ray detection signal output from the X-ray detector in accordance with the detection of the transmitted X-ray, and the X-ray fluoroscopic image is processed. Data is obtained.

That is, in the case of the invention described in claim 1,
By advancing and retracting the two arm members with the X-ray source and the X-ray detector attached to the tip, both the X-ray source and the X-ray detector face each other near the ring-shaped rotary base during high-speed X-ray CT imaging. In this state, not only can the rigidity of the arm member be secured, the situation in which the positions of the X-ray source and the X-ray detector become unstable at high speeds can be avoided, and high image quality can be maintained,
At the time of oblique X-ray fluoroscopy, the X-ray source and the X-ray detector should face each other at a large distance obliquely, and the inclination angle should be increased to realize a large inclination angle for oblique X-ray fluoroscopy. is there.

According to the second aspect of the present invention, when performing high-speed X-ray CT imaging, one arm member having either the X-ray source or the X-ray detector attached to the tip thereof is covered. By largely retracting in the direction parallel to the body axis of the sample, both the X-ray source and the X-ray detector are set in the non-diagonal imaging mode arrangement state in which they face each other in the vicinity of the ring-shaped rotary base, and a large tilt is obtained. On the other hand, when performing oblique angle X-ray fluoroscopic imaging, the X-ray source and the X-ray detector are opposed to each other at a large distance diagonally by advancing the arm member largely in the direction parallel to the body axis of the subject. Except for setting the oblique-angle shooting mode arrangement of the inclination angle, the configuration is the same as in the case of the invention described in claim 1, and therefore the other description is omitted.

According to the invention described in claim 3, X
Since the facing direction moving means for moving at least one of the radiation source and the X-ray detector in the facing direction is provided, the facing distance between the X-ray source and the X-ray detector can be adjusted, and X The magnification of the transmission image detected by the line detector can be changed.

According to the invention described in claim 4, X
The X-rays emitted from the X-ray source during X-ray CT imaging are cone-beam X-rays, and many slice sections are simultaneously projected on the two-dimensional X-ray detection surface, so many slice sections are imaged at once. In addition to being able to
Signal processing for reconstructed images for dimensional reconstructed images is performed,
Finally, a three-dimensional reconstructed image can be created.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an X-ray imaging apparatus of the present invention will be described below with reference to the drawings. 1 is a block diagram showing the overall configuration of an X-ray imaging apparatus according to an embodiment of the invention described in claim 1, and FIG. 2 is a side view showing the configuration of the imaging apparatus side of the embodiment apparatus.

The X-ray imaging apparatus of the embodiment has an X-ray tube 1 as an X-ray source for irradiating X-rays and a flat panel type X-ray detector 2 as an X-ray detector having a two-dimensional X-ray detection surface. (Hereinafter, referred to as a panel type detector 2 as appropriate) is the subject M.
A ring-shaped rotary base 4 that is disposed so as to face each other with the object in between and is rotatably arranged around the body axis Z of the subject M.
Is equipped with. Ring-shaped rotating base 4 for X-ray CT imaging
As the X-ray tube 1 rotates, the X-ray tube 1 and the panel-type detector 2 rotate around the body axis Z of the subject M, and the X-ray tube 1 emits X-rays to the subject M on the top plate 3. Simultaneously with the irradiation, the panel type detector 2 detects the X-rays (transmitted X-rays) that have passed through the subject M. During X-ray fluoroscopy, when the X-ray tube 1 and the panel-type detector 2 are set at predetermined positions with respect to the subject M, the ring-shaped rotary base 4 does not rotate and the X-ray tube 1 does not rotate. Normally, the panel type detector 2 is immobile, and in this state the X-ray tube 1
Is irradiated with X-rays and the panel-type detector 2 detects transmitted X-rays. In other words, this X-ray imaging apparatus uses two methods of X-ray CT imaging and X-ray fluoroscopy.
You can perform line photography.

On the side of the imaging table of the apparatus of the embodiment, as shown in FIG. 2, the ring-shaped fixed base 5 has a center of, for example, a circular opening into which the top plate 3 on which the subject M is placed is inserted. The axis
It is installed so as to be substantially aligned with the direction of the body axis Z of the subject M. The ring-shaped rotary base 4 is fitted inside the ring-shaped fixed base 5 via a bearing member 6. A ring-shaped rack 7 is continuously provided integrally with one end of the ring-shaped rotary base 4 along the circumferential direction, and a drive motor provided at the bottom end of the ring-shaped fixed base 5. The pinion 9 that is rotated by 8 is provided so as to mesh with the ring-shaped rack 7 of the ring-shaped rotary base 4, and the rotational force of the drive motor 8 is applied to the ring-shaped rotary base 4 by the pinion 9 and the ring-shaped rack 7. Be transmitted to. That is, when the drive motor 8 rotates, the ring-shaped rotary base 4 is configured to rotate inside the ring-shaped fixed base 5 in the circumferential direction.

Two arm members 10 and 11 are provided at two opposing positions inside the ring-shaped rotary base 4 so that the longitudinal direction of the arm members 10 and 11 is parallel to the body axis Z of the subject M. They are installed so that they can move back and forth in a direction parallel to the body axis Z of. The X-ray tube 1 is attached to the tip of the arm member 10 via an X-ray tube support plate 17. The panel-type detector 2 is attached to the tip of the arm member 11 via a detector support plate 18. Arm member 1
The position of the X-ray tube 1 changes along the direction parallel to the body axis Z of the subject M as 0 moves back and forth, and the position of the panel type detector 2 changes the position of the subject M as the arm member 11 moves back and forth. It is configured to change along a direction parallel to the body axis Z of.

Further, the advancing / retreating mechanism of the arm member 11 will be described more specifically with reference to FIG. FIG. 3 is a partial front view showing the installation situation of the arm member 11 in the apparatus of this embodiment. As shown in FIG. 3, the inner surface of the ring-shaped rotary base 4 and the arm member 1 are arranged along the longitudinal direction of the arm member 11.
Two linear ways 11A, 11 provided on the outer surface of 1
The arm member 11 is locked to the ring-shaped rotary base 4 at B, and the linear rack 11C is installed on the outer surface of the arm member 11 along the longitudinal direction of the arm member 11, and the ring-shaped rotary base is provided. 4 is provided with a pinion 11E rotated by a drive motor 11D so as to mesh with the linear rack 11C. The pinion 11E rotates with the rotation of the drive motor 11D, and the rotational movement of the pinion 11E is changed by the linear rack 11C. Is configured to be converted into forward and backward movements of the arm member 11. Note that the advancing / retreating mechanism of the arm member 10 is the same as that of the arm member 11 and is the same as that of the arm member 11.

Returning to FIG. 2, in the case of the imaging stand of the apparatus of the embodiment, the orientations of the X-ray tube 1 and the panel type detector 2 are set so that the X-ray tube 1 and the panel type detector 2 are accurately arranged to face each other. A facing arrangement adjusting mechanism is provided for adjusting. That is, each support plate 17, 18 is attached to the tip of each arm member 10, 11 so as to be swingable about the pins 17a, 18a as the center of rotation, and at the same time each support plate 17, 1 is
It is configured so that the X-ray tube 1 and the panel-type detector 2 can be accurately placed to face each other by holding 8 at an appropriate rotation position. Specifically, ball screws 21 and 22 that rotate with the rotation of the drive motors 19 and 20 are provided on the side surfaces of the arm members 10 and 11 in the longitudinal direction thereof.
Of the rocking supports 23 and 24, one end of each of the rocking supports 23 and 24 is locked to the support plates 17 and 18, and the other end of the rocking supports 23 and 24 is connected to the screw coupling pieces 25 and 26.
Is locked to the ball screws 21 and 22 with the drive motor 1
As the screw coupling pieces 25, 26 move as the ball screws 21, 22 rotate by 9, 20, the inclination of the swing supports 23, 24 changes, and the rotational positions of the support plates 17, 18 change. The X-ray tube 1 and the panel type detector 2 are configured so that the directions thereof can be adjusted.

Further, in the case of the imaging stand of the apparatus of the embodiment, a facing distance adjusting mechanism 48 for adjusting the facing distance between the X-ray tube 1 and the panel type detector 2 is also provided. That is, in the facing distance adjusting mechanism 48, the ball screws 29 and 30 that rotate with the rotation of the drive motors 27 and 28 are provided near the front ends of the side surfaces of the support plates 17 and 18 in the longitudinal direction of the X-ray tube 1 and the panel. The X-ray tube 1 and the panel type detector 2 are attached so as to face each other in the direction opposite to the die detector 2, and are locked via the screw coupling piece 31 and the screw coupling plate 32. , 20 as the ball screws 21, 22 rotate, the screw coupling piece 31 or the screw coupling plate 32 moves, so that the X-ray tube 1 and the panel type detector 2 approach or separate from each other in opposite directions. The tube 1 and the panel-type detector 2 are configured so that the facing distance between them changes. The above-mentioned facing distance adjusting mechanism 48 corresponds to the facing direction moving means of the present invention.

In this way, the X-ray tube 1 and the panel type detector 2 are
The magnification of the transmission image detected by the panel-type detector 2 can be changed by adjusting the facing interval of the.

When adjusting the facing distance between the X-ray tube 1 and the panel type detector 2, both the X-ray tube 1 and the panel type detector 2 may be moved, or only one of them may be moved. May be. Further, in the imaging stand of the apparatus of the embodiment, both the X-ray tube 1 and the panel type detector 2 are movable to adjust the facing distance. However, for example, the heavy X-ray tube 1 is fixed. Only the panel type detector 2 may be moved to adjust the facing distance.

Then, high-speed X-ray CT is used in the apparatus of the embodiment.
When performing radiography, normally, as shown in FIG. 4, the two arm members 10 and 11 are both retracted as much as possible in a direction parallel to the body axis Z of the subject M to thereby obtain the X-ray tube 1 and the panel type. Both of the detectors 2 are arranged in the vertical direction in the vicinity of the ring-shaped rotary base 4 and set in the non-diagonal photographing mode arrangement state in which they face each other in a horizontal posture. Even in the case of high-speed X-ray CT imaging, the X-ray tube 1 or the panel type detector 2 is not completely close to the ring-shaped rotary base 4, or the X-ray tube 1 and the panel type detector 2 are completely horizontal. It is also possible to set a non-diagonal shooting mode arrangement state in which the user does not face each other but in a slightly tilted posture.

When performing oblique-incidence X-ray fluoroscopic imaging with a large inclination angle, as shown in FIG. 5, two arm members 10 and 1 are used.
1 (arm member 11 in FIG. 5) is largely retracted and the other (arm member 10 in FIG. 5) is largely advanced, and the X-ray tube 1 and the panel type detector 2 are diagonally opposed to each other in an oblique photographing mode arrangement. Set. Of course, when performing oblique-incidence X-ray fluoroscopic imaging with a large inclination angle, as shown in FIG. 2, the arm member 10 is largely retracted and the arm member 11 is greatly advanced to set the oblique-incidence imaging mode arrangement with a large inclination angle. May be.

As described above, in the apparatus of the embodiment, the X-ray tube 1
Since the X-ray tube 1 and the panel-type detector 2 can be moved by adjusting the forward and backward movements of the arm members 10 and 11, respectively, when the oblique-entry imaging mode is set so that the panel-type detector 2 and the panel-type detector 2 are diagonally opposed to each other. There is a large degree of freedom when setting the shooting mode layout.

Returning to FIG. 1, in the case of the apparatus of the embodiment, an input section 33 comprising an input device such as an operation console or a mouse for inputting necessary operations and data necessary for execution of X-ray imaging, and this input. The X-ray tube 1 and the panel-type detector 2 are arranged on the side of the imaging stand, which is provided with an imaging control section 34 that transmits command signals to each section in a timely manner in response to an input operation from the section 33 and progress of X-ray imaging. Is set by an input operation of the input unit 33 and the like, and the image pickup system arrangement setting unit 3 sets the arrangement to the set arrangement.
4A is configured to drive each drive motor 11D, 19, 20, 27, 28, etc. in accordance with a command signal from the photographing control unit 34. In addition, the irradiation control unit 34B that causes the X-ray tube 1 to perform X-ray irradiation and the top plate driving unit 34C that moves the top plate 3 horizontally and vertically also follow the command signal from the imaging control unit 34. Control the board 3.

When performing X-ray CT imaging in the apparatus of the embodiment, the X-ray tube 1 and the panel type detector 2 move around the body axis Z of the subject M in association with the rotation of the ring-shaped rotary base 4. The X-ray tube 1 is moved to the subject M while rotating to the collimator 1A.
The panel type detector 2 detects the transmitted X-rays by irradiating the X-rays shaped into a cone beam. When performing X-ray fluoroscopy, the ring-shaped rotary base 4 is not rotated and the X-ray tube 1 and the panel-type detector 2 are normally immobile, and the X-ray tube 1 is a cone-beam X-ray on the subject M. The panel type detector 2 detects the transmitted X-ray by irradiating the X-ray.

Further, in the case of X-ray CT imaging, signal processing such as convolution integration using a reconstruction function is performed on the X-ray detection signal output from the panel type detector 2 in accordance with the detection of transmitted X-rays. In this way, the signal processing unit 35 performs signal processing for the three-dimensional reconstructed image, data for the three-dimensional reconstructed image is obtained, and stored in the reconstructed image data memory unit 36. The 3D reconstructed image data needs to be taken on a very large number of slice planes of the subject M, but when cone beam X-rays are used, the two-dimensional X-ray detection plane of the panel type detector 2 is used. The projected X-ray has a wide square shape and a large number of slice planes are simultaneously projected onto the surface of the panel-type detector 2, so that it becomes possible to image-process a large number of slice planes at a time. You can shoot quickly.

Further, in the case of X-ray fluoroscopy, the panel type detector 2 removes noise and adjusts the density (pixel value) with respect to the X-ray detection signal output from the X-ray detector upon detection of the transmitted X-ray. Signal processing unit 3 by performing signal processing such as
In step 5, the X-ray fluoroscopic image data is obtained and stored in the X-ray fluoroscopic image data memory unit 37.

Furthermore, in the apparatus of the embodiment, the reconstructed image creating section 38 creates a three-dimensional reconstructed image based on the data stored in the reconstructed image data memory section 36 and the created three-dimensional reconstructed image. The constituent image is the image display control unit 39.
It is sent to the display monitor 40 via and is displayed. An X-ray fluoroscopic image is also displayed on the display monitor 40 based on the data stored in the X-ray fluoroscopic image data memory unit 37.
Further, the image display control unit 39 also superimposes and displays the three-dimensional reconstructed image and the X-ray fluoroscopic image as needed.

The photographing method setting unit 34D includes the input unit 3
The ring-shaped rotary base 4 on the side of the imaging table according to a command signal issued from the imaging control unit 34 according to whether the imaging method is X-ray CT imaging or X-ray fluoroscopic imaging in accordance with the setting operation or the like by 3. And the way of processing in the signal processing unit 35 are controlled. In addition to the above, the apparatus of the embodiment may be provided with a hand switch or the like for controlling the timing of the fluoroscopic X-ray imaging on the imaging table side.

Further, in the case of the X-ray imaging apparatus of the embodiment, 2
Since it is very useful that the X-ray detector having the dimensional X-ray detection surface is the flat panel X-ray detector (FPD) 2, the panel type detector 2 will be specifically described.

The panel type detector 2 detects the transmitted X-rays of the subject M caused by the X-ray irradiation by the X-ray tube 1, converts them into electric signals as X-ray detection signals, and outputs them. An X-ray detector having a large number of X-rays, as shown in FIG.
This is a so-called two-dimensional matrix type X-ray detector in which the line detection elements Du are arranged vertically and horizontally. The array of the X-ray detection elements Du in the panel type detector 2 of the embodiment is assumed to be, for example, a square matrix of horizontal (Y) direction 1024 and vertical (X) direction 1024, and in FIG. In the matrix configuration, only a total of nine matrix configurations are shown. Panel type detector 2 having a rectangular planar shape
The X-ray detector is a useful X-ray detector because, unlike the I / I tube, which has a circular detection surface, a square detection surface suitable for imaging a large area such as the chest or abdomen is possible.

The panel type detector 2, as shown in FIG.
X-ray conversion layer 12 for converting incident X-rays into charges or light
And a detection array layer 13 in which elements for detecting charges or light generated in the X-ray conversion layer 12 are vertically and horizontally arranged in a matrix. The plane size of the X-ray conversion layer 12 of the panel type detector 2 may be, for example, about 30 cm in length and width.

The panel type detector 2 includes a direct conversion type shown in FIG. 8A and an indirect conversion type shown in FIG. 8B. 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 is a charge collection electrode group formed on the surface of the detection array layer 13 as a charge detection element 14 facing the surface electrode 15. Accordingly, the charge is detected and stored in the capacitor Cs, and one X-ray detection element Du is formed by each charge detection element 14 and a part of the X-ray conversion layer 12 thereon. . In the case of the latter indirect conversion type, the X-ray conversion layer 12 is composed of a scintillator layer that converts incident X-rays into light, and light is detected by a photodiode group formed as a photodetection element 16 on the surface of the detection array layer 13. The capacitor Cs is charged and stored in the capacitor Cs.
One X-ray detection element Du is formed with a part of 2.

The panel type detector 2, as shown in FIG.
An X-ray detection substrate 41 on which the X-ray conversion layer 12 and the detection array layer 13 are formed, and a capacitor Cs that stores a collection carrier (collection charge) via a carrier collection electrode (charge collection electrode) of the X-ray detection substrate 41. , A thin film transistor (TF) which is a normally-off (cut-off) charge extraction switch element 42 for extracting charges accumulated in the capacitor Cs.
T) and the multiplexer 4 of the read circuit in the X and Y directions.
5 and a gate driver 47.

Further, in the panel type detector 2, as shown in FIG. 6, the source of the thin film transistor for the switch element 42 of the X-ray detecting element Du is connected to the vertical read wiring 43 arranged in the X-axis direction, and the gate is formed. Are connected to the horizontal read wiring 46 arranged in the Y-axis direction. Read wiring 43
Is connected to the multiplexer 45 via the charge-voltage converter group (preamplifier group) 44, and the read wiring 46 is connected to the gate driver 47. In the charge-voltage converter group 44, although not shown, the charge-voltage converter group 44 is provided for one read wiring 43.
Are respectively connected.

In the case of the panel type detector 2, a scanning signal for signal extraction is sent to the multiplexer 45 and the gate driver 47. Each X-ray detecting element Du in the panel type detector 2 is specified in the X direction and Y direction.
Since the scanning is performed based on the addresses (in the case of 1024 X-ray detecting elements Du, for example, 1 to 1024) sequentially assigned to each X-ray detecting element Du along the arrangement in the direction, scanning for extraction is performed. The signals are signals that specify an X-direction address or a Y-direction address, respectively.

As the voltage for extraction is applied from the gate driver 47 to the readout wiring 46 in the Y direction according to the scanning signal in the X direction, each X-ray detection element Du is selected in column units. Then, the multiplexer 45 is switched in accordance with the scanning signal in the X direction, so that the charge accumulated in the capacitor Cs of the X-ray detection element Du in the selected column is passed through the charge-voltage converter group 44 and the multiplexer 45 in this order to the outside. Will be sent to. In this way, the X-ray detection signals detected by the panel type detector 2 are sequentially output in real time and processed. Of course,
Each X-ray detection element Du corresponds to each pixel of the X-ray image.

In the case of the flat panel type X-ray detector 2, since it is only a simple linear distortion that is uniquely determined by the geometrical arrangement of the X-ray detecting elements Du, the distortion of the image due to the image distortion of the detection system does not occur. In addition to easy correction, I ・ I
Since it is lighter in weight than a tube, the weight of the X-ray detector causes X
Mechanical distortion of the line imaging system is also reduced, and an accurate image without distortion of the image that is difficult to correct can be obtained. In addition, in the case of the X-ray tomography of the type in which the two-dimensional array type panel detector 2 detects the X-rays using the cone-beam-shaped X-rays like the apparatus of the embodiment, the fan-shaped beam X-rays are used. Compared with the case of X-ray CT imaging in which X-rays are detected by a one-dimensional array type X-ray detector, multiple slice planes can be imaged at once, so X-ray CT imaging can be performed in a short imaging time. can do.

Next, the operation of the apparatus when performing high-speed X-ray CT imaging and oblique-incidence X-ray fluoroscopic imaging with a large inclination angle by the X-ray imaging apparatus of the above-described embodiment will be described with reference to the drawings. FIG. 9 is a flowchart showing an X-ray imaging process by the apparatus of the embodiment. Note that the subject M is assumed to be placed on the top plate 3 and already set at the imaging position.

[Step S1] In order to execute X-ray CT imaging, as shown in FIG. 4, the two arm members 10 and 11 are maximally retracted so that both the X-ray tube 1 and the panel type detector 2 ring. The non-diagonal shooting mode is set to face the horizontal rotation base 4 in a horizontal posture.

[Step S2] The X-ray tube 1 and the panel detector 2 rotate around the body axis Z of the subject M as the ring-shaped rotary base 4 rotates due to the start of X-ray CT imaging. The panel type detector 2 detects the transmitted X-rays while irradiating the X-rays.

[Step S3] The signal processing unit 35 performs signal processing for the three-dimensional reconstructed image on the basis of the X-ray detection signal output from the panel type detector 2 to reconstruct the data for the three-dimensional reconstructed image. When the data is collected and stored in the image data memory unit 36, the X-ray CT imaging ends. Note that the three-dimensional reconstructed image is created by the reconstructed image creation unit 38 based on the three-dimensional reconstructed image data in the reconstructed image data memory unit 36 at appropriate times.

[Step S4] In order to execute X-ray fluoroscopic imaging, for example, as shown in FIG. 5, the arm member 10 is retracted to the maximum extent and only the arm member 11 is advanced to the maximum extent to allow the X-ray tube 1 and the panel to be moved. The mold detector 2 is set to the oblique-incidence photographing mode arrangement state in which the mold detector 2 is diagonally opposed to the maximum distance and has a maximum inclination angle.

[Step S5] The X-ray tube 1 and the panel-type detector 2 are immobile and the panel-type detector 2 is irradiated while the ring-shaped rotary base 4 is stopped by the start of X-ray fluoroscopy. Detects transmitted X-rays.

[Step S6] X-ray fluoroscopic image signal processing is performed in the signal processing unit 35 based on the X-ray fluoroscopic image signal output from the panel type detector 2, and the X-ray fluoroscopic image data is converted into the X-ray fluoroscopic image. When the data is collected and stored in the use data memory unit 37, the X-ray fluoroscopic imaging ends.

[Step S7] When the three-dimensional reconstructed image or the X-ray fluoroscopic image is displayed on the screen of the display monitor 40, or when they are multi-displayed (displayed in parallel on the same screen), all photographing is completed. Becomes

Examples of the three-dimensional reconstructed image obtained by X-ray CT imaging include a three-dimensional image in which the blood vessel image around the heart of the subject M is clearly shown, and as the X-ray fluoroscopic image, An example is an X-ray fluoroscopic image in which a catheter that pushes into the blood vessel toward the heart is displayed in real time.

As described above in detail, according to the X-ray imaging apparatus of the embodiment, the X-ray tube 1 and the panel type detector are used for high-speed X-ray CT imaging by adjusting the advancing / retreating of the arm members 10 and 11. The two are opposed to each other in the vicinity of the ring-shaped rotary base 4, the rigidity of the arm members 10 and 11 is secured, and the positions of the X-ray tube 1 and the panel type detector 2 become unstable at high speed rotation. Not only is it possible to avoid the above problem, but also to maintain high image quality, and at the time of oblique X-ray fluoroscopy, the position of the X-ray tube 1 and the panel-type detector 2 should be diagonally largely opposed to each other, and a large inclination is required. It is possible to secure an angle and realize a large inclination angle for oblique X-ray fluoroscopic imaging.

The present invention is not limited to the above embodiment, but can be modified as follows.

(1) In the above embodiment, the X-ray tube 1 is attached to the tip.
The arm members 10 and 11 to which the panel type detector 2 and the panel type detector 2 are attached are installed on the ring-shaped rotary base 4 so as to be able to move back and forth in the direction parallel to the body axis Z of the subject M. , The same as the above-mentioned embodiment except that only the arm member 10 having the X-ray tube 1 attached to its tip is installed on the ring-shaped rotary base 4 so as to be able to move back and forth in the direction parallel to the body axis Z of the subject M. Device with the above configuration or panel type detector 2
Only the arm member 11 attached to the tip of the subject M
As a modified example, an apparatus having the same configuration as that of the above-described embodiment except that it is installed on the ring-shaped rotary base 4 so as to be able to advance and retreat in a direction parallel to the body axis Z of FIG.

(2) In the above embodiment, the X-ray detector having the two-dimensional X-ray detection surface was a flat panel X-ray detector, but the X-ray detector may be an I / I tube, an imaging plate, or the like. Other types of detectors are possible.

(3) In the embodiment, the non-diagonal imaging mode arrangement shown in FIG. 4 can be used for X-ray CT imaging as well as X-ray fluoroscopic imaging, and the oblique incidence imaging mode arrangement shown in FIG. It is possible to perform X-ray CT imaging as well as fluoroscopic imaging.

[0059]

As is apparent from the above description, according to the X-ray imaging apparatus of the first aspect, the X-ray source and the X-ray detector are provided at the tip and the X-ray detector is parallel to the body axis of the subject. Two arm members that can move back and forth in the direction are arranged on a ring-shaped rotary base that can rotate around the body axis of the subject, and when high-speed X-ray CT imaging is performed, an X-ray source and an X-ray are used. The two arm members to which the detectors are attached are largely retracted so that both the X-ray source and the X-ray detectors face each other in the vicinity of the ring-shaped rotary base. It is possible to avoid the situation where the positions of the radiation source and the X-ray detector become unstable due to high-speed rotation, and maintain high image quality. Not only that, but also for oblique X-ray fluoroscopy, the X-ray source and X-ray
X-ray source and X-ray source
Since the line detectors are diagonally largely opposed to each other, the inclination angle can be increased to achieve a large inclination angle for oblique X-ray fluoroscopic imaging. Therefore, high-quality high-speed X-ray CT imaging and oblique-angle X-ray fluoroscopic imaging with a large inclination angle can be executed by a single device. Furthermore, when setting the oblique incidence imaging mode arrangement in which the X-ray source and the X-ray detector diagonally face each other, X
Since the position of each of the radiation source and the X-ray detector can be changed by advancing and retracting two arm members, the degree of freedom in setting the oblique incidence imaging mode arrangement is large.

Further, according to the X-ray imaging apparatus of the second aspect, either the X-ray source or the X-ray detector is provided at the tip, and the X-ray imaging apparatus can move back and forth in the direction parallel to the body axis of the subject. One arm member is arranged on a ring-shaped rotary base that can rotate around the body axis of the subject, and high-speed X-ray CT
At the time of photographing, one arm member to which either the X-ray source or the X-ray detector was attached was greatly retracted and both the X-ray source and the X-ray detector faced each other in the vicinity of the ring-shaped rotary base. Since the state is set, the rigidity of the arm member can be secured, the situation where the positions of the X-ray source and the X-ray detector become unstable at high speed rotation can be avoided, and high image quality can be maintained. Not only that, but in the case of oblique X-ray fluoroscopy, the X-ray source or X-ray
Since the X-ray source and the X-ray detector face each other at a large distance diagonally by greatly advancing one arm member to which either one of the line detectors is attached, the inclination angle is increased and the oblique insertion is performed. It is possible to realize a large inclination angle for X-ray fluoroscopy. Therefore, high-quality high-speed X-ray CT imaging and oblique-angle X-ray fluoroscopic imaging with a large inclination angle can be performed by a single device.
Furthermore, since only one of the X-ray source and the X-ray detector is attached to the arm member that can move back and forth in the direction parallel to the body axis of the subject, the device configuration becomes simple.

According to the invention of claim 3, X
Since the facing direction moving means for moving at least one of the radiation source and the X-ray detector in the facing direction is provided, the facing distance between the X-ray source and the X-ray detector can be adjusted, and X The magnification of the transmission image detected by the line detector can be changed.

According to the invention described in claim 4, X
Since the X-rays emitted from the X-ray source during X-ray CT imaging are cone-beam-shaped X-rays and a large number of slice sections are simultaneously projected on the two-dimensional X-ray detection surface, a large number of slice sections can be recorded at once. Since it is possible to shorten the photographing time by photographing and the signal processing unit performs the signal processing for the reconstructed image for the three-dimensional reconstructed image, it is possible to finally create the three-dimensional reconstructed image.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of an X-ray imaging apparatus according to an embodiment.

FIG. 2 is a side view showing a configuration of a photographing table side of the embodiment apparatus.

FIG. 3 is a partial front view showing an installation state of arm members in the apparatus of the embodiment.

FIG. 4 is a schematic diagram showing a non-diagonal imaging mode arrangement for X-ray CT imaging in an embodiment.

FIG. 5 is a schematic diagram showing an oblique imaging mode arrangement for fluoroscopic imaging in an example.

FIG. 6 is a configuration diagram of a flat panel X-ray detector.

FIG. 7 is a perspective view showing a schematic configuration of a flat panel X-ray detector.

8A and 8B are cross-sectional views showing the layer structure of a flat panel X-ray detector.

FIG. 9 is a flowchart showing an imaging process when X-ray CT imaging and X-ray fluoroscopic imaging are sequentially executed by the apparatus of the embodiment.

FIG. 10 is a schematic configuration diagram showing a main part of a conventional X-ray CT apparatus.

FIG. 11 is a schematic configuration diagram showing a main part of a conventional X-ray fluoroscopic imaging apparatus.

[Explanation of symbols]

1 ... X-ray tube (X-ray source) 2 Flat panel X-ray detector (X-ray detector) 4… Ring-shaped rotating base 10 ... Arm member 11 ... Arm member 35 ... Signal processing unit 48 ... Opposing interval adjusting mechanism (opposing direction moving means) M ... Subject Z ... Body axis

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masahiro Kono             1st Nishinokyo Kuwabara-cho, Nakagyo-ku, Kyoto City Stock Association             Inside the Shimadzu factory (72) Inventor Isao Nakata             1st Nishinokyo Kuwabara-cho, Nakagyo-ku, Kyoto City Stock Association             Inside the Shimadzu factory (72) Inventor Hiroshi Miyata             1st Nishinokyo Kuwabara-cho, Nakagyo-ku, Kyoto City Stock Association             Inside the Shimadzu factory (72) Inventor Katsunori Yuan             1st Nishinokyo Kuwabara-cho, Nakagyo-ku, Kyoto City Stock Association             Inside the Shimadzu factory F term (reference) 4C093 AA01 AA16 AA22 BA20 CA37                       EB12 EB13 EB17 EC02 EC12                       EC15 EC23 EC28 EC43

Claims (4)

[Claims] 1. An (A) X-ray source for irradiating X-rays and an X-ray detector having a two-dimensional X-ray detection surface are arranged so as to face each other with the subject in between, and around the body axis of the subject. A ring-shaped rotary base that is rotatably mounted on the base, and (B) the X-ray source and the X-ray detector, respectively, attached to the tips and moved back and forth in a direction parallel to the body axis of the subject. Two arm members installed on the ring-shaped rotary base as much as possible, and (C) both the X-ray source and the X-ray detector are adjusted by advancing and retracting the arm members so that the ring-shaped rotary base is It is configured such that a non-diagonal imaging mode arrangement state in which the X-ray source and the X-ray detector diagonally oppose each other in the vicinity of the table can be set. (D) If the X-ray detector is used after the X-ray detector at the time of X-ray tomography. Reconstructed image signal processing for obtaining reconstructed image data based on an X-ray detection signal output from
A signal processing unit for performing fluoroscopic image signal processing for obtaining X-ray fluoroscopic image data based on an X-ray detection signal output from the X-ray detector during X-ray fluoroscopic imaging is provided. X-ray imaging device. 2. (a) An X-ray source for irradiating X-rays and an X-ray detector having a two-dimensional X-ray detection surface are arranged to face each other with the subject in-between, and the body axis of the subject is rotated. A direction in which one of the ring-shaped rotary base rotatably arranged and (b) the X-ray source or the X-ray detector is attached to the tip and is parallel to the body axis of the subject. And an arm member installed on the ring-shaped rotary base so that the X-ray source and the X-ray detector are both in the ring shape. It is configured such that a non-diagonal imaging mode arrangement state in which the X-ray source and the X-ray detector face each other in the vicinity of the rotary base can be set, and an oblique incidence imaging mode arrangement state in which the X-ray source and the X-ray detector diagonally oppose each other. (D) The X-ray detector is provided after the X-ray detector during the X-ray tomography. Image signal processing for obtaining reconstructed image data based on the X-ray detection signal output from the X-ray detector, and X-ray detection based on the X-ray detection signal output from the X-ray detector during X-ray fluoroscopy. An X-ray imaging apparatus, comprising a signal processing unit for performing fluoroscopic image signal processing for obtaining fluoroscopic image data. 3. The X-ray imaging apparatus according to claim 1, further comprising a facing direction moving unit that moves at least one of the X-ray source and the X-ray detector in a facing direction thereof. An X-ray imaging apparatus characterized by being provided. 4. The X-ray imaging apparatus according to claim 1, wherein the X-rays emitted from the X-ray source during X-ray tomography are cone-beam X-rays, and signal processing is performed. An X-ray imaging apparatus, wherein the reconstructed image signal processing performed by the unit is for a three-dimensional reconstructed image.