阅读说明：本技术 一种应用于ct设备的ma值调节方法、系统及计算机可读存储介质 (MA value adjusting method and system applied to CT equipment and computer readable storage medium ) 是由 朱炯 蒋唯 方泽莉 徐亦飞 于 2020-12-24 设计创作，主要内容包括：本发明提供了一种应用于CT设备的MA值调节方法、系统及计算机可读存储介质。所述MA值调节方法包括如下步骤：设定CT设备的初始MA值；获取当前时刻的所述CT设备的探测器的输出值,通过所述探测器的输出值获取当前时刻的所述探测器的合理数据值K；当合理数据值K在预设范围内时,将当前时刻的MA值作为下一时刻的MA值,进行下一时刻的高压曝光过程；当合理数据值K不在预设范围内时,根据合理数据值K获取下一时刻的MA值,进行下一时刻的高压曝光过程,该方法使得在图像质量不变或者更好的基础上,可以降低辐射剂量。(The invention provides an MA value adjusting method, a system and a computer readable storage medium applied to CT equipment. The MA value adjusting method comprises the following steps: setting an initial MA value of the CT equipment; acquiring an output value of a detector of the CT equipment at the current moment, and acquiring a reasonable data value K of the detector at the current moment through the output value of the detector; when the reasonable data value K is within the preset range, taking the MA value at the current moment as the MA value at the next moment, and performing the high-pressure exposure process at the next moment; and when the reasonable data value K is not in the preset range, acquiring the MA value at the next moment according to the reasonable data value K, and performing the high-pressure exposure process at the next moment.)

1. An MA value adjusting method applied to a CT device is characterized by comprising the following steps:

setting an initial MA value of the CT equipment;

acquiring an output value of a detector of the CT equipment at the current moment, and acquiring a reasonable data value K of the detector at the current moment through the output value of the detector;

when the reasonable data value K is within the preset range, taking the MA value at the current moment as the MA value at the next moment, and performing the high-pressure exposure process at the next moment;

and when the reasonable data value K is not in the preset range, acquiring the MA value at the next moment according to the reasonable data value K, and carrying out the high-pressure exposure process at the next moment.

2. The MA value adjustment method according to claim 1, whichCharacterized in that the output value of the detector of the CT device at the current moment comprises an average valueMaximum value K_maxMinimum value K_minStandard deviation K_std；

Reasonable data value of the detectorWherein, ω is₁、ω₂、ω₃、ω₄Are constant coefficients.

3. The MA value adjustment method according to claim 1, wherein the preset range is 8 x 10⁶-10*10⁶。

4. The MA value adjustment method according to claim 1, wherein the MA value MA at the next time is obtained from the rational data value K when the rational data value K is not within the preset range_jThe performing of the high-pressure exposure process at the next time further includes:

obtaining the MA value MA of the next moment through the reasonable data value K_jMA value MA from the current time_iIntermediate value between delta ma_ij；

Acquiring the time t between the current time i and the next time j_ij；

By the formulaObtaining a change rate eta;

when eta is less than or equal to eta_maxWhen, will ma_jAs the MA value at the next time, when eta>η_maxWhen, will ma_iAs the MA value at the next time.

5. A MA value adjustment method according to claim 4, characterized in that the MA value MA at the next moment is obtained by the rational data value K_jAnd the currentMA value MA of time_iIntermediate value between delta ma_ijThe method comprises the following steps:

the reasonable data value K of the current moment_iK is obtained through PID algorithm calculation₀；

By the formulaObtaining the intermediate value delta ma_ijWherein, θ, ma_c、K_cIs a preset constant.

6. The MA value adjusting system is applied to a CT device, the CT device comprises an X-ray tube and a detector, and is characterized by further comprising a control module, wherein the control module is connected with the X-ray tube and the detector; the control module comprises a processing unit and an FPGA unit which are connected;

setting an initial MA value of the CT equipment through the processing module;

acquiring the output value of the detector at the current moment through the processing module, and acquiring a reasonable data value K of the detector at the current moment through the output value of the detector;

the processing unit judges that when the reasonable data value K is in a preset range, the MA value at the current moment is used as the MA value at the next moment, and the high-pressure exposure process at the next moment is carried out;

and the processing unit judges that when the reasonable data value K is not in the preset range, the FPGA unit is controlled to acquire the MA value at the next moment according to the reasonable data value K, and the high-pressure exposure process at the next moment is carried out.

7. The MA value adjustment system of claim 6, wherein the detector comprises a detector middle module for obtaining the detector output values, including an average valueMaximum value K_maxMinimum value K_minStandard deviation K_std；

The processing unit is based on a formulaObtaining a reasonable data value K of the detector at the current moment, wherein omega₁、ω₂、ω₃、ω₄Are constant coefficients.

8. The MA value adjustment system of claim 6, wherein the control module further comprises a timing unit, the timing unit being connected to the processing unit and the FPGA unit;

the FPGA unit acquires a reasonable data value K through the processing unit;

the FPGA unit obtains the MA value MA at the next moment through calculation of the reasonable data value K_jMA value MA from the current time_iIntermediate value between delta ma_ij；

The processing unit acquires the time t between the current time i and the next time j through the timing unit_ij；

The processing unit passes through the formulaObtaining a change rate eta; and judging when eta is less than or equal to eta_maxWhen, will ma_jAs the MA value at the next time, when eta>η_maxWhen, will ma_iAs the MA value at the next time.

9. The MA value adjustment system of claim 6, wherein the control module further comprises a memory unit having the preset range and preset constants θ, MA stored therein_c、K_c(ii) a The preset range is 8 x 10⁶-10*10⁶；

The storage unit is connected with the processing unit and the FPGA unit, and the processing unit and the FPGA unit acquire the preset range and the preset constants theta and ma through the storage unit_c、K_c；

The FPGA unit comprises a PID calculation circuit; the FPGA unit controls the PID calculation circuit to calculate a reasonable data value K according to the current moment_iCalculating to obtain K₀；

The FPGA unit obtains preset constants theta and ma through the storage unit_c、K_cAnd by the formulaCalculating to obtain an intermediate value delta ma_ij。

10. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of any of claims 1-5.

Technical Field

The invention relates to the technical field of electronic computed tomography equipment, in particular to an MA value adjusting method and system applied to CT equipment and a computer readable storage medium.

Background

In the CT scanning process, the radiation will affect the patient, so the radiation dose needs to be reduced as much as possible, and a common method adopted to reduce the radiation dose at present is a VMA method, that is, the MA value of each position and angle of the whole spiral scanning is predicted according to the result obtained by the flat scanning, so as to realize intelligent milliamp control. However, the method only predicts the MA required for scanning the three-dimensional object from the two-dimensional image, so that the image quality is not enough to meet the requirement, or extra ineffective dose is used for meeting the image requirement.

Disclosure of Invention

In order to overcome the technical defects, the invention aims to provide an MA value adjusting method, a system and a computer readable storage medium applied to a CT device, wherein the MA value adjusting method, the system and the computer readable storage medium can reduce the radiation dose on the basis of unchanged or better image quality.

The invention discloses an MA value adjusting method applied to CT equipment, which comprises the following steps: setting an initial MA value of the CT equipment; acquiring an output value of a detector of the CT equipment at the current moment, and acquiring a reasonable data value K of the detector at the current moment through the output value of the detector; when the reasonable data value K is within the preset range, taking the MA value at the current moment as the MA value at the next moment, and performing the high-pressure exposure process at the next moment; and when the reasonable data value K is not in the preset range, acquiring the MA value at the next moment according to the reasonable data value K, and carrying out the high-pressure exposure process at the next moment.

Preferably, the output value of the detector of the CT device at the current time includes an average value K and a maximum value K_maxMinimum value K_minStandard deviation K_std(ii) a Reasonable data value of the detectorWherein, ω is₁、ω₂、ω₃、ω₄Are constant coefficients.

Preferably, the preset range is 8 x 10⁶-10*10⁶。

Preferably, when the reasonable data value K is not within the preset range, the MA value MA at the next moment is obtained according to the reasonable data value K_jPerforming the next high-pressure exposure process further comprises: obtaining the MA value MA of the next moment through the reasonable data value K_jMA value MA from the current time_iIntermediate value between delta ma_ij(ii) a Acquiring the time t between the current time i and the next time j_ij(ii) a By the formulaObtaining a change rate eta; when eta is less than or equal to eta_maxWhen, will ma_jAs the MA value at the next time, when eta>η_maxWhen, will ma_iAs the MA value at the next time.

Preferably, the MA value MA at the next time is obtained by the reasonable data value K_jMA value MA from the current time_iIntermediate value between delta ma_ijThe method comprises the following steps: the reasonable data value K of the current moment_iK is obtained through PID algorithm calculation₀(ii) a By the formulaObtaining the intermediate value delta ma_ijWherein, θ, ma_c、K_cIs a preset constant.

The invention also discloses an MA value adjusting system applied to the CT equipment, wherein the CT equipment comprises an X-ray tube, a detector and a control module, and the control module is connected with the X-ray tube and the detector; the control module comprises a processing unit and an FPGA unit which are connected; setting an initial MA value of the CT equipment through the processing module; acquiring the output value of the detector at the current moment through the processing module, and acquiring a reasonable data value K of the detector at the current moment through the output value of the detector; the processing unit judges that when the reasonable data value K is in a preset range, the MA value at the current moment is used as the MA value at the next moment, and the high-pressure exposure process at the next moment is carried out; and the processing unit judges that when the reasonable data value K is not in the preset range, the FPGA unit is controlled to acquire the MA value at the next moment according to the reasonable data value K, and the high-pressure exposure process at the next moment is carried out.

Preferably, the probe comprises a probe intermediate module for acquiring the probeOutput values of the measuring device, including the mean valueMaximum value K_maxMinimum value K_minStandard deviation K_std(ii) a The processing unit is based on a formulaObtaining a reasonable data value K of the detector at the current moment, wherein omega₁、ω₂、ω₃、ω₄Are constant coefficients.

Preferably, the control module further comprises a timing unit, and the timing unit is connected with the processing unit and the FPGA unit; the FPGA unit acquires a reasonable data value K through the processing unit; the FPGA unit obtains the MA value MA at the next moment through calculation of the reasonable data value K_jMA value MA from the current time_iIntermediate value between delta ma_ij(ii) a The processing unit acquires the time t between the current time i and the next time j through the timing unit_ij(ii) a The processing unit passes through the formulaObtaining a change rate eta; and judging when eta is less than or equal to eta_maxWhen, will ma_jAs the MA value at the next time, when eta>η_maxWhen, will ma_iAs the MA value at the next time.

Preferably, the control module further includes a storage unit, and the storage unit stores the preset range and preset constants θ and ma_c、K_c(ii) a The preset range is 8 x 10⁶-10*10⁶(ii) a The storage unit is connected with the processing unit and the FPGA unit, and the processing unit and the FPGA unit acquire the preset range and the preset constants theta and ma through the storage unit_c、K_c(ii) a The FPGA unit comprises a PID calculation circuit; the FPGA unit controls the PID calculation circuit to calculate a reasonable data value K according to the current moment_iCalculating to obtain K₀(ii) a The FPGA unit acquires preset data through the storage unitConstants theta and ma_c、K_cAnd by the formulaCalculating to obtain an intermediate value delta ma_ij。

The invention also discloses a computer readable storage medium having a computer program stored thereon, which when executed by a processor implements any of the above steps.

The invention adopts a discrete PID algorithm, tracks the data feedback of the detector in real time, calculates and obtains an output reasonable MA value through the data change of the detector, selects or abandons the calculated and obtained MA value by combining the MA value change rate of the high-voltage generator, and continues to use the MA value at the last moment if abandoning. The whole spiral scanning stage can smoothly and efficiently carry out MA value conversion, and the radiation dose can be reduced on the basis of unchanged or better image quality through calculating and selecting the obtained MA value.

Drawings

FIG. 1 is a flowchart of an MA value adjustment method applied to a CT apparatus according to the present invention;

FIG. 2 is a schematic structural diagram of an MA value adjustment system applied to a CT apparatus according to the present invention;

FIG. 3 is a schematic diagram of a control structure of an FPGA unit of an MA value adjustment system applied to a CT apparatus according to the present invention;

fig. 4 is a graph of the output result of the simulink algorithm applied to the MA value adjusting system of the CT apparatus.

Reference numerals: 1-detector, 2-rotor, 3-X-ray tube, 4-control module, 5-scanning object, 6-data terminal, 7-PID calculating circuit, 8-MA arithmetic unit and 9-scope unit.

Detailed Description

The advantages of the invention are further illustrated in the following description of specific embodiments in conjunction with the accompanying drawings.

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the exemplary embodiments below are not intended to represent all implementations consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.

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

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

In the description of the present invention, it is to be understood that the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience of description and for simplicity of description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present invention.

In the description of the present invention, unless otherwise specified and limited, it is to be noted that the terms "mounted," "connected," and "connected" are to be interpreted broadly, and may be, for example, a mechanical connection or an electrical connection, a communication between two elements, a direct connection, or an indirect connection via an intermediate medium, and specific meanings of the terms may be understood by those skilled in the art according to specific situations.

In the following description, suffixes such as "module", "component", or "unit" used to denote elements are used only for facilitating the explanation of the present invention, and have no specific meaning in themselves. Thus, "module" and "component" may be used in a mixture.

The CT apparatus performs cross-sectional scanning one by one around a certain part of a human body together with the detector 1 having extremely high sensitivity by using an X-ray beam, a gamma ray, an ultrasonic wave, etc. which are precisely collimated, has the characteristics of fast scanning time, clear images, etc., and can be used for the examination of various diseases. The X-ray tube scanning device comprises an X-ray tube 3, a detector 1 and a rotor 2, wherein a scanning object 5 is arranged in the middle of the rotor 2, detection data of the scanning object 5 are acquired through the detector 1, and an X-ray beam is emitted to the scanning object 5 through the X-ray tube 3.

Referring to fig. 1, the present invention discloses an MA value adjusting method applied to a CT apparatus, comprising the following steps:

s1, setting an initial MA value of the CT equipment;

s2, obtaining an output value of the detector 1 of the CT equipment at the current moment, and obtaining a reasonable data value K of the detector 1 at the current moment through the output value of the detector 1;

s3, judging the reasonable data value K by combining the preset range:

s301, when the reasonable data value K is within a preset range, taking the MA value at the current moment as the MA value at the next moment, and performing a high-pressure exposure process at the next moment;

and S302, when the reasonable data value K is not in the preset range, acquiring the MA value at the next moment according to the reasonable data value K, and performing the high-pressure exposure process at the next moment.

The invention obtains a reasonable MA value through the calculation of a discrete PID algorithm according to the data K of the pixel value detected and fed back by the detector 1, and selects or abandons the MA value obtained through calculation by combining the MA value change rate of the high-voltage generator, and continues to use the MA value at the last moment if the MA value is abandoned, and the aim of reducing the radiation dose can be realized by the finally selected MA value on the basis of unchanged or better image quality, thereby ensuring the safety of a patient.

In step S2, the output value of the detector 1 includes an average valueMaximum value K_maxMinimum value K_minStandard deviation K_std(ii) a The reasonable data value K of the detector 1 is obtained through formula calculation:wherein, ω is₁、ω₂、ω₃、ω₄Are constant coefficients.

In step S3, the preset range is preferably 8 × 10⁶-10*10⁶This range is the target range for K values where the quality of the image obtained during the CT scan does not degrade or is even better. In other embodiments, the range may also be adjusted according to actual requirements, and is not limited herein.

In step S302, when the reasonable data value K is not within the preset range, the MA value MA at the next moment is obtained according to the reasonable data value K_jThe method also needs to select or discard the MA value obtained by calculation by combining the MA value change rate of the high-voltage generator, and specifically includes:

s30201, obtaining the MA value MA at the next moment through the reasonable data value K_jMA value MA from the current time_iIntermediate value between delta ma_ij；

S30202, acquiring time t between the current time i and the next time j_ij；

S30203, by formulaObtaining a change rate eta;

s30204 and binding η_maxJudging eta:

s3020401, when eta is less than or equal to eta_maxWhen, will ma_jAs the MA value of the next time；

S3020402, when η>η_maxWhen, will ma_iAs the MA value at the next time.

Because the inside of the high-voltage generator has certain limit to the change rate, when the change rate exceeds the maximum change rate, the high-voltage generator can report errors, therefore, the MA switching can be carried out only when the change rate is less than the maximum value, otherwise, the exposure is carried out according to the last MA value.

In step S30201, the MA value MA at the next time is obtained from the rational data value K_jMA value MA from the current time_iIntermediate value between delta ma_ijThe method specifically comprises the following steps:

s3020101, calculating the reasonable data value K of the current moment_iK is obtained through PID algorithm calculation₀；

S3020102, by formulaObtaining the intermediate value delta ma_ijWherein, θ, ma_c、K_cA predetermined constant for this formula.

Because the data collected by the detector 1 to different scanning objects 5 through rotating the receiving end are different, through the steps, the required MA value can be accurately calculated according to the difference of each scanning object 5, compared with the VMA algorithm in the prior art, the MA value can be more accurately calculated, as shown in fig. 4, in the output result of the simulink simulation, the MA value can be correspondingly adjusted according to the change of the data of the detector 1, namely, the MA value fluctuates along with the K value in real time.

Referring to fig. 2, the invention discloses an MA value adjusting system applied to a CT apparatus, the CT apparatus includes an X-ray tube 3 and a detector 1, and further includes a control module 4, the control module 4 is connected with the X-ray tube 3 and the detector 1, and is used for controlling the X-ray tube 3 and the detector 1. The control module 4 comprises a processing unit and an FPGA unit connected to each other.

Setting an initial MA value of the CT equipment through a processing module; acquiring an output value of the detector 1 at the current moment through the processing module, and acquiring a reasonable data value K of the detector 1 at the current moment through the output value of the detector 1; when the reasonable data value K is within the preset range, the processing unit judges that the MA value at the current moment is taken as the MA value at the next moment, and the high-pressure exposure process at the next moment is carried out; and the processing unit judges that when the reasonable data value K is not in the preset range, the FPGA unit is controlled to acquire the MA value at the next moment according to the reasonable data value K, and the high-pressure exposure process at the next moment is carried out.

Preferably, the detector 1 comprises a detector 1 intermediate module, i.e. a rotating receiver for obtaining the output value of the detector 1, including the average valueMaximum value K_maxMinimum value K_minStandard deviation K_std。

Preferably, the control module 4 further includes a timing unit, the timing unit is connected to the processing unit and the FPGA unit, the FPGA unit obtains the reasonable data value K through the processing unit, and calculates and obtains the MA value MA at the next time through the reasonable data value K_jMA value MA from the current time_iIntermediate value between delta ma_ij(ii) a The processing unit acquires the time t between the current time i and the next time j through the timing unit_ijAnd by the formulaObtaining the change rate eta, comparing the change rate with the maximum change rate to decide whether to keep the MA value obtained by calculation or continue to use the MA value at the last moment, namely when eta is less than or equal to eta_maxWhen, will ma_jAs the MA value at the next time, when eta>η_maxWhen, will ma_iAs the MA value at the next time.

Preferably, referring to fig. 3, the control module 4 further includes a storage unit, in which the preset range and the preset constants θ and ma are stored_c、K_cAnd a predetermined range of 8 x 10⁶-10*10⁶. The storage unit is connected with the processing unit and the FPGA unit, and the processing unit and the FPGA unit acquire a preset range and preset constants theta and ma through the storage unit_c、K_c. The FPGA unit comprises a PID calculation circuit, is controlled to be simulated through simulink and is controlled through a data terminal6, acquiring real-time data of the K value; the PID calculating circuit 7 calculates the reasonable data value K according to the current moment_iCalculating to obtain K₀(ii) a And obtaining preset constants theta and ma through a storage unit_c、K_c(ii) a By means of the formula stored in the MA algorithm unit 8Calculating to obtain an intermediate value delta ma_ijAnd finally observing the result in the scope unit 9 environment.

The invention also discloses a computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the above-mentioned method.

It should be noted that the embodiments of the present invention have been described in terms of preferred embodiments, and not by way of limitation, and that those skilled in the art can make modifications and variations of the embodiments described above without departing from the spirit of the invention.