CN118130512A - Equivalent average photon energy measuring method and device, storage medium and electronic equipment - Google Patents

Abstract

The embodiment of the specification discloses an equivalent average photon energy measuring method, a device, a storage medium and electronic equipment, wherein the method comprises the following steps: and controlling a CT system to scan a target object by using a tube voltage to be detected to obtain a measured CT value of the target object, obtaining a theoretical CT value of the target object at least one photon energy level value, determining a target photon energy level value from the photon energy level values based on the theoretical CT value and the measured CT value at each photon energy level value, and taking the target photon energy level value as the equivalent average photon energy of the CT system under the tube voltage to be detected.

Description

Equivalent average photon energy measuring method and device, storage medium and electronic equipment

Technical Field

The present disclosure relates to the field of scanning imaging technologies, and in particular, to a method and apparatus for measuring equivalent average photon energy, a storage medium, and an electronic device.

Background

CT is a computerized tomography technique, which refers to that a certain part of an object is scanned by an X-ray beam according to a certain thickness layer, when the X-ray irradiates the object, part of the X-ray is absorbed by the object, and part of the X-ray passes through the object and is received by a detector, and different signals are generated due to different absorption coefficients of all parts of the object on the X-ray, so that equivalent average photon energy corresponding to an X-ray spectrum of a CT system is measured and determined in advance in various applications such as material attenuation estimation in the CT energy spectrum imaging process.

Disclosure of Invention

The embodiment of the specification provides an equivalent average photon energy measuring method, an equivalent average photon energy measuring device, a storage medium and electronic equipment, wherein the technical scheme is as follows:

in a first aspect, embodiments of the present specification provide an equivalent average photon energy measurement method, the method comprising:

The CT system is controlled to scan a target object by the voltage of the tube to be detected, and a measured CT value of the target object at least one photon energy level value is obtained;

acquiring a theoretical CT value of the target object at the photon energy level value;

And determining a target photon energy level value from the photon energy level values based on the theoretical CT value and the measured CT value at the photon energy level value, and taking the target photon energy level value as the equivalent average photon energy of the CT system under the voltage of the tube to be measured.

In a possible embodiment, said determining a target photon energy level value from said photon energy level values based on said theoretical CT value and said measured CT value at each of said photon energy level values comprises:

A CT value difference for each of the photon energy level values is calculated based on the theoretical CT value and the measured CT value at each of the photon energy level values, and a target photon energy level value is determined from the photon energy level values based on the CT value difference for each of the photon energy level values.

In a possible implementation, the determining the target photon energy level value from the photon energy level values based on the CT value difference value of each of the photon energy level values includes:

determining a minimum CT value difference from the CT value differences for each of the photon energy level values;

and determining a target photon energy level value corresponding to the minimum CT value difference value from the photon energy level values.

In a possible embodiment, the target object comprises a plurality of target individuals of different material composition, the determining a target photon energy level value from the photon energy level values based on the theoretical CT value and the measured CT value at each of the photon energy level values comprises:

calculating an absolute proportional error for each target individual at each of the photon energy level values based on the theoretical CT value and the measured CT value for each of the target individual at each of the photon energy level values;

calculating a sample standard deviation at each of the photon energy level values based on an absolute proportional error at the photon energy level value for each of the target individuals;

A target photon energy level value is determined from the photon energy level values based on a sample standard deviation at each of the photon energy level values.

In a possible embodiment, said determining a target photon energy level value from said photon energy level values based on a sample standard deviation at each of said photon energy level values comprises:

determining a minimum sample standard deviation from the sample standard deviation at each of said photon energy level values;

and determining a target photon energy level value corresponding to the minimum sample standard deviation from the photon energy level values.

In one possible implementation manner, before the control CT system scans the target object with the tube voltage to be measured to obtain the measured CT value of the target object, the control CT system further includes:

selecting at least one CT quality control detection die body as a target object, and obtaining the material composition of the CT quality control detection die body;

at least one photon energy level value for a target object is determined, and a theoretical CT value for the target object at the at least one photon energy level value is calculated based on the material composition.

In a possible embodiment, the determining at least one photon energy level value for the target object includes:

And determining a reference photon energy level value aiming at the target object based on the voltage of the tube to be detected, and selecting at least one photon energy level value by taking the reference photon energy level value as a reference.

In a second aspect, embodiments of the present disclosure provide an equivalent average photon energy measurement apparatus, the apparatus comprising:

The scanning module is used for controlling the CT system to scan the target object by the voltage of the tube to be detected to obtain a measured CT value of the target object;

The acquisition module is used for acquiring a theoretical CT value of the target object at least one photon energy level value;

And the determining module is used for determining a target photon energy level value from the photon energy level values based on the theoretical CT value and the measured CT value at each photon energy level value, and taking the target photon energy level value as the equivalent average photon energy of the CT system under the voltage of the tube to be detected.

In a third aspect, the present description provides a computer storage medium storing a plurality of instructions adapted to be loaded by a processor and to perform the above-described method steps.

In a fourth aspect, embodiments of the present disclosure provide an electronic device, which may include: a processor and a memory; wherein the memory stores a computer program adapted to be loaded by the processor and to perform the above-mentioned method steps.

The technical scheme provided by some embodiments of the present specification has the following beneficial effects:

In one or more embodiments of the present disclosure, an electronic device controls a CT system to scan a target object with a tube voltage to be measured, obtains a measured CT value of the target object, obtains a theoretical CT value of the target object at least one photon energy level value, and determines a target photon energy level value from the photon energy level values based on the theoretical CT value and the measured CT value at each photon energy level value, so that the target photon energy level value can be used as an equivalent average photon energy of the CT system at the tube voltage to be measured. The whole equivalent average photon energy determining process can avoid that spectrum calculation can be carried out to obtain equivalent average photon energy after the X-ray spectrum is acquired, thereby greatly simplifying the equivalent average photon energy determining process, avoiding the complicated X-ray spectrum acquisition process, improving the equivalent average photon energy determining efficiency and reducing the measuring cost.

Drawings

In order to more clearly illustrate the embodiments of the present description or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present description, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a flow chart of an equivalent average photon energy measurement method provided by embodiments of the present disclosure;

FIG. 2 is a flow chart of a target photon energy level value determination provided in an embodiment of the present disclosure;

FIG. 3 is a flow chart of an equivalent average photon energy measurement method provided by embodiments of the present disclosure;

FIG. 4 is a schematic diagram of another equivalent average photon energy measurement method provided by embodiments of the present disclosure;

FIG. 5 is a schematic diagram of an equivalent average photon energy measurement method provided by embodiments of the present disclosure;

FIG. 6 is a chart of experimental tabular data for an equivalent average photon energy measurement scenario provided by embodiments of the present disclosure;

FIGS. 7-10 are graphs of virtual monochromatic CT values generated after scanning each rod of material provided in embodiments of the present disclosure;

FIG. 11 is a schematic diagram of an equivalent average photon energy measurement device according to an embodiment of the present disclosure;

Fig. 12 is a schematic structural diagram of an electronic device according to an embodiment of the present disclosure.

Detailed Description

The technical solutions of the embodiments of the present specification will be clearly and completely described below with reference to the drawings in the embodiments of the present specification, and it is apparent that the described embodiments are only some embodiments of the present specification, not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are intended to be within the scope of the present disclosure.

In the description of the present specification, it should be understood that the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. In the description of the present specification, it should be noted that, unless expressly specified and limited otherwise, "comprise" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those listed steps or elements but may include other steps or elements not listed or inherent to such process, method, article, or apparatus. The specific meaning of the terms in this specification will be understood by those of ordinary skill in the art in the light of the specific circumstances. In addition, in the description of the present specification, unless otherwise indicated, "a plurality" means two or more. "and/or", describes an association relationship of an association object, and indicates that there may be three relationships, for example, a and/or B, and may indicate: a exists alone, A and B exist together, and B exists alone. The character "/" generally indicates that the context-dependent object is an "or" relationship.

In the related art, the X-rays output by a CT bulb of a CT system are mixed spectra, i.e., the energy of each X-ray photon is distributed at different operating energy levels keV. In the bulb aspect, different tube voltage settings, different anode target materials, different anode target angles and different window filtering can all influence the distribution of the X-ray spectrum. In addition, the radiation filtering device of the CT machine can further change the spectrum distribution of the X-ray. In this way, the CT systems formed by different bulb tubes and filtering devices and different tube voltage scanning conditions generate different X-ray spectra, and usually, the equivalent average photon energy corresponding to the X-ray spectrum of the CT system needs to be measured in the actual CT energy spectrum imaging process.

In the prior art, the method for acquiring the equivalent average photon energy corresponding to the X-ray spectrum is to acquire the X-ray spectrum first and then calculate the equivalent average photon energy through the spectrum. The method for obtaining the X-ray spectrum is divided into two kinds, one is obtained through simulation by using some empirical or semi-empirical physical model, and the other is obtained indirectly by partially measuring the spectrum and then carrying out numerical approximation. In the first type of method, a great deal of priori knowledge and experiments are needed for building a physical model and taking the value of a correlation coefficient, and the equivalent average photon energy is complex and inconvenient to measure. In the second category of methods, it is often necessary to make specific motifs or materials for the acquisition of measurement data, and equivalent average photon energy measurements are cumbersome and inconvenient.

It can be seen that there are certain limitations to equivalent average photon energy measurements in the related art.

The present specification is described in detail below with reference to specific examples.

In one embodiment, as shown in fig. 1, an equivalent average photon energy measurement method is specifically proposed, which can be implemented in dependence on a computer program, and can be run on an equivalent average photon energy measurement device based on von neumann system. The computer program may be integrated in the application or may run as a stand-alone tool class application. The equivalent average photon energy measuring device may be an electronic device with a CT system, including but not limited to: CT machines, personal computers, tablet computers, handheld CT devices, vehicle-mounted CT devices, wearable CT devices, computing devices, or other electronic devices connected to a wireless modem, and the like.

Specifically, the equivalent average photon energy measurement method includes:

s102: the CT system is controlled to scan a target object by the voltage of the tube to be detected, and a measured CT value of the target object is obtained;

the equivalent average photon energy measurement is to measure the equivalent average photon energy of the CT system under a certain tube voltage to be measured (such as 80kV, 140kV and the like of the tube voltage to be measured);

further, the CT system is controlled to work at the position of the voltage of the tube to be detected (such as 80kV, 140kV and the like), the target object is scanned, the measured CT value of the target object after the CT system is used can be obtained by scanning the target object, and the measured CT value of the target object is recorded;

Further, the number of the target objects may be plural, the material composition of the target objects is known, the CT quality control detection module including plural different target objects is scanned under a certain set tube voltage to be measured (for example, 140kV and 80 kV), and the measured CT value of each target object is obtained.

S104: acquiring a theoretical CT value of the target object at least one photon energy level value;

Optionally, a CT quality control detection module of a known material composition is selected in advance as a target object, where the target object is generally made of a specific material, such as water, calcium, iodine, and the like, and the target object corresponds to a theoretical CT value at a corresponding photon energy level value, where the theoretical CT value may be a theoretical CT value calculated at one or more photon energy level values based on the known material composition. Photon energy level values may be characterized using keV;

calculating theoretical CT values of the target object under each X-ray photon energy level value (such as 50-90 keV) according to known substance composition components of the target object;

alternatively, the photon energy level value may be set based on the actual situation, and for example, the photon energy level value may be set to 40keV, 50keV, 60keV, 70keV, 80keV, 90keV, 100keV, 110keV, 120keV, 130keV, 140keV, or the like.

For example, the CT system is controlled to work at the position of 80kV or 140kV of the tube voltage to be detected, the target object is scanned to obtain CT scanning data, and the CT scanning data is subjected to energy spectrum imaging to obtain a measured CT value of the target object; theoretical CT values at a plurality of photon energy level values (e.g., 40keV, 50keV, 60keV, 70keV, 80keV, 90keV, 100keV, 110keV, 120keV, 130keV, 140 keV) are calculated based on known material composition of the target object.

Optionally, before the control CT system scans the target object with the tube voltage to be measured to obtain the measured CT value of the target object, the following manner may be further executed:

a2: selecting at least one CT quality control detection die body as a target object, and obtaining the material composition of the CT quality control detection die body;

For example: the CT quality control detection die body can be a 15mg/L iodine material rod, a 10mg/L iodine material rod, a 5mg/L iodine material rod and a 2mg/L iodine material rod;

A4: at least one photon energy level value for a target object is determined, and a theoretical CT value for the target object at the at least one photon energy level value is calculated based on the material composition.

Determining at least one photon energy level value for the target object may be in the following manner:

Determining a reference photon energy level value aiming at a target object based on the voltage of the tube to be detected, and selecting at least one photon energy level value by taking the reference photon energy level value as a reference;

The reference photon energy level value may be an empirical value set for the tube voltage to be measured according to expert experience, for example, the tube voltage to be measured 140kV is empirically assumed to be 76keV, and at least one photon energy level value of 76keV, 76.1keV.

Optionally, one or more CT quality control detecting mold bodies are selected in advance as target objects, the CT quality control detecting mold bodies are made of specific materials, such as water, calcium, iodine and the like, and the CT quality control detecting mold bodies correspond to theoretical CT values at corresponding photon energy level values and can be obtained by calculating known substance components;

In one exemplary theoretical CT value calculation scenario, the following is:

First, the known substance composition of the target object is determined, including the elements of known substance composition and the relative proportions of the elements. For example, if the material rod is composed of elements such as hydrogen, oxygen, and carbon, the ratio of hydrogen is a%, the ratio of oxygen is B%, the ratio of carbon is C%, and the like.

Second, a table of linear attenuation coefficients (also referred to as linear absorption coefficients) for known elements is used to obtain the linear attenuation coefficients for each element at different photon energy level values. These coefficients are generally given in units of/cm.

Again, the linear absorption coefficient of the target object at each photon energy level value is calculated from the ratio of the elements and the linear attenuation coefficient. The calculation can be performed using the following formula:

linear absorption coefficient = Σ (proportion of elements x linear attenuation coefficient of elements)

Finally, the linear absorption coefficient is converted into a theoretical CT value. The CT value is expressed in Hounsfield Units (HU), and can be calculated, for example, using the following formula:

CT value= (linear absorption coefficient-linear absorption coefficient of water)/linear absorption coefficient of water×1000

The above theoretical CT value calculation is only for illustrative purposes, and may be implemented by a theoretical CT value calculation method in the related art.

Illustratively, when the CT system scans a target object to acquire data, a mixed spectrum (a collection of photons with various energies) is generated at a certain voltage kV of a tube to be detected, as shown in fig. 2, fig. 2 is a scanning schematic diagram of the CT system, and in fig. 2, the peak energy of a photon is denoted as kVp, and the value of the peak energy of the photon is the same as the value of kV. Different sources and filters can affect the morphology of the spectrum.

Illustratively, an image generated by scanning a target object under a certain tube voltage kV in a CT system is a measured CT value obtained in a fixed region of interest at a certain level, and the measured CT value should be close to the CT value of an image generated under a single spectrum (i.e., a set of photons of only one energy) of the equivalent average photon energy corresponding to the mixed energy spectrum of the kV.

For example, the CT value of an image generated under a 140kV mixed spectrum should be close to the CT value of an image generated under a 76.4keV (assuming an equivalent average photon energy of the mixed spectrum of 140 kV) single spectrum.

Schematically, but under the conventional common CT, it is difficult to perform single-energy spectrum scanning, and based on this, in this specification, a theoretical CT value of a target object under each photon energy level value keV can be theoretically calculated by using a target object with known substance component information.

S106: and determining a target photon energy level value from the photon energy level values based on the theoretical CT value and the measured CT value at each photon energy level value, and taking the target photon energy level value as the equivalent average photon energy of the CT system under the voltage of the tube to be measured.

In one or more embodiments of the present description, it is contemplated by the inventors' inventive effort that when a CT system scans a uniform object of known composition of matter at a given tube voltage, the measured CT value obtained should be close to the theoretical CT value of the object at the X-ray spectral equivalent average photon energy of the given tube voltage. Based on this, the first and second light sources,

The method comprises the steps of scanning the target object to obtain measurement CT values respectively under the voltage of the tube to be measured, traversing the theoretical CT value of the target object at the photon energy level value keV, and when the target CT value in the measurement CT value is matched with the theoretical CT value, the photon energy level value keV corresponding to the target CT value can be used as the equivalent average photon energy of the voltage of the tube to be measured.

For example, when the target CT value and the theoretical CT value in the measured CT values are equal, the photon energy level keV corresponding to the target CT value can be used as the equivalent average photon energy of the tube voltage to be measured.

For example, when the difference between the target CT value and the theoretical CT value in the measured CT values is the smallest, the photon energy level keV corresponding to the target CT value can be used as the equivalent average photon energy of the tube voltage to be measured.

For example, when the difference between the target CT value and the theoretical CT value in the measured CT values is smaller than the difference threshold, the photon energy level keV corresponding to the target CT value can be used as the equivalent average photon energy of the tube voltage to be measured.

In one or more embodiments of the present disclosure, an electronic device controls a CT system to scan a target object with a tube voltage to be measured, obtains a measured CT value of the target object, obtains a theoretical CT value of the target object at least one photon energy level value, and determines a target photon energy level value from the photon energy level values based on the theoretical CT value and the measured CT value at each photon energy level value, so that the target photon energy level value can be used as an equivalent average photon energy of the CT system at the tube voltage to be measured. The whole equivalent average photon energy determining process can avoid that spectrum calculation can be carried out to obtain equivalent average photon energy after the X-ray spectrum is acquired, thereby greatly simplifying the equivalent average photon energy determining process, avoiding the complicated X-ray spectrum acquisition process, improving the equivalent average photon energy determining efficiency and reducing the measuring cost.

Referring to fig. 3, fig. 3 is a schematic flow chart of determining a target photon energy level value according to the present disclosure. In an embodiment provided in the present specification, determining a target photon energy level value from the photon energy level values based on the theoretical CT value and the measured CT value at the photon energy level value includes:

S202: calculating a CT value difference for each of the photon energy level values based on the theoretical CT value and the measured CT value at each of the photon energy level values;

Optionally, the CT value difference formula satisfies: CT value difference = measured CT value-theoretical CT value;

Optionally, the CT value difference formula satisfies: CT value difference = theoretical CT value-measured CT value;

Specifically, determining a theoretical CT value and a measured CT value at each photon energy level value, and obtaining a CT value difference value corresponding to each photon energy level value by adopting the CT value difference value calculation formula;

S204: a target photon energy level value is determined from the photon energy level values based on the CT value differences for each of the photon energy level values.

In one possible implementation, a difference threshold for the CT value difference may be set, where the difference threshold is a threshold or a critical value set for the CT value difference, traversing the CT value differences of all photon energy level values, selecting a target CT value difference from the CT value differences that meets the difference threshold, and determining a target photon energy level value corresponding to the target CT value difference based on the CT value difference because the CT value difference corresponds to the photon energy level value one to one.

Further, determining a target CT value difference value satisfying the difference threshold from the CT value differences may refer to: and selecting a target CT value difference value with the absolute value of the CT value difference value smaller than a difference value threshold value.

In a possible implementation, please refer to fig. 4, fig. 4 is a schematic flow chart of determining a target photon energy level value from photon energy level values, and in an example provided in the present specification, determining the target photon energy level value from the photon energy level values based on a CT value difference of the photon energy level values includes:

S3002: determining a minimum CT value difference from the CT value differences for each of the photon energy level values;

the minimum CT value difference may be the CT value difference having the smallest absolute value among all CT value differences.

S3004: and determining a target photon energy level value corresponding to the minimum CT value difference value from the photon energy level values.

And traversing CT value differences of all photon energy level values, determining a minimum CT value difference from the CT value differences, and determining a target photon energy level value corresponding to the minimum CT value difference based on the CT value differences and the photon energy level values in a one-to-one correspondence.

In the specification, the target photon energy level value is determined by comparing the CT value difference between the theoretical CT value and the measured CT value at each photon energy level value, so that the accurate equivalent average photon energy can be found conveniently and rapidly based on the target photon energy level value, and the whole process is simple, convenient and easy to implement.

Alternatively, the target object may include a plurality of target individuals with different substance components, and it is understood that the plurality of target individuals with different substance components may be used in performing the equivalent photon energy measurement, and please refer to fig. 5, fig. 5 is a schematic diagram of an equivalent average photon energy measurement method, specifically:

S4004: the CT system is controlled to scan a plurality of target individuals respectively according to the voltage of the tube to be detected, and a measurement CT value of each target individual is obtained;

Alternatively, the target object may include a plurality of target individuals of different substance compositions, and the plurality of target individuals may be a plurality of target individuals of the same object type;

Alternatively, the object types of the plurality of target individuals may not be identical;

the CT system is controlled to scan a plurality of target individuals respectively according to the tube voltage to be detected, and a measured CT value of the target individuals at least one photon energy level value is obtained;

s4006: acquiring a theoretical CT value of each target individual at the photon energy level value;

For example, a CT quality control detection motif for a plurality of different material compositions may be preselected as a plurality of target individuals, and theoretical CT values for the plurality of target individuals at corresponding photon energy level values may be calculated based on known material compositions.

S4008: and determining a target photon energy level value from the photon energy level values based on the theoretical CT value and the measured CT value at the photon energy level value, and taking the target photon energy level value as the equivalent average photon energy of the CT system under the voltage of the tube to be measured.

S4010: acquiring target photon energy level values respectively determined based on a plurality of target individuals;

The determination of the target photon energy level value of any target individual may be achieved in accordance with all or part of the method steps in the equivalent average photon energy measurement method of one or more embodiments of the present specification.

S4012: calculating an absolute proportional error for each target individual at each of the photon energy level values based on the theoretical CT value and the measured CT value for each of the target individual at each of the photon energy level values;

absolute proportional error= | (theoretical CT value-measured CT value)/theoretical CT value|;

For a better understanding of the equivalent average photon energy measurement method shown in the present specification, please refer to fig. 6, which is a chart of experimental table data of an equivalent average photon energy measurement scenario. The equivalent average photon energy measurement process can be assisted by fig. 6 (where the numerical values of fig. 6 are merely references and are merely used for logic description) to understand that, without any limitation in the present specification, in fig. 6, material rods of 3 known substance compositions are used as target individuals, namely, material rod a, material rod B, and material rod C; assuming that the voltage of the tube to be measured is 140kV, the control CT system scans a plurality of target individuals "material rod a, material rod B and material rod C" with the voltage of the tube to be measured of 140kV, so as to obtain a measurement CT value of 50 for the material rod a, a measurement CT value of 100 for the material rod B and a measurement CT value of 200 for the material rod C, and the values of 6 photon energy levels (i.e., equivalent average photon energy candidate values shown in fig. 6) are set as follows: 76.0keV, 76.1keV, 76.2keV, 76.3keV, 76.4keV, 76.5keV;

Further, as shown in fig. 6, the calculation is performed for the material rod a: theoretical CT value of material rod a at photon energy level 76.0keV is 50, theoretical CT value at photon energy level 76.1keV is 49, theoretical CT value at photon energy level 76.2keV is 48. The theoretical CT value of material rod B at photon energy level 76.0keV is 106, the theoretical CT value at photon energy level 76.1keV is 103, the theoretical CT value at photon energy level 76.2keV is 97.

Illustratively, the absolute proportional error of the target individual at the photon energy level value is calculated based on the theoretical CT value and the measured CT value of the target individual "material rod a" at the photon energy level value. For example, a theoretical CT value 50 and a measured CT value 50 for "material rod a" at a photon energy level value of 76.0keV, then an absolute proportional error of 0% for the target individual "material rod a" at a photon energy level value of 76.0keV, a theoretical CT value 49 and a measured CT value 50 for material rod a "at a photon energy level value of 76.1keV, then an absolute proportional error of 2.04% for the target individual" material rod a "at a photon energy level value of 76.1keV, and so forth, as in fig. 6, can result in absolute proportional errors for material rod a at each photon energy level value (76.0 keV, 76.1keV, 76.2keV, 76.3keV, 76.4keV, 76.5 keV);

Illustratively, the absolute proportional error of the target individual at the photon energy level value is calculated based on the theoretical CT value and the measured CT value of the target individual "material rod B" at the photon energy level value. For example, the theoretical CT value 106 and the measured CT value 100 for "material rod B" at the photon level value 76.0keV, the absolute proportional error 5.66% for the target individual "material rod a" at the photon level value 76.0keV, the theoretical CT value 103 and the measured CT value 100 for the material rod B "at the photon level value 76.1keV, the absolute proportional error 2.91% for the target individual" material rod B "at the photon level value 76.1keV, and so on, the absolute proportional error at each photon level value (76.0 keV, 76.1keV, 76.2keV, 76.3keV, 76.4keV, 76.5 keV) for the material rod B as in fig. 6 can be obtained;

Illustratively, the absolute proportional error of the target individual at the photon energy level value is calculated based on the theoretical CT value and the measured CT value of the target individual "material rod C" at the photon energy level value. For example, the theoretical CT value 250 and the measured CT value 200 for "material bar C" at a photon level value of 76.0keV, then the absolute proportional error 20% for the target individual "material bar a" at a photon level value of 76.0keV, the theoretical CT value 240 and the measured CT value 200 for "material bar C" at a photon level value of 76.1keV, then the absolute proportional error 16.67% for the target individual "material bar C" at a photon level value of 76.1keV, and so forth, the absolute proportional error for material bar C at each photon level value (76.0 keV, 76.1keV, 76.2keV, 76.3keV, 76.4keV, 76.5 keV) as in fig. 6 can be obtained;

......

s4014: calculating a sample standard deviation at each of the photon energy level values based on an absolute proportional error at the photon energy level value for each of the target individuals;

1. Taking the absolute proportional error of each target individual at the photon energy level value as a sample x _i, calculating a sample average value, and adopting the following formula:

Where N is the total number of target individuals, i represents the ith target individual, Representing the average value of the samples;

2. based on the sample mean, the sample standard deviation is calculated using the following formula:

Wherein s is the sample standard deviation;

For example, as shown in fig. 6, the absolute ratio errors of the target individual "material rod a, material rod B, and material rod C" at the photon energy level value "76.0keV" are "0.00%, 5.66%, and 20.00%", respectively, and the standard deviation of the sample at the photon energy level value "76.0keV" is calculated as "10.31%", with three absolute ratio errors "0.00%, 5.66, and 20.00%", respectively (the standard deviation of the ratio errors is shown in fig. 6);

For example, as shown in fig. 6, the absolute ratio errors of the target individuals "material rod a, material rod B, and material rod C" at the photon energy level value "76.1keV" are "2.04%, 2.91%, and 16.67%", respectively, and the standard deviation of the sample at the photon energy level value "76.1keV" is calculated as "16.67%", with three absolute ratio errors "2.04%, 2.91, and 16.67%", respectively (the standard deviation of the ratio errors is shown in fig. 6);

For example, as shown in fig. 6, the absolute ratio errors of the target individuals "material rod a, material rod B, and material rod C" at the photon energy level value "76.2keV" are "4.17%, 0.00%, and 13.04%", respectively, and the standard deviation of the sample at the photon energy level value "76.2keV" is calculated as "6.66%", with three absolute ratio errors "4.17%, 0.00, and 13.04%", respectively;

For example, as shown in fig. 6, the absolute ratio errors of the target individuals "material rod a, material rod B, and material rod C" at the photon energy level value "76.3keV" are "6.38%, 3.09%, and 9.09%", respectively, and the standard deviation of the sample at the photon energy level value "76.3keV" is calculated as "3.00%", with three absolute ratio errors "6.38%, 3.09, and 9.09%", respectively (the standard deviation of the ratio errors is shown in fig. 6);

For example, as shown in fig. 6, the absolute ratio errors of the target individuals "material rod a, material rod B, and material rod C" at the photon energy level value "76.4keV" are "8.70%, 6.38%, and 4.76%", respectively, and the standard deviation of the sample at the photon energy level value "76.4keV" is calculated as "1.98%", with three absolute ratio errors "8.70%, 6.38, and 4.76%", respectively;

For example, as shown in fig. 6, the absolute ratio errors of the target individuals "material rod a, material rod B, and material rod C" at the photon energy level value "76.5keV" are "11.11%, 9.89%, and 0.00%", respectively, and the standard deviation of the sample at the photon energy level value "76.5keV" is calculated as "6.09%", with three absolute ratio errors "11.11%, 9.89, and 0.00%", respectively;

S4016: a target photon energy level value is determined from the photon energy level values based on a sample standard deviation at each of the photon energy level values.

Determining a minimum sample standard deviation based on the sample standard deviation at each photon level value, determining a target photon level value from the photon level values indicated by the minimum sample standard deviation;

As shown in fig. 6, the sample standard deviation at the photon level value "76.5keV" is "6.09%", the sample standard deviation at the photon level value "76.4keV" is "1.98%", the sample standard deviation at the photon level value "76.3keV" is "3.00%", the sample standard deviation at the photon level value "76.1keV" is "16.67%", and the sample standard deviation at the photon level value "76.0keV" is "10.31%", the minimum sample standard deviation is "1.98%" of the sample standard deviation at the photon level value "76.4keV", and based on this, it is determined that "76.4keV" is the target photon level value.

Specifically, to improve accuracy, multiple target individuals may be used to calculate, and by calculating the standard deviation of samples for all target individuals at each keV, a relatively most balanced result may be obtained.

In one or more embodiments of the present disclosure, by adopting the above manner, the whole equivalent average photon energy determining process can avoid that spectrum calculation can be performed to obtain equivalent average photon energy only after an X-ray spectrum is acquired, thereby greatly simplifying the equivalent average photon energy determining process, avoiding a complicated X-ray spectrum acquiring process, improving the equivalent average photon energy determining efficiency, and reducing the measurement cost.

In a specific implementation scenario, the equivalent average photon energy measurement method according to one or more embodiments of the present disclosure is used to determine a final equivalent average photon energy, and then the technical effect of the equivalent average photon energy determined based on the final equivalent average photon energy is verified as follows:

the equivalent average photon Energy measuring method according to one or more embodiments of the present disclosure is used to determine the final equivalent average photon Energy under a certain tube voltage to be measured (e.g., 80kV and 140 kV), then scanning each material rod of a Multi-Energy CT phantom of Sun Nuclear company by controlling the CT system to work under a certain tube voltage to be measured (e.g., 80kV and 140 kV) to obtain scanning data, and obtaining a measured CT value of a virtual monochromatic CT value of each material rod at each photon Energy level keV by imaging the scanning data Energy spectrum, where the virtual monochromatic CT value graph of each material rod is shown in fig. 7-10;

FIG. 7 is a graph of virtual monochromatic CT values generated after scanning a bar of material, in FIG. 7, a 15mg/L bar of iodine material is used for technical effect verification, and in FIG. 7, where the 15mg/L bar of iodine material is used, the photon energy level values are 40keV, 50keV, 60keV, 70keV, 80keV, 90keV, 100keV, 110keV, 120keV, 130keV, 140keV, respectively corresponding to the measured CT values and calibrated theoretical CT values, and the R2 value of the 15mg/L bar of iodine material is compared to reach 0.999;

FIG. 8 is a graph of a virtual monochromatic CT value generated after scanning a bar of material, in FIG. 8, a technical effect verification is performed by using a 10mg/L bar of iodine material, and in FIG. 8, the photon energy level values are 40keV, 50keV, 60keV, 70keV, 80keV, 90keV, 100keV, 110keV, 120keV, 130keV and 140keV respectively corresponding to the measured CT value and the calibrated theoretical CT value, and the R2 value of the 15mg/L bar of iodine material is compared to reach 0.999;

FIG. 9 is a graph of a virtual monochromatic CT value generated after scanning a bar of material, in FIG. 9, a technical effect verification is performed by using a 10mg/L bar of iodine material, and in the case of using a 5mg/L bar of iodine material, in FIG. 9, the photon energy level values are 40keV, 50keV, 60keV, 70keV, 80keV, 90keV, 100keV, 110keV, 120keV, 130keV and 140keV respectively corresponding to the measured CT value and the calibrated theoretical CT value, and the R2 value of the 15mg/L bar of iodine material is 0.999 by comparison;

FIG. 10 is a graph of a virtual monochromatic CT value generated after scanning a bar of material, in FIG. 10, a 2mg/L bar of iodine material is used for technical effect verification, and in the case of using a 2mg/L bar of iodine material shown in FIG. 10, the photon energy level values are 40keV, 50keV, 60keV, 70keV, 80keV, 90keV, 100keV, 110keV, 120keV, 130keV, 140keV respectively corresponding to the measured CT value and the calibrated theoretical CT value, and the R2 value of the 15mg/L bar of iodine material is compared to reach 0.999;

Wherein, the R2 value refers to a determining coefficient, which is a statistical index in regression analysis and is used for measuring the technical effect of data. In the above technical effect verification, the R2 value is used to evaluate the coincidence degree between the measured CT value and the theoretical CT value after measuring the equivalent average photon energy of the X-ray spectrum and applying it, and the closer the R2 value is to 1, the better the technical effect is, and the more reliable the measured result is.

In summary, all iodine material bars are compared with the theoretical CT value, and the R2 value corresponding to each material bar reaches 0.999.

The equivalent average photon energy measuring device provided in the embodiment of the present specification will be described in detail with reference to fig. 11. It should be noted that, the equivalent average photon energy measuring device shown in fig. 11 is used to perform the method of the embodiment shown in fig. 1 to 10 of the present specification, and for convenience of description, only the portion relevant to the embodiment of the present specification is shown, and specific technical details are not disclosed, please refer to the embodiment shown in fig. 1 to 10 of the present specification.

Referring to fig. 11, a schematic structural diagram of an equivalent average photon energy measuring device according to an embodiment of the present disclosure is shown. The equivalent mean photon energy measuring means 1 may be implemented as all or part of an electronic device by software, hardware or a combination of both. According to some embodiments, the equivalent mean photon energy measuring device 1 comprises a scanning module 11, an acquisition module 12 and a determination module 13, in particular for:

The scanning module 11 is used for controlling the CT system to scan the target object by the voltage of the tube to be detected to obtain a measured CT value of the target object;

an acquisition module 12 for acquiring theoretical CT values of the target object at least one photon energy level value;

A determining module 13 for determining a target photon energy level value from the photon energy level values based on the theoretical CT value and the measured CT value at each of the photon energy level values, and using the target photon energy level value as an equivalent average photon energy of the CT system at the tube voltage to be measured

Optionally, the determining module 13 is configured to:

A CT value difference for each of the photon energy level values is calculated based on the theoretical CT value and the measured CT value at each of the photon energy level values, and a target photon energy level value is determined from the photon energy level values based on the CT value difference for each of the photon energy level values.

Optionally, the determining module 13 is configured to:

determining a minimum CT value difference from the CT value differences for each of the photon energy level values;

and determining a target photon energy level value corresponding to the minimum CT value difference value from the photon energy level values.

Optionally, the target object includes a plurality of target individuals with different substance compositions, and the determining module 13 is configured to determine a target photon energy level value from the photon energy level values based on the theoretical CT value and the measured CT value at each of the photon energy level values:

calculating an absolute proportional error for each target individual at each of the photon energy level values based on the theoretical CT value and the measured CT value for each of the target individual at each of the photon energy level values;

calculating a sample standard deviation at each of the photon energy level values based on an absolute proportional error at the photon energy level value for each of the target individuals;

A target photon energy level value is determined from the photon energy level values based on a sample standard deviation at each of the photon energy level values.

Optionally, the determining module 13 is configured to:

determining a minimum sample standard deviation from the sample standard deviation at each of said photon energy level values;

and determining a target photon energy level value corresponding to the minimum sample standard deviation from the photon energy level values.

Optionally, the device 1 is further configured to:

selecting at least one CT quality control detection die body as a target object, and obtaining the material composition of the CT quality control detection die body;

at least one photon energy level value for a target object is determined, and a theoretical CT value for the target object at the at least one photon energy level value is calculated based on the material composition.

Optionally, the device 1 is further configured to: and determining a reference photon energy level value aiming at the target object based on the voltage of the tube to be detected, and selecting at least one photon energy level value by taking the reference photon energy level value as a reference.

It should be noted that, when the equivalent average photon energy measuring device provided in the above embodiment performs the equivalent average photon energy measuring method, only the division of the above functional modules is used for illustration, and in practical application, the above functional allocation may be completed by different functional modules according to needs, that is, the internal structure of the device is divided into different functional modules, so as to complete all or part of the functions described above. In addition, the equivalent average photon energy measuring device and the equivalent average photon energy measuring method provided in the above embodiments belong to the same concept, and the implementation process is detailed in the method embodiments, which are not described herein.

The foregoing embodiment numbers of the present specification are merely for description, and do not represent advantages or disadvantages of the embodiments.

The embodiment of the present disclosure further provides a computer storage medium, where the computer storage medium may store a plurality of instructions, where the instructions are adapted to be loaded by a processor and execute the equivalent average photon energy measurement method according to the embodiment shown in fig. 1 to 10, and the specific execution process may refer to the specific description of the embodiment shown in fig. 1 to 10, which is not repeated herein.

The present disclosure further provides a computer program product, where at least one instruction is stored, where the at least one instruction is loaded by the processor and executed by the processor to perform the method for measuring equivalent average photon energy according to the embodiment shown in fig. 1 to 8, and the specific execution process may refer to the specific description of the embodiment shown in fig. 1 to 8, which is not repeated herein.

Referring to fig. 12, a block diagram of an electronic device according to an embodiment of the present disclosure is provided. The electronic device in this specification may include one or more of the following: processor 110, memory 120, input device 130, output device 140, and bus 150. The processor 110, the memory 120, the input device 130, and the output device 140 may be connected by a bus 150.

Processor 110 may include one or more processing cores. The processor 110 connects various parts within the overall terminal using various interfaces and lines, performs various functions of the terminal 100 and processes data by executing or executing instructions, programs, code sets, or instruction sets stored in the memory 120, and invoking data stored in the memory 120. Alternatively, the processor 110 may be implemented in at least one hardware form of Digital Signal Processing (DSP), field-programmable gate array (FPGA), programmable logic array (programmable logic Array, PLA). The processor 110 may integrate one or a combination of several of a central processor (central processing unit, CPU), an image processor (graphics processing unit, GPU), and a modem, etc. The CPU mainly processes an operating system, a user interface, an application program and the like; the GPU is used for being responsible for rendering and drawing of display content; the modem is used to handle wireless communications. It will be appreciated that the modem may not be integrated into the processor 110 and may be implemented solely by a single communication chip.

The memory 120 may include a random access memory (random Access Memory, RAM) or a read-only memory (ROM). Optionally, the memory 120 includes a non-transitory computer readable medium (non-transitory computer-readable storage medium). Memory 120 may be used to store instructions, programs, code, sets of codes, or sets of instructions.

The input device 130 is configured to receive input instructions or data, and the input device 130 includes, but is not limited to, a keyboard, a mouse, a camera, a microphone, or a touch device. The output device 140 is used to output instructions or data, and the output device 140 includes, but is not limited to, a display device, a speaker, and the like. In the embodiment of the present disclosure, the input device 130 may be a temperature sensor for acquiring an operation temperature of the terminal. The output device 140 may be a speaker for outputting audio signals.

In addition, those skilled in the art will appreciate that the configuration of the terminal illustrated in the above-described figures does not constitute a limitation of the terminal, and the terminal may include more or less components than illustrated, or may combine certain components, or may have a different arrangement of components. For example, the terminal further includes components such as a radio frequency circuit, an input unit, a sensor, an audio circuit, a wireless fidelity (WIRELESS FIDELITY, WIFI) module, a power supply, a bluetooth module, and the like, which are not described herein.

In the embodiment of the present specification, the execution subject of each step may be the terminal described above. Optionally, the execution subject of each step is an operating system of the terminal. The operating system may be an android system, an IOS system, or other operating systems, which embodiments of the present specification are not limited to.

In the electronic device of fig. 12, the processor 110 may be configured to invoke the program stored in the memory 120 and execute to implement the equivalent average photon energy measurement method as described in various method embodiments of the present specification.

Those skilled in the art will appreciate that implementing all or part of the above-described methods in accordance with the embodiments may be accomplished by way of a computer program stored on a computer readable storage medium, which when executed may comprise the steps of the embodiments of the methods described above. The storage medium may be a magnetic disk, an optical disk, a read-only memory, a random access memory, or the like.

The foregoing disclosure is only illustrative of the preferred embodiments of the present invention and is not to be construed as limiting the scope of the claims, which follow the meaning of the claims of the present invention.

Claims (10)

1. A method of equivalent average photon energy measurement, the method comprising:

The CT system is controlled to scan a target object by the voltage of the tube to be detected, and a measured CT value of the target object is obtained;

acquiring a theoretical CT value of the target object at least one photon energy level value;

And determining a target photon energy level value from the photon energy level values based on the theoretical CT value and the measured CT value at each photon energy level value, and taking the target photon energy level value as the equivalent average photon energy of the CT system under the voltage of the tube to be measured.

2. The method of claim 1, wherein said determining a target photon energy level value from said photon energy level values based on said theoretical CT value and said measured CT value at each of said photon energy level values comprises:

A CT value difference for each of the photon energy level values is calculated based on the theoretical CT value and the measured CT value at each of the photon energy level values, and a target photon energy level value is determined from the photon energy level values based on the CT value difference for each of the photon energy level values.

3. The method of claim 2, wherein said determining a target photon energy level value from said photon energy level values based on CT value differences for each of said photon energy level values comprises:

determining a minimum CT value difference from the CT value differences for each of the photon energy level values;

and determining a target photon energy level value corresponding to the minimum CT value difference value from the photon energy level values.

4. The method of claim 1, wherein the target object comprises a target individual of a plurality of different material compositions, the determining a target photon energy level value from the photon energy level values based on the theoretical CT value and the measured CT value at each of the photon energy level values comprising:

calculating an absolute proportional error for each target individual at each of the photon energy level values based on the theoretical CT value and the measured CT value for each of the target individual at each of the photon energy level values;

calculating a sample standard deviation at each of the photon energy level values based on an absolute proportional error at the photon energy level value for each of the target individuals;

A target photon energy level value is determined from the photon energy level values based on a sample standard deviation at each of the photon energy level values.

5. The method of claim 4, wherein said determining a target photon energy level value from said photon energy level values based on a sample standard deviation at each of said photon energy level values comprises:

determining a minimum sample standard deviation from the sample standard deviation at each of said photon energy level values;

and determining a target photon energy level value corresponding to the minimum sample standard deviation from the photon energy level values.

6. The method of claim 1, wherein the controlling the CT system to scan the target object with the tube voltage to be measured, before obtaining the measured CT value of the target object, further comprises:

selecting at least one CT quality control detection die body as a target object, and obtaining the material composition of the CT quality control detection die body;

at least one photon energy level value for a target object is determined, and a theoretical CT value for the target object at the at least one photon energy level value is calculated based on the material composition.

7. The method of claim 6, wherein the determining at least one photon energy level value for the target object comprises:

And determining a reference photon energy level value aiming at the target object based on the voltage of the tube to be detected, and selecting at least one photon energy level value by taking the reference photon energy level value as a reference.

8. An equivalent average photon energy measurement device, the device comprising:

The scanning module is used for controlling the CT system to scan the target object by the voltage of the tube to be detected to obtain a measured CT value of the target object;

The acquisition module is used for acquiring a theoretical CT value of the target object at least one photon energy level value;

And the determining module is used for determining a target photon energy level value from the photon energy level values based on the theoretical CT value and the measured CT value at each photon energy level value, and taking the target photon energy level value as the equivalent average photon energy of the CT system under the voltage of the tube to be detected.

9. A computer storage medium storing a plurality of instructions adapted to be loaded by a processor and to perform the method steps of any one of claims 1 to 7.

10. An electronic device, comprising: a processor and a memory; wherein the memory stores a computer program adapted to be loaded by the processor and to perform the method steps of any of claims 1-7.