CN102961160B - A kind of compound filter compensated spectrum modulating device - Google Patents
A kind of compound filter compensated spectrum modulating device Download PDFInfo
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- CN102961160B CN102961160B CN201210425016.8A CN201210425016A CN102961160B CN 102961160 B CN102961160 B CN 102961160B CN 201210425016 A CN201210425016 A CN 201210425016A CN 102961160 B CN102961160 B CN 102961160B
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Abstract
The invention discloses a kind of compound filter compensated spectrum modulating device.Described device comprises by the high density filtering optimization sheet having K layer characteristic absorption sapwood material and be made, low-density filtering compensation sheet, filter disc connecting device and external support support, described high density filtering optimization sheet and described low-density filtering compensation sheet are joined together to form complex spectrum manipulator by wherein said filter disc connecting device, and described low-density filtering compensation sheet is positioned at the side near X-ray source; Described complex spectrum manipulator is supported the ad-hoc location be arranged between X-ray source and breast to be detected by described external support support, and described external support support is fixing on the supporting plate.For DBCT system under the prerequisite ensureing reconstructed image quality, the dosage that patient accepts can be reduced, significantly improves the diagnosis success rate of system to mastopathy simultaneously, and the spectral distribution being more suitable for breast imaging is provided by this device.
Description
Technical field
The present invention relates to breast imaging technical field, particularly relate to a kind of compound filter compensated spectrum modulating device.
Background technology
At present, mastopathy is the most common in women's diseases, and the fatality rate of breast carcinoma occupy the second in female tumor.It is the effective means improving its cure rate to the early detection of breast carcinoma, in order to reduce the diagnosis of mammary gland biopsy, create in a large number for the Nondestructive method of mastopathy, mainly comprise: molybdenum target breast X-ray is photographed, ultrasonic breast examination, magnetic resonance (MRI) breast examination and other functional imaging methods.Wherein the photography of molybdenum target breast X-ray is current use is the most also the most effective breast carcinoma earlier detection method, but its by the breast structure information superposition of three-dimensional in the plane of two dimension, cause detection sensitivity relatively low, in addition, mammography for diagnosing is also very low for the breast disease diagnosis success rate of compactness.
In order to improve the diagnosis success rate to mastopathy, a kind of new breast imaging technology of rising in recent years, i.e. the special CT technology (DBCT) of mammary gland, it rebuilds mammary gland interior three-dimensional structure by mammary gland at the data for projection of different directions.DBCT system can provide higher picture contrast and spatial resolution under the dosage identical with two frame mammography for diagnosing, possesses the ability of microcalcifications and several millimeters of focuses (lump) can differentiating 100 to 200 micron dimensions, compared with traditional mammography for diagnosing, DBCT system has many good qualities, if provide mammary gland tomograph, can to finer and close mammary gland tissue imaging, corpus mamma dose distribution during imaging evenly, when patient detects, comfort level improves, and simultaneously can provide higher spatial positioning accuracy etc. for pathology detection and treatment.
But the weak point that above-mentioned DBCT system exists is exactly it would be better mammography for diagnosing for the detection of microcalcifications, in order to improve the power of test to microcalcifications further, improve DBCT system to the diagnosis performance of mastopathy, need to make full use of photon information under limited roentgendosis.A kind of feasible way is exactly carry out modulation optimization to the X-ray spectrum of incidence, dose efficiency time namely by changing the distribution intensity of spectrum and improving imaging and image quality, thisly can be called optical spectral modulator to the device that spectrum is modulated.But DBCT system is as a kind of novel breast imaging equipment, the optical spectral modulator development used for it is still in the elementary step, therefore is necessary the design carrying out optical spectral modulator for this special imaging configuration of breast, to improve the overall performance of DBCT system.
Summary of the invention
The object of this invention is to provide a kind of compound filter compensated spectrum modulating device, can for DBCT system under the prerequisite ensureing reconstructed image quality, reduce the dosage that patient accepts, significantly improve the diagnosis success rate of system to mastopathy simultaneously, and the spectral distribution being more suitable for breast imaging is provided.
The object of the invention is to be achieved through the following technical solutions, a kind of compound filter compensated spectrum modulating device, described device comprises by the high density filtering optimization sheet having characteristic absorption sapwood material and be made, the low-density filtering compensation sheet be made by the material close with mammary gland linear attenuation coefficient, filter disc connecting device and external support support, wherein:
Described high density filtering optimization sheet and described low-density filtering compensation sheet are joined together to form complex spectrum manipulator by described filter disc connecting device, and described low-density filtering compensation sheet is positioned at the side near X-ray source;
Described complex spectrum manipulator is supported the ad-hoc location be arranged between X-ray source and breast to be detected by described external support support, and described external support support is fixing on the supporting plate;
The X-ray sent from described X-ray source passes breast to be detected after described complex spectrum modulators modulate, and the structural information of carrying described breast to be detected is received by x-ray detector.
The structure size of described complex spectrum manipulator and position are determined according to X-ray source and the position of x-ray detector and the shape of breast to be detected, and different X-ray total penetrating length in described complex spectrum manipulator and described breast to be detected is remained unchanged.
The structure of described low-density filtering compensation sheet is the reeded cuboid of a band, described groove is relevant with shape with the attitude of described breast to be detected, the cross section of described groove is the two-dimensional symmetric curved surface of CT rotating shaft place vertical plane, and the side at groove surface place is the side close to breast to be detected;
X-ray in the different angles of departure that described X-ray source sends is through described low-density filtering compensation sheet, and the filter disc different by thickness is modulation compensated.
The structure of described high density filtering optimization sheet is the thin slice of thickness equalization, and its thickness decides by allowing the dosage accepted when the attenuation ratio of incident X-rays spectrum and described breast imaging to be detected;
Described high density filtering optimization sheet passes through the resonance absorption realization modulation to incident X-rays spectrum of K electron to incident photon of its material atom, and described high density filtering optimization sheet absorbs the photon produced by Compton Compton scattering by described low-density filtering compensation sheet, realizes compound filter.
Described high density filtering optimization sheet is made by cerium or gadolinium material;
Described low-density filtering compensation sheet is made by lucite.
As seen from the above technical solution provided by the invention, described device comprises by the high density filtering optimization sheet having K layer characteristic absorption sapwood material and be made, the low-density filtering compensation sheet be made by the material close with mammary gland linear attenuation coefficient, filter disc connecting device and external support support, described high density filtering optimization sheet and described low-density filtering compensation sheet are joined together to form complex spectrum manipulator by wherein said filter disc connecting device, and described low-density filtering compensation sheet is positioned at the side near X-ray source; Described complex spectrum manipulator is supported the ad-hoc location be arranged between X-ray source and breast to be detected by described external support support, and described external support support is fixing on the supporting plate; The X-ray sent from described X-ray source passes breast to be detected after described complex spectrum modulators modulate, and the structural information of carrying described breast to be detected is received by x-ray detector.For DBCT system under the prerequisite ensureing reconstructed image quality, the dosage that patient accepts can be reduced, significantly improves the diagnosis success rate of system to mastopathy simultaneously, and the spectral distribution being more suitable for breast imaging is provided by this device.
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 structural representation that Fig. 1 applies in the special CT system of mammary gland for the compound filter compensated spectrum modulating device that the embodiment of the present invention provides;
The structural representation of the complex spectrum manipulator that Fig. 2 provides for the embodiment of the present invention;
Fig. 3 be in the embodiment of the present invention incident light spectrum by have K layer characteristic absorption limit high density filtering optimization sheet modulation after distribution schematic diagram;
Fig. 4 is that the incident light spectrum of intensity of the same race is through the outgoing spectrum schematic diagram after different-thickness lucite;
Fig. 5 by intensity spectrum of the same race through in prior art the outgoing spectrum schematic diagram after employing aluminum;
Fig. 6 is the change schematic diagram that incident light spectrum passes average energy after after bi-material.
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.
The compound filter compensated spectrum modulating device that the embodiment of the present invention provides is in conjunction with attitude during breast imaging to be detected and shape, by high density filtering optimization sheet and low-density filtering compensation sheet, the modulation of horizontal direction and rotating shaft place vertical is realized simultaneously to incident X-rays spectrum, the complex spectrum manipulator of two kinds of filter discs composition is by the filtering compensation of different x-ray bundle and the resonance absorption that connect light source and detector pixel, reach the modulation to the incident X-rays spectrum of scanning breast to be detected and optimization, realize reducing breast acceptable dose, improve the object of image quality.Below in conjunction with accompanying drawing, the embodiment of the present invention is described in further detail, the structural representation that the compound filter compensated spectrum modulating device that being illustrated in figure 1 the embodiment of the present invention provides is applied in the special CT system of mammary gland, be illustrated in figure 2 the structural representation of the complex spectrum manipulator that the embodiment of the present invention provides, composition graphs 1 and Fig. 2, described compound filter compensated spectrum modulating device mainly comprises by the high density filtering optimization sheet 2 having feature (such as K layer feature) ABSORPTION EDGE material and be made, the low-density filtering compensation sheet 1 be made by the material close with mammary gland linear attenuation coefficient, filter disc connecting device and external support support 7, wherein:
High density filtering optimization sheet 2 and low-density filtering compensation sheet 1 are joined together to form complex spectrum manipulator 4 by described filter disc connecting device, and low-density filtering compensation sheet 1 is positioned at the side near X-ray source 3;
Described complex spectrum manipulator 4 is supported the ad-hoc location be arranged between X-ray source 3 and breast to be detected 5 by described external support support 7, and described external support support is fixed in gripper shoe 8;
The X-ray sent from described X-ray source 3 passes breast 5 to be detected after described complex spectrum manipulator 4 is modulated, and the structural information of carrying described breast to be detected 5 is received by x-ray detector 6, in specific implementation, motor 9 also can be utilized to rotate obtain breast 5 to be detected in the projection of different angles, finally utilize three dimensional structure image and then the diagnosis of breast diseases of algorithm for reconstructing reconstructive breast.
In specific implementation, the material that above-mentioned low-density filtering compensation sheet 1 uses same breast attenuation quotient close, except using lucite, also can use the low density material of other easy-formations, as polrvinyl chloride (PVC) etc.; Above-specified high density filtering optimization sheet 2 uses the material with K characteristic absorption limit, and ABSORPTION EDGE characteristic of correspondence energy is between 30keV to 60keV, except using cerium, also can use other materials, as gadolinium etc.
In specific implementation, the structure size of described complex spectrum manipulator 4 and position are determined according to X-ray source 3 and the position of x-ray detector 6 and the shape of breast to be detected 5.For different mammary gland CT equipment, the principle of complex spectrum modulator design ensures that the projection of breast to be detected on x-ray detector is almost finally constant, namely different X-ray total penetrating length in complex spectrum manipulator and breast to be detected almost remains unchanged, and incident photon energy is optimized to the energy section of the most applicable breast imaging to be detected.
As shown in Figure 2: the structure of low-density filtering compensation sheet 1 is the reeded cuboid of a band, described groove is relevant with shape with the attitude of described breast to be detected, the cross section of described groove is the two-dimensional symmetric curved surface of CT rotating shaft place vertical plane, and the side at groove surface place is the side close to breast to be detected;
X-ray in the different angles of departure that described X-ray source 3 sends is through described low-density filtering compensation sheet 1, and the filter disc different by thickness is modulation compensated.Specifically, X-ray X-ray source distally sends, X-ray in the different angle of departure is modulation compensated by the filter disc that thickness is different through described low-density filtering compensation sheet, modulation compensated principle is when X-ray needs to run through longer distance in breast to be detected, the length that X-ray decays in described low-density filtering compensation sheet is just less, when penetrating length is less in breast to be detected for X-ray, its attenuation length in described low-density filtering compensation sheet is just larger, to ensure that total attenuation length almost remains unchanged, such as in horizontal plane near the breast tissue in thoracic cavity, central ray penetrating length is wherein the longest, then the length that decays in low-density filtering compensation sheet of X-ray is just minimum.
The structure of Fig. 2 middle-high density filtering optimization sheet 2 is the thin slice of thickness equalization, and its thickness decides by allowing the dosage accepted when the attenuation ratio of incident X-rays spectrum and described breast imaging to be detected;
High density filtering optimization sheet 2 passes through the resonance absorption realization modulation to incident X-rays spectrum of K electron to incident photon of its material atom, and high density filtering optimization sheet 2 absorbs the photon produced by Compton scattering Compton scattering by described low-density filtering compensation sheet, realize compound filter, improve breast imaging quality further; Specifically, for the special CT equipment of mammary gland, incident photon is multi-color spectrum, only when incident photon is certain specific energy, can obtain maximum dose efficiency during system imaging, the effect of high density filtering optimization sheet 2 is exactly the energy range incident light spectrum of polychrome being modulated to the most applicable breast imaging.
Be described with the specific works process of concrete example to above-mentioned compound filter compensated spectrum modulating device below, composition graphs 1 and Fig. 2:
Be the lucite cuboid of 70mm × 100mm × 130mm sized by the substrate of low-density filtering compensation sheet 1, in the side towards breast, remove a symmetrical grooves, channel section is Two-dimensional Surfaces ABCD, and this Two-dimensional Surfaces is determined by such as under type:
First, in horizontal plane, be that circular condition determines the compensation thickness that different ray emission angle is corresponding, terminal forming curves ACB on lucite of compensation according to cross section during breast imaging; Secondly in the vertical plane at the center of mistake, according to cross section during breast imaging be oval condition determine different ray vertical subtended angle time corresponding compensation thickness, determine compensating curve CD; Then to use the same method the compensating curve ADB determining that lucite is corresponding being parallel to X-ray detector plane, finally utilize the method for Two-dimensional Surfaces interpolation to obtain whole compensation curved surface ABCD according to these three curves.In this example, the thinnest compensation thickness is 20mm, penetrating length maximum in corresponding breast.
In Fig. 2: connect high density filtering optimization sheet 2 at above-mentioned lucite near the end face of breast, in the present embodiment, this high density filtering optimization sheet 2 adopts cerium (Ce) material of the corresponding 40.4keV of K ABSORPTION EDGE characteristic energy, its thickness (being required to determine by incident X-rays intensity and breast imaging) is 0.15mm, in actual use, can regulate thickness according to image-forming condition.Because the photon of different-energy is different to dose efficiency during breast imaging, therefore wish during imaging that the score shared in spectrum of the maximum photon of dose efficiency is maximum, filtered by the optimization of cerium material, the score be used in incident light spectrum near 40keV shared by photon can be significantly improved, be illustrated in figure 3 incident light spectrum in the embodiment of the present invention by the distribution schematic diagram had after the high density filtering optimization sheet modulation on K layer characteristic absorption limit, as can be known from Fig. 3: the spectrum after optimization can when ensureing image quality, the radiation dose that breast accepts is minimum, thus realize the highest photon doses efficiency.
In Fig. 1: X-ray source is respectively 740mm to the distance of X-ray detector and center of rotation, 560mm, complex spectrum manipulator near light source side to the distance of light source focus be 280mm.In the present embodiment, this complex spectrum manipulator is not arranged on X-ray source exit portal, therefore insensitive for small displacement error, reduces the difficulty of installation.Except the structure described in the present embodiment, can also according to different mammary gland special CT equipment, design different size complex spectrum manipulator.
The compound filter compensated spectrum modulating device that the embodiment of the present invention provides is conducive to provide the better spectrum of Space Consistency, be illustrated in figure 4 the incident light spectrum of intensity of the same race through the outgoing spectrum schematic diagram after different-thickness lucite, be illustrated in figure 5 intensity spectrum of the same race through in prior art adopt the outgoing spectrum schematic diagram after aluminum, be illustrated in figure 6 the change schematic diagram of incident light spectrum through average energy rear after bi-material, from above-mentioned Fig. 4, known in Fig. 5 and Fig. 6: the spectrum impact of the embodiment of the present invention on differential declines length is less, that is can provide concordance better imaging spectral, be conducive to reducing imaging artefacts, improve image quality.
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 (3)
1. a compound filter compensated spectrum modulating device, it is characterized in that, described device comprises by the high density filtering optimization sheet having characteristic absorption sapwood material and be made, the low-density filtering compensation sheet be made by the material close with mammary gland linear attenuation coefficient, filter disc connecting device and external support support, wherein:
Described high density filtering optimization sheet and described low-density filtering compensation sheet are joined together to form complex spectrum manipulator by described filter disc connecting device, and described low-density filtering compensation sheet is positioned at the side near X-ray source;
Described complex spectrum manipulator is supported the ad-hoc location be arranged between X-ray source and breast to be detected by described external support support, and described external support support is fixing on the supporting plate;
The X-ray sent from described X-ray source passes breast to be detected after described complex spectrum modulators modulate, and the structural information of carrying described breast to be detected is received by x-ray detector;
Wherein, the structure size of described complex spectrum manipulator and position are determined according to X-ray source and the position of x-ray detector and the shape of breast to be detected, and different X-ray total penetrating length in described complex spectrum manipulator and described breast to be detected is remained unchanged;
The structure of described low-density filtering compensation sheet is the reeded cuboid of a band, described groove is relevant with shape with the attitude of described breast to be detected, the cross section of described groove is the two-dimensional symmetric curved surface of CT rotating shaft place vertical plane, and the side at groove surface place is the side close to breast to be detected;
X-ray in the different angles of departure that described X-ray source sends is through described low-density filtering compensation sheet, and the low-density filtering compensation sheet different by thickness is modulation compensated.
2. compound filter compensated spectrum modulating device as claimed in claim 1, is characterized in that,
The structure of described high density filtering optimization sheet is the thin slice of thickness equalization, and its thickness decides by allowing the dosage accepted when the attenuation ratio of incident X-rays spectrum and described breast imaging to be detected;
Described high density filtering optimization sheet passes through the resonance absorption realization modulation to incident X-rays spectrum of K electron to incident photon of its material atom, and described high density filtering optimization sheet absorbs the photon produced by Compton scattering by described low-density filtering compensation sheet, realizes compound filter.
3. compound filter compensated spectrum modulating device as claimed in claim 1, it is characterized in that, described high density filtering optimization sheet is made by cerium or gadolinium material;
Described low-density filtering compensation sheet is made by lucite.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3963933A (en) * | 1975-08-18 | 1976-06-15 | General Electric Company | Mammography fixture |
| US6345194B1 (en) * | 1995-06-06 | 2002-02-05 | Robert S. Nelson | Enhanced high resolution breast imaging device and method utilizing non-ionizing radiation of narrow spectral bandwidth |
| CN102621576A (en) * | 2012-03-29 | 2012-08-01 | 中国科学院高能物理研究所 | Glandular dose distribution detection method and device aiming at computed tomography (CT) equipment special for mammary gland |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| US6475150B2 (en) * | 2000-12-01 | 2002-11-05 | The Regents Of The University Of California | System and method for ultrasonic tomography |
| US6950492B2 (en) * | 2003-06-25 | 2005-09-27 | Besson Guy M | Dynamic multi-spectral X-ray projection imaging |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3963933A (en) * | 1975-08-18 | 1976-06-15 | General Electric Company | Mammography fixture |
| US6345194B1 (en) * | 1995-06-06 | 2002-02-05 | Robert S. Nelson | Enhanced high resolution breast imaging device and method utilizing non-ionizing radiation of narrow spectral bandwidth |
| CN102621576A (en) * | 2012-03-29 | 2012-08-01 | 中国科学院高能物理研究所 | Glandular dose distribution detection method and device aiming at computed tomography (CT) equipment special for mammary gland |
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