Thyroid cancer near-field imaging quality improvement method

Abstract

The invention discloses a thyroid cancer near-field imaging quality improvement method, belongs to the technical field of terahertz biological imaging, and mainly solves the problems of small test signals, imaging scratches and insufficient definition of thyroid cancer in a near-field imaging test. The method mainly comprises the following steps: S110, scanning a sample without adjustment to observe a near-field imaging effect; s120, carrying out stylus marking operation, and then carrying out secondary scanning; s130, adjusting an integral proportion and a differential gain parameter, and carrying out three times of scanning; and S140, changing the integral time in the lock-in amplifier, and carrying out near-field imaging scanning test on the thyroid cancer sample for four times. The method has the advantages that the near-field imaging quality of the thyroid cancer sample can be effectively improved, and the operation is simple and easy to operate.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of terahertz biological imaging, and particularly relates to a method for improving the quality of near-field imaging of thyroid cancer. BACKGROUND

[0002] Thyroid cancer is a malignant tumor originating from thyroid follicular epithelium or parafollicular epithelial cells, and has a good overall prognosis. It is one of the malignant tumors with a high cure rate. There are some shortcomings in the current diagnosis of thyroid cancer, including early symptoms that are hidden and are often painless lumps in the thyroid gland, which are easily ignored or misjudged as benign lesions. Although imaging examinations such as ultrasound and CT are important, they may fail to accurately diagnose small cancer lesions, special types of cancer, or cancer lesions similar to benign nodules. Invasive methods such as fine needle aspiration cytology have a certain misdiagnosis rate, and pathological diagnosis relies on the experience and judgment of doctors, which is subjective. In addition, the puncture sample may not be accurate, and the sample size may be insufficient. In addition, there is a problem of over-diagnosis, which may misdiagnose some tumors that almost do not cause symptoms or death as cancer, resulting in unnecessary treatment for patients.

[0003] Terahertz near-field imaging technology provides a unique advantage for the diagnosis of thyroid cancer. The core is that it can realize the non-labeled and non-destructive detection of thyroid tissue at high resolution, which makes up for some shortcomings of traditional diagnostic techniques. The main advantages are as follows:

[0004] 1. High resolution and high contrast, accurate identification of small lesions:

[0005] The wavelength of terahertz waves is between microwaves and infrared rays. Combined with near-field imaging technology, the spatial resolution can break through the diffraction limit and reach the micron level or even the nanometer level. This allows it to clearly present the microscopic structure of the thyroid tissue, including cell morphology, gland follicle arrangement, and other subtle changes. Compared to ultrasound examination, which is easily disturbed when judging small cancer lesions (especially those less than 5 mm in diameter), this technology can more accurately identify the microscopic abnormalities of early thyroid cancer, reducing the probability of missed diagnosis due to small lesions. At the same time, terahertz waves are sensitive to the differences in dielectric constant and absorption coefficient of different tissues, and can clearly distinguish between normal thyroid tissue, benign nodules, and malignant tumors through signal contrast, further improving the accuracy of diagnosis.

[0006] 2. Non-destructive, no ionizing radiation, higher safety:

[0007] The terahertz near-field imaging technology does not need to contact the tissue, does not produce ionizing radiation, and only obtains image information through the interaction between terahertz waves and the tissue, and the whole detection process is non-invasive and has no side effects on the thyroid and surrounding tissues, can be applied to special groups such as pregnant women and children, and can also meet the needs of multiple detections such as postoperative review, greatly improving the safety of diagnosis and patient compliance.

[0008] 3. Label-free detection, simplifying the diagnosis process:

[0009] The commonly used pathological diagnosis technologies such as immunohistochemistry and molecular detection need to perform complex pretreatments such as staining and labeling on the sample, and the process is complicated and time-consuming, which may delay the diagnosis and treatment decision. The terahertz near-field imaging technology does not need to perform any chemical labeling or pretreatment on the thyroid tissue sample (or the human body when in vivo detection), can directly image and analyze the tissue, can quickly obtain the structural and component information required for diagnosis, and effectively shortens the diagnosis cycle, which saves time for early intervention of thyroid cancer.

[0010] 4. Potential in vivo real-time detection capability, expanding application scenarios:

[0011] At present, most thyroid cancer diagnosis technologies need to rely on ex vivo samples (such as puncture biopsy samples) or static imaging, and it is difficult to observe the dynamic changes of the thyroid tissue in real time. The terahertz near-field imaging technology has potential in the development of device miniaturization and portability, and in the future, it is expected to realize in vivo real-time imaging of the thyroid, which can not only more intuitively observe the lesion position, size and relationship with the surrounding blood vessels and nerves, but also can assist the doctor in accurately positioning the tumor boundary during surgery, reduce the resection of normal tissue, improve the accuracy of surgical treatment, and at the same time, provide the possibility for real-time evaluation of the surgical effect after surgery, thereby expanding its application value in the whole process of thyroid cancer diagnosis and treatment.

[0012] However, due to the great difference in sample types and sample heights of thyroid cancer samples, the amplitude of the terahertz signal received during near-field imaging will be significantly different, thereby affecting the signal strength and scanning stability, and ultimately leading to poor imaging quality. For example, the Z voltage amplitude fluctuation is large during scanning, and the voltage signal of open1 in the phase-locked loop decays. These factors will all lead to a decrease in imaging quality, so specific parameters and operations need to be performed during the near-field imaging of thyroid cancer to improve and maintain the quality of near-field imaging. A method for improving the quality of near-field imaging of thyroid cancer is needed, which can effectively improve the terahertz signal strength and stability, and perform high-quality near-field imaging on thyroid cancer samples. SUMMARY

[0013] In view of the above technical problems, the present application provides a method for improving the quality of near-field imaging of thyroid cancer, which adopts methods such as changing the integration time, drawing a needle and adjusting the related gain parameters to improve the quality of near-field imaging of thyroid cancer.

[0014] The technical solution of the present application is as follows:

[0015] A method for improving the quality of near-field imaging of thyroid cancer, comprising the following steps:

[0016] S110: performing a primary near-field imaging scan on a thyroid cancer sample without adjusting any parameters;

[0017] S120: performing a second near-field imaging scan on the same thyroid cancer sample after performing a needle scraping operation;

[0018] S130: performing a third near-field imaging scan after dynamically adjusting the proportional gain parameter, the integral gain parameter, and the differential gain parameter;

[0019] S140: adjusting the integration time of the lock-in amplifier to 5ms and performing a fourth near-field imaging scan on the thyroid cancer sample.

[0020] In the above technical solution, the needle scraping operation in step S120 includes controlling the probe to move along the X, Y, and Z axis directions to remove attachments on the surface of the probe, and maintaining the Z axis voltage in the range of -50V to 50V.

[0021] In the above technical solution, in step S130:

[0022] The proportional gain parameter is used to improve the system response speed;

[0023] The integral gain parameter is used to suppress low-frequency noise;

[0024] The differential gain parameter is used to enhance high-frequency details;

[0025] The parameters are dynamically adjusted in real time to optimize the imaging clarity.

[0026] In the above technical solution, the adjustment range of the proportional gain parameter, the integral gain parameter, and the differential gain parameter is 50%-200% of the system default value.

[0027] In the above technical solution, the adjustment of the integration time in step S140 includes shortening the integration time of the lock-in amplifier from 9ms to 5ms.

[0028] A near-field imaging system for thyroid cancer, comprising:

[0029] A terahertz near-field imaging module;

[0030] A probe control unit for performing a needle scraping operation and maintaining the Z axis voltage in the range of -50V to 50V;

[0031] Signal processing unit, for dynamic adjustment of proportional gain parameters, integral gain parameters and differential gain parameters;

[0032] The lock-in amplifier supports integral time switching from 9ms to 5ms.

[0033] In the above technical solution, the probe control unit adopts piezoelectric ceramic driving, and the displacement accuracy is ±0.1μm.

[0034] A thyroid cancer diagnosis method comprises:

[0035] The high-resolution image of the thyroid cancer sample is obtained by the method.

[0036] The cancerous region is determined based on the abnormal microstructure of the tissue in the image.

[0037] In the above technical solution, the spatial resolution of the high-resolution image is ≤5μm.

[0038] A computer-readable storage medium stores a computer program, which, when executed, implements the above-mentioned thyroid cancer near-field imaging quality improvement method.

[0039] Beneficial effects:

[0040] The present application discloses a kind of thyroid cancer near-field imaging quality improvement methods, this kind of improvement method is simple to operate, beneficial to beginner, while imaging quality effect is remarkable, to effectively solve the imaging defect and predicament of thyroid cancer in terahertz near-field imaging at present. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 It is the imaging diagram without any adjustment;

[0042] Figure 2 It is the imaging diagram after needle operation;

[0043] Figure 3 It is the imaging diagram after adjusting gain parameter;

[0044] Figure 4 It is the imaging diagram after adjusting integral time. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0046] Embodiment:

[0047] According to the embodiment of the present application, a method for improving near-field imaging quality of thyroid cancer is provided, which comprises the following steps:

[0048] S110, scanning the sample without adjustment to observe the near-field imaging effect;

[0049] S120, performing a needle operation and then performing a second scanning;

[0050] S130, adjusting the integral ratio and differential gain parameters to perform a third scanning;

[0051] S140, changing the integral time of the phase-locked amplifier to perform a fourth near-field imaging scanning test on the thyroid cancer sample.

[0052] In the above step S120, the needle operation refers to moving the probe up and down and left and right to enhance the signal size, and generally needs to ensure that the SUM voltage is between-50V-50V, otherwise the probe may be damaged; in the above step S130, the integral ratio and differential gain parameters specifically include: the proportional gain parameter, the integral gain parameter, and the differential gain parameter, wherein the proportional gain parameter and the integral gain parameter represent the feedback sensitivity, and the differential gain parameter represents the oscillation sensitivity. The proportional gain parameter, the integral gain parameter, and the differential gain parameter can be adjusted in real time during the test process, thereby ensuring the improvement of the imaging quality; in the above step S140, the integral time of the phase-locked amplifier is changed, and different integral times will have different test effects for different test samples. For the near-field imaging test of the thyroid cancer sample, the integral time is generally changed from 9m to 5m, and the test imaging effect is best under this integral time.

[0053] The following describes an example process of the above method:

[0054] According to the technical scheme of the present application, for the thyroid cancer sample, the first imaging is not adjusted, and the terahertz near-field imaging system is used to perform the initial imaging on the thyroid cancer sample, which mainly serves as a reference for the subsequent imaging improvement operation and verifies the effectiveness of the method. As shown in Figure 1 It can be seen that the initial image has poor imaging quality without any adjustment, and there are many defects in the imaging image, and effective information cannot be obtained from the imaging image.

[0055] After the initial imaging, the needle operation is performed to ensure that the SUM voltage is between-50V-50V, and then the second imaging is performed, as shown in Figure 2As shown in FIG. 9, it can be seen that after the sample adhered to the probe is scraped off by the scraping needle, the near-field imaging quality is slightly improved, and some sample information can be observed from the picture. This is because after the scraping, the sample of thyroid cancer adhered to the probe is scraped off, so that the probe and the sample can directly act on each other, the signal strength of the terahertz near-field imaging is improved, and the overall imaging quality is improved to a certain extent. However, the imaging quality still has a lot of room for improvement.

[0056] After the second imaging, the adjustment work is performed again, the proportional gain, integral gain and differential gain are dynamically adjusted, and the third imaging is performed. Figure 3 As shown in FIG. 10, it can be seen that after the dynamic adjustment of the three parameters, the imaging quality is greatly improved. In the near-field system, the three parameters are comprehensively adjusted to form a synergistic effect of "signal amplification-noise suppression-detail enhancement": the proportional gain ensures that the signal basis amplitude is sufficient, the integral gain reduces the noise interference, and the differential gain highlights the key details. The three cooperate to comprehensively improve the clarity, contrast and detail resolution of the near-field imaging, especially suitable for the accurate identification of small and weak signal lesions in the early diagnosis of thyroid cancer, and provide higher quality image support for subsequent pathological analysis and treatment decision. Although the imaging quality is improved to a certain extent, there is still room for improvement.

[0057] After the third imaging, the integral time in the lock-in amplifier control software is changed from 9m to 5m, and the fourth imaging is performed, as shown in FIG. 11. Figure 4 As shown in FIG. 11, it can be seen that the internal condition of the sample can be simply observed, and the clarity and signal are greatly improved, and the blur of the sample imaging picture is solved. This is because the integral time is changed, the shorter the integral time, the faster the response speed of the lock-in amplifier, and the faster the lock-in amplifier can follow the change of the input signal. The response speed of 5m integral time is relatively faster than that of 9m integral time, and is more suitable for detecting fast-changing signals. The 9m integral time is relatively slow in response speed due to the long integral time, and is more suitable for detecting signals with high signal stability and slow changes. In the case of fixed sampling rate, the integral time is related to the cutoff frequency of the filter, and the longer the integral time, the lower the cutoff frequency of the filter. Therefore, the cutoff frequency of the filter corresponding to the 9m integral time is lower than that of the 5m integral time, and the attenuation of the high-frequency signal is greater. Therefore, the imaging clarity is greatly improved. If the clarity of the fourth imaging picture is not greatly improved, the parameters can be modified for subsequent scanning if necessary.

[0058] In summary, the method for improving the quality of near-field imaging of thyroid cancer mainly solves the problem of poor imaging quality of the thyroid cancer sample in the terahertz near-field system due to the height difference of the sample itself. The method is divided into four steps: firstly, initial scanning without any operation, as a test control map; secondly, second scanning by performing the needle operation to ensure that the SUM voltage is within-50V-50V, which slightly improves the test signal and the imaging quality; thirdly, third scanning by adjusting the proportional gain parameter, integral gain parameter and differential gain parameter, which further improves the imaging clarity; finally, fourth scanning by adjusting the integral time of the phase-locked amplifier from 9m to 5m, at this time the signal is maximum and the image clarity is optimal. The method has the characteristics of simple operation and high image clarity.

[0059] The above description is merely that of a specific implementation of the application and persons skilled in the art can understand or implement the application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the application. Therefore, the application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for improving the quality of near-field imaging of thyroid cancer, characterized by, The method comprises the following steps: S110: performing a first near-field imaging scan on the thyroid cancer sample without adjusting any parameters; S120: performing a second near-field imaging scan on the same thyroid cancer sample after a needle scratching operation; S130: performing a third near-field imaging scan after dynamically adjusting proportional gain parameters, integral gain parameters and differential gain parameters; S140: adjusting the integral time of the lock-in amplifier to 5 ms and performing a fourth near-field imaging scan on the thyroid cancer sample.

2. The method of claim 1, wherein, The needle scratching operation in step S120 comprises: controlling the probe to move along the X, Y and Z axis directions to remove attachments on the surface of the probe, and maintaining the Z axis voltage in the range of -50 V to 50 V.

3. The method according to claim 1 or 2, characterized in that, In step S130: The proportional gain parameters are used to improve the system response speed; The integral gain parameters are used to suppress low-frequency noise; The differential gain parameters are used to enhance high-frequency details; and The parameters are dynamically adjusted in real time to optimize the imaging clarity.

4. The method of claim 3, wherein, The adjustment range of the proportional gain parameters, integral gain parameters and differential gain parameters is 50%-200% of the system default value.

5. The method of claim 1, wherein, The adjustment of the integral time in step S140 comprises: shortening the integral time of the lock-in amplifier from 9 ms to 5 ms.

6. A thyroid cancer near-field imaging system, comprising: The method comprises: a terahertz near-field imaging module; a probe control unit for performing a needle scratching operation and maintaining the Z axis voltage in the range of -50 V to 50 V; a signal processing unit for dynamically adjusting proportional gain parameters, integral gain parameters and differential gain parameters; a lock-in amplifier supporting integral time switching from 9 ms to 5 ms.

7. The system of claim 6, wherein, The probe control unit adopts piezoelectric ceramic driving, and the displacement accuracy is ±0.1 μm.

8. A method for diagnosing thyroid cancer, characterized by, The method comprises: obtaining a high-resolution image of a thyroid cancer sample by using the method of any one of claims 1-5; determining a cancerous region based on the abnormal microstructure of the tissue in the image.

9. The diagnostic method according to claim 8, characterized in that, The spatial resolution of the high-resolution image is ≤5 μm.

10. A computer-readable storage medium, characterized in that, A computer program is stored, and when the program is executed, the method for improving the quality of near-field imaging of thyroid cancer is realized. The method comprises: a terahertz near-field imaging module; a probe control unit for performing a needle scratching operation and maintaining the Z axis voltage in the range of -50 V to 50 V; a signal processing unit for dynamically adjusting proportional gain parameters, integral gain parameters and differential gain parameters; a lock-in amplifier supporting integral time switching from 9 ms to 5 ms. The probe control unit adopts piezoelectric ceramic driving, and the displacement accuracy is ±0.1 μm. The method comprises: obtaining a high-resolution image of a thyroid cancer sample by using the method of any one of claims 1-5; determining a cancerous region based on the abnormal microstructure of the tissue in the image. The spatial resolution of the high-resolution image is ≤5 μm. A computer program is stored, and when the program is executed, the method for improving the quality of near-field imaging of thyroid cancer is realized.

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