WO2016206093A1

WO2016206093A1 - Method and apparatus for fusion display of cerebral cortex electrode and magnetic resonance images

Info

Publication number: WO2016206093A1
Application number: PCT/CN2015/082501
Authority: WO
Inventors: 汤洁; 李卓; 任乐枫; 胡楠; 谢菲
Original assignee: 深圳市美德医疗电子技术有限公司
Priority date: 2015-06-26
Filing date: 2015-06-26
Publication date: 2016-12-29
Also published as: CN105849777B; CN105849777A

Abstract

A method and an apparatus for fusion display of cerebral cortex electrode and magnetic resonance images. The method comprises: extracting an MRI image obtained by MRI scanning before an intracranial electrode is implanted into a patient and a post-implantation CT image obtained by CT scanning after the intracranial electrode is implanted into the patient (S01); registering the MRI image and the post-implantation CT image under an identical coordinate space (S02); extracting electrode image information from the registered CT image (S03); extracting cerebral cortex tissue image information from the registered MRI image (S04); spatially fusing the electrode image information and the cerebral cortex tissue image information, and displaying the spatially-fused information by means of a three-dimensional visual method (S05); and adjusting a three-dimensional visual display effect and angle, converting an adjustment result into a needed format for output and storage (S06). By implementing method and apparatus for fusion display of cerebral cortex electrode and magnetic resonance images, position information about electrodes can be acquired.

Description

Method and device for fused display of cerebral cortex electrode and magnetic resonance image

Technical field

The invention relates to the field of information fusion, in particular to a method and a device for fused display of a cerebral cortex electrode and a magnetic resonance image.

Background technique

Surgery is an important means of treating certain craniocerebral diseases. The key to surgical treatment is the location of the lesion, which is to find the abnormally excited neuron population. At present, intracranial electrodes have been identified as the gold standard for localization of lesions. The intracranial electrodes can directly record the brain electrical activity of the cerebral cortex and internal brain tissue, and can detect abnormal cortical discharge within 1 cm, with clear graphics and high sensitivity. For those cases where non-invasive examination can not identify the lesion, intracranial electrode EEG monitoring is a safe and reliable method of localization.

technical problem

After the electrode is implanted in the brain, CT scan can be used to obtain the positional distribution information of the electrode in the brain. However, CT scans are not sensitive to the inner cortical tissue of the brain. CT scans are not able to obtain information about the inner cortex of the brain, which is not conducive to obtaining the position information of the electrodes. MRI scans are the best way to obtain information on the inner cortical tissue of the brain, but since the implanted electrodes are usually metal electrodes, MRI scans cannot be performed after implantation.

Technical solution

The technical problem to be solved by the present invention is to provide a method and apparatus for fused display of a cerebral cortex electrode and a magnetic resonance image capable of acquiring position information of an electrode in view of the above-mentioned drawbacks of the prior art which are disadvantageous for acquiring position information of the electrode.

The technical solution adopted by the present invention to solve the technical problem thereof is: constructing a method for fusion display of a cerebral cortex electrode and a magnetic resonance image, comprising the following steps:

A) taking the MRI image obtained by MRI scan before the patient is implanted into the intracranial electrode and the post-implantation CT image obtained by CT scanning after the patient implants the intracranial electrode;

B) registering the MRI image and the post-implantation CT image in the same coordinate space;

C) extracting electrode image information from the registered CT image;

D) extracting cerebral cortical tissue image information from the registered MRI images;

E) spatially merging the electrode image information and the cerebral cortex tissue image information, and displaying the spatially fused information through a three-dimensional visualization method;

F) Adjust the effect and angle of the 3D visual display, and convert the adjusted result into the desired format output for saving.

In the method of the cerebral cortex electrode and the magnetic resonance image fusion display of the present invention, the step B) further comprises:

B1) converting the MRI image and the post-implant CT image into the same coordinate system, and moving the physical center of the MRI image to the same point of the physical center of the post-implant CT image;

B2) rotating, translating, and comparing partial image pixels in the MRI image and partial image pixels in the post-implant CT image using a first scale until the contour of the MRI image and the post-implant CT The similarity of the outline of the image reaches the first similarity;

B3) using the second scale to rotate and translate the partial image pixels in the MRI image after the first scale adjustment and the partial image pixels in the post-implant CT image; the first scale includes more pixels than the first scale The number of pixels included in the second scale;

B4) determining whether the similarity between the MRI image after the second scale adjustment and the position pixel of the post-implant CT image reaches a second similarity, and if so, ending the registration process; otherwise, returning to step B3); The degree is greater than the first similarity.

In the method of the cerebral cortex electrode of the present invention and the magnetic resonance image fusion display, the step C) further includes:

C1) setting a grayscale threshold range of the registered CT image, the set grayscale threshold range including the electrode image;

C2) An image in which the image gray scale falls within the set grayscale threshold value is extracted as the electrode image information.

In the method of the cerebral cortex electrode and the magnetic resonance image fusion display according to the present invention, before the step A), the method further includes:

A0) taking a pre-implantation CT image obtained by performing a CT scan before the patient is implanted into the intracranial electrode;

Between the step A) and the step B), the method further includes:

B0) Register the MRI image and the pre-implant CT image in the same coordinate space.

In the method of the cerebral cortex electrode and the magnetic resonance image fusion display of the present invention, the step B0) further includes:

B01) converting the MRI image and the pre-implant CT image into the same coordinate system, and moving the physical center of the MRI image to the same point as the physical center of the pre-implant CT image;

B02) rotating, translating, and comparing partial image pixels in the MRI image and partial image pixels in the pre-implant CT image, respectively, using a first scale until a contour of the MRI image and the pre-implantation CT The similarity of the outline of the image reaches the first similarity;

B03) rotating and translating the partial image pixels in the MRI image after the first scale adjustment and the partial image pixels in the pre-implant CT image by using the second scale; the first scale includes the number of pixels larger than The number of pixels included in the second scale;

B04) determining whether the similarity between the MRI image after the second scale adjustment and the position pixel corresponding to the pre-implant CT image reaches a second similarity, and if so, ending the registration process; otherwise, returning to step B03); The degree is greater than the first similarity.

In the method for fused fusion of a cerebral cortex electrode and a magnetic resonance image according to the present invention, the registered CT image includes a pre-implantation CT image after registration and a post-implantation CT image after registration, Step C) further includes:

C1') The post-implantation CT image after the registration is subtracted from the pre-implantation CT image after the registration, and the portion where the gradation difference value is not zero is the electrode image information.

In the method of the cerebral cortex electrode and the magnetic resonance image fusion display of the present invention, the step D) further comprises:

D1) arbitrarily selecting a seed point from the registered MRI image;

D2) selecting, in an area centered on the seed point and having a radius of the first set value, a point whose pixel value falls within the set interval, and incorporating the point where the seed point is located;

D3) expanding the radius, and determining whether there is a point in the enlarged area whose pixel value falls within the set interval, and if so, incorporating it into the area where the seed point is located, and performing step D4 ); otherwise, the region where the seed point is located is used as cerebral cortical tissue image information;

D4) returns to step D3).

In the method of the cerebral cortex electrode of the present invention and the magnetic resonance image fusion display, the step E) further includes:

E1) converting the data type of the electrode image information and the data type of the cerebral cortex tissue image information into the same data type;

E2) mapping different gray values of each pixel in the electrode image and the cerebral cortex tissue image into different colors and transparency through the set color mapping table, respectively adjusting the color and transparency;

E3) Display the fused image by face drawing or volume rendering.

In the method of the cerebral cortex electrode and the magnetic resonance image fusion display of the present invention, the size of the first scale is eight pixels, the size of the second scale is one pixel, the MRI image, before implantation Both the CT image and the post-implantation CT image are image files in DICOM format, and the required format is a DICOM file, a picture file, or a video file.

The present invention also relates to an apparatus for implementing a method for fusion display of a cerebral cortex electrode and a magnetic resonance image, comprising:

Registration unit: used to register the MRI image and the post-implantation CT image in the same coordinate space;

An electrode information extracting unit: configured to extract electrode image information from the registered CT image;

Cerebral cortex information extraction unit: for extracting cerebral cortical tissue image information from the registered MRI image;

The information fusion unit is configured to spatially fuse the electrode image information and the cerebral cortex tissue image information, and display the spatially fused information through a three-dimensional visualization method;

Display effect adjustment unit: used to adjust the effect and angle of the 3D visual display, and convert the adjusted result into the required format output for saving.

In the device of the present invention, the registration unit further includes:

a coordinate conversion module: configured to convert the MRI image and the post-implant CT image into the same coordinate system, and move the physical center of the MRI image to the same point of the physical center of the post-implant CT image;

Post-implantation rotational translation alignment module for respectively rotating, translating and comparing partial image pixels in the MRI image and partial image pixels in the post-implant CT image using the first scale until the MRI image The similarity between the contour of the CT image and the contour of the post-implant CT image reaches a first similarity;

Post-implantation rotation translation module: for rotating and translating partial image pixels in the MRI image after the first scale adjustment and partial image pixels in the post-implant CT image using the second scale; The number of pixels included is greater than the number of pixels included in the second scale;

Post-implantation similarity judgment module: for judging whether the similarity between the MRI image adjusted by the second scale and the pixel corresponding to the post-implantation CT image reaches the second similarity, and if so, ending the registration process; otherwise, proceeding The adjustment of the second scale; the second similarity is greater than the first similarity.

In the device of the present invention, the electrode information extracting unit further includes:

Grayscale threshold setting module: configured to set a grayscale threshold range of the registered CT image, the set grayscale threshold range including the electrode image;

Electrode image extraction module: an image for extracting an image gray scale within a set grayscale threshold range as electrode image information.

In the device of the present invention, the device further includes:

Pre-implantation registration unit: for registering the MRI image and the pre-implantation CT image in the same coordinate space.

In the device of the present invention, the pre-implantation registration unit further comprises:

Pre-implantation coordinate conversion module: for converting the MRI image and the pre-implant CT image into the same coordinate system, and moving the physical center of the MRI image to the same point as the physical center of the pre-implant CT image ;

Pre-implantation rotational translation alignment module: for respectively rotating, translating and comparing partial image pixels in the MRI image and partial image pixels in the pre-implant CT image using the first scale until the MRI image The similarity between the contour of the CT image and the contour of the pre-implant CT image reaches a first similarity;

a pre-implantation rotation translation module for rotating and translating a partial image pixel in the first scale-adjusted MRI image and a partial image pixel in the pre-implant CT image using a second scale; The number of pixels included is greater than the number of pixels included in the second scale;

The pre-implantation similarity judgment module is configured to determine whether the similarity between the MRI image adjusted by the second scale and the pixel corresponding to the pre-implant CT image reaches a second similarity, and if so, the registration process ends; otherwise, return to continue Performing a second scale adjustment; the second similarity is greater than the first similarity.

In the device of the present invention, the registered CT image includes a pre-implantation CT image after registration and a post-implantation CT image after registration, and the electrode information extraction unit further includes:

The CT image subtraction module: the post-implantation CT image after the registration is subtracted from the pre-implantation CT image, and the portion where the gradation difference value is not 0 is the electrode image information.

In the device of the present invention, the cerebral cortex information extracting unit further comprises:

Seed point selection module: for arbitrarily selecting a seed point from the registered MRI image;

a seed point selection module for setting an interval: for selecting a point whose pixel value falls within a set interval in an area centered on the seed point and having a radius of a first set value, and incorporating the The area where the seed point is located;

Setting a pixel value judgment module in the interval: for expanding the radius, and determining whether there is a point in the enlarged region whose pixel value falls within the set interval, and if so, incorporating the radius The area where the seed point is located; otherwise, the area where the seed point is located is used as image information of the cerebral cortex tissue;

The pixel value judgment module is configured to continue the determination of the pixel value in the set interval.

In the device of the present invention, the information fusion unit further includes:

a data type conversion module: configured to convert a data type of the electrode image information and a data type of the cerebral cortex tissue image information into the same data type;

Gray value mapping module: for mapping different gray values of each pixel in the electrode image and the cerebral cortex tissue image into different colors and transparency through the set color mapping table, respectively adjusting the color and transparency thereof;

Image display module: used to display the fused image by face drawing or volume drawing.

In the device of the present invention, the first size is eight pixels, the second size is one pixel, and the MRI image, the pre-implant CT image, and the post-implant CT image are both An image file in DICOM format, the required format is a DICOM file, a picture file, or a video file.

Beneficial effect

The method and device for realizing the fusion display of the cerebral cortex electrode and the magnetic resonance image of the present invention have the following beneficial effects: the MRI image obtained by MRI scan before the patient is implanted into the intracranial electrode and the CT after the patient is implanted with the intracranial electrode The scanned CT image is scanned, and then the CT image is registered with the MRI image, and then the extracted electrode information is fused and displayed on the MRI image, so that the brain tissue information can be seen and the position of the electrode can be seen at the same time. Information, so it can get the position information of the electrode.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are only It is a certain embodiment of the present invention, and other drawings can be obtained from those skilled in the art without any creative work.

1 is a flow chart of an embodiment of a method and apparatus for fusion display of a cerebral cortex electrode and a magnetic resonance image of the present invention;

2 is a specific flowchart of registering an MRI image and an implanted CT image in the same coordinate space in the embodiment;

3 is a specific flowchart of a case where electrode image information is extracted from a registered CT image in the embodiment;

4 is a specific flowchart of registering an MRI image and a pre-implant CT image in the same coordinate space in the embodiment;

FIG. 5 is a specific flowchart of extracting cerebral cortex tissue image information from the registered MRI image in the embodiment; FIG.

6 is a specific flowchart of spatially merging electrode image information and cerebral cortex tissue image information in the embodiment, and displaying the spatially fused information through a three-dimensional visualization method;

Figure 7 is a schematic view showing the structure of the apparatus in the embodiment.

Embodiments of the invention

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, but not all embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

In the embodiment of the method and apparatus for fused display of the cerebral cortex electrode and the magnetic resonance image of the present invention, a flow chart of the method for displaying the cerebral cortex electrode and the magnetic resonance image is shown in FIG. 1 . In Fig. 1, the method for displaying the cerebral cortex electrode and the magnetic resonance image fusion comprises the following steps:

Step S01 takes the MRI image obtained by MRI scan before the patient implants the intracranial electrode and the post-implant CT image obtained by CT scan after the patient implants the intracranial electrode: in this step, the patient is implanted before the intracranial electrode is implanted. The MRI image obtained by MRI scan and the post-implantation CT image obtained by CT scan of the patient after implantation of the intracranial electrode. The above MRI image and post-implantation CT image are both image files in DICOM format.

Step S02 registers the MRI image and the post-implantation CT image in the same coordinate space: in this step, the MRI image and the post-implantation CT image are registered by calling the three-dimensional spatial data registration algorithm, and the registered MRI is performed. The image and the CT image data after implantation are in the same coordinate space, which facilitates data fusion. It is worth mentioning that, in this embodiment, a software system is provided, which is a fusion display system of a cerebral cortex electrode and a magnetic resonance image. Firstly, the MRI image and the post-implantation CT image are copied to the host where the cerebral cortex electrode and the magnetic resonance image fusion display system are located, and the MRI image and the post-implantation CT image are imported through the software of the cerebral cortex electrode and the magnetic resonance image fusion display system. The data is then registered by the 3D spatial data registration algorithm to register the MRI image and the post-implant CT image in the same coordinate space. For details on how to register, a detailed description will be given later.

Step S03 extracts electrode image information from the registered CT image: in this step, extracting electrode image information from the registered CT image, specifically extracting electrode image information from the registered CT image by using an electrode extraction algorithm .

Step S04 extracting cerebral cortical tissue image information from the registered MRI image: The data of the MRI image includes not only the information of the cerebral cortex, but also other parts of the skull, the neck, etc., and this part of the information has an adverse effect on the position of the doctor to observe the electrode. In this step, the cerebral cortex tissue image information is extracted from the registered MRI image, specifically, the image segmentation algorithm is used to extract the information of the cerebral cortex tissue from the registered MRI image, and the other useless information is removed.

Step S05 The electrode image information and the cerebral cortex tissue image information are spatially fused, and the spatially fused information is displayed by a three-dimensional visualization method: in this step, the electrode image information and the cerebral cortex tissue image information are spatially fused, and the spatial fusion is performed. The subsequent information is displayed by a three-dimensional visualization method.

Step S06 Adjust the effect and angle of the 3D visualization display, and adjust the adjusted result to the desired format. Output preservation: In this step, the cerebral cortex tissue and electrode position can be visually seen in the cerebral cortex electrode and magnetic resonance image fusion display system. Related information, you can also observe the brain from different directions by mouse drag, you can adjust the effect and angle of the 3D visual display, and adjust the results to convert to the desired format output save. It is worth mentioning that the above required format is a DICOM file, a picture file or a video file, and the results of different formats can be used for various purposes. Since the electrode information of the extraction process is fused and displayed on the MRI image, the brain tissue information can be seen and the position information of the electrode can be seen at the same time, so that the position information of the electrode can be obtained.

For the embodiment, the above step S02 can be further refined, and the refined flowchart is as shown in FIG. 2 . In FIG. 2, the above step S02 further includes:

Step S21 Convert the MRI image and the post-implant CT image to the same coordinate system, and move the physical center of the MRI image and the physical center of the post-implant CT image to the same point: registration is for MRI images and post-implantation CT The pixels at the corresponding positions of the image are spatially consistent. Since the MRI image and the post-implantation CT image are from different devices, the rates are also different. In this embodiment, a multi-resolution registration strategy is adopted. In this step, the MRI image and the post-implant CT image are converted to the same coordinate system, and the physical center of the MRI image and the physical center of the post-implant CT image are moved to the same point, so that the two images will substantially coincide. This will reduce the number of moves and the number of rotations.

Step S22 Rotating, translating, and comparing partial image pixels in the MRI image and partial image pixels in the post-implant CT image using the first scale until the contour of the MRI image is similar to the contour of the CT image after implantation. A similarity degree: in this step, the first image (rough scale) is used to rotate, translate and compare partial image pixels in the MRI image and partial image pixels in the post-implant CT image, respectively, until the contour of the MRI image The contour of the CT image after implantation is substantially coincident, that is, the contour of the MRI image and the contour of the CT image after implantation satisfy the set first similarity. For example, the first similarity is set to be 90%. Of course, in some cases of the embodiment, the first similarity may also be other values. In the first embodiment, the size of the first size is eight pixels. Of course, in some cases of the first embodiment, the size of the first size may be adjusted to other values, and the specific adjustment may be based on specific The situation is fixed.

Step S23 uses the second scale to rotate and translate the partial image pixels in the MRI image after the first scale adjustment and the partial image pixels in the post-implant CT image: in this step, the second scale is used first. Partial image pixels in the scale-adjusted MRI image and partial image pixels in the post-implantation CT image are rotated and translated again, specifically, using a second scale (precise scale), and using the result of the previous layer Its parameters are initialized, and the above rotation and translation processes are iterated until the most accurate scale is reached. It is worth mentioning that the number of pixels included in the first scale is greater than the number of pixels included in the second scale; the size of the second scale is one pixel, of course, in some cases of the first embodiment, The size of the second scale is adjusted according to the specific situation.

Step S24 determines whether the similarity between the MRI image after the second scale adjustment and the position pixel of the post-implant CT image reaches the second similarity: in this step, the MRI image after the second scale adjustment and the CT after implantation are determined. Whether the similarity of the image corresponding to the position pixel reaches the second similarity. Specifically, the mutual information similarity comparison algorithm is used to determine whether the similarity between the MRI image adjusted by the second scale and the pixel corresponding to the post-implant CT image reaches the second degree. Similarity, if the result of the determination is YES, step S25 is performed; otherwise, step S23 is returned. It is worth mentioning that in the first embodiment, the second similarity is greater than the first similarity. For example, the second similarity may be set to 99.8%. Of course, in some cases of the embodiment, the second similarity may also be set to other values.

Step S25 Ending the registration process: If the result of the above step S24 is YES, the present step is performed. In this step, the registration process of the MRI image and the post-implantation CT image is ended. This method from coarse to fine, looking at the whole on a large scale, and looking at the details on a small scale can greatly improve the success rate of registration.

For the first embodiment, the above step S03 can be further refined, and the refined flowchart is as shown in FIG. 3. In FIG. 3, the above step S03 further includes:

Step S31 sets a grayscale threshold range of the registered CT image, and the set grayscale threshold range includes the electrode image: the threshold segmentation algorithm is suitable for the grayscale of the electrode image to be distinct from the grayscale of the soft tissue and the flesh. Happening. In this step, the grayscale threshold range of the registered CT image is set, and the set grayscale threshold range includes the electrode image. It is worth mentioning that the registered CT image (herein referred to A set grayscale threshold range is displayed in the post-implantation CT image after registration.

Step S32 The image whose image gray scale falls within the set grayscale threshold value is extracted as the electrode image information: in this step, the image whose image grayscale falls within the set grayscale threshold value is extracted as the electrode image information. Specifically, the set grayscale threshold range may be adjusted to an appropriate range in the vicinity of the set grayscale threshold range according to a specific situation, that is, adjusted to a required grayscale range, and the grayscale of the image is dropped. The image in the desired gray scale range is extracted as the electrode image information. It is worth mentioning that most of the non-electrode images can be removed by setting a suitable gray scale range and including most of the electrode images. The electrode is left so that the electrode image information can be obtained.

It is worth mentioning that, in order to better extract the position information of the electrode, the method for displaying the cerebral cortex electrode and the magnetic resonance image needs to include some steps. As shown in FIG. 1 , before the step S01, the method further includes:

Step S00 Pre-implantation CT image obtained by CT scan before the patient is implanted into the intracranial electrode: In this step, the pre-implantation CT image obtained by CT scan before the patient is implanted into the intracranial electrode is taken, and then the CT image before implantation is taken. Introduced into the above cerebral cortex electrode with a magnetic resonance image fusion display system. The pre-implantation CT image is an image file in DICOM format.

Between the above steps S01 and S02, the method further includes:

Step S20 The MRI image and the pre-implantation CT image are registered in the same coordinate space: in this step, the MRI image and the pre-implantation CT image are registered in the same coordinate space. A detailed description of how to register will follow.

For the embodiment, the above step S20 can be further refined, and the refined flowchart is as shown in FIG. 4 . In FIG. 4, the above step S20 further includes:

Step S201 converts the MRI image and the pre-implant CT image into the same coordinate system, and moves the physical center of the MRI image and the physical center of the pre-implant CT image to the same point: in this step, the registration is to make the MRI The pixels in the position corresponding to the image and the pre-implant CT image are spatially consistent. Since the MRI image and the pre-implant CT image are from different devices, the rates are also different. In this embodiment, multi-resolution registration is adopted. Strategy. In this step, the MRI image and the pre-implant CT image are converted to the same coordinate system, and the physical center of the MRI image and the physical center of the pre-implant CT image are moved to the same point, so that the two images will substantially coincide. This will reduce the number of moves and the number of rotations.

Step S202 Rotating, translating, and comparing partial image pixels in the MRI image and partial image pixels in the pre-implant CT image using the first scale until the contour of the MRI image is similar to the contour of the pre-implant CT image. A similarity degree: in this step, the first image (rough scale) is used to rotate, translate and compare partial image pixels in the MRI image and partial image pixels in the pre-implant CT image, respectively, until the contour of the MRI image The contour of the CT image before implantation is substantially coincident, that is, the contour of the MRI image and the contour of the CT image before implantation satisfy the set first similarity. In the first embodiment, the size of the first size is eight pixels. Of course, in some cases of the first embodiment, the size of the first size may be adjusted to other values, and the specific adjustment may be based on specific The situation is fixed.

Step S203 Using a second scale, the partial image pixels in the MRI image after the first scale adjustment and the partial image pixels in the pre-implant CT image are rotated and translated again: in this step, the second scale is adjusted by the first scale. Part of the image pixels in the post-MRI image and part of the image pixels in the pre-implant CT image are rotated and translated again, specifically, using the second scale (precise scale), and using the result of the previous layer for its parameters Initialize, iterating through the above rotation and translation process until the most accurate scale is reached. It is worth mentioning that the number of pixels included in the first scale is greater than the number of pixels included in the second scale; the size of the second scale is one pixel, of course, in some cases of the first embodiment, The size of the second scale is adjusted according to the specific situation.

Step S204: determining whether the similarity between the MRI image after the second scale adjustment and the position pixel corresponding to the pre-implant CT image reaches the second similarity: in this step, determining the MRI image after the second scale adjustment and the pre-implant CT Whether the similarity of the pixel corresponding to the position reaches the second similarity, and specifically, using the mutual information similarity comparison algorithm to determine whether the similarity of the pixel corresponding to the position of the first CT image and the MRI image after the second scale adjustment reaches the second similarity If the result of the determination is yes, then step S205 is performed; otherwise, the process returns to step S203. It is worth mentioning that in this embodiment, the second similarity is greater than the first similarity.

Step S205 ends the registration process: if the result of the above step S204 is YES, the present step is executed. In this step, the registration process for the MRI image and the pre-implant CT image is ended. That is, after registration, the CT image before implantation, the CT image after implantation, and the MRI image are in the same coordinate system, which is convenient for data fusion. This method from coarse to fine, looking at the whole on a large scale, and looking at the details on a small scale can greatly improve the success rate of registration.

It is worth mentioning that in the case of CT scan before implanting the electrode and CT scan after implanting the electrode, the CT image after registration includes the pre-implantation CT image after registration and the registration. After the post-implant CT image, when extracting the electrode image information, the extraction steps used in the above step S03 are as follows:

The post-implantation CT image after registration is subtracted from the pre-implantation CT image, and the portion where the gradation difference value is not 0 is the electrode image information: this embodiment uses the subtraction segmentation algorithm to extract the electrode image information. The idea of the subtraction segmentation algorithm is to subtract the two images, the pixels with the same position in the image are subtracted and the gray value is 0, and the remaining gray is not 0, which is the difference between the two images. The basis of the subtractive segmentation algorithm is registration. Theoretically, the pre-implantation CT image and the post-implantation CT image are respectively registered to the same coordinate system, so that the difference between the two images is only in the presence or absence of the electrode, so the two images are The electrode can be extracted by subtraction. In this step, the post-implantation CT image after registration is subtracted from the pre-implantation CT image, and the portion where the gradation difference value is not zero is the electrode image information. The cerebral cortex electrode and the magnetic resonance image fusion display system combine the pre-implantation CT image and the post-implantation CT image comparison algorithm and the threshold segmentation algorithm to extract the position information of the implanted electrode. This makes it possible to extract the electrode position information better.

For the embodiment, the above step S04 can be further refined, and the refined flowchart is as shown in FIG. 5. In Figure 5, the above step S04 further includes:

Step S41 Arbitrarily selecting a seed point from the registered MRI image: In this embodiment, an image segmentation algorithm is used to extract cerebral cortical tissue image information, and the image segmentation algorithm is based on a region growing algorithm, and the idea is to set a similarity pixel set. Together form the area. In this step, a seed point is arbitrarily selected from the registered MRI image, and a seed point is randomly selected as a starting point for growth.

Step S42 selects a point whose pixel value falls within the set interval in a region centered on the seed point and whose radius is the first set value, and incorporates it into the region where the seed point is located: in this step, in the seed A point whose center is the center and whose radius is the first set value is selected from the point where the pixel value falls within the set interval, and is included in the area where the seed point is located, that is, the seed point and the seed point around the pixel point. Pixels with the same or similar properties of pixels (as judged according to some predetermined growth or similarity criteria) are merged into the region where the seed point pixels are located. In the first embodiment, the first set value is set in advance by software.

Step S43 The radius is expanded, and it is judged whether there is a point in the enlarged area whose pixel value falls within the set interval: in this step, the radius is expanded, and it is judged whether or not the pixel value still exists in the enlarged area. The point in the set interval, that is, the new pixel in the region where the nano seed point pixel is located is regarded as a new seed pixel, and the above process is continued, and it is determined whether there is still a point where the pixel value falls within the set interval, if If the result of the determination is yes, then step S44 is performed; otherwise, step S45 is performed.

Step S44 It is included in the area where the seed point is located: if the result of the above step S43 is YES, this step is performed. In this step, it is included in the area where the seed point is located. After performing this step, the process returns to step S43.

Step S45 uses the region where the seed point is located as cerebral cortical tissue image information: if the result of the above-described step S43 is NO, the present step is executed. In this step, the region where the seed point is located is used as image information of the cerebral cortex tissue. That is, when a pixel that does not satisfy the condition is included, such an area becomes long. That is to say, the growth criterion used by the current image segmentation algorithm is that the point pixel values in the field with a certain radius are within a certain interval, and then the points are included in the region where the seed pixel is located, and when there is no point meeting the criterion, When incorporated, the image segmentation algorithm terminates. This extracts the electrode image information and the cerebral cortex tissue image information.

For the embodiment, the above step S05 can be further refined, and the refined flowchart is as shown in FIG. 6. In Figure 6, the above step S05 further includes:

Step S51 Converting the data type of the electrode image information and the data type of the cerebral cortex tissue image information into the same data type: in this step, the data type of the electrode image information and the data type of the cerebral cortex tissue image information are converted into the same data type. In the first embodiment, the same data type is Byte type, that is, the electrode image information and the cerebral cortex tissue image information are both converted into eight-bit data.

Step S52 Through the set color map, the gray values of each pixel in the electrode image and the cerebral cortex tissue image are respectively mapped into different colors and transparency, and the color and transparency are respectively adjusted: in this step, the set color is adopted. The mapping table maps different gray values of each pixel in the electrode image and the cerebral cortex tissue image into different colors and transparency, respectively, and adjusts the color and transparency thereof. It is worth mentioning that in the process of fusion, the brain tissue and the electrode are respectively given different colors, and finally they are displayed in the same coordinate system, so that they can adjust their color and transparency separately, which brings a very good use. Great convenience.

Step S53 displays the fused image by surface rendering or volume rendering: in this step, the fused image is displayed by surface rendering or volume rendering.

The embodiment further relates to a device for realizing the method for displaying the fusion of the cerebral cortex electrode and the magnetic resonance image, and a schematic structural view thereof is shown in FIG. 7 . In Fig. 7, the apparatus comprises a registration unit 2, an electrode information extraction unit 3, a cerebral cortex information extraction unit 4, an information fusion unit 5, and a display effect adjustment unit 6; wherein the registration unit 2 is used for implanting MRI images and implants The post CT image is registered in the same coordinate space; the electrode information extracting unit 3 is configured to extract electrode image information from the registered CT image; the cerebral cortex information extracting unit 4 is configured to extract the brain from the registered MRI image. Cortical tissue image information; the information fusion unit 5 is configured to spatially fuse the electrode image information and the cerebral cortex tissue image information, and display the spatially fused information through a three-dimensional visualization method; the display effect adjustment unit 6 is configured to adjust the three-dimensional visual display The effect and angle, and the adjusted result is converted to the desired format output saved. It is worth mentioning that the above MRI image and the post-implant CT image are both DICOM format image files. The above required format is a DICOM file, a picture file or a video file, and the results of different formats can be used for various purposes. Since the electrode information of the extraction process is fused and displayed on the MRI image, the brain tissue information can be seen and the position information of the electrode can be seen at the same time, so that the position information of the electrode can be obtained.

In this embodiment, the registration unit 2 further includes a coordinate conversion module 21, a post-implantation rotation translation comparison module 22, a post-implantation rotation translation module 23, and a post-implantation similarity determination module 24; wherein, the coordinate conversion module 21 uses The MRI image and the post-implantation CT image are converted to the same coordinate system, and the physical center of the MRI image is moved to the same point as the physical center of the post-implant CT image; the post-implantation rotation translation comparison module 22 is used for Rotating, translating, and comparing partial image pixels in the MRI image and partial image pixels in the post-implant CT image using the first scale until the contour of the MRI image is similar to the contour of the CT image after implantation. a similarity; the post-implantation rotation translation module 23 is configured to rotate and translate a portion of the image pixels in the MRI image after the first scale adjustment and a portion of the image pixels in the post-implant CT image using the second scale; The number of pixels included in the first scale is greater than the number of pixels included in the second scale; the post-implant similarity judgment module 24 is configured to determine the MRI image and the implant after the second scale adjustment CT image corresponding to the pixel position of the similarity reaches a second degree of similarity, and if so, the end of the registration process; otherwise, continue adjusting the second scale; and the second similarity is larger than the first similarity. This completes the registration of the MRI image and the post-implantation CT image. It is worth mentioning that, in this embodiment, the size of the first size is eight pixels, and the size of the second size is one pixel. Of course, in some cases of the embodiment, the first size and the second size The size can be adjusted according to the specific situation.

In this embodiment, when only the pre-implant MRI scan and the post-implant CT scan are performed, the electrode information extracting unit 3 further includes a grayscale threshold setting module 31 and an electrode image extracting module 32; The degree threshold setting module 31 is configured to set a grayscale threshold range of the registered CT image, the set grayscale threshold range includes the electrode image; the electrode image extraction module 32 is configured to drop the image grayscale An image within the set grayscale threshold range is extracted as electrode image information. This completes the extraction of the electrode information.

In order to better extract the electrode position information, it is also necessary to take a pre-implantation CT image obtained by CT scanning before the patient is implanted into the intracranial electrode, and perform a CT scan. At this time, the device further includes a pre-implantation registration unit 20, The pre-implantation registration unit 20 is used to register the MRI image and the pre-implantation CT image in the same coordinate space. The pre-implantation CT image is an image file in DICOM format.

In this embodiment, the pre-implantation registration unit 20 further includes a pre-implantation coordinate conversion module 201, a pre-implantation rotational translation comparison module 202, a pre-implantation rotation translation module 203, and a pre-implantation similarity determination module 204; The pre-implantation coordinate conversion module 201 is configured to convert the MRI image and the pre-implant CT image into the same coordinate system, and move the physical center of the MRI image to the same point of the physical center of the pre-implant CT image; The front rotation translation comparison module 202 is configured to respectively rotate, translate, and compare partial image pixels in the MRI image and partial image pixels in the pre-implant CT image using the first scale until the contour of the MRI image and the pre-implantation The similarity of the contour of the CT image reaches a first similarity; the pre-implantation rotation translation module 203 is configured to use a second scale to pass a partial image pixel in the MRI image after the first scale adjustment and a portion in the pre-implant CT image The pixel of the image is rotated and translated again; the number of pixels included in the first scale is greater than the number of pixels included in the second scale; the pre-implantation similarity determining module 204 is configured to determine the second Whether the similarity between the adjusted MRI image and the pre-implant CT image corresponds to the second similarity, if yes, the registration process is ended; otherwise, the second calibration is continued; the second similarity is greater than the first Similarity. This completes the registration of the MRI image with the pre-implantation CT image.

In this embodiment, the CT image after registration includes the pre-implantation CT image after registration and the post-implantation CT image after registration. In this case, the electrode information extracting unit 3 further includes CT image subtraction. The module 31', the CT image subtraction module 31' is configured to subtract the registered pre-implant CT image after the registration of the post-implantation CT image, and the portion where the gradation difference value is not 0 is the electrode image information. . This completes the extraction of the electrode information. It is worth mentioning that, in practical applications, the electrode information extraction unit 3 may be configured to include the grayscale threshold setting module 31 and the electrode image extraction module 32, or the electrode information extraction unit 3 may be configured to include CT image subtraction module 31'.

In this embodiment, the cerebral cortex information extracting unit 4 further includes a seed point selecting module 41, a set interval intra-segment point selecting module 42, a set interval intra-pixel value judging module 43 and a pixel value judging module 44; wherein, the seed point is selected The module 41 is configured to arbitrarily select one seed point from the registered MRI image; the seeding point selection module 42 is configured to select the pixel in the region with the seed point as the center and the radius as the first set value. The value falls within the set interval and is included in the region where the seed point is located; the set interval intra-pixel value judgment module 43 is configured to expand the radius and determine whether the pixel value still exists in the enlarged region. a point falling within the set interval, if yes, is included in the region where the seed point is located; otherwise, the region where the seed point is located is used as cerebral cortical tissue image information; the pixel value judging module 44 is configured to continue to perform the pixel in the set interval The judgment of the value. This completes the extraction of cerebral cortex information.

In this embodiment, the information fusion unit 5 further includes a data type conversion module 51, a gray value mapping module 52, and an image display module 53. The data type conversion module 51 is configured to use the data type of the electrode image information with the The data type of the cerebral cortex tissue image information is converted into the same data type; the gray value mapping module 52 is configured to respectively map different gray values of each pixel in the electrode image and the cerebral cortical tissue image through the set color mapping table. Different colors and transparency are used to adjust their color and transparency respectively; the image display module 53 is used to display the fused image by face drawing or volume rendering. In this way, you can see the information of the cerebral cortex and the position information of the electrodes to help the user.

In summary, in the present embodiment, the data of the pre-implant CT image, the post-implant CT image and the MRI image are taken and introduced into the cerebral cortex electrode and the magnetic resonance image fusion display system, and the cerebral cortex electrode and the magnetic resonance image fusion display system are automatically performed. Processing and visualizing the results in a three-dimensional visualization, by combining the information of the implanted electrodes with the information of the cerebral cortex, provides a wealth of auxiliary information, and can obtain more satisfactory results without increasing the burden. .

The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., which are included in the spirit and scope of the present invention, should be included in the present invention. Within the scope of protection.

Claims

A method for fused display of a cerebral cortex electrode and a magnetic resonance image, comprising the steps of:

A) taking the MRI image obtained by MRI scan before the patient is implanted into the intracranial electrode and the post-implantation CT image obtained by CT scanning after the patient implants the intracranial electrode;

B) registering the MRI image and the post-implantation CT image in the same coordinate space;

C) extracting electrode image information from the registered CT image;

D) extracting cerebral cortical tissue image information from the registered MRI images;

E) spatially merging the electrode image information and the cerebral cortex tissue image information, and displaying the spatially fused information through a three-dimensional visualization method;

F) Adjust the effect and angle of the 3D visual display, and convert the adjusted result into the desired format output for saving.

2 . The method of claim 1 , wherein the step B) further comprises:

B1) converting the MRI image and the post-implant CT image into the same coordinate system, and moving the physical center of the MRI image to the same point of the physical center of the post-implant CT image;

B2) rotating, translating, and comparing partial image pixels in the MRI image and partial image pixels in the post-implant CT image using a first scale until the contour of the MRI image and the post-implant CT The similarity of the outline of the image reaches the first similarity;

B3) using the second scale to rotate and translate the partial image pixels in the MRI image after the first scale adjustment and the partial image pixels in the post-implant CT image; the first scale includes more pixels than the first scale The number of pixels included in the second scale;

B4) determining whether the similarity between the MRI image after the second scale adjustment and the position pixel of the post-implant CT image reaches a second similarity, and if so, ending the registration process; otherwise, returning to step B3); The degree is greater than the first similarity.

The method of claim 2, wherein the step C) further comprises:

C1) setting a grayscale threshold range of the registered CT image, the set grayscale threshold range including the electrode image;

C2) An image in which the image gray scale falls within the set grayscale threshold value is extracted as the electrode image information.

4. According to the claims 2, wherein the cerebral cortex electrode is fused with a magnetic resonance image, and the method further comprises: before the step A):

A0) taking a pre-implantation CT image obtained by performing a CT scan before the patient is implanted into the intracranial electrode;

Between the step A) and the step B), the method further includes:

B0) Register the MRI image and the pre-implant CT image in the same coordinate space.

The method of claim 4, wherein the step B0) further comprises:

B01) converting the MRI image and the pre-implant CT image into the same coordinate system, and moving the physical center of the MRI image to the same point as the physical center of the pre-implant CT image;

B02) rotating, translating, and comparing partial image pixels in the MRI image and partial image pixels in the pre-implant CT image, respectively, using a first scale until a contour of the MRI image and the pre-implantation CT The similarity of the outline of the image reaches the first similarity;

B03) rotating and translating the partial image pixels in the MRI image after the first scale adjustment and the partial image pixels in the pre-implant CT image by using the second scale; the first scale includes the number of pixels larger than The number of pixels included in the second scale;

B04) determining whether the similarity between the MRI image after the second scale adjustment and the position pixel corresponding to the pre-implant CT image reaches a second similarity, and if so, ending the registration process; otherwise, returning to step B03); The degree is greater than the first similarity.

6. A method of fusion display of a cerebral cortex electrode and a magnetic resonance image according to claim 5, wherein the registered CT image comprises a pre-implantation CT image after registration and an implant after registration After the CT image, the step C) further includes:

C1') The post-implantation CT image after the registration is subtracted from the pre-implantation CT image after the registration, and the portion where the gradation difference value is not zero is the electrode image information.

The method of fused display of a cerebral cortex electrode and a magnetic resonance image according to any one of claims 1 to 6, wherein the step D) further comprises:

D1) arbitrarily selecting a seed point from the registered MRI image;

D2) selecting, in an area centered on the seed point and having a radius of the first set value, a point whose pixel value falls within the set interval, and incorporating the point where the seed point is located;

D3) expanding the radius, and determining whether there is a point in the enlarged area whose pixel value falls within the set interval, and if so, incorporating it into the area where the seed point is located, and performing step D4 ); otherwise, the region where the seed point is located is used as cerebral cortical tissue image information;

D4) returns to step D3).

The method of the cerebral cortex electrode and the magnetic resonance image fusion display according to claim 7, wherein the step E) further comprises:

E1) converting the data type of the electrode image information and the data type of the cerebral cortex tissue image information into the same data type;

E2) mapping different gray values of each pixel in the electrode image and the cerebral cortex tissue image into different colors and transparency through the set color mapping table, respectively adjusting the color and transparency;

E3) Display the fused image by face drawing or volume rendering.

The cerebral cortex electrode and the magnetic resonance image fusion display method according to claim 8, wherein the size of the first scale is eight pixels, and the size of the second scale is one pixel, The MRI image, the pre-implantation CT image, and the post-implantation CT image are all image files in DICOM format, and the required format is a DICOM file, a picture file, or a video file.

10. A device for implementing a method for fused display of a cerebral cortex electrode and a magnetic resonance image according to claim 1, comprising:

Registration unit: used to register MRI images and CT images in the same coordinate space;

An electrode information extracting unit: configured to extract electrode image information from the registered CT image;

Cerebral cortex information extraction unit: for extracting cerebral cortical tissue image information from the registered MRI image;

The information fusion unit is configured to spatially fuse the electrode image information and the cerebral cortex tissue image information, and display the spatially fused information through a three-dimensional visualization method;

Display effect adjustment unit: used to adjust the effect and angle of the 3D visual display, and convert the adjusted result into the required format output for saving.

The device according to claim 10, wherein the registration unit further comprises:

a coordinate conversion module: configured to convert the MRI image and the post-implant CT image into the same coordinate system, and move the physical center of the MRI image to the same point of the physical center of the post-implant CT image;

Post-implantation rotational translation alignment module for respectively rotating, translating and comparing partial image pixels in the MRI image and partial image pixels in the post-implant CT image using the first scale until the MRI image The similarity between the contour of the CT image and the contour of the post-implant CT image reaches a first similarity;

Post-implantation rotation translation module: for rotating and translating partial image pixels in the MRI image after the first scale adjustment and partial image pixels in the post-implant CT image using the second scale; The number of pixels included is greater than the number of pixels included in the second scale;

Post-implantation similarity judgment module: for judging whether the similarity between the MRI image adjusted by the second scale and the pixel corresponding to the post-implantation CT image reaches the second similarity, and if so, ending the registration process; otherwise, proceeding The adjustment of the second scale; the second similarity is greater than the first similarity.

The device according to claim 11, wherein the electrode information extracting unit further comprises:

Grayscale threshold setting module: configured to set a grayscale threshold range of the registered CT image, the set grayscale threshold range including the electrode image;

Electrode image extraction module: an image for extracting an image gray scale within a set grayscale threshold range as electrode image information.

13. Apparatus according to claim 11 wherein said apparatus further comprises:

Pre-implantation registration unit: for registering the MRI image and the pre-implantation CT image in the same coordinate space.

14. The device of claim 13, wherein the pre-implantation registration unit further comprises:

Pre-implantation coordinate conversion module: for converting the MRI image and the pre-implant CT image into the same coordinate system, and moving the physical center of the MRI image to the same point as the physical center of the pre-implant CT image ;

Pre-implantation rotational translation alignment module: for respectively rotating, translating and comparing partial image pixels in the MRI image and partial image pixels in the pre-implant CT image using the first scale until the MRI image The similarity between the contour of the CT image and the contour of the pre-implant CT image reaches a first similarity;

a pre-implantation rotation translation module for rotating and translating a partial image pixel in the first scale-adjusted MRI image and a partial image pixel in the pre-implant CT image using a second scale; The number of pixels included is greater than the number of pixels included in the second scale;

The pre-implantation similarity judgment module is configured to determine whether the similarity between the MRI image adjusted by the second scale and the pixel corresponding to the pre-implant CT image reaches a second similarity, and if so, the registration process ends; otherwise, return to continue Performing a second scale adjustment; the second similarity is greater than the first similarity.

15. The apparatus according to claim 14, wherein the registered CT image comprises a pre-implantation CT image after registration and a post-implantation CT image after registration, the electrode information extraction unit Further includes:

The CT image subtraction module: the post-implantation CT image after the registration is subtracted from the pre-implantation CT image, and the portion where the gradation difference value is not 0 is the electrode image information.

The apparatus according to any one of claims 10 to 15, wherein the cerebral cortex information extracting unit further comprises:

Seed point selection module: for arbitrarily selecting a seed point from the registered MRI image;

a seed point selection module for setting an interval: for selecting a point whose pixel value falls within a set interval in an area centered on the seed point and having a radius of a first set value, and incorporating the The area where the seed point is located;

Setting a pixel value judgment module in the interval: for expanding the radius, and determining whether there is a point in the enlarged region whose pixel value falls within the set interval, and if so, incorporating the radius The area where the seed point is located; otherwise, the area where the seed point is located is used as image information of the cerebral cortex tissue;

The pixel value judgment module is configured to continue the determination of the pixel value in the set interval.

The apparatus according to claim 16, wherein the information fusion unit further comprises:

a data type conversion module: configured to convert a data type of the electrode image information and a data type of the cerebral cortex tissue image information into the same data type;

Gray value mapping module: for mapping different gray values of each pixel in the electrode image and the cerebral cortex tissue image into different colors and transparency through the set color mapping table, respectively adjusting the color and transparency thereof;

Image display module: used to display the fused image by face drawing or volume drawing.

18. The apparatus according to claim 17, wherein said first size has a size of eight pixels, said second size has a size of one pixel, said MRI image, pre-implantation CT image and implant The CT images are all image files in DICOM format, and the required format is a DICOM file, a picture file or a video file.