CN1526360B - X-ray diagnostic apparatus - Google Patents

Abstract

The present invention provides an X-ray diagnostic apparatus for performing X-ray imaging of lower limbs and the like under optimal conditions following the flow of a contrast medium administered to a subject. In this X-ray diagnostic apparatus, an X-ray tube and an X-ray detector, which are arranged facing each other, are held by a holding device such as a C-arm such that a bed on which a subject is placed is located therebetween. One of the bed board and the C-arm is relatively moved relative to the other, and X-ray imaging is performed along the body axis direction of the subject. This X-ray diagnostic apparatus includes: relatively moving one of the bed board and the holding device relative to the other, and performing fluoroscopy on the subject injected with a contrast medium for each position along the body axis direction of the subject. photography, a device for obtaining the perspective image of each position; and a device for setting photography parameters necessary for main photography for each position according to the perspective image of each position obtained through the perspective photography. Perform main photography on the subject according to the set photography parameters.

Description

X-ray diagnostic device

technical field

The present invention relates to an X-ray diagnostic device and an X-ray imaging method, in particular to an X-ray diagnostic device and an X-ray imaging method suitable for carrying out contrast examination of lower limbs.

Background technique

The X-ray diagnostic apparatus is equipment that can be used for inspection and diagnosis of various parts of a subject. One of the examinations performed by this X-ray diagnostic apparatus is a lower extremity imaging examination.

In the lower extremity contrast examination performed by this X-ray diagnostic apparatus, a contrast medium is injected into an artery from the groin of the subject to follow the flow of the contrast medium, and X-ray photography is performed. Therefore, the imaging range spans a wide range from the vicinity of the pelvis to the toes. Since the entire image cannot be obtained by one imaging, partial imaging is performed several times, and then the images are spliced to obtain the entire image. However, in this imaging range, since parts of different sizes such as legs, knees, shins, and ankles are connected, if the X-ray irradiation range is, for example, the original state of a size that can cover the vicinity of the pelvis, and the shin part is photographed, for example, Vignetting will occur, impairing picture quality.

Therefore, in order to eliminate such a defect, the divergence in the width direction of the X-ray aperture device is currently adjusted so that X-rays are not irradiated to the outer region of the contour of the subject.

In addition, the following method is known: as shown in JP-A-6-217973 (pp. 21-22, FIG. 50 ), when performing moving photography of the lower limbs, the position corresponding to the position data of the bed is extracted by pre-scanning. The contour data of the subject is created as a control table, and the control table is referred to during X-ray imaging. That is, referring to the control table, the divergence in the width direction of the X-ray aperture device is controlled for each bed position, and as a result, X-rays are not irradiated to the outer region of the outline of the subject. In this case, the divergence in the longitudinal direction of the X-ray aperture device (that is, in the body axis direction of the subject) is always constant.

However, in a wide range from the vicinity of the pelvis to the toes, the blood flow velocity is not constant, and there are places where the flow velocity is slow and places where the flow velocity is fast, and there are also places where the blood vessel course is simple and complicated. Therefore, if the divergence in the longitudinal direction (that is, the direction of the subject's lower limbs) of the X-ray aperture device is constant and the moving photography of the lower limbs is performed, there is a problem that some of the images obtained by photography do not satisfy the diagnosis. parts.

To deal with such a problem, it is possible to adopt a method of narrowing the imaging interval in the direction of the subject's lower limbs and increasing the number of imaging times. In this way, the divergence in the longitudinal direction of the X-ray aperture device must be narrow, which can solve the above-mentioned problems. However, since the operator must follow the flow of the contrast agent in the state where the display area of the photographed image is narrow, it is necessary to perform photography. The operation is complex and bulky.

Contents of the invention

Therefore, an object of the present invention is to provide an X-ray diagnostic apparatus and an X-ray imaging method capable of tracking the flow of a contrast agent and performing X-ray imaging under optimum conditions, reducing the burden on the operator, and improving operability.

In order to solve the above-mentioned problems, according to one form of the X-ray diagnostic apparatus related to the present invention, it is provided with: an X-ray source generating X-rays; an X-ray detector detecting X-rays from the X-ray source; A relative holding device for the source and the above-mentioned X-ray detector; a bed board holding device for holding a bed board loaded with an object in the space between the relatively held X-ray source and the X-ray detector; making the above-mentioned bed board and the above-mentioned relative holding device The device relatively moves along the body axis direction of the above-mentioned subject injected with a contrast agent, and performs fluoroscopic photography of each imaging position in the contrast inspection range to obtain a partial fluoroscopic image of each imaging position; according to the above Partial perspective image, a photography parameter setting device for setting the optimal photography parameters for each of the above-mentioned photography positions; a photography parameter memory for storing the best photography parameters for each of the above-mentioned photography positions set by the above-mentioned photography parameter setting device; according to the above-mentioned The imaging parameter read from the imaging parameter memory is a main imaging device for relatively moving the bed board and the relative holding device to perform main imaging of the contrast examination range on the subject.

Thereby, it is possible to control and follow the flow of the contrast agent so that the X-ray irradiation range can be optimized, and a good X-ray diagnostic image can be obtained. In addition, it is possible to provide an X-ray diagnostic apparatus that greatly reduces the burden on the operator and has good operability.

In this case, as an example, the imaging parameter setting device is configured to set the imaging parameters in accordance with manual information of an operator.

For example, the relative moving speed of the bed board or the holding device may be controlled according to the flow velocity of the contrast medium, and the imaging rate of X-ray imaging may be controlled according to the flow velocity of the contrast medium. Accordingly, it is possible to further optimize the X-ray imaging conditions according to the flow of the contrast medium.

On the other hand, according to another suitable example, the imaging parameter setting device may be configured to automatically identify the flow region of the contrast agent according to the fluoroscopic image of each position obtained by the fluoroscopic imaging device, and set the imaging parameters according to the identification result. . By such automatic recognition, it is possible to automatically track the flow of the contrast medium even in fluoroscopy, and it is possible to adjust the divergence of the X-ray aperture in fluoroscopy in almost real time. In addition, imaging parameters such as the opening of the X-ray aperture at each imaging position and the relative moving speed between the holding device and the bed board can be automatically set corresponding to the flow velocity and movement amount of the tracked contrast agent, which can significantly reduce the operator's operations on the burden.

Description of drawings

FIG. 1 is a perspective view showing a schematic configuration of a holding device portion in Embodiment 1 of an X-ray diagnostic apparatus according to the present invention.

FIG. 2 is a system diagram showing a schematic configuration of the first embodiment.

Fig. 3 is a plan view for explaining the function of the X-ray aperture.

4A and 4B are explanatory diagrams explaining the case where the X-ray diaphragm is manually set for each imaging site in the first embodiment.

FIG. 5 is an explanatory diagram for explaining how to set imaging conditions suitable for a desired site in Example 1. FIG.

FIG. 6 is a diagram showing an example of a storage table of setting values (radiography parameters) determined by setting operations of imaging conditions.

FIG. 7 is a flowchart illustrating an example of an operation procedure in the first embodiment.

FIG. 8 is an explanatory diagram of a line graph display function of a contrast medium moving speed and a C-arm moving speed in Embodiment 1. FIG.

FIG. 9 is a diagram illustrating other functions in the first embodiment.

10A and 10B are diagrams illustrating still other functions in the first embodiment.

Fig. 11 is a perspective view showing a schematic configuration of a holding device portion in Embodiment 2 of the X-ray diagnostic apparatus according to the present invention.

FIG. 12 is a functional block diagram showing an outline of processing performed by the contour processor used in Embodiment 2. FIG.

FIG. 13 is a flowchart showing an outline of processing performed by the profile processor to automatically set the aperture opening of the X-ray aperture.

Fig. 14 is a flowchart of an outline of processing performed by the contour processor to automatically set the moving speed of the C-arm.

FIG. 15 is a diagram illustrating automatic setting of the aperture opening of the X-ray aperture based on contour extraction and differential processing of a contrast agent.

FIG. 16 is a diagram illustrating automatic setting of a C-arm moving speed based on contrast agent contour extraction and difference processing.

Detailed ways

Hereinafter, preferred embodiments of the X-ray diagnostic apparatus according to the present invention will be described in detail with reference to the drawings.

(Example 1)

Embodiment 1 of the X-ray diagnostic apparatus according to the present invention will be described in detail with reference to FIGS. 1 to 7 .

The X-ray diagnostic apparatus according to the first embodiment includes a holding device 10 , an X-ray tube 20 , an X-ray detector 30 , and a control device 50 .

1 is a perspective view showing a partial schematic structure of a holding device 10 of the X-ray diagnostic apparatus.

The holding device main body 11 is fixed to the floor, and holds the C-arm holding mechanism 12 smoothly and freely in a direction substantially parallel to the floor (indicated by an arrow A in the figure). The C-arm 13 is centered on the position installed on the C-arm holding mechanism 12, and can rotate on a substantially vertical plane (indicated by arrow B in the figure) with respect to the floor, and can rotate in an arc direction (indicated by arrow B in the figure) at the same time. (indicated by arrow C) is mounted on the C-arm holding mechanism 12 so as to be slidable upwards, so as to be able to incline relative to the bed board 15 described later. Furthermore, an X-ray tube 20 and an X-ray detector 30 to be described later are oppositely attached to the C-arm 13 with the bed board 15 interposed therebetween.

On the other hand, the bed board holding mechanism 14 is held so as to be movable up and down (indicated by arrow D in the figure) and rotatable (indicated by arrow E in the figure) relative to the holding device main body 11 .

The bed board 15 is attached to the bed board holding mechanism 14 so as to be slidable in its width direction (indicated by an arrow F in the figure) and movable in a thickness direction (indicated by an arrow G in the figure). In addition, the bed base 15 is capable of rotational movement around the central axis in the longitudinal direction relative to the base board holding mechanism 14 (indicated by an arrow H in the figure). Further, the bed board 15 is loaded with the subject P as shown in FIG. 2 .

In addition, the X-ray tube 20 is mounted on one end of the C-arm 13 held on the C-arm holding mechanism 12 toward the bed board 15 side, and the X-ray aperture 21 and the compensation filter 22 are arranged on the front of the X-ray tube 20 , that is, on the bed board 15 side (see Figure 2). This X-ray aperture 21 gathers the irradiation range of the X-rays irradiated from the X-ray tube 20 to a desired range, and does not irradiate unnecessary parts of the subject. Therefore, for example, as shown in FIG. 21a to 21d are combined to form a square shape. The aperture blades 21a to 21d are each driven by a servo motor through a rack gear mechanism not shown, so that the opposing aperture blades 21a, 21b and 21c, 21d are brought into contact with each other to form a desired irradiation range (in FIG. Indicated by a slash, also known as the field of view or aperture opening). In addition, the compensation filter 22 is used to partially attenuate the amount of X-rays with respect to the irradiation range of X-rays. These X-ray tube 20, X-ray aperture 21, and compensation filter 22 can move forward and backward from the side where the C-arm 13 is attached to the side of the bed board 15 (indicated by arrow J in the figure).

Furthermore, the X-ray detector 30 is mounted on the other end of the C-arm 13 so as to face the X-ray tube 20 with the bed board 15 interposed therebetween. The X-ray detector 30, for example, as shown in FIG. 2, is formed by combining an image intensifier (Image Intensifier: hereinafter abbreviated as I.I.) and a TV camera 32 through an optical system 33, wherein the TV camera 32 is equipped with an imaging tube or a solid-state imaging device. An element (such as a charge-coupled device: CCD) is provided with an X-ray grid 34 on the front of the I.I. Here, the I.I. 31 receives X-rays transmitted through the subject P irradiated from the X-ray tube 20 and converts them into optical images, and the optical images enter the TV camera 32 through the optical system 33 and are converted into TV video signals. In addition, the X-ray grid 34 prevents scattered X-rays generated by the subject P from entering the I.I. 31 . Such an X-ray detector 30 can advance and retreat from the side where the C-arm 13 is attached to the side of the bed board 15 (indicated by an arrow I in FIG. 1 ).

Next, the control device 50 that is one of the main components of the present X-ray diagnostic apparatus in parallel with the holding device 10 will be described with reference to FIG. 2 . In addition, in FIG. 2 , the X-ray tube 20 and the X-ray detector 30 installed in the holding device 10 are shown, and various devices constituting the control device 50 are also shown as a system diagram.

That is, the control device 50 is provided with a system controller 51 centrally in charge of collectively controlling the operation of the entire X-ray diagnostic apparatus; An operation panel 52 of a pointing device such as a trackball; a high voltage generating device 53 for generating a high voltage applied to the X-ray tube 20 and an X-ray controller 54 for controlling it; The X-ray aperture controller 55 that controls the amount of movement of the aperture blades 21a to 21d to achieve desired divergence; the compensation filter controller 56 that controls the position of the compensation filter 22; and the C arm holding mechanism 12 that is controlled by it. A holding device controller 57 and the like for the operation of the arm 13 and the operation of the bed board holding mechanism 14 and the bed board 15 supported by it.

In addition, in the control device 50, an I.I. controller 58 for controlling the I.I.31 is also provided; a TV camera controller 59 for controlling the TV camera 32; The processed image is based on the X-ray control conditions of the X-ray controller 54, the X-ray aperture controller 55, and the compensation filter controller 56, or based on the imaging position of the holding device controller 57 and the image processor 60. The image memory 61 that stores image processing conditions etc. together; for the image stored in the image memory 61 and the image obtained from the TV camera 32 in real time, implement grayscale processing and spatial filter processing, or implement addition An image processor 60 for processing and subtraction processing, etc.; a display device 62 for displaying an image obtained from the television camera 32 in real time, or an image processed by the image processor 60, and the like.

Furthermore, in the control device 50, for the image stored in the image memory 61, an appropriate aperture is calculated for the image according to the position signal obtained from the X-ray aperture controller 55 when the image is obtained. Position, size, angle, etc., and generate the aperture position, size, and angle calculator 63 of the graph; calculate the appropriate moving speed of the C-arm 13 for multiple parts based on the moving point of the contrast agent of interest and the imaging position information, and compare it with The photographing parameter memory 64 that stores the aperture position, its size, and photographing interval together; under the prescribed photographing sequence, according to its position information at any time, in order to become the appropriate moving speed of the C-arm 13 stored in the photographing parameter memory 64, On the other hand, the imaging parameter controller 65 and the like that control the X-ray aperture controller 55 and the holding device controller 57 and the like.

Hereinafter, the operation in the case of performing a lower extremity radiography examination by the X-ray diagnostic apparatus configured in this way will be described. In addition, in FIG. 2 , arrows indicate directions, X indicates the width direction of the subject P placed on the bed 15 , Y indicates the body axis direction, and Z indicates the thickness direction.

First, fluoroscopic imaging is performed in a wide range from the vicinity of the pelvis to the toes of the subject P, and the opening degree of the X-ray aperture 21 is set for each site. As the pre-scan fluoroscopy using a contrast agent, for example, a small amount of contrast agent is injected into the lower limbs of the subject in large batches, positioning of the main radiography is performed by weak X-rays, and the like. In this case, since the overall image of the desired diagnostic range cannot be obtained by one photography, the bed board 15 is kept stationary, and the C-arm 13 (that is, the X-ray tube 20 and the X-ray detector 30) is moved toward the bed board 15. The length direction (namely the Y direction) moves, and the partial photography is carried out in several times, and then the images are spliced to obtain the whole image. This moving operation is performed by moving the C-arm holding mechanism 12 in the direction of arrow A shown in FIG. 1 via the holding device controller 57 . In addition, the rotation angle (see the direction of arrow B in FIG. 1 ) and the inclination angle (see the direction of arrow C in FIG. 1 ) of the C-arm 13 corresponding to the bed board 15 are set in order to best draw the desired site.

FIG. 4A shows with arrows the approximate range of the subject P to be X-rayed in the lower extremity contrast examination. FIG. 4B shows the situation when the opening of the X-ray aperture 21 is set for each part in order to perform main photography on the long-sized displayed image by splicing the images collected in advance through fluoroscopy.

That is, first, a contrast agent is injected into the subject P shown in FIG. Then, under the control of the system controller 51, read out the perspective images stored in the image memory 61, and in the image processor 60, they are spliced, as shown in Figure 4B, as the whole image length of the lower limbs It is displayed on the display device 62 in selected lines.

With regard to the perspective image displayed on the display device 62 in a long size or the perspective image of the focused imaging area, the operator sets the most desired position in the main imaging through the pointing device provided on the operation panel 52 . The size of the X-ray aperture 21 is suitable. That is, in a wide range from the vicinity of the pelvis to the toes, the imaging range and the corresponding aperture opening are set in accordance with the site of special interest to be observed, the size of each site, the flow of the contrast agent, etc., so that It becomes the part indicated by the dotted black line in Fig. 4B.

That is, in FIG. 4B, the state in which the opening degree of the X-ray aperture 21 is set to 1 on the imaging position 1 is shown, and then, the state in which the opening degree of the X-ray aperture 21 is set to 2 on the imaging position 2, and then , the opening degree of the X-ray diaphragm 21 is set to 3 at the imaging position 3, and the opening degree of the X-ray diaphragm 21 is set to n at the imaging position n. Here, the openings 1, 2, 3...n of the X-ray aperture 21 are not necessarily all different, and may be the same opening depending on the imaging position. In addition, at adjacent imaging positions, it is ideal that the imaging areas do not overlap as much as possible in the body axis direction (Y direction) of the subject P in order to reduce radiation exposure. However, in order to converge the flowing contrast medium on the screen In , even if the imaging rate f is adjusted corresponding to the speed λ of the contrast agent (the maximum is 30 frames per second, but it can also be changed to 15 frames or 7.5 frames by setting), a certain degree of overlap cannot be avoided.

In this way, if the aperture opening is set for each photographing position by the pointing device, the movement amount of the blades 21 a to 21 d constituting the X-ray aperture 21 in the X and y directions is calculated by the aperture position, size, and angle calculator 63, and the calculated The results are stored in the imaging parameter memory 64.

In addition, a plurality of X-ray fluoroscopy images obtained by pre-fluoroscopy collection can be read out from the image memory 61, and can be tracked and displayed. Through the feedback flow shown in FIG. 5, the imaging rate corresponding to the speed λ of the contrast agent can be set. f and the moving speed of the C-arm 13, etc.

That is, as shown in FIG. 5, fluoroscopic collection is performed in a state in which a contrast medium is previously injected into the subject, and the image stored in the image memory 61 is displayed on the display device 62 as shown in FIG. 5(b). Perform movie display or track display of each set frame as a track image. In addition, in Fig. 5 (a), the image from frame m to frame n stored in the image memory 61 is schematically shown, the imaging time of the image of frame m is Tm, the collection position is lm, frame n The collection time of the image is Tn, and the collection location is ln. Here, m<n, the collection rate f is, for example, 30 fps.

Next, the operator sequentially displays the images on the display device 62 as shown in FIG. 5(b), and confirms the diffusion state of the contrast agent while looking at it, and stops it at a desired image. Then, as shown by the dotted line frame in FIG. 5(c), the opening of the X-ray aperture 21 (positions of the blades 21a to 21d in the X and y directions) optimal for the main imaging is set for the image. This setting is performed by operating the X-ray aperture controller 55 with the pointing device on the operation panel 52 .

Thus, since the frame interval of the images acquired by tracking is m~n, the moving speed λ of the contrast agent can be known from Equation (1) based on the position information of two designated points and the time information based on the collection rate f.

λ=(ln-lm)/(Tn-Tm) ...(1)

If the moving speed λ of the contrast agent is faster than the moving speed of the C-arm 13 during imaging, the flow of the contrast agent may not be displayed on the screen. Increase or increase the imaging rate f, and reset it so that the part that the doctor pays special attention to and observe is taken as the imaging area, and the flow of the contrast agent is included in the entire area.

In addition, at this time, an error (Δ) for joining the front and rear images is automatically added when the whole image is displayed in a long size according to the size of the X-ray aperture 21 provided for each image. Also, the imaging elapsed times Tm, Tn and imaging positions lm, ln serve as reference information for determining the imaging interval K and imaging rate f.

By performing this operation on each photographing site in turn, corresponding to each photographing position in the entire photographing range, that is, the position of the C-arm 13 corresponding to the bed board 15, various setting values such as its rotation angle, tilt angle, speed, etc. The imaging parameters (set values) such as the speed of the contrast agent and the speed of the contrast agent are stored in the imaging parameter memory 64 as a storage table shown in FIG. 6 , for example.

After such preparations, when the aperture, imaging interval, and moving speed of each imaging site are determined, main imaging is performed. The main imaging consists of a masking sequence performed before injecting the contrast medium into the subject, and a contrast sequence performed after the contrast medium is injected. That is, for the subject before the contrast agent is injected in the masking sequence, under the control of the imaging parameter controller 65, the aperture opening, imaging ratio, moving speed, etc. determined by the above-mentioned fluoroscopic acquisition are determined, for example, from the direction of the pelvis. A predetermined site is photographed in the direction of the toe, and the obtained mask image is stored in the image memory 61 together with the position information.

Then, a contrast agent is injected into the subject, and imaging based on contrast time series is performed under the control of the same imaging parameter controller 65 according to the direction of the flow of the contrast agent to obtain a contrast image. In addition, since information such as the moving speed of the C-arm 13 and the like during imaging and the elapsed time after injection of the contrast agent are sequentially provided to the imaging parameter controller 65, the imaging parameter controller 65 controls such that the information stored in the imaging parameter memory 64 Take pictures under the conditions.

If the contrast image is obtained, the image is stored together with the position information in the image memory 61, and then in the image processor 60, the mask image taken before is read out from the image memory 61, and In the image processor 60, subtraction processing with the contrast image is performed to obtain a subtraction image. The subtracted image is stored in the image memory 61 including position information, and displayed on the display device 62 in real time. In addition, the contrast image and the mask image subjected to the subtraction processing are, of course, images taken of the same part of the subject. In addition, the subtraction image is an image in which the same background portion of the contrast image and the mask image is removed, and only the portion where the contrast agent flows is displayed.

Like this, if during main photographing, read out the various setting values (photographing parameters) stored in the photographing parameter memory 64, according to this setting value, under the control of system controller 51, obtain mask image and contrast image, Then, while greatly reducing the burden on the operator, it is possible to obtain appropriate diagnostic images for each imaging site.

The operation procedure of this embodiment is shown in a flow chart in FIG. 7, and will be described again along the flow chart.

That is, as step S10, the position and angle of the C-arm 13 are first set as the initial position. Specifically, the position and angle of the C-arm 13 corresponding to the bed board 15 are detected to detect whether it has not deviated from the initial position, and if it deviates, it is corrected by the action of the holding device controller 57 . This instruction is issued by the system controller 51 . If the position and angle of the C-arm 13 are set, then as step S11, from the set values (see FIG. x, y positions), the X-ray aperture controller 55 is operated to set a predetermined divergence. This is also done by the system controller 51 . Next, as step S12 , the moving speed β of the C-arm 13 at the position is also retrieved from the setting values stored in the imaging parameter memory 64 . These data on the divergence of the X-ray aperture 21 and the moving speed β of the C-arm 13 are transmitted to the imaging parameter controller 65 as step S13 . Therefore, as step S14, according to the setting values stored in the imaging parameter memory 64, under the control of the imaging parameter controller 65, the main imaging is performed to obtain a mask image and a contrast image.

In addition, when the contrast image is obtained during the main shooting, if the operator continuously presses the shooting button (not shown) provided on the operation panel 52 while looking at the contrast image displayed on the display device 62 in real time, , the C-arm 13 is moved automatically following the flow of the contrast agent, and the contrast image is photographed. However, if the tracking of the contrast medium by the automatic control deviates for some reason, by operating a lever (not shown) or the like provided on the operation panel, it is manually switched to the subsequent movement operation of the C-arm 13 . While tracking the contrast agent, at this time, only the control of the X-ray aperture 21 is automatic.

Thus, according to the embodiments of the present invention, an X-ray diagnostic apparatus with excellent operability can be provided, which greatly reduces the burden on the operator.

In addition, as another embodiment of the present invention, based on the information stored in the setting value storage table (see FIG. 6 ) in the imaging parameter memory 64, as shown in FIG. The relationship between the position of the C-arm 13 and the moving speed of the contrast medium or the moving speed of the C-arm 13 can be provided as diagnostic information.

In addition, if an image useful for diagnosis is read from the captured image stored in the image memory 61, it is displayed on the display unit 62 in a grid as shown in FIG. The measurement start point and measurement end point of the contrast agent, the measured movement speed of the contrast agent, etc. are displayed in characters, etc., so that information can be provided as a reference at a good time when a doctor makes a diagnosis.

Furthermore, as shown in FIG. 10A, by using a pointing device provided on the operation panel 52 to arbitrarily set a region of interest (ROI) on a long-sized displayed image, it is possible to read the ROI from the image memory 61. A subtracted image of the portion is displayed on the display device 62. Then, for example, when the part is composed of a plurality of images such as m1 and m2, these images can be displayed on the display device 62 in a spliced form as shown in FIG. 10B. In this case, the moving speed of the contrast agent and the like may be superimposed and displayed.

In addition, since blood vessels are separated in joints such as knees and ankles, the blood flow velocity is slower than in linear parts such as legs and shin, so it can be seen that the flow of contrast medium in joints is slow. Therefore, when it is particularly desired to observe the conditions of joints such as knees and ankles, the X-ray diaphragm controller 55 can control the X-ray diaphragm 21 to become suitable when the X-ray imaging position reaches the designated position by specifying the position in advance. The burden on the operator can be further reduced by operating the slow contrast agent flow opening (for example, narrow opening) in the imaging site.

In order to designate the specific part, a region particularly desired to be observed is set in advance as a region of interest (ROI) using a pointing device provided on the operation panel 52 . This setting information can be stored in the photography parameter memory 64 via the system controller 51 . Accordingly, when the imaging parameter controller 65 reads out the setting information from the imaging parameter memory 64 , the relevant setting information is sent to the X-ray aperture controller 55 via the system controller 51 . As a result, in the region of interest, the aperture opening of the X-ray aperture 21 , that is, the X-ray irradiation range is optimally adjusted in accordance with the installation information. Thereby, X-ray radiation dose can be reduced, and at the same time, the burden on the operator can be reduced.

In addition, when the flow of the contrast agent reaches a specific site that is slow in this way, the imaging rate can also be lowered. Thereby, X-ray radiation dose can be further reduced.

(Example 2)

An X-ray diagnostic apparatus according to Embodiment 2 of the present invention will be described with reference to FIGS. 11 to 16 . In this second embodiment, it is characterized in that: the process of performing the above-mentioned pre-scan and setting the imaging parameters for main imaging based on the image obtained by the pre-scan by manual processing without manual operation by the operator can be automatically performed. implement.

In order to perform the automatic setting of the imaging parameters, the X-ray diagnostic apparatus according to the present embodiment newly includes a contour processor 70 for extracting and processing the contour of the model as a contrast agent, as shown in FIG. 11 . In addition, a lock switch 71 is additionally attached to the operation panel 52 . Other hardware configurations are the same as described in the first embodiment above.

The contour processor 70 is, for example, a processor constituted by a computer including a CPU and various memories (not shown) for program storage, computation, and data storage. When the outline processing 70 is activated, the program stored in the program memory is read into the calculation memory, and the processing is performed according to the predetermined procedure described in the program. Fig. 12 shows the outline of this processing. That is, as shown in the figure, it is functionally provided with: an image input unit F1 for inputting an image collected by a pre-scan; and a contour extraction for performing differential processing for extracting a model (hereinafter referred to as a contour) of an input contrast agent. Component F2; storage component F3 for storing contour image; detection component F4 for position detection of the image at the time tn/tn-1 of difference; difference extraction component (difference circuit) F5 for differential processing between contours; A processing unit F6 for calculating the aperture opening and extracting the moving speed.

More specifically, the contour processor 70 executes the processing shown in FIGS. 13 and 14 in parallel, for example, in time-division and during execution of the pre-scan. Among them, the processing shown in FIG. 13 represents processing for determining the aperture opening of the X-ray aperture 21, and the processing shown in FIG. 14 represents processing for determining relative movement to one of the C-arm 13 and the bed board 15 Speed (moving the C-arm 13 relative to the deck 15 in the embodiment). In addition, the outline processor 70 may execute only any one of the processes in FIG. 13 and FIG. 14 .

The contour processor 70 inputs the image data at a certain sampling time tn collected by the pre-scan currently being performed from the image recording unit 60 via the system controller 51 (step S51). Next, the contour processor 70 reads out the contour image data of the contrast agent processed at the previous sampling time tn-1 at a certain imaging position from the built-in memory (step S52).

Then, the contour processor 70 sequentially performs processing of contour extraction, difference image generation, and aperture opening determination.

First, the contour of the contrast agent at the current sampling time tn is extracted by differential processing (pattern recognition), and the image data of each pixel of the contour is temporarily stored in the built-in memory (step S53). Next, a pixel-by-pixel difference is performed between the contours of the contrast agent at the two sampling times tn and tn-1 to generate a difference image (step S54). Fig. 15 shows the state of generation of this differential image.

Next, calculation of the difference amount (difference area) is performed on the data of the difference image, and it is judged whether the difference amount is equal to or greater than a predetermined threshold (step S55). In the case that the difference amount is above the threshold value, determine the difference amount, that is, the aperture opening degree of the X-ray aperture 21 corresponding to the outline area as the difference result, and store the data representing the aperture opening degree in the built-in memory (step S56 ). On the other hand, when the difference amount (difference area) is less than the threshold value, the difference amount, that is, the aperture opening of the X-ray aperture 21 corresponding to the contour area as the difference result is also determined, and the data representing the aperture opening Store in the built-in memory (step S57). By performing threshold processing on the difference amount in this way, the aperture opening can be determined in more detail and easily according to the degree of the flow velocity of the contrast agent.

If the aperture opening is determined in this way, the pre-scan image data at the next sampling time tn+1 is input again (step S51). In this way, the above-mentioned processing is performed cyclically.

Along with the execution of this pre-scan, the fluoroscopic image is displayed in real time during the execution. Therefore, from the data of the fluoroscopic image displayed at the sampling rate planned in advance based on empirical values, etc., the contour of the contrast agent is sequentially extracted by differential processing. Here, a difference image between the contour image extracted at the present display timing tn and the contour image extracted at the previous display timing tn-1 is obtained. Fig. 15(a) to (c) schematically show an example of generation of this difference image. The diaphragm opening at a certain imaging position can be determined from this difference image (the region RG in the dotted line in FIG. 15(c) represents the optimum diaphragm opening), and the flow velocity of the contrast medium can be obtained.

On the other hand, as shown in FIG. 14, the contour processor 70 inputs image data at a certain sampling time tn collected by the pre-scan currently being performed from the image recording unit 60 via the system controller 51 (step S61). Next, the contour processor 70 reads out the contour image data of the contrast agent processed at the previous sampling time tn-1 from the built-in memory (step S62).

Then, the contour processor 70 sequentially performs processing of contour extraction, difference image generation, and moving speed determination.

First, at this sampling time tn, the contour of the contrast agent is extracted by differential processing (pattern recognition), and the image data of each pixel of the contour is temporarily stored in the built-in memory (step S63). Next, a pixel-by-pixel difference is performed between the contours of the contrast agent at the two sampling times tn and tn-1 to generate a difference image (step S64). Fig. 16 shows the state of generation of this differential image.

Next, calculation of the amount of movement of the contrast agent is performed on the data of the difference image, and it is judged whether the amount of movement is equal to or greater than a predetermined threshold (step S65). When the amount of movement is equal to or greater than the threshold value, the movement speed of the C-arm 13 corresponding to the large contour area (large aperture opening) as a result of the difference is determined, and data representing the movement opening is stored in the built-in memory ( Step S66). On the other hand, when the moving amount of the contrast agent is less than the threshold value, the moving speed of the C-arm 13 corresponding to the small contour area (small aperture opening) as a result of the difference is determined similarly, and the The data is stored in the built-in memory (step S67). By performing threshold processing on the movement amount in this way, the movement speed of the C-arm 13 can be determined in more detail and easily in accordance with the degree of the movement amount of the contrast medium.

If the moving speed is determined in this way, the pre-scanned image data of the next sampling time tn+1 is input again (step S61). In this way, the above-mentioned processing is performed cyclically.

Along with the execution of this pre-scan, the fluoroscopic image is displayed in real time during the execution. Therefore, from the data of the fluoroscopic image displayed at the sampling rate planned in advance based on empirical values or the like, the contour of the contrast agent is sequentially extracted by differential processing. Here, a difference image between the contour image extracted at the current display timing tn and the contour image extracted at the previous display timing tn-1 is obtained at each imaging position. 16 (a) to (c) and (d) to (f) schematically show an example of generation of the difference image.

Based on these difference images, the aperture opening of a certain imaging position (time t1) can be determined (area P1 (x, y) in the dotted line in FIG. 16(c)), and at the same time, the aperture of the next imaging position (time t2) Aperture opening (area P2(x, y) of the dotted line in FIG. 16(f)) (steps S65, S66 in FIG. 14). Therefore, the position of the diaphragm opening from a certain photographing position (time t1) of the C-arm 13 to the next photographing position (time t2) can be calculated by the following formula, that is, the moving speed V (mm/sec) of the C-arm 13 ( It is also executed through steps S65 and S66 in FIG. 14).

V=(P1-P2)/(t1-t2)

The moving speed V of the C-arm 13 is stored in the imaging parameter memory 64 .

As described above, in the imaging parameter memory 64, imaging parameters necessary for the main imaging are also stored in the same way as the main imaging in the above-mentioned embodiment. Therefore, during the main imaging, these imaging parameters are read out by the imaging parameter controller 65, and the aperture opening of the X-ray aperture 21 is automatically adjusted for each imaging position determined by the pre-scan, and at the same time according to the desired imaging ratio of the standby imaging position. In the imaging of f and the desired imaging interval K, the C-arm 13 moves to the next imaging position following the contrast agent.

Therefore, according to the second embodiment, in the pre-scan, the contour of the contrast agent is recognized from the fluoroscopy image obtained by the pre-scan, and the diaphragm opening is obtained from the information recognized by the pattern in almost real time, and stored in the imaging system. In the parameter memory 64. Therefore, the imaging parameter controller 65 reads the aperture opening information from the imaging parameter memory 64 and transmits it to the X-ray aperture controller 55 via the system controller 51 . Thus, in the pre-scan, since the aperture opening of the X-ray aperture 21 is adjusted one by one in almost real time to the value specified by the X-ray aperture controller 55, it is possible to shield the area where the contrast agent flows at each imaging position. X-ray radiation, and reduce the reading amount of X-ray radiation to the subject.

Since the flow rate of the contrast agent, that is, the blood flow at the general disease site is slow, the aperture opening of the X-ray aperture 21 can be set at the position of the sputum affected site by using the automatic tracking function corresponding to the contour of the contrast agent in Embodiment 2. for extremely narrow values. In the judgment of the sputum-affected part, the thresholds used in the threshold processing of the difference amount and the movement amount in FIGS. 13 and 14 may be set to appropriate values based on empirical values.

In addition, using the determination tendency and imaging position at past sampling times based on the threshold processing, it is possible to predict the degree of the flow velocity of the contrast agent in the future, and this prediction information can be stored as a part of imaging parameter information. This prediction information can be used for the control of the aperture opening of the X-ray aperture and the C-arm, thereby enabling more accurate control of imaging parameters during main imaging. The processing of this predictive information may be performed, for example, by the contour processor 70 .

In addition, according to the second embodiment, the outline of the contrast agent is recognized as a pattern from the fluoroscopic image of each position obtained by the pre-scan, and the position of the X-ray aperture 21 at the standby imaging position for the main imaging is determined based on the pattern recognition information. The photographing parameters such as the aperture opening, the flow rate of the contrast agent, and the moving speed of the C-arm 13 are automatically stored in the photographing parameter memory 64 . Therefore, unlike the first embodiment described above, the operator does not need to manually set the imaging parameters for each imaging position while displaying the fluoroscopic image after the pre-scan. Therefore, the operation assistance is further strengthened, and the operation work is significantly reduced.

Furthermore, during the main imaging as described above, the automatically set imaging parameters are read out by the imaging parameter controller 65 and automatically sent to the X-ray aperture controller 55 and the holding device controller 57 via the system controller 51 . Therefore, at the time of main photography, using the photography parameters automatically set based on the fluoroscopic image based on the pre-scan, as in the first embodiment above, the main photography is performed with the aperture opening and the C-arm moving speed automatically adjusted.

As a result, the operator does not need to manually move the C-arm 13, and the relevant operator is freed from the operation work, so that he can concentrate on the image diagnosis displayed simultaneously with the main imaging. Therefore, the operational work of the operator is significantly reduced, while the operational efficiency is improved and the accuracy of inspection is improved.

Furthermore, while the above-mentioned simplification and lightening of the operation are performed, the lock switch 71 can reliably cope with the occurrence of an abnormality. While the operator (performer) is holding down the lock switch 71, the X-ray diagnostic apparatus operates normally, but in the event of abnormal failures in the X-ray tube, C-arm, bed board, etc., the operator stops until then. The pressing operation of the lock switch 71, which has been pressed until now, can immediately avoid the relevant abnormal state.

In addition, in each of the above-mentioned embodiments, as the X-ray detector 30, the structure in which the I.I. 31 and the television camera 32 are combined via the optical system 33 has been described, but the X-ray detector applicable to the present invention is not necessarily limited to this , It may also be a flat panel radiation detector (Flat Panel Detector: FPD) composed of a semiconductor array formed by covering switching elements and capacitors formed on a glass substrate, for example, with a photoconductive film that converts radiation into electric charges. In this case, the I.I. controller 58 and the television camera controller 59 are replaced with FPD control means that control the FPD.

In addition, in each of the above-mentioned embodiments, X-ray imaging was performed with the bed board stationary and the C-arm 13 moved. However, X-ray imaging may be performed with the C-arm 13 stationary and the bed board 15 moved depending on circumstances.

Claims (11)

1. radiodiagnosis device is characterized in that comprising:

Produce the x-ray source of X ray;

Detection is from the X-ray detector of the X ray of above-mentioned x-ray source;

The relative holding device that relatively keeps above-mentioned x-ray source and above-mentioned X-ray detector mutually;

The bed board holding device that in this x-ray source that is kept relatively and the space between the X-ray detector, keeps the bed board of loading subject;

Above-mentioned bed board is relatively moved relative to the axon direction of holding device along the above-mentioned subject that has injected contrast agent with above-mentioned, photography is had an X-rayed in each camera positions to the contrast examination scope, obtains the panoramic photography device of the part perspective picture of these each camera positions;

According to above-mentioned part perspective picture, the photographic parameter setting device to the photographic parameter of above-mentioned each camera positions optimum is set;

The photographic parameter memorizer that storage is provided with by above-mentioned photographic parameter setting device to the photographic parameter of above-mentioned each camera positions optimum;

According to the photographic parameter of reading from above-mentioned photographic parameter memorizer, above-mentioned bed board is relatively moved relative to holding device with above-mentioned, above-mentioned subject is carried out the main photographic attachment of the main photography of above-mentioned contrast examination scope.

2. radiodiagnosis device according to claim 1 is characterized in that:

Above-mentioned photographic parameter setting device constitutes the manual information corresponding to the operator, and above-mentioned photographic parameter is set.

3. radiodiagnosis device according to claim 1 is characterized in that:

Above-mentioned main photographic attachment has: the range of exposures control device, this range of exposures control device is according to above-mentioned photographic parameter, with the flow condition of the size of above-mentioned camera positions or contrast agent accordingly, the above-mentioned X ray that control produces from above-mentioned x-ray source is to the range of exposures of above-mentioned subject.

4. radiodiagnosis device according to claim 3 is characterized in that:

Above-mentioned photographic parameter setting device will flow through the device that be provided with of the relative moving speed of above-mentioned tested intravital speed, above-mentioned bed board and above-mentioned relative holding device as above-mentioned photographic parameter corresponding to above-mentioned contrast agent,

Above-mentioned range of exposures control device constitutes corresponding to above-mentioned translational speed, controls above-mentioned range of exposures.

5. radiodiagnosis device according to claim 3 is characterized in that:

Above-mentioned photographic parameter setting device will flow through the device that be provided with of the photography rate of above-mentioned tested intravital speed, X ray photography as above-mentioned photographic parameter corresponding to above-mentioned contrast agent,

Above-mentioned range of exposures control device constitutes corresponding to above-mentioned photography rate and controls above-mentioned range of exposures.

6. radiodiagnosis device according to claim 3 is characterized in that:

The position specified device that also possesses the specific part of specifying above-mentioned subject,

Above-mentioned range of exposures control device has with lower device: when having arrived the specific part that is provided with by above-mentioned position specified device in the position based on the above-mentioned X ray photography of above-mentioned main photographic attachment, above-mentioned range of exposures is controlled at the aperture of the above-mentioned specific part that is suitable for photographing.

7. radiodiagnosis device according to claim 1 is characterized in that:

Above-mentioned photographic parameter setting device constitutes the flow region of discerning above-mentioned contrast agent according to the perspective picture of each position that obtains by above-mentioned panoramic photography device automatically, according to this recognition result above-mentioned photographic parameter is set.

8. radiodiagnosis device according to claim 7 is characterized in that:

Above-mentioned photographic parameter setting device possesses

According to the perspective picture of each position that obtains by above-mentioned panoramic photography device,, calculate the accountant of the flow region of above-mentioned contrast agent automatically by pattern recognition;

According to the result of calculation that calculates by this accountant, corresponding to the flow region of above-mentioned contrast agent, the device that the aperture aperture of the above-mentioned X ray of above-mentioned each position is provided with as the part of above-mentioned photographic parameter,

Above-mentioned main photographic attachment possesses

Corresponding to the aperture aperture of above-mentioned X ray, the device of control X ray aperture.

9. radiodiagnosis device according to claim 7 is characterized in that:

Above-mentioned photographic parameter setting device possesses

According to the perspective picture of each position that obtains by above-mentioned panoramic photography device,, calculate the accountant of the flow region of above-mentioned contrast agent automatically by pattern recognition;

According to the result of calculation that calculates by this accountant, corresponding to the flowing velocity of above-mentioned contrast agent, the device that the relative moving speed of the above-mentioned bed board of above-mentioned each position and above-mentioned relative holding device is provided with as the part of above-mentioned photographic parameter,

Above-mentioned main photographic attachment possesses

Corresponding to the relative moving speed of above-mentioned setting, control the device of the relative moving speed of above-mentioned bed board and above-mentioned relative holding device.

10. radiodiagnosis device according to claim 7 is characterized in that:

Above-mentioned photographic parameter setting device possesses

According to the perspective picture of each position that obtains by above-mentioned panoramic photography device,, calculate the accountant of the flow region of above-mentioned contrast agent automatically by pattern recognition;

According to the result of calculation that calculates by this accountant, the device that will be provided with as the part of above-mentioned photographic parameter corresponding to the relative moving speed of the aperture aperture each above-mentioned position, above-mentioned X ray of the flow region of above-mentioned contrast agent and above-mentioned bed board and above-mentioned relative holding device

Above-mentioned main photographic attachment possesses

Corresponding to the aperture aperture of above-mentioned X ray, the device of control X ray aperture;

Corresponding to the relative moving speed of above-mentioned setting, control the device of the relative moving speed of above-mentioned bed board and above-mentioned relative holding device.

11. radiodiagnosis device according to claim 7 is characterized in that: possess

According to the perspective picture of each position that obtains by above-mentioned panoramic photography device,, calculate the accountant of the flow region of above-mentioned contrast agent automatically by pattern recognition;

According to the result of calculation that calculates by this accountant, with based on the photography of the perspective picture of above-mentioned panoramic photography device concurrently, control the above-mentioned X ray that produces from above-mentioned x-ray source range of exposures control device in real time and automatically to the range of exposures of above-mentioned subject.

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