KR101082322B1 - The DICOM file conversion method of microwave tomography data - Google Patents

Abstract

Disclosed is a method of visualizing data of permittivity and conductivity of a microwave tomogram capable of accurately diagnosing the type, size, and location of breast cancer in a diagnostic apparatus using electromagnetic waves, and converting the image data into a dicom file. . The present invention provides a method for converting the dielectric constant and conductivity resulting from microwave tomogram data used for the purpose of a diagnostic device in the medical / hospital field to the DICOM standard, thereby converting the obtained dielectric constant and conductivity information into 2D or 3D color images. In this case, users can easily determine the presence or absence of cancer cells by accessing the patient's image information anywhere in the hospital.

Description

The dicom file conversion method of microwave tomography data

The present invention relates to a method of converting data of a microwave tomogram into a dicom file, and in particular, the dielectric constant and conductivity data of a microwave tomogram capable of accurately diagnosing the type, size, and location of breast cancer in a diagnostic apparatus using electromagnetic waves. To visualize the image and convert the imaged data into DICOM (Digital Image and Communication in Medicine) standard.

Breast cancer is a particularly important medical problem for women, and early diagnosis of this is essential, and various breast cancer diagnosis apparatuses have been developed for this purpose. The most commonly used one is by X-ray mammography, and recently, tomography using microwaves has been introduced. A conventional display method for these two methods will be described with reference to FIGS. 1 and 2.

Figure 1 shows the results of X-ray imaging for the diagnosis of breast cancer showing a breast (tumor) suspected of cancer in the breast (breast) and the inside of the patient. In this X-ray imaging, when the X-ray generator and the image detection unit are located on the vertical line, when the tumor overlaps in a vertical line, the image of only one tumor is obtained, and thus the tumor location and size can be estimated. In addition, the accurate positioning of the tumor is also difficult as a two-dimensional planar image is acquired. In addition, when the density of the mammary gland distributed in the breast is high, an image similar to the color of the mammary gland and the tumor is obtained, thereby limiting the reading by the visual examiner.

Another method for diagnosing breast cancer is to diagnose tumors by predicting the distribution of permittivity and conductivity within the breast using the scattering characteristics of electromagnetic waves (Meaney et al., Systems and methods for 3-d data acquisition for microwave). imaging, US Patent Application No. 2003-407886, Apr. 4, 2003). This method is called microwave tomogram method. Figure 2 shows an example of the permittivity and conductivity distribution for the breast tomography produced by this microwave tomogram.

In addition, as the computer and communication technologies have developed, the medical community dealing with patients' lives can use the computer and data communication technology to search X-ray films converted into digital data using computer communication networks in each office when necessary. The Picture Arching Communication System (hereinafter referred to as 'PACS') has been introduced. PACS acquires medical images, especially radiological diagnostic images in digital form, and then transmits them through a high-speed network. Medical images are stored as digital data instead of past X-ray films. It refers to a comprehensive digital image management system and transmission system that uses a video retrieval device to treat patients.

 In a PACS system, the configured devices must be able to support the Digital Imaging and Communications in Medicine (DICOM) protocol (hereinafter referred to as 'DICOM'). It means a communication protocol that effectively supports communication between various digital image acquisition devices and other information systems.

However, the microwave tomogram for breast cancer, that is, the display of permittivity and conductivity for data breast tomography, must also be converted to DICOM's protocol in order to use the PACS system. There is no standard for converting microwave tomogram data into DICOM files. It is true.

In order to achieve the above object, the present invention provides a method for converting permittivity and conductivity, which are a result of microwave tomogram data used for the purpose of a diagnostic apparatus in the medical / hospital field, to the DICOM standard, thereby obtaining the permittivity and conductivity information. To visualize 2D or 3D color images, and convert the data of the microwave tomogram into a dicom file so that users anywhere in the hospital can access the patient's image information and easily determine the presence or absence of cancer cells. The purpose is to provide a method.

The present invention for achieving such an object,

The test object of the examinee is positioned in the multi-channel antenna in which a plurality of mono pull antennas are arranged at regular intervals, and the RF signal is generated by the multi-channel transmission / reception apparatus and transmitted to one of the multi-channel antennas, and the remaining antennas Channel pass information obtaining step of obtaining channel pass information by repeating an operation of receiving an RF signal through a network;

In the channel pass information acquisition step, the inspector's test object is divided into meshes, and an arbitrary dielectric constant and conductivity are assigned to each mesh to analyze the field, and the error is constant compared with the result of the field analysis and the actual measured value. Performing an inverse scattering analysis algorithm which performs an inverse scattering analysis algorithm for finding the optimal value and obtaining the dielectric constant and conductivity in the subject's test object while changing the values of permittivity and conductivity so as to fall within a range;

X and Y axes on the triangular point coordinates using the coordinate values of the X and Y axes, the permittivity and conductivity values of the test subject's test object, and the triangular point coordinate values obtained by performing the inverse scattering analysis algorithm. A mapping step of mapping the permittivity or conductivity values onto points coinciding with the coordinates;

A color information display step of displaying color information using a randomly designated color as a reference color after finding the minimum and maximum values of the total dielectric constant or the conductivity value in the mapping step; And,

And converting the data of which mapping and color information is completed into image data and dividing a portion for recording patient information or image information into a header part to convert to a dicom file.

The method for converting microwave tomogram data into a dicom file according to the present invention provides a function of visualizing permittivity and conductivity information obtained through microwave tomogram data in a 2D or 3D color image in a breast cancer diagnosis apparatus. In addition, precise tomogram image analysis enables users to easily determine the presence or absence of cancer cells by providing the function of displaying the location and size of a specific region as well as the cross section of the image.

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

In the present invention, by converting the dielectric constant and the conductivity, which are the result of microwave tomogram data generated using a breast cancer diagnosis apparatus using electromagnetic waves, to a DICOM standard, the examiner can view and interpret the patient's image information wherever PACS is constructed. The tumor inside the breast of the examinee is conveniently diagnosed.

FIG. 3 is a block diagram illustrating a method of converting microwave tomogram data into a dicom file according to the present invention, FIG. 4 is a block diagram illustrating the data acquisition process of FIG. 3 in detail, and FIG. 5. Is a flowchart illustrating an inverse scattering analysis algorithm in a method for converting microwave tomogram data into a dicom file according to the present invention.

As shown in FIG. 3, the configuration of the microwave tomogram data acquisition device according to the present invention for diagnosing breast cancer includes an electromagnetic wave exposure device for data acquisition, a multi-channel microwave transceiver for reconstruction of acquired data, visualization and image analysis. It consists of an inverse scattering analysis algorithm. Acquisition of permittivity and conductivity data, which is the microwave tomogram data of a test specimen for breast cancer diagnosis, generates an RF signal from a multi-channel microwave transceiver and transmits it to one of the antennas of an electromagnetic wave exposure apparatus composed of a plurality of monopole antennas. Receive the RF signal. In addition, the dielectric constant and conductivity information of the inside of the test object are calculated through an inverse scattering analysis algorithm from the data of the received RF signal.

Referring to FIG. 4, an electromagnetic wave exposure apparatus (bath) in which a test subject for breast cancer is located includes a multichannel antenna and a transceiver. The multi-channel antenna is configured in a circular shape with a plurality of mono pull antennas at regular intervals, and is configured such that the test object (test object) of the examinee is located at the center thereof. The multi-channel transmitter / receiver generates an RF signal and transmits the signal to one of the antennas of the exposure apparatus, and receives the RF signal through the remaining antennas. Channel transmission information is obtained by repeating several transmissions for all antennas constituting the multichannel antenna. The frequency used is 500MHz ~ 3GHz, and when the channel consists of n channels, it measures channel pass information for n * (n-1) received signals, moves the position of the measuring object, and acquires data. Here, a high frequency may be used to increase the resolution, and when measuring at P antenna positions and M frequencies, channel pass information is collected for P * M * n * (n-1) received signals.

The inverse scattering analysis algorithm that obtains the dielectric constant and conductivity inside the test object from the channel pass information of the received signal collected from the multi-channel electromagnetic wave transmitting and receiving device divides the test subject's test object into a mesh and assigns a random permittivity and conductivity to each mesh. To analyze the electromagnetic field. Compared with the result of the electromagnetic analysis and the measured value, it is a method of finding the optimal value by changing the dielectric constant and conductivity so that the error is within a certain range.

The backscatter analysis algorithm checks the presence of abnormal cells through the human tissue and finds the location of the abnormal cells, and compares them with the result of the electromagnetic field analysis and the measured value so that the error is within a certain range. It is the way to find the optimal value by changing the dielectric constant and conductivity value.

The inverse scattering analysis algorithm that obtains the dielectric constant and conductivity inside the test object from the amplitude and phase information of the received signal collected from the multi-channel transceiver is shown in FIG. 5, when the electromagnetic wave passes through the general cells of the human tissue and the abnormal cells. A step of specifying an initial predicted value is performed by using a point in which a relative dielectric constant or a conductivity value at the time of passage has a difference. (Step 101)

That is, after the initial channel information value is assigned by assigning the dielectric constant and the conductivity value of the human tissue of the subject to be measured as initial values, the field value at the reception position is determined for the signal transmitted from the multi-channel microwave transceiver. A field value estimating step of estimating electromagnetic waves is performed (step 102). A field value measuring step of measuring a field value at an actually received position is performed on a signal transmitted from a multi-channel microwave transmitting / receiving apparatus. (Step 103)

In steps 102 and 103, the measured estimated field value is compared with the measured value, and the result of the comparison is determined to be within an error range. (Step 104, 105)

Steps 102 to 105 calculate the estimated value at the reception position by the transmission signal in a state where the relative dielectric constant value and the conductivity value of the human tissue to be measured are known in advance, and compare the estimated value with the actually measured field value. . If the difference between the estimated value and the measured field value is within the error range, it can be regarded as the expected medium. If it is out of the error range, the medium is not the expected medium. Can determine the presence and location of

If the estimated value and the measured field value are not within the error range in step 105, the Jacobian, which is an important correlation formula for calculating the multivariate function, is calculated, the regulation parameter is determined, and the initial predicted value is calculated again to perform step 102. do.

The inverse scattering analysis algorithm passes the electromagnetic wave through the human tissue and checks whether the measurement data has the expected dielectric constant, conductivity, or the result calculated by the medium and is within the margin of error. Based on this, the relative dielectric constant and conductivity of human tissues are estimated. The predicted field value at the receiving position for the transmitted signal can be calculated using the finite difference time domain (FDTD), and the electromagnetic field values measured at the measurement objects of the human tissue and the expected electromagnetic waves. By analyzing the data whether the difference between the field values falls within the error range, the presence and absence of abnormal cells can be analyzed.

FIG. 6 is an example of microwave tomogram data generated by using a breast cancer diagnosis apparatus. The data obtained by performing an inverse scattering analysis algorithm is composed of coordinates of the X-axis and the Y-axis, such as the basic index data and the data in a rectangle indicated by a dotted line. Value, permittivity and conductivity values, and set of triangles coordinate values.

As shown in FIG. 7, the imaging method for each of the permittivity and the conductivity includes a position mapping according to triangular point coordinates and a color mapping according to the permittivity and conductivity values. As shown in FIG. 7, the 2D image visualization method for each piece of information on the permittivity and the conductivity obtained through the inverse scattering analysis algorithm includes position mapping according to a set of triangular coordinates of the obtained data. Implemented by the color mapping of the and data values. That is, the inverse scattering analysis algorithm performs mapping of permittivity or conductivity values on points corresponding to X and Y axis coordinates in order on each triangle point coordinate in the obtained data, and then the minimum and maximum values of the predetermined reference color table. Color information is displayed by comparing the minimum and maximum values of permittivity or conductivity value with.

In addition, the visualization method of the 3D image is implemented to confirm the three-dimensional information of the subject under the assumption that the dielectric constant or conductivity data value from the coordinates to the Z axis.

That is, in the method of converting the data of the microwave tomogram according to the present invention into the dicom file, the color mapping process maps the dielectric constant or conductivity value on the points corresponding to the X and Y axis coordinates in order on the respective triangular point coordinates. The color mapping finds the minimum and maximum values of the total dielectric value or the conductivity value, selects a predetermined color or a type of color desired by the user, and displays the color information as a reference color bar.

FIG. 8 shows an example of a method of imaging microwave tomogram data, that is, permittivity or conductivity data and converting it into a DICOM file. The DICOM file is composed of a header portion for recording patient information or image information and an image data portion for storing image data. 9 shows an example of displaying the result of converting the image data of the microwave tomogram into a DICOM file.

As shown in FIGS. 8 and 9, the examiner can view and interpret the patient's image information wherever PACS is constructed by converting the permittivity and conductivity resulting from microwave tomogram data into the DICOM standard. The examiner can diagnose a tumor inside the breast.

Although the preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, the present invention is not limited thereto and may be improved or modified by those skilled in the art within the scope of the technical idea of the present invention.

1 is a diagram illustrating an X-ray imaging result for conventional breast cancer diagnosis.

2 is a diagram illustrating a microwave tomogram result for breast cancer diagnosis according to the present invention.

3 is a block diagram illustrating a method for converting microwave tomogram data into a dicom file according to the present invention.

4 is a block diagram for explaining in detail the data acquisition process of FIG.

5 is a flowchart illustrating an inverse scattering analysis algorithm in a method of converting microwave tomogram data into a dicom file according to the present invention.

6 is an example of microwave tomogram data for showing a result of diagnosing breast cancer using microwave tomogram data according to the present invention.

FIG. 7 is a diagram illustrating an example of a method of mapping microwave tomogram data into positions and colors according to the present invention.

8 is a view showing a method of converting the microwave tomogram data according to the present invention and then converted to the DICOM standard.

9 is an exemplary view of a microwave tomogram image converted into a DICOM file and displayed according to the present invention.

Claims (3)

The test object of the examinee is positioned in the multi-channel antenna in which a plurality of mono pull antennas are arranged at regular intervals, and the RF signal is generated by the multi-channel transmission / reception apparatus and transmitted to one of the multi-channel antennas, and the remaining antennas Channel pass information acquiring step of acquiring channel pass information by repeating an operation of receiving an RF signal with a channel; In the step of acquiring the channel pass information, the test object of the examinee is divided into a mesh, and an electric field analysis is performed by assigning an arbitrary permittivity and conductivity to each mesh, and comparing the result of the field analysis with the actual measured result. Performing an inverse scattering analysis algorithm for performing an inverse scattering analysis algorithm for finding an optimal value and obtaining a dielectric constant and conductivity within an inspection object by changing the values of permittivity and conductivity so that an error is within a certain range; The inverse scattering analysis algorithm performs an inverse scattering analysis algorithm and has coordinate values of the X and Y axes, permittivity and conductivity values of the test object of the examinee, and triangular point coordinate values. Mapping a permittivity or conductivity value onto a point coincident with the axis coordinates; A color information display step of displaying color information using a randomly designated color as a reference color after finding the minimum and maximum values of the total dielectric constant or the conductivity value in the mapping step; And, The data of the microwave tomogram comprising the step of converting the data of the mapping and color information is completed as the image data and dividing the portion for recording the patient information or the information of the image into a header portion into a dicom file. How to convert. The method of claim 1, wherein the obtaining of the channel information uses an RF frequency of 500 MHz to 3 GHz, and measures channel pass information for n * (n-1) received signals when the antenna is composed of n channels. And converting the data of the microwave tomogram into a dicom file. The method of claim 1, wherein the inverse scattering analysis algorithm, A field value estimating step of designating a dielectric constant and a conductivity value of human tissue of an examinee as an initial value and estimating a field value of electromagnetic waves at a reception position with respect to a signal transmitted from a multi-channel electromagnetic wave transceiver;  A field value measuring step of measuring a field value at an actually received position with respect to a signal transmitted from the multi-channel microwave transceiving device after the field value estimating step; The field value estimated in the field value estimating step and the field value measured in the field value measuring step are compared, and the presence or absence and position of abnormal cells in the human tissue to be measured are determined by determining whether the result of the comparison is within an error range. Identifying a comparison step; And, If the estimated field value and the measured field value in the comparison step does not fall within the error range, calculating the Jacobian, determining a regulation parameter and recalculating the initial value to perform the field value estimation step. How to convert data from microwave tomogram to dicom file.

Images