A method, system, device, and medium for low signal noise suppression of a CT scanning device

Abstract

This invention provides a method, system, device, and medium for suppressing low-signal noise in CT scanning equipment. The method includes: filtering low-signal channels from data acquired by the CT scanning equipment using a low-signal threshold; obtaining the neighborhood of the low-signal channels; calculating the mean and standard deviation of the neighborhood signal intensity; and calculating adaptive parameters based on these parameters. The method then uses the adaptive parameters and a fixed filter kernel to filter the low-signal channels to suppress noise, and calculates the updated signal intensity of the low-signal channels. The above steps are repeated until the calculated adaptive parameters indicate that filtering of the low-signal channels should cease, resulting in noise-suppressed low-signal data. This method can recover low-signal data that is too weak due to dark current noise and suppress noise signals before the signal intensity transitions to the line integral, thus improving the quality of the reconstructed image.

Description

Technical Field

[0001] This invention relates to the field of signal processing in CT scanning equipment, and more particularly to a method, system, device, and medium for suppressing low-signal noise in CT scanning equipment. Background Technology

[0002] Computed tomography (CT) is a device that uses rotating X-rays to irradiate an object and then processes the data to obtain a cross-sectional image. After X-ray photons pass through the irradiated object, they reach a detector and are collected. Following a series of conversions, the photon signal is transformed into an electronic signal, which is then received. The received electronic signal contains noise, primarily composed of electronic noise and photon noise (Poisson noise). As X-ray penetration attenuation increases, fewer X-ray photons reach the detector, resulting in a lower received electronic signal. Low-signal data is often primarily affected by dark current noise; therefore, directly using low-signal data for image reconstruction can easily lead to stripe artifacts. Furthermore, subtracting dark current noise from low-signal data can also affect the low-signal data itself, hindering successful image reconstruction. Summary of the Invention

[0003] In order to overcome the above-mentioned technical defects, the purpose of this invention is to provide a method, system, device and medium for low-signal noise suppression of CT scanning equipment.

[0004] This invention discloses a method for suppressing low-signal noise in a CT scanning device, comprising the following steps:

[0005] The data acquired by the CT scan equipment is processed through a low signal threshold. Filter out low signal channels The low signal channel Current signal strength Not greater than the low signal threshold ;

[0006] Acquire the low signal channel The neighborhood of the signal is calculated to obtain the mean signal strength of the neighborhood. Standard deviation of neighboring signal strength And based on the average signal strength of the neighborhood Compared with the standard deviation of the neighborhood signal strength Calculate and obtain adaptive parameters ;

[0007] Using the adaptive parameters With a fixed filter core, for the low signal channel Filtering is performed to suppress noise, and the low-signal channel is calculated and obtained. Updated signal strength ;

[0008] Repeat the above steps until the adaptive parameters are calculated. Indicates stopping the low signal channel Filtering is performed to obtain low-signal data after noise suppression.

[0009] Preferably, the calculation obtains the low signal channel. Updated signal strength ,include:

[0010] Obtain the spatial convolution filter value of the fixed filter kernel in the neighborhood. And obtain the filtering degree parameter. ;

[0011] pass Calculate and obtain the updated signal strength .

[0012] Preferably, the calculation obtains the adaptive parameters. ,include:

[0013] Get the filter threshold The signal strength dispersion coefficient of the neighborhood and compare the filter thresholds With the signal strength dispersion coefficient ;

[0014] when When, obtain the adaptive parameters If the value is 0, stop the operation on the low signal channel. Perform filtering;

[0015] when When, obtain the adaptive parameters ,in, This is the adaptive parameter adjustment coefficient.

[0016] Preferably, the calculation obtains the adaptive parameters. It also includes:

[0017] Get the mean threshold Compare the mean signal strength of the neighborhood With the mean threshold ;

[0018] when The adaptive parameters are obtained in time. When it is 1, Then, further compare the filter thresholds. With the signal strength dispersion coefficient ;

[0019] when When, obtain the adaptive parameters A value of 0 indicates that the low signal channel is stopped. Perform filtering;

[0020] when When, obtain the adaptive parameters ,in, This is the adaptive parameter adjustment coefficient.

[0021] Preferably, the calculation obtains the adaptive parameters. It also includes:

[0022] when and When, obtain the adaptive parameters The value is 1.

[0023] Preferably, the fixed filter core is The low-pass filter kernel, wherein, The pixel length dimension of the fixed filter kernel.

[0024] The present invention also discloses a low-signal noise suppression system for a CT scanning device, comprising a signal processing module and a filtering module;

[0025] The signal processing module processes the data acquired by the CT scanning equipment through a low signal threshold. Filter out low signal channels The low signal channel Current signal strength Not greater than the low signal threshold ;

[0026] The signal processing module acquires the low signal channel. The neighborhood of the signal is calculated to obtain the mean signal strength of the neighborhood. Standard deviation of neighboring signal strength And based on the average signal strength of the neighborhood Compared with the standard deviation of the neighborhood signal strength Calculate and obtain adaptive parameters ;

[0027] The filtering module uses the adaptive parameters. The low signal channel is compared with the fixed filter. Filtering is performed, and the low signal channel is calculated and obtained. Updated signal strength ;

[0028] Repeat the above steps until the adaptive parameters calculated and obtained by the signal processing module are obtained. Indicates stopping the low signal channel Filtering is performed to obtain low-signal data after noise suppression.

[0029] The present invention also discloses an electronic device including a memory storing computer-executable instructions and a processor, wherein when the instructions are executed by the processor, the electronic device performs the aforementioned low-signal noise suppression method of the CT scanning device.

[0030] The present invention also discloses a computer-readable storage medium having a computer program stored thereon, characterized in that, when the computer program is run on a computer, the computer causes the computer to perform the aforementioned method for suppressing low-signal noise in a CT scanning device.

[0031] Compared with existing technologies, the above technical solution has the following advantages:

[0032] 1. Perform iterative adaptive filtering in the signal strength domain to restore the reliability of low signal data that is too small due to dark current noise, so that the noise signal is suppressed before the signal strength is transformed to the line integral;

[0033] 2. Determine the adaptive parameters of the filter by using the statistical characteristics of the signal strength in the neighborhood of the low-signal channel, and avoid over-filtering. Attached Figure Description

[0034] Figure 1 A schematic flowchart illustrating the low-signal noise suppression method for a CT scanning device provided by the present invention;

[0035] Figure 2 The reconstructed image provided by the present invention is neither processed by the low-signal noise suppression method nor by the low-signal noise suppression method. Detailed Implementation

[0036] The advantages of the present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments.

[0037] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0038] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0039] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various information, such information should not be limited to these terms. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0040] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0041] In the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0042] In the following description, suffixes such as "module," "part," or "unit" used to denote elements are used only for the convenience of the description of the invention and have no specific meaning in themselves. Therefore, "module" and "part" can be used interchangeably.

[0043] like Figure 1 As shown, this invention discloses a method for suppressing low-signal noise in a CT scanning device, comprising the following steps:

[0044] S100, The data acquired by the CT scanning equipment is processed through a low signal threshold. Filter out low signal channels Low signal channel Current signal strength Not greater than the low signal threshold .

[0045] S200, Acquire Low Signal Channel The neighborhood of the signal is calculated to obtain the mean signal strength of the neighborhood. Standard deviation of neighboring signal strength And based on the average signal strength of the neighborhood Standard deviation of neighboring signal strength Calculate and obtain adaptive parameters .

[0046] S300, using adaptive parameters Compared with a fixed filter core, for low signal channels Filtering is performed to suppress noise, and the low-signal channel is calculated and obtained. Updated signal strength .

[0047] Repeat the above steps until the adaptive parameters are calculated. Indicates stopping the low signal channel Filtering is performed to obtain low-signal data after noise suppression.

[0048] Specifically, low-signal data is typically affected primarily by dark current noise, making it prone to stripe artifacts when directly used for image reconstruction. Furthermore, subtracting dark current noise from low-signal data can also negatively impact the low-signal data itself, causing it to approach or even fall below zero, hindering successful image reconstruction. The noise suppression method proposed in this invention selects low-signal data within the projection domain of signal intensity for adaptive filtering to suppress noise, and further optimizes the low-signal channel... The signal strength is updated, which can recover low signal data that is close to or even less than zero due to the influence of suppressed dark current noise. It can filter out noise from low signal data in the projection domain image of the signal strength, avoid most of the singularity problem of the signal, and suppress artifact signals before the signal strength is transformed to the line integral. Moreover, it does not require data sorting or calculation of Gaussian filter kernel and its size.

[0049] Preferably, the low signal channel is calculated and obtained. Updated signal strength ,include:

[0050] Obtain the spatial convolution filter value of the fixed filter kernel within the neighborhood. And obtain the filtering degree parameter. Filtering degree parameter Used to control the upper limit of the adaptive filtering level;

[0051] pass Calculate and obtain the updated signal strength .

[0052] Preferably, adaptive parameters are calculated and obtained. ,include:

[0053] Get the filter threshold The coefficient of variation of the signal strength in the neighborhood And compare the filter thresholds With signal strength dispersion coefficient ;

[0054] when At that time, obtain adaptive parameters If the value is 0, stop the operation on the low signal channel. Perform filtering;

[0055] when At that time, obtain adaptive parameters ,in, This is the adaptive parameter adjustment coefficient.

[0056] Specifically, the signal strength dispersion coefficient The signal strength dispersion coefficient is used to represent the distribution of signal strength across all channels in a neighborhood. The smaller the value, the more concentrated the signal strength distribution; the signal strength dispersion coefficient. The larger the value, the more dispersed the signal strength distribution. Therefore, when noise is present in the data collected from a certain channel, the signal strength of that channel will change abruptly compared to other channels in the neighborhood, resulting in a greater dispersion coefficient of the signal strength in the neighborhood. Increase.

[0057] Set a filter threshold Filter threshold Used to prevent over-filtering. Compare filter thresholds. With signal strength dispersion coefficient ,when At that time, the signal strength dispersion coefficients can be considered as... Small enough, low signal channel Isolated noise signals have been suppressed to an ideal level, eliminating the need for further suppression of the low-signal channel. Filtering is performed, and then adaptive parameters are obtained. If the value is 0, stop the operation on the low signal channel. Perform filtering.

[0058] Preferably, adaptive parameters are calculated and obtained. It also includes:

[0059] Get the mean threshold Compare the mean signal strength of the neighborhood With mean threshold ;

[0060] when At that time, obtain adaptive parameters The value is 1, meaning it represents a low-signal channel with a low mean signal strength in its neighborhood. The largest adaptive parameter can be used directly. Enhance its signal strength;

[0061] when At that time, further comparison of the filter thresholds With the coefficient of variation ;

[0062] when At that time, obtain adaptive parameters A value of 0 indicates that the low signal channel is stopped. Perform filtering;

[0063] when At that time, obtain adaptive parameters ,in, This is the adaptive parameter adjustment coefficient.

[0064] Preferably, adaptive parameters are calculated and obtained. It also includes:

[0065] when and At that time, obtain adaptive parameters The value is 1, that is, the adaptive parameter is set to 1. The maximum value is limited to 1.

[0066] Preferably, the fixed filter core is Low-pass filter kernels, such as Gaussian kernels, mean kernels, or self-designed hollow kernels, etc. The pixel length size of the fixed filter kernel.

[0067] See Figure 2 , Figure 2 (a) is a reconstructed image that has not been processed by the noise suppression method of the present invention. This image is significantly contaminated by low-signal noise, exhibiting numerous horizontal stripes; while Figure 2 (b) A reconstructed image after using the low-signal noise suppression method of the present invention, the image being compared with... Figure 2 (a) Compared to the previous version, the number and intensity of horizontal stripes were significantly reduced, resulting in a significant improvement in image quality.

[0068] The present invention also discloses a low-signal noise suppression system for a CT scanning device, comprising a signal processing module and a filtering module;

[0069] The signal processing module processes the data acquired by the CT scanning equipment through a low signal threshold. Filter out low signal channels Low signal channel Current signal strength Not greater than the low signal threshold ;

[0070] Signal processing module acquires low signal channel The neighborhood of the signal is calculated to obtain the mean signal strength of the neighborhood. Standard deviation of neighboring signal strength And based on the average signal strength of the neighborhood Standard deviation of neighboring signal strength Calculate and obtain adaptive parameters ;

[0071] The filtering module uses adaptive parameters Low signal channel compared with fixed filter Filtering is performed, and the low-signal channel is calculated and obtained. Updated signal strength ;

[0072] Repeat the above steps until the adaptive parameters calculated and obtained by the signal processing module are obtained. Indicates stopping the low signal channel Filtering is performed to obtain low-signal data after noise suppression.

[0073] The present invention also discloses an electronic device, which includes a memory storing computer-executable instructions and a processor, wherein when the instructions are executed by the processor, the electronic device performs the aforementioned low-signal noise suppression method of the CT scanning device.

[0074] The present invention also discloses a computer-readable storage medium having a computer program stored thereon, characterized in that, when the computer program is run on a computer, it causes the computer to perform the aforementioned method for suppressing low-signal noise in a CT scanning device.

[0075] It should be noted that the embodiments of the present invention have better implementability and are not intended to limit the present invention in any way. Any person skilled in the art may use the above-disclosed technical content to change or modify it into equivalent effective embodiments. However, any modifications or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A method for suppressing low-signal noise in a CT scanning device, characterized in that, Includes the following steps: The data acquired by the CT scan equipment is processed through a low signal threshold. Filter out low signal channels The low signal channel Current signal strength Not greater than the low signal threshold ; Acquire the low signal channel The neighborhood of the signal is calculated to obtain the mean signal strength of the neighborhood. Standard deviation of neighboring signal strength And based on the average signal strength of the neighborhood Compared with the standard deviation of the neighborhood signal strength Calculate and obtain adaptive parameters ; Using the adaptive parameters With a fixed filter core, for the low signal channel Filtering is performed to suppress noise, and the low-signal channel is calculated and obtained. Updated signal strength ; Repeat the above steps until the adaptive parameters are calculated. Indicates stopping the low signal channel Filtering is performed to obtain low-signal data after noise suppression; The calculation obtains the low signal channel. Updated signal strength ,include: Obtain the spatial convolution filter value of the fixed filter kernel in the neighborhood. And obtain the filtering degree parameter. ; pass Calculate and obtain the updated signal strength ; The calculation obtains the adaptive parameters. ,include: Get the filter threshold The signal strength dispersion coefficient of the neighborhood and compare the filter thresholds With the signal strength dispersion coefficient ; when When, obtain the adaptive parameters If the value is 0, stop the operation on the low signal channel. Perform filtering; when When, obtain the adaptive parameters ,in, This is the adaptive parameter adjustment coefficient.

2. The noise suppression method according to claim 1, characterized in that, The calculation obtains the adaptive parameters. It also includes: Get the mean threshold Compare the mean signal strength of the neighborhood With the mean threshold ; when The adaptive parameters are obtained in time. When it is 1, Then, further compare the filter thresholds. With the signal strength dispersion coefficient ; when When, obtain the adaptive parameters A value of 0 indicates that the low signal channel is stopped. Perform filtering; when When, obtain the adaptive parameters ,in, This is the adaptive parameter adjustment coefficient.

3. The noise suppression method according to claim 1, characterized in that, The calculation obtains the adaptive parameters. It also includes: when and When, obtain the adaptive parameters The value is 1.

4. The noise suppression method according to claim 1, characterized in that, The fixed filter kernel is The low-pass filter kernel, wherein, The pixel length dimension of the fixed filter kernel.

5. A low-signal noise suppression system for a CT scanning device, characterized in that, Includes a signal processing module and a filtering module; The signal processing module processes the data acquired by the CT scanning equipment through a low signal threshold. Filter out low signal channels The low signal channel Current signal strength Not greater than the low signal threshold ; The signal processing module acquires the low signal channel. The neighborhood of the signal is calculated to obtain the mean signal strength of the neighborhood. Standard deviation of neighboring signal strength And based on the average signal strength of the neighborhood Compared with the standard deviation of the neighborhood signal strength Calculate and obtain adaptive parameters ; The filtering module uses the adaptive parameters. The low signal channel is compared with the fixed filter. Filtering is performed, and the low signal channel is calculated and obtained. Updated signal strength ; Repeat the above steps until the adaptive parameters calculated and obtained by the signal processing module are obtained. Indicates stopping the low signal channel Filtering is performed to obtain low-signal data after noise suppression; The calculation obtains the low signal channel. Updated signal strength ,include: Obtain the spatial convolution filter value of the fixed filter kernel in the neighborhood. And obtain the filtering degree parameter. ; pass Calculate and obtain the updated signal strength ; The calculation obtains the adaptive parameters. ,include: Get the filter threshold The signal strength dispersion coefficient of the neighborhood and compare the filter thresholds With the signal strength dispersion coefficient ; when When, obtain the adaptive parameters If the value is 0, stop the operation on the low signal channel. Perform filtering; when When, obtain the adaptive parameters ,in, This is the adaptive parameter adjustment coefficient.

6. An electronic device, characterized in that, The electronic device includes a memory storing computer-executable instructions and a processor, which, when executed by the processor, cause the electronic device to implement a low-signal noise suppression method for a CT scanning device according to any one of claims 1-4.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is run on a computer, it causes the computer to perform a low-signal noise suppression method for a CT scanning device according to any one of claims 1-4.

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