CN102621576B - Glandular dose distribution detection method and device aiming at computed tomography (CT) equipment special for mammary gland - Google Patents
Glandular dose distribution detection method and device aiming at computed tomography (CT) equipment special for mammary gland Download PDFInfo
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Abstract
The invention discloses a glandular dose distribution detection method aiming at computed tomography (CT) equipment special for a mammary gland. The method comprises the following steps of: acquiring spectral information at a corresponding angle by simulating a light tube of an X-ray source which is used actually; determining the positions of key dose points in glandular dose distribution detection and the distance from the X-ray source to the central plane of a mammary gland die body by utilizing the mammary gland die body; and performing X-ray scanning in all directions on the mammary gland die body by utilizing the X-ray source, obtaining an average glandular dose value and a normalized glandular dose coefficient of the mammary gland die body according to the acquired spectral information, and determining boundary conditions of dose measurement of the die body to realize the detection of the glandular dose distribution. By implementing the method, the total average glandular dose is not more than or lower than a dose guidance level of mammary gland X-ray photography of a typical adult subject; moreover, uniform average dose distribution in a mammary gland body is obtained; glandular tissue injuries caused by non-uniform dose distribution or local high glandular dose are reduced; and secondary cancer caused by the glandular tissue injuries is avoided.
Description
Technical field
The present invention relates to standard X-ray tomography CT technical field, particularly relate to a kind of mammary gland dosage for the special CT equipment of mammary gland distribution detection method and device.
Background technology
At present, the incidence of disease of breast cancer has been in the first place of female malignant, and in existing multiple breast examination method, X-ray molybdenum target imaging (Mammography) is the most widely used means.But molybdenum target imaging technique is two-dimentional DR picture, and on imaging direction, organizational information superposes mutually, easily there is false positive mistaken diagnosis for dense form mammary gland in stereoscopic localized poor accuracy; Also use standard X-ray tomography (CT) clinically, comprise spiral CT and carry out breast examination.But these devices can only carry out transverse axis bit scan to human body and can not scan separately mammary gland, therefore these CT scan devices must could obtain the CT scan image of mammary gland while scanning human chest, and this adds the x-ray dose of absorption of human body undoubtedly.Therefore, what the special CT of mammary gland became a kind of fast development in the last few years is considered to more superior early-stage breast cancer diagnostic method, along with the increasingly extensive use of X-ray in diagnosis of breast disease, amount of radiation size suffered during breast examination also more and more receives the concern of people.
No matter but be use molybdenum target imaging or the special CT imaging of mammary gland, tested newborn body all can be subject to the radiation of doses, research according to Radiation On Human bulk damage shows, mammary gland is one of ray height sensitive organization, and the dosage that its irradiation dose can not exceed the photography of typical adult person under inspection breast X-ray is each gland mean dose thrown end to end according to 3mGy.In a breast molybdenum target checks, the Average Glandular Dose under single mammary gland two visuals field is about 6mGy.For the special CT equipment of mammary gland, the dose value that the dose value that patient receives in scanning process should check with molybdenum target is suitable, even lower.
Corresponding mammary gland special CT dose of radiation Guidance Levels is not had in prior art, the experimental technique of effective mammary gland Radiation dose distribution for Special breast CT equipment is not had yet, also with regard to the uncontrollable and dose level of radiation of assessment suffered by mammary gland, thus the probability of the secondary injury brought by X-ray is added.
Summary of the invention
The object of this invention is to provide a kind of mammary gland dosage for the special CT equipment of mammary gland distribution detection method and device, the dosage guidance level that total Average Glandular Dose is no more than or photographs lower than typical adult person under inspection breast X-ray can be guaranteed, and the uniform dose distribution obtained in mammary gland body, obtain simultaneously and divide at most uniform dose the optimum picture quality planted, reduce the gland tissue damage because the high body of gland dosage of dosage skewness or local causes, avoid the secondary causing cancer to occur.
The object of the invention is to be achieved through the following technical solutions, a kind of distribution of the mammary gland dosage for the special CT equipment of mammary gland detection method, described method comprises:
First to the light pipe simulation of the x-ray source that reality uses, and carry out flow estimation, determine line be uniformly distributed under photon shooting angle, and the spectral information under obtaining respective angles;
Utilize the mammary gland die body being applicable to Asians's mammary gland size, body of gland and fat components ratio, establish the position of crucial dose point in the distribution of mammary gland dosage detects, and described x-ray source is to the distance of described mammary gland die body central plane;
Utilize described x-ray source to carry out the X-ray scanning in each orientation to described mammary gland die body, and obtain Average Glandular Dose value and the normalization body of gland dose factor of described mammary gland die body according to obtained spectral information, realize the detection of mammary gland dosage distribution.
Carrying out in X-ray scanning process, described method also comprises:
According to the size of described mammary gland die body, adjust described x-ray source subtended angle angle and the described x-ray source distance to described mammary gland die body central plane, to regulate the measuring center plan-position of described mammary gland die body, the beamwidth being irradiated to described mammary gland die body is made to meet requirement in the vertical.
Described method also comprises:
Arrange thermoluminescent dosemeter in described mammary gland die body, the placement location of this thermoluminescent dosemeter covers the transverse axis position of described mammary gland die body, longitudinal axis position and nearly skin area;
Pen type ionisation chamber is placed in the shaft core position of described mammary gland die body, the location point measured by this pen type ionisation chamber as dosage reference point, and utilizes thermoluminescent dosemeter and X-ray film dosimeter to carry out the detection of dosage distribution.
When utilizing thermoluminescent dosemeter to measure, completed by the mode of monolithic demarcation, grouping mea-sure, to improve the accuracy that thermoluminescent dosemeter detects.
Described method also comprises:
Change the voltage of described x-ray source, half-value layer, electric current, irradiation time, air kerma rate, obtain the dosage distribution under different effective energy;
Read the lower mammary gland of each dosage distribution longitudinal between chest wall to nipple, laterally from the dosage distributed points numerical value measuring center point to skin, take out maximum and minimum of a value in all directions to compare, obtain the optimal dose distribution under some values of described voltage, half-value layer, electric current, irradiation time, air kerma rate;
Under described optimal dose distribution occasion, carry out standard X-ray tomography CT imaging, obtain the optimized image resolution ratio under described optimal dose distribution occasion.
The embodiment of the present invention additionally provides a kind of mammary gland dosage distribution detecting device for the special CT equipment of mammary gland, and described device comprises X-ray baffle plate, X-ray machine, slit and filter disc, mammary gland die body, slide rail, bracing frame, bearing plate and electric rotating machine, wherein:
Described X-ray machine, slit and filter disc, mammary gland die body hang on described X-ray baffle plate, this X-ray baffle plate is the bed body with the effect of being in the light, and simulates, and carry out flow estimation to the light pipe of described X-ray machine, determine line be uniformly distributed under photon shooting angle, and the spectral information under obtaining respective angles;
Mammary gland die body is vertically downward placed in light path can the not extruded mammary gland vertically downward of Reality simulation, and the mammary gland size of this mammary gland die body, body of gland and fat components ratio can set as required; Place thermoluminescent dosemeter in described mammary gland die body, the placement location of this thermoluminescent dosemeter covers the transverse axis position of described mammary gland die body, longitudinal axis position and nearly skin area; Described mammary gland die body needs the position establishing crucial dose point in the distribution of mammary gland dosage detects, and described X-ray machine is to the distance of described mammary gland die body central plane;
Regulate described X-ray machine, amplification ratio distance between mammary gland die body and bracing frame by described slide rail, described mammary gland die body is all placed in light path; Wherein, bracing frame is hung with detector, and this detector is used for determining the CT imaging after exposure dose distribution, and described detector is as far as possible near described mammary gland die body;
The two pieces of bearing plates utilizing described electric rotating machine to hold up are to rotate described X-ray machine and bracing frame, described mammary gland die body is carried out to the X-ray scanning in each orientation, and Average Glandular Dose value and the normalization body of gland dose factor of described mammary gland die body is obtained according to obtained spectral information, establish the boundary condition of die body dosage measurement, realize the detection of mammary gland dosage distribution.
As seen from the above technical solution provided by the invention, first described method utilizes DSMC to simulate the light pipe of the x-ray source that reality uses, and carry out flow estimation, determine line be uniformly distributed under photon shooting angle, and the spectral information under obtaining respective angles; Utilize the mammary gland die body being applicable to Asians's mammary gland size, body of gland and fat components ratio, establish the position of crucial dose point in the distribution of mammary gland dosage detects, and described x-ray source is to the distance of described mammary gland die body central plane; Described x-ray source is utilized to carry out the X-ray scanning in each orientation to described mammary gland die body, and Average Glandular Dose value and the normalization body of gland dose factor of described mammary gland die body is obtained according to obtained spectral information, establish the boundary condition of die body dosage measurement, realize the detection of mammary gland dosage distribution.The dosage guidance level just can guaranteeing that total Average Glandular Dose is no more than or photographs lower than typical adult person under inspection breast X-ray is implemented by the method, and the uniform dose distribution obtained in mammary gland body, obtain simultaneously and divide at most uniform dose the optimum picture quality planted, reduce the gland tissue damage because the high body of gland dosage of dosage skewness or local causes, avoid the generation causing secondary cancer.
Accompanying drawing explanation
In order to be illustrated more clearly in the technical scheme of the embodiment of the present invention, below the accompanying drawing used required in describing embodiment is briefly described, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawings can also be obtained according to these accompanying drawings.
The distribution of the mammary gland dosage for the special CT equipment of the mammary gland detection method that Fig. 1 provides for the embodiment of the present invention;
Fig. 2 is the schematic diagram that in embodiment of the present invention example, x-ray source is practiced shooting;
Fig. 3 is for carrying out the schematic diagram of the X-ray scanning in each orientation to mammary gland die body described in the embodiment of the present invention;
Fig. 4 is the structural representation of embodiment of the present invention institute generator.
Detailed description of the invention
Below in conjunction with the accompanying drawing in the embodiment of the present invention, be clearly and completely described the technical scheme in the embodiment of the present invention, obviously, described embodiment is only the present invention's part embodiment, instead of whole embodiments.Based on embodiments of the invention, those of ordinary skill in the art, not making the every other embodiment obtained under creative work prerequisite, belong to protection scope of the present invention.
Be described in further detail the embodiment of the present invention below in conjunction with accompanying drawing, be illustrated in figure 1 the distribution of the mammary gland dosage for the special CT equipment of the mammary gland detection method that the embodiment of the present invention provides, in Fig. 1, described method comprises:
Step 11: the spectral information determining the x-ray source of actual use.
In this step, DSMC first can be utilized to simulate the light pipe of the x-ray source that reality uses, and carry out flow estimation, determine line be uniformly distributed under photon shooting angle, and the spectral information under obtaining respective angles.
For example, first the process of X-ray machine (i.e. x-ray source) electronic target can be simulated, use tungsten as the target material of X-ray tube, electronics under certain energy and tungsten target surface are angledly incided in yz plane, be illustrated in figure 2 the schematic diagram that in embodiment of the present invention example, x-ray source is practiced shooting, in Fig. 2: the angle of cut of the vertical line of outgoing photon direction and tungsten target plane is theta (Θ), the angle of cut of projection and the incident electron direction projection extended line on tungsten target plane of outgoing photon direction in tungsten target plane is phi (φ).Therefore, the flow of outgoing photon in different orientations and solid angle and the change of power spectrum can be obtained, determine the azimuth of outgoing photon, and obtain the spectral information under this angle;
Further, the spectrum of above-mentioned simulation and actual measurement X-ray machine spectrum can also be contrasted, such as in actual measurement, the x-ray generator that X-ray machine can be provided by Comet company of Switzerland, according to the parameter such as specifying information adjustment incident electron energy, angle, target thickness of X-ray machine, expect that the spectrum simulated is the spectrum information used under measurement environment, thus guarantee the dependable with function based on the die body dose distributions computation under this spectrum; The spectral information of actual measurement X-ray machine, the spectrometer system based on CdZnTe detector is utilized to complete surveying work, measurement is obtained spectrum information compared with above-mentioned analog computation result, revise analog result, thus obtain surveying the modifying factor S between spectrum and simulated spectrum, and can revise according to this modifying factor S the spectral information Φ (E) obtaining x-ray source.
In addition, in specific implementation process, before the light pipe simulation of the x-ray source that reality is used, value, air kerma rate, the voltage and current value of x-ray source half-value layer can also be measured, wherein:
The value of x-ray source half-value layer is a very important analog input parameter, by measuring the half-value layer (HVL) of X-ray machine, uniquely can determine the relation between voltage and filter disc.Ionisation chamber is placed in the position (distance X source is about 60cm) that die body central plane is placed, regulates ray machine voltage, electric current, measure the exposure rate not adding and absorb aluminium flake.Absorption aluminium flake is placed in beam and ionisation chamber centre position, allows beam axle center overlap with the center absorbing aluminium flake also mutually vertical.Add the aluminium flake of different-thickness, measure the exposure rate of beam by different-thickness aluminium flake.When air kerma rate is down to initially the aluminium flake thickness of (without absorbing aluminium flake) half, be the half-value layer value of the useful beam of acquisition.Aluminium flake purity is chosen as 99.99%, and measuring normally used crest voltage for mammary gland is 40kVp to 70kVp.By the measurement to half-value layer, available energy value (Eeff) can be obtained simultaneously.
Then, obtain air kerma rate according to voltage, the current condition that HVL measures, equally ionisation chamber is placed in the position that die body central plane is placed, the central shaft of ionisation chamber is vertical with beam, continuous measurement more than 5 times, gets its mean value, by environmental factor correction factor (K
tPh):
In formula, P is the atmospheric pressure (mmHg) of ionisation chamber working environment; P1 is the pressure (mmHg) of steam, and t is the temperature (DEG C) of ionisation chamber working environment.
With above-mentioned measure geometry condition, measure the voltage and current stability of x-ray source and linear, change voltage duplicate measurements at least 5 times from 40kVp to 70kVp, get its mean value; Calculate relative deviation EV; Change electric current duplicate measurements at least 5 times from 1mA to 10mA, get its mean value; Calculate relative deviation EI.
Step 12: select applicable mammary gland die body, establish the position of crucial dose point in the distribution of mammary gland dosage detects, and x-ray source is to the distance of described mammary gland die body central plane.
In this step, first the mammary gland die body of applicable Asians's mammary gland size, body of gland and fat components ratio is selected, then establish the position of crucial dose point in the distribution of mammary gland dosage detects, and described x-ray source is to the distance of described mammary gland die body central plane.
For example, the shape of the mammary gland die body in selected model is oval, the newborn body naturally drooped when emulating prostrate, and the size Selection of die body is applicable to the mammary gland of Asians, and diameter is about 11 ~ 16cm; Die body can be made up of the fatty mixed materials respectively accounting for 50% of body of gland, fat or body of gland.
In simulation process, Dose Module is loaded in mammary gland die body, together rotate with mammary gland die body; Dose Module can be set to the equal three-dimensional matrice of voxel size, if D (E) is the mean value of all voxel dosage in mammary gland die body, then
Wherein, N is the voxel sum in mammary gland die body, and D (i) is the dosage of i-th voxel.Because the body of gland in mammary gland is high to susceptible-dose degree, easily be subject to irradiation damage and again carcinogenic possibility, the Average Glandular Dose using body of gland to receive in therapeutic radiation dose level instructs is to judge the degree that mammary gland sustains damage, the ratio of body of gland shared by mammary gland varies with each individual, the component ratio adjusting body of gland and fat can be considered when modeling, under normal circumstances, 50% body of gland and 50% fat is used to simulate.Therefore, need to obtain by calculating body of gland percentage correction coefficient G (E) to the calculating of Average Glandular Dose value, its expression formula is:
Wherein (μ en (E)/ρ) g and (μ en (E)/ρ) a is respectively the mass-absorption coefficient of body of gland and fat, and fg is the mass percent of body of gland.Dosage is by sedimentary energy divided by quality, and in above formula, fraction is above for sedimentary energy, and 1/fg is below for quality.
In addition, be placed with thermoluminescent dosemeter in mammary gland die body, the position that this thermoluminescent dosemeter is placed needs to cover transverse axis position in die body, longitudinal axis position and nearly skin area; The point that detector is placed is The more the better in theory, and the distribution of measuring like this can be more accurate, certainly in real work, also can increase very large workload.
In specific implementation, pen type ionisation chamber can be placed in the shaft core position of mammary gland die body, can record along the CT dose index parameter in axle center, dosage and close rate in die body, because the precision of ionisation chamber detection is higher, so the location point measured by ionisation chamber can be used as dosage reference point; Consider in the present invention that what need to measure is dosage distribution in die body, so except using except ionisation chamber, also needing thermoluminescent dosemeter and X-ray film dosimeter to carry out dosage distribution and detecting.In addition, in order to improve thermoluminescent dosemeter precision, can adopt chip select mode, here because thermoluminescent dosemeter dosage sheet belongs to passive probe, its measurement result is determined by set of system, and this cover system comprises 1, annealing furnace+cycle of annealing; 2, read-out device+reading program; 3, thermoluminescent dosemeter dosage sheet.When utilizing thermoluminescent dosemeter to measure, more accurate method is completed by the mode of monolithic demarcation, grouping mea-sure.For example, can operate in the following way:
The first step: repeated monolithic is demarcated
In 137Cs field, carry out irradiation to thermoluminescence sheet, dosage selected by irradiation is best and finally measure comparable doses, repeats annealing, reads irradiation process 10 times.Add up the repeatability of every a slice.
Second step: energy response
For be concerned about energy range, choose 5 energy points and irradiate, draw dosage sheet energy response curve.Concrete energy point is selected to determine according to actual requirement.
3rd step: dose response
Utilize 137Cs source, in be concerned about dosage range, choose 5 dose points, 0.5mGy, 3mGy, 6mGy, 10mGy, 15mGy, draw dose response curve, can irradiate 1mGy to 1 batch of dosage sheet, parameter adjustment is carried out to used readout meter, and then completes the demarcation of whole system.
By said method, just for every a slice thermoluminescent dosemeter measurement reproducibility, stability, energy and dose response, when actual measurement, by reasonably grouping, the difference of dosage sheet itself can be reduced.
Step 13: utilize x-ray source to carry out the X-ray scanning in each orientation to mammary gland die body, and the Average Glandular Dose value and the normalization body of gland dose factor that obtain described mammary gland die body according to obtained spectral information.
In this step, utilize described x-ray source to carry out the X-ray scanning in each orientation to described mammary gland die body, be illustrated in figure 3 the schematic diagram of the X-ray scanning described in the embodiment of the present invention, mammary gland die body being carried out to each orientation; And then Average Glandular Dose value and the normalization body of gland dose factor of described mammary gland die body is obtained according to obtained spectral information, establish the boundary condition of die body dosage measurement, realize the detection of mammary gland dosage distribution.
For example, first spectral information Φ (E) can be obtained according in above-mentioned steps 11, this spectral information Φ (E) is revised by the modifying factor S between actual measurement spectrum and simulated spectrum and obtains, then Average Glandular Dose value under multipotency is by above-mentioned formula (2) and (3) acquisition:
Can find out in formula (4), Average Glandular Dose value and energy, spectrum and body of gland percentage correction coefficient closely related.
Then, normalization body of gland dose factor of reentrying further, the computational methods according to normalization body of gland dose factor in X-ray molybdenum target:
MGD=AirKermaD
gn, and by formula (3) and (4), by MGD=mAs air kerma rate D
gn
cT, can derive based on the normalization body of gland dose factor D under cone-beam mammary gland CT
gn
cT.
According to China's medical radioactive dosage guidance level, if the Average Glandular Dose value upper limit of cone-beam mammary gland CT in single pass process is 6mGy, therefore milliampere-second (mAs) this parameter can be regulated under given spectral information, if when mammary gland can blur-free imaging time the condition of scanning corresponding to MGD value be greater than 6mGy time, just need to regulate other systematic parameter.
In addition, carry out in X-ray scanning process in described mammary gland die body, can also according to the size of described mammary gland die body, adjust described x-ray source subtended angle angle and the described x-ray source distance to described mammary gland die body central plane, to regulate the measuring center plan-position of described mammary gland die body, the beamwidth being irradiated to described mammary gland die body is made to meet requirement in the vertical.
In specific implementation, by changing voltage, half-value layer, milliampere-second, the air kerma rate of described x-ray source (X-ray machine), the mean dose distribution under different effective energy can also be obtained;
Read mammary gland in the distribution of each mean dose longitudinal between chest wall to nipple, laterally from the dosage distributed points numerical value measuring center point to skin, take out maximum and minimum of a value in all directions to compare, obtain the optimal dose distribution under some values of described voltage, half-value layer, milliampere-second, air kerma rate;
Under described optimal dose distribution occasion, carry out standard X-ray tomography CT imaging, thus obtain the optimized image resolution ratio under described optimal dose distribution occasion.
As can be seen here, by said method embodiment, just can guarantee the dosage guidance level that total Average Glandular Dose is no more than or photographs lower than typical adult person under inspection breast X-ray, and the uniform dose distribution obtained in mammary gland body, obtain simultaneously and divide at most uniform dose the optimum picture quality planted, reduce the gland tissue damage because the high body of gland dosage of dosage skewness or local causes, avoid the secondary causing cancer to occur.
The embodiment of the present invention additionally provides a kind of mammary gland dosage distribution detecting device for the special CT equipment of mammary gland, be illustrated in figure 4 the structural representation of embodiment of the present invention institute generator, device described in Fig. 4 comprises X-ray baffle plate 1, X-ray machine 2, slit and filter disc 3, mammary gland die body 4, bracing frame 5, slide rail 6, bearing plate 7 and electric rotating machine 8, wherein:
Described X-ray machine 2 (i.e. x-ray source), slit and filter disc 3, mammary gland die body 4 hang on described X-ray baffle plate 1, this X-ray baffle plate 1 is for having the bed body of the effect of being in the light, the light pipe of described X-ray machine 2 is simulated, and carry out flow estimation, determine line be uniformly distributed under photon shooting angle, and the spectral information under obtaining respective angles; The mode of specifically carrying out simulating is shown in described in above embodiment of the method.
Mammary gland die body 4 is vertically downward placed in light path can the not extruded mammary gland vertically downward of Reality simulation, and the mammary gland size of this mammary gland die body 4, body of gland and fat components ratio can set as required; Can place thermoluminescent dosemeter and/or X-ray film dosimeter in described mammary gland die body 4, the placement location of this thermoluminescent dosemeter covers the transverse axis position of described mammary gland die body, longitudinal axis position and nearly skin area; Described mammary gland die body 4 needs the position establishing crucial dose point in the distribution of mammary gland dosage detects, and described X-ray machine 2 is to the distance of described mammary gland die body 4 central plane; The mode of specific implementation is shown in described in above embodiment of the method.
Regulate described X-ray machine 2, amplification ratio distance between mammary gland die body 4 and bracing frame 5 by described slide rail 6, described mammary gland die body 4 is all placed in light path.Wherein, bracing frame 5 can hang detector, and this detector is used for determining the CT imaging after exposure dose distribution, and by described detector as far as possible near described mammary gland die body 4.
The two pieces of bearing plates 7 utilizing described electric rotating machine 8 to hold up are to rotate described X-ray machine 2 and bracing frame 5, described mammary gland die body 4 is carried out to the X-ray scanning in each orientation, and Average Glandular Dose value and the normalization body of gland dose factor of described mammary gland die body 4 is obtained according to obtained spectral information, realize the detection of mammary gland dosage distribution.The mode of specifically carrying out detecting is shown in described in above embodiment of the method.
In sum, because the embodiment of the present invention have employed said structure and implementation method, be both convenient to detection and the system parameter settings of mammary gland dosage, be conducive to again the true dose distribution obtained in Special breast CT machine light path; Can also guarantee be no more than at total Average Glandular Dose or under dosage guidance level lower than the photography of typical adult person under inspection breast X-ray, obtain the uniform dose distribution in mammary gland body simultaneously, obtain and divide at most uniform dose the optimum picture quality planted.
The above; be only the present invention's preferably detailed description of the invention, but protection scope of the present invention is not limited thereto, is anyly familiar with those skilled in the art in the technical scope that the present invention discloses; the change that can expect easily or replacement, all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection domain of claims.
Claims (5)
1., for a mammary gland dosage distribution detection method for the special CT equipment of mammary gland, it is characterized in that, described method comprises:
First to the light pipe simulation of the x-ray source that reality uses, and carry out flow estimation, determine line be uniformly distributed under photon shooting angle, and the spectral information under obtaining respective angles;
Utilize the mammary gland die body being applicable to Asians's mammary gland size, body of gland and fat components ratio, establish at mammary gland dosage
The position of crucial dose point during distribution detects, and described x-ray source is to the distance of described mammary gland die body central plane;
Utilize described x-ray source to carry out the X-ray scanning in each orientation to described mammary gland die body, and obtain Average Glandular Dose value and the normalization body of gland dose factor of described mammary gland die body according to obtained spectral information, realize the detection of mammary gland dosage distribution;
Wherein, described method also comprises:
Arrange thermoluminescent dosemeter in described mammary gland die body, the placement location of this thermoluminescent dosemeter covers the transverse axis position of described mammary gland die body, longitudinal axis position and nearly skin area;
Pen type ionisation chamber is placed in the shaft core position of described mammary gland die body, the location point measured by this pen type ionisation chamber as dosage reference point, and utilizes thermoluminescent dosemeter and X-ray film dosimeter to carry out the detection of dosage distribution.
2., as claimed in claim 1 for the mammary gland dosage distribution detection method of the special CT equipment of mammary gland, it is characterized in that, carrying out in X-ray scanning process, described method also comprises:
According to the size of described mammary gland die body, adjust described x-ray source subtended angle angle and the described x-ray source distance to described mammary gland die body central plane, to regulate the measuring center plan-position of described mammary gland die body, the beamwidth being irradiated to described mammary gland die body is made to meet requirement in the vertical.
3., as claimed in claim 1 for the mammary gland dosage distribution detection method of the special CT equipment of mammary gland, it is characterized in that,
When utilizing thermoluminescent dosemeter to measure, completed by the mode of monolithic demarcation, grouping mea-sure, to improve the accuracy that thermoluminescent dosemeter detects.
4., as claimed in claim 1 for the mammary gland dosage distribution detection method of the special CT equipment of mammary gland, it is characterized in that, described method also comprises:
Change the voltage of described x-ray source, half-value layer, electric current, irradiation time, air kerma rate, obtain the dosage distribution under different effective energy;
Read the lower mammary gland of each dosage distribution longitudinal between chest wall to nipple, laterally from the dosage distributed points numerical value measuring center point to skin, take out maximum and minimum of a value in all directions to compare, obtain the optimal dose distribution under some values of described voltage, half-value layer, electric current, irradiation time, air kerma rate;
Under described optimal dose distribution occasion, carry out standard X-ray tomography CT imaging, obtain the optimized image resolution ratio under described optimal dose distribution occasion.
5., for a mammary gland dosage distribution detecting device for the special CT equipment of mammary gland, it is characterized in that, described device comprises X-ray baffle plate, X-ray machine, slit and filter disc, mammary gland die body, slide rail, bracing frame, bearing plate and electric rotating machine, wherein:
Described X-ray machine, slit and filter disc, mammary gland die body hang on described X-ray baffle plate, this X-ray baffle plate is the bed body with the effect of being in the light, and simulates, and carry out flow estimation to the light pipe of described X-ray machine, determine line be uniformly distributed under photon shooting angle, and the spectral information under obtaining respective angles;
Mammary gland die body is vertically downward placed in light path can the not extruded mammary gland vertically downward of Reality simulation, and the mammary gland size of this mammary gland die body, body of gland and fat components ratio can set as required; Thermoluminescent dosemeter is placed in described mammary gland die body, the placement location of this thermoluminescent dosemeter covers the transverse axis position of described mammary gland die body, longitudinal axis position and nearly skin area, pen type ionisation chamber is placed in the shaft core position of described mammary gland die body, the location point measured by this pen type ionisation chamber as dosage reference point, and utilizes thermoluminescent dosemeter and X-ray film dosimeter to carry out the detection of dosage distribution; Described mammary gland die body needs the position establishing crucial dose point in the distribution of mammary gland dosage detects, and described X-ray machine is to the distance of described mammary gland die body central plane;
Regulate described X-ray machine, amplification ratio distance between mammary gland die body and bracing frame by described slide rail, described mammary gland die body is all placed in light path; Wherein, bracing frame is hung with detector, and this detector is used for determining the CT imaging after exposure dose distribution, and described detector is as far as possible near described mammary gland die body;
The two pieces of bearing plates utilizing described electric rotating machine to hold up are to rotate described X-ray machine and bracing frame, described mammary gland die body is carried out to the X-ray scanning in each orientation, and Average Glandular Dose value and the normalization body of gland dose factor of described mammary gland die body is obtained according to obtained spectral information, establish the boundary condition of die body dosage measurement, realize the detection of mammary gland dosage distribution.
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Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102961160B (en) * | 2012-10-30 | 2016-01-06 | 中国科学院高能物理研究所 | A kind of compound filter compensated spectrum modulating device |
| CN104111469B (en) * | 2013-04-17 | 2015-06-10 | 上海联影医疗科技有限公司 | Method for simulating attenuation intensity of X ray penetrating body assembly |
| KR101500481B1 (en) * | 2014-01-24 | 2015-03-10 | 연세대학교 원주산학협력단 | Average glandular dose calculation method for digital mammography and digital breast tomosynthesis and computer readable record-midium on which program for excuiting method thereof |
| CN104076310B (en) * | 2014-07-17 | 2017-01-11 | 中国科学院高能物理研究所 | Device for performance testing and dosage estimation of CT device special for mammary gland |
| CN109239755A (en) * | 2018-09-26 | 2019-01-18 | 深圳蓝韵医学影像有限公司 | Calculate mammary X-ray system Average Glandular Dose method, system, equipment and medium |
| CN112946714A (en) * | 2021-01-22 | 2021-06-11 | 益阳市计量测试检定所 | Device for detecting double-source CT radiation volume dose index and using method |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101011617A (en) * | 2006-12-29 | 2007-08-08 | 成都川大奇林科技有限责任公司 | Method for determining radiating field output dose accurately in conformalradiotherapy |
| CN201226027Y (en) * | 2008-06-12 | 2009-04-22 | 中国测试技术研究院辐射研究所 | Detector for strong-regulating dose distribution map |
| CN201591544U (en) * | 2009-12-21 | 2010-09-29 | 中国科学院高能物理研究所 | Prone positive electron emitting imaging equipment for diagnosing breast cancer |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007062178A2 (en) * | 2005-11-21 | 2007-05-31 | The Regents Of The University Of California | Method for computing patient radiation dose in computed tomoraphy |
| JP2011024773A (en) * | 2009-07-24 | 2011-02-10 | National Institute Of Advanced Industrial Science & Technology | X-ray component measuring apparatus |
-
2012
- 2012-03-29 CN CN201210088944.XA patent/CN102621576B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101011617A (en) * | 2006-12-29 | 2007-08-08 | 成都川大奇林科技有限责任公司 | Method for determining radiating field output dose accurately in conformalradiotherapy |
| CN201226027Y (en) * | 2008-06-12 | 2009-04-22 | 中国测试技术研究院辐射研究所 | Detector for strong-regulating dose distribution map |
| CN201591544U (en) * | 2009-12-21 | 2010-09-29 | 中国科学院高能物理研究所 | Prone positive electron emitting imaging equipment for diagnosing breast cancer |
Non-Patent Citations (5)
| Title |
|---|
| Beam hardening correction for a cone-beam CT system and its effect on spatial resolution;ZHAO Wei等;《Chinese Physics C》;20111031;第35卷(第10期);全文 * |
| Dose Distribution in Cone-Beam Breast Computed Tomography: An Experimental Phantom Study;Paolo Russo等;《IEEE TRANSACTIONS ON NUCLEAR SCIENCE》;20100228;第57卷(第1期);全文 * |
| High resolution dual detector volume-of-interest cone beam breast CT––Demonstration with a bench top system;Youtao Shen等;《Med.Phys.》;20111231;第38卷(第12期);第6431-6439页的第II-III部分、图1-9、表I-III * |
| Radiation doses in cone-beam breast computed tomography A Monte Carlo simulation study;Ying Yi等;《Med.Phys.》;20110228;第38卷(第2期) * |
| Scatter enhanced breast CT using a mono-energetic first generation scanner：Feasibility study;J.E.Alpuche Aviles等;《IEEE Nuclear Science Symposium Conference Record》;20081231;全文 * |
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