WO2019074152A1

WO2019074152A1 - Method for analyzing eyeball image

Info

Publication number: WO2019074152A1
Application number: PCT/KR2017/013058
Authority: WO
Inventors: 김학수; 신동호; 김태현; 문성호; 이세병; 임영경; 정종휘
Original assignee: 국립암센터
Priority date: 2017-10-13
Filing date: 2017-11-17
Publication date: 2019-04-18
Also published as: KR20190041752A; KR102024993B1

Abstract

The present invention relates to a method for analyzing an eyeball image, the method comprising the steps of: acquiring a 3D-image of an eyeball; acquiring a 3D-model of the eyeball from the 3D-image; and determining the central rotational axis of the eyeball by means of the 3D-model.

Description

Image analysis method of eyeball

The present invention relates to an image analysis method of an eyeball.

An ocular tumor treatment method using an ocular tumor treatment system using a proton beam has been developed and used. Proton beam treatment has the advantage of precisely aiming and destroying only the cancer cells present at a certain depth in the human body by regulating the energy of the proton beam passing through the human body.

To minimize the radiation dose to important organs such as the lens and optic nerve in the treatment of ocular tumors using proton beams, it is necessary to establish a treatment plan through analysis of the ocular image.

In the prior art, the position of the clip inserted into the eye was confirmed using an x-ray image. An eye model was created using the eye size measured from the position of the identified clip and the dose was calculated to establish the treatment plan.

However, the prior art does not sufficiently reflect the three-dimensional shape of the eyeball, so that accurate dose calculation and tumor contouring are difficult, and it is difficult to establish an accurate treatment plan.

Accordingly, it is an object of the present invention to provide an image analysis method of an eyeball capable of establishing an accurate treatment plan.

According to another aspect of the present invention, there is provided a method of analyzing an image of an eyeball, comprising: obtaining a 3D image of the eyeball; Obtaining a 3D model of the eyeball from the 3D image; And obtaining the rotational center axis of the eyeball using the 3D model.

And determining an eyeball angle for particle beam treatment using the 3D model and the rotation center axis.

The determination of the eyeball angle can be made based on the particle treatment beam amount applied to the lens of the eyeball and the optic nerve.

And obtaining the eyeball rotation image by rotating the eyeball in the 3D image using the determined eyeball angle.

And developing an eye treatment plan from the eye rotation image.

The establishment of the eye treatment plan may include the determination of the ocular gaze direction during treatment.

The 3D image may be obtained using at least one of CT and MR.

The 3D image may be obtained for a plurality of eye directions of the eyeball.

The plurality of gaze directions can be obtained by changing the position of the light gauges.

According to the present invention, an eye image analysis method capable of establishing an accurate treatment plan is provided.

1 is a flowchart of an image analysis method of an eyeball according to an embodiment of the present invention,

FIGS. 2A, 2B and 2C illustrate 3D image acquisition and rotation center axis determination in an eye image analysis method according to an embodiment of the present invention,

FIGS. 3A and 3B illustrate eyeball angle determination in an image analysis method of an eyeball according to an embodiment of the present invention,

FIG. 4 is a view for explaining generation of an eyeball rotation image in a method of analyzing an image of an eyeball according to an embodiment of the present invention,

Figure 5 is intended to illustrate the treatment of an ocular tumor of a patient.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail with reference to the drawings.

The accompanying drawings are merely illustrative and do not limit the scope of the present invention.

In the following description, the rotational center axis of the eyeball obtained according to the present invention is utilized for establishing the eye treatment plan, but the rotational center axis of the eyeball obtained according to the present invention can be used for other purposes.

Hereinafter, an image analysis method of an eyeball according to the present invention will be described with reference to FIGS. 1 to 5. FIG.

FIG. 1 is a flowchart of a method of analyzing an image of an eye according to an embodiment of the present invention. FIGS. 2A, 2B, and 2C illustrate a method of analyzing an image of an eye according to an embodiment of the present invention. FIGS. 3A and 3B are views for explaining the eyeball angle determination in the eyeball image analysis method according to an embodiment of the present invention, and FIG. 4 are views for explaining an eyeball image analysis method according to an embodiment of the present invention Fig. 5 illustrates the treatment of an ocular tumor of a patient. Fig.

In the following description, a proton beam is exemplified as a particle treatment beam for treatment, but the particle treatment beam of the present invention is not limited to a proton beam, and a carbon beam or the like may be used.

First, a 3D image of the eyeball is obtained (S100). The 3D image can be obtained by using computed tomography (CT) and / or magnetic resonance (MR), but is not limited thereto. The 3D image consists of a set of slices by tomography.

At this time, the 3D image can be obtained from a plurality of eye directions of the eyeball as shown in FIGS. 2A and 2B. A light gauge can be used to change and fix the direction of eye gaze. When acquiring a 3D image, the image is acquired while the gaze is fixed in a specific direction.

On the other hand, before 3D image acquisition, tantalum clips are inserted into the patient's retina or eye size is measured. The inserted clip is used to verify the rotational position of the eyeball with the X-ray image to match the eye rotation angle of the treatment plan prior to patient treatment. Eye size is used for semi-automatic eye segmentation.

Next, a 3D model for the eyeball is generated based on the 3D image (S200). The 3D model can be obtained by performing semi-auto ocular segmentation on each of a plurality of photographed images. Various methods can be used for the generation of the 3D model, and the following methods can be used.

The 3D model of the eye is made using eye size information such as eyeball length, sclera thickness, rim bus diameter, and lens thickness measured in ophthalmology. The generated model automatically matches the outline of the eyeball in the 3D image.

In the 3D image, the outline of the eyeball automatically sets the segmentation area and performs automatic segmentation by clustering, compression-based, and histogram-based methods. These methods are common methods used for segmentation and methods that can accurately extract the outline of the eye from a 3D image can be used.

After generating the 3D model, the rotation center axis of the eyeball is determined from the 3D model (S300). The rotation center axis can be obtained from the intersection point of the line passing through the lens of the eye in the different viewing direction as shown in Fig. 2C.

3D models can be generated for different viewing directions, and the rotation center axis can be calculated using a plurality of 3D models. When the intersection of the lines passing through the lens from three or more 3D models is not a single point, a point at which the sum of the distances to a plurality of intersection points becomes minimum can be selected as the rotation center axis to minimize the error.

Then, the eyeball angle at the time of treatment is determined while rotating the eyeball on the 3D model (S400). The eye angle at the time of treatment, i.e., the optimal eye angle, can be determined based on the amount of radiation applied to the lens of the eye and the optic nerve.

As in Figures 3a and 3b, the proton beam emitted from the proton beam passes through the eye to treat an ocular tumor. Adjusting the angle of rotation of the eye and the energy of the proton beam irradiator can reduce the radiation dose to the lens and optic nerve while treating the ocular tumor.

This process determines the optimal angle of the eye at the time of treatment.

Next, the rotation image of the eyeball is generated while only the eyeball is rotated in the 3D image (S500). That is, as shown in FIG. 4, the eye image is rotated around the rotation center axis in the 3D image. The 3D image has a three-dimensional coordinate system and can acquire a rotated image of the eyeball by moving all the pixel values on the image in the 3D model of the eyeball by the eyeball rotation angle. In this case, a three-dimensional spherical coordinate system having a rotation center axis as an origin is used. The position of the pixel to be moved can be calculated from the spherical coordinate system (r, θ, φ) by the Cartesian coordinate system transformation.

r is the distance from the origin, θ is the angle between the origin and the pixel position from the positive direction of the z axis, and φ is the angle between the origin and the pixel position from the positive direction of the x axis.

Next, an eye treatment plan is established based on the rotation image of the eyeball (S600). The eye treatment plan uses a rotating image of the eyeball. The angle of the proton beam entering the eye, the amount of radiation that must be applied to the tumor, and the energy and width to cover the tumor in the beam direction. The width of the beam in the beam incidence direction covering the tumor can be controlled using a brass block. The brass block should be made to conform to the shape of the tumor in a plane perpendicular to the beam incidence direction. The energy covering the tumor reaches the end of the tumor in the direction of beam incidence and can be used as a spread-out Bragg Peak (SOBP) to cover the thickness of the tumor in the direction of incidence.

The margin of the patient's treatment fixture can be placed in consideration of the inaccuracy of the fixation device and the penumbra of the proton beam caused by the brass block.

The treatment plan may include the use of a light gauze or tantalum clip positioning using an X-ray image for therapeutic setup. In order to confirm the position of the tantalum clip, the position of the tantalum clips formed by taking two X-ray images in the direction perpendicular to the beam direction and the beam direction is compared with a virtual DRR (Digitally Reconstructed Radiography) Adjust the angle so that it is the same as the plan.

During treatment, the patient may be subjected to proton beam treatment in a lying state as shown in FIG.

The above-described embodiments are illustrative of the present invention, and the present invention is not limited thereto. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims.

Claims

In an image analysis method of an eyeball,

Obtaining a 3D image of the eyeball;

Obtaining a 3D model of the eyeball from the 3D image;

And obtaining the rotation center axis of the eyeball using the 3D model.
The method according to claim 1,

Further comprising the step of determining an eye angle for particle beam treatment using the 3D model and the rotation center axis.
3. The method of claim 2,

Wherein the determination of the eyeball angle is based on an amount of a particle treatment beam applied to the lens of the eyeball and the optic nerve.
3. The method of claim 2,

Further comprising rotating the eyeball in the 3D image to obtain an eyeball rotation image using the determined eyeball angle.
5. The method of claim 4,

Further comprising the step of establishing an eye treatment plan from the eye rotation image.
5. The method of claim 4,

Wherein the establishment of the eye treatment plan comprises the determination of the direction of the ocular gaze during treatment.
5. The method of claim 4,

Wherein the 3D image is obtained using at least one of CT and MR.
8. The method of claim 7,

Wherein the 3D image comprises:

Wherein the image is obtained with respect to a plurality of eye directions of the eyeball.
9. The method of claim 8,

Wherein the plurality of gaze directions are obtained by changing the positions of the light gauges.