KR100624756B1 - A Method for Checking the Alignment Status of the Stereotactic Frame in Cerebral Angiography for Radiosurgery - Google Patents

Abstract

An object of the present invention is to easily determine the alignment of the stereotension to be mounted on the patient at the time of imaging in order to minimize the error of the image obtained through the angiographic apparatus and based on this the stereotactic alignment of the angiographic apparatus to enable accurate alignment It provides a method of checking alignment.

Accordingly, the present invention comprises the steps of fixing the aforesight frame marked reference points on the front and rear, respectively, to a specific site of the specimen; Preliminary photographing the reference point display surface of the azimuth before the main photographing; It provides a method for aligning the angiography device, including the step of aligning the position of the azimuth by checking the matching of the corresponding reference point in the front and rear respectively by contrasting the photographed image of the two sides.

Axial, Marking, Base Point, Intersection

Description

A method for checking the alignment status of the stereotactic frame in cerebral angiography for radiosurgery

1 is a basic configuration of a digital angiography device,

2 is a flow chart showing a stereotactic alignment process of the angiography device according to an embodiment of the present invention,

Figure 3 is a schematic perspective view showing a stereotactic wedge used in the angiography device according to an embodiment of the present invention,

4 is a schematic diagram illustrating a preliminary photographing screen of an angiography device for alignment of a stereotactic according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

10: right frame 11: base frame

12: vertical frame 20: front display

21: rear display surface 22, 23: reference point

30,31 Diagonal 32,33: Intersection

40: azimuth 50: video

The present invention relates to a medical imaging device for radiation surgery, and more particularly, to an angiographic device and a stereotactic to minimize the error that can occur when measuring the three-dimensional coordinates in the two-dimensional image taken through the angiography device It is about sorting method of.

Radiation surgery for the treatment of cerebrovascular malformations is to calculate and simulate the radiation distribution and intensity to irradiate the lesion using medical imaging equipment such as angiography device and radiographic computer program.

Since the lesion to be treated is a solid volume, not a dot, there is a difference in the radiation dose entering the center and surrounding areas of the lesion. Of particular importance here is that the radiation dose given to the interface of the lesion directly affects the therapeutic effect and complications. Therefore, the error and image distortion of the medical imaging equipment is a serious burden on the medical staff when planning the actual radiation surgery plan.

The above-mentioned angiography apparatus of the imaging medical equipment is an essential equipment for identifying the condition, location and size of lesions in the treatment of vascular diseases in the brain such as cerebral arteriovenous malformations. The blood vessels in the brain are taken.

After the shooting, the two-dimensional image is analyzed to obtain necessary numerical information. At this time, the distortion of the image is the biggest problem, and the angiography apparatus is known to have the most image distortion and error.

In addition, recently, digital subtraction angiography (DSA) has been developed and widely used, which provides much higher resolution than images of conventional angiography devices. As shown in FIG. 1, the digital angiography apparatus uses a cone beam to convert X-rays transmitted through a human body into light in an image intensifier and then converts light into a photodetector (image tube of a TV camera). Or CCD camera), and digitally process the image information generated here and make it into visible 2D image on the monitor. X-rays of a conical beam radiated from an X-ray tube high voltage generator are irradiated and transmitted to the human body, and then converted into a light signal in an image multiplier and converted into an electrical signal in a photodetector through an optical system. Unlike conventional angiography, in which a digital angiography image is processed with a conventional film, the digital angiography device subtracts the image after contrast injection to the image before contrast injection to remove anatomical shadows except for the driving state of the contrast medium, thereby obtaining an image having excellent blood contrast. Obtained digital subtraction angiography is mainly used.

There are two types of image distortion and error in the image obtained by the digital angiography apparatus, which can be divided into two types. The first is image distortion and error in the equipment itself, and the second is caused by the operator.

The image distortion elements present in the angiography apparatus are due to the distance between the X-ray tube and the image multiplier, the lens aberration by the optical system, the curvature aberration between the image multiplier and the photodetector, and the nonuniformity of the magnetic field. In general, the angiography apparatus additionally includes a function of restoring image distortion after photographing. When there is no such function, an image processing correction function for processing an image and correcting it using a mathematical algorithm is used manually. .

The digital subtraction angiography with such image distortion is not suitable for applying directly to stereotactic surgery or radiosurgery, and even if the image distortion correction process is applied, it eliminates the factors of external image processing that occur more fundamentally before such image processing. There is a problem that you can not.

That is, a larger and fatal error than the distortion caused by the angiography device itself during image analysis occurs in the tilted stereotactic frame during the imaging.

It is natural that the image obtained from the tilted stereoscopic frame cannot obtain accurate position information, no matter how accurate the correction is later.

Therefore, the alignment should be accurately aligned before shooting, conventionally, the alignment of the alignment is dependent on the eyes of the operator, there is a problem that the alignment misalignment occurs, resulting in severe distortion of the image.

Therefore, the present invention has been devised to solve the above problems, for example, to minimize the fundamental error of the image obtained through the angiography device, to easily check the alignment of the alignment during shooting and based on this accurately Making it alignable is a technical problem to be achieved in the present invention.

The present invention to achieve the object as described above. The main point is to simply check the alignment status of the alignment, to determine the degree of error in advance, and to correct it before the official shooting.

To this end, in the image correction method of the present invention, fixing the azimuth marked with a reference point on the front and the rear, respectively, to a specific portion of the specimen, photographing the reference point display surface of the azimuth, and comparing the photographed images of the two surfaces. And confirming whether the corresponding reference points correspond to each other at the rear surface.

The present invention may further include calculating an error value when the reference point does not match, and rearranging the alignment according to the calculated error value.

In addition, in order to perform the image correction method, in the angiography apparatus, front and rear display surfaces are respectively installed on the front and rear surfaces of the abutment that is mounted on the patient's body and fixed to the body, the front and rear display surfaces Has a structure in which reference points are displayed at mutually corresponding positions.

In this case, the reference point is preferably displayed at each corner of the front and rear display surfaces. In this case, whether the reference points coincide is compared between the intersection of two lines connecting each point diagonally on one display surface and the intersection point on the other display surface. You will get

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a basic configuration of a digital angiography device, Figure 2 is a flow chart illustrating a process of alignment alignment of the angiographic apparatus according to an embodiment of the present invention, Figure 3 is an angiographic apparatus according to an embodiment of the present invention Figure 4 is a schematic perspective view showing a stereotactic to be used in, Figure 4 is a schematic diagram showing a preliminary screen shot of the angiography device for alignment of the stereotactic according to an embodiment of the present invention.

In the following description, the position of the cerebral angiography apparatus used for preliminary analysis of the condition, location, and size of the lesion as a preliminary operation in the treatment of vascular diseases in the brain through radiosurgery, which is recently increasing in use. Explain how to arrange the frames.

Of course, the present invention is not limited to this and will be applicable to all medical imaging equipment for image processing the body using a stereotactic. In addition, the structure of the abutment used in the present invention is not particularly limited and will be possible in the case where the structure can be fixed to the head of the patient and can be mounted on the cerebrovascular apparatus.

Looking at the process of radiosurgery, after installing a stereotactic wartle in the patient's brain, and through the process of pinpointing the treatment site through the cerebral angiography device, the treatment plan is made and the patient is placed on a radiosurgery device such as a gamma knife. Position and fix the abutment to irradiate the previously identified treatment site.

For better understanding, radiation surgery is the same method of reducing radiation or inhibiting growth by strongly irradiating radiation on the tumor site in the same way that radiation is used in comparison with radiation therapy. Intensive care is given to intensive treatment of the tumor site, as if the sun is focused on a magnifying glass and the paper is burned.In radiation surgery, it is very important for successful treatment to accurately irradiate only the treatment site. Identifying the exact location of treatment in the brain is absolutely critical.

The correction of the image taken by the cerebrovascular apparatus and the correction of the image is important for the correct treatment site, the image correction method of the present invention for this purpose, the front and rear of the reference point (22, 23) marked with a stereotactic frame (10) ) Fixing the head to the patient's head (S100), aligning the stereotactic frame with the cerebrovascular apparatus (S110), and the tomography of the plane on which the reference points (22, 23) are displayed so that the reference points (22, 23) appear. Preliminary shooting step (S120), by contrasting the photographed image of the front and rear of the wobble 10 to determine whether the corresponding reference points (22, 23) corresponding to each of the front and rear (S130, S140), If the reference point (22, 23) is matched to start the main shooting (S150), and if the reference point (22, 23) does not match the step of calculating the error value (S160), before the pre-shooting step Realigning the alignment frame 10 according to the error value (S170).

Therefore, before photographing, the front and rear tomography of the abutment 10, in which the reference points 22 and 23 are preliminarily photographed, is imaged and the position of the reference points 22 and 23 is compared, according to the position between the reference points 22 and 23. The alignment error of the alignment frame 10 can be detected.

Here, the method of comparing the reference point can be confirmed through the intersection of the diagonal lines of the reference point, which will be described later.

Meanwhile, referring to the relationship between the reference points 22 and 23 displayed on the image 50 and the abutment 10, the first abutment 10 is for positioning the patient's brain later on the radiosurgery device. As shown in FIG. 2, the abutment 10 includes a rectangular base frame 11 extending along a patient's head circumference, and a vertical frame 12 extending substantially perpendicular to each corner portion of the base frame 11. And a fixing screw 13 fastened inward to an upper end of the vertical frame 12 to fix the abutment 10 to the head of the patient.

In addition, the front display surface 20 is provided between the front vertical frame 12, the reference point 22 is displayed, the rear display surface 21 is also displayed between the rear vertical frame 12, the reference point 23 is also displayed. Is installed.

In addition, one reference point 22 is displayed on the left and right sides of the top and left and right sides of the upper display surface 20, and four reference points are displayed on one display surface. Similarly, the rear display surface 21 also displays one reference point 23 on each of the left and right sides of the top and the left and right sides of the bottom.

Accordingly, each reference point 22 displayed at the corresponding position of the front display surface 20 corresponds to each reference point 23 displayed at the corresponding position of the rear display surface 21.

On the other hand, according to another embodiment of the present invention, the azimuth point 40 on the front display surface 20 or the rear display surface 21 to check the position of the upper, lower or left, right of the captured image 50 This is further indicated.

Here, the azimuth point 40 uses a mark that is distinguished from the reference points 22 and 23, and shows the position of the azimuth point shown in the image by causing the square image to appear to be biased toward one corner. It is desirable to be able to immediately check the lower, left, and right positions.

For example, in FIG. 2, the azimuth point 40 is displayed on the upper right side of the front display surface 20. When shooting toward the front display surface, the operator points the azimuth point 40 displayed on the captured image 50 as well. By aligning the image 50 to be located at the top, bottom, left, right of the image 50 will be able to immediately.

Hereinafter, referring to FIG. 1, a process of checking the alignment state of the abutment using the reference point will be described.

First, the abutment 10 is fixed to the patient's head with the front display surface 20 installed on the vertical frame 12 of the aforesaid frame 10 facing forward and the rear display surface 21 disposed behind the brain vessel. Place it in the imaging system. (S100-S110)

In addition, the tomography is performed by operating the cerebrovascular apparatus. At this time, the preliminary photographing is performed to photograph only the front display surface 20 and the rear display surface 21. (S120).

The captured image signal is output as an image signal through a control device and is implemented as an image 50 in an image device such as a monitor.

3 illustrates an image 50 implemented in a monitor. According to the drawing, it can be seen that the eight reference points 22 and 23 are all displayed on one image 50 because each display surface is overlapped.

In the drawing, * marks represent four reference points 22 of the front display surface 20, and + marks represent four reference points 23 of the rear display surface 21.

Accordingly, the operator connects the reference points 22 and 23 placed to face diagonally among the reference points 22 and 23 of the same display surface, so that two diagonal lines 30 and 31 intersect each other on one display surface and each intersection point. (32,33) will be made.

The position of the intersections 32 and 33 can be obtained directly through the calculation of the control device by checking the positions of the reference points 22 and 23. For example, in the case of a touch screen, a diagonal line and an intersection point thereof can be calculated by checking a position by taking a reference point displayed on the monitor screen with a pen.

When the positions of the intersection points 32 and 33 on the front display surface 20 and the rear display surface 21 are calculated by the same process, the control device compares them to determine whether the positions of the intersection points 32 and 33 are the same or different. (S130-S140)

When the positions of the two intersections 32 and 33 coincide with each other, the present photographing may be started (S150). When the positions of the intersections are different, the control device may provide information about the distance, angle, and direction between the two intersections. The frame 10 is inclined at which angle and in what direction to calculate an error value for breaking parallel to the photographing surface.

Therefore, the rearrangement 10 is rearranged based on the error value, thereby minimizing a fundamental distortion factor of an image that may occur during the main shooting.

It can be seen that the present invention provides a method of confirming a significant breakthrough alignment as described above. While exemplary embodiments of the present invention have been shown and described, various modifications and other embodiments may be made by those skilled in the art. Such modifications and other embodiments are all considered and included in the appended claims, without departing from the true spirit and scope of the invention.

According to the method for confirming the alignment of the angiographic apparatus according to the present invention as described above, by eliminating the fundamental error factor causing the image distortion, it is possible to maximize the error correction efficiency and thus more accurate position information about the treatment site You can get it.

In addition, the correct treatment is possible to obtain the additional effect of improving the treatment and increase the treatment rate.

Claims (4)

In the process of angiography by installing the head of the patient fixed in the stereotactic to the angiography device, Preliminary photographing of the reference point display surface of the aorta by installing a stereotactic mark on the angiography device in front and rear on the angiographic device; Comparing the pre-recorded images to check whether the reference points are identical at the front and rear; Calculating a position error value to be aligned when the reference point is mismatched; Correcting a position error between the angiography device and the stereotactic frame according to the calculated error value Alignment check method of angiography device comprising a delete The method of claim 1, In the step of checking whether the reference points match, the positions of the diagonal intersection points connecting the reference points of the rear display surface and the diagonal intersection points connecting the reference points of the front display surface by photographing the front display surface and the rear display surface of each of the four reference points How to check the alignment alignment of the angiography device, characterized in that the comparison. The method of claim 3, wherein The error value calculation method of the alignment alignment check of the angiography device, characterized in that calculated through the distance and direction between the corresponding intersection point.

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