CN104306008A - Method for calibrating X-ray detector on basis of auxiliary module - Google Patents
Method for calibrating X-ray detector on basis of auxiliary module Download PDFInfo
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- CN104306008A CN104306008A CN201410563078.4A CN201410563078A CN104306008A CN 104306008 A CN104306008 A CN 104306008A CN 201410563078 A CN201410563078 A CN 201410563078A CN 104306008 A CN104306008 A CN 104306008A
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Abstract
The invention discloses a method for calibrating an X-ray detector on basis of an auxiliary module. According to the method, the auxiliary module detected along with a sample to be detected is provided; the auxiliary module and the sample to be detected are detected together. After primary imaging, the auxiliary module and an object to be detected are separated by graph partitioning and a recognition algorithm, module imaging data is compared with actual known features, a system is subjected to secondary calibration on basis of offline calibration, and imaging is performed again. The method according to the technical scheme has the advantages that parameters of the detector can be calibrated online during checking, image results are more precise and more accurate, image precision is improved, and cost is low.
Description
Technical field
The invention belongs to digital X ray detector field, be specifically related to a kind of X-ray detector calibration steps based on auxiliary die body.
Background technology
Along with the progress of technology, the initial analog imaging technology of X radial imaging is replaced by digital imaging technology substantially.For analog imaging technology, digital imaging technology is short with imaging time, and image quality is good is easy to the features such as transmission and storage with digital picture, and in medical science, industrial flaw detection, the fields such as public safety obtain a wide range of applications.
Digital X ray detector structural representation as shown in Figure 1, its operation principle is that the X-ray of incidence is after scintillation crystal layer is converted to visible ray, by non-crystalline silicon array photoelectric diode, optical signal is converted to electric charge, last reading circuit is converted to digital signal after taking out numbering one by one to charge signal, is resent to computer disposal.In the process, the visual intensity that beam intensity and the scintillation crystal layer of X-ray are changed is directly proportional, and the quantity of electric charge that visual intensity is changed to photodiode array is directly proportional, and therefore by after quantity of electric charge digitized, process obtains X-ray digital image.
By the restriction of manufacturing process and circuit characteristic, the scintillator on each pixel is different with non-crystalline silicon array photoelectric diode conversion efficiency, and under the condition that incident X-rays intensity is identical, the numerical values recited that each pixel obtains is different.Therefore the original image that detector exports has to pass through a series of trimming processes such as biased, gain and bad pixel.The gain calibration of current main flow first obtains the response (sky adopts image) without detector array under X-ray, then without the flat field image (sky expose to the sun image) of object-exposing under X-ray; Two secondary data are processed, detector is corrected.This method Problems existing is: the program belongs to off-line correction method, detector is subject to temperature, working condition, and service time etc. factor impact, its response becomes when being, when can not ensure timing parameter and use, the gain of parameter is completely the same, therefore needs regular correction, safeguards detector performance.And, owing to lacking standard shape, to the distortion of detector and the calibration result of scatter artefacts poor.
On this basis, patent CN201110260595-mono-kind apply to dull and stereotyped CCD distort bearing calibration give a kind of new off-line correction method.It is adopted image at sky and exposes to the sun on the basis of image with empty, adds the tabular component that planform known process has array hole, according to component diagram picture, after carrying out dividing processing to it.The distortion of detector and scatter artefacts are corrected.
A kind of method of on-line correction is given in patent CN201010520739-flat panel detector and temperature correction method thereof and method for correcting image.It is provided with several temperature sensor at flat panel detector back, according to the numerical value of temperature sensor, carries out difference matching to the temperature field at flat panel detector place.Then the estimation temperature on each detector pixel position is obtained.Finally, according to estimation temperature, the gain correction coefficient of calculating detector, corrects the gain of detector.This method, reduces the image of detector performance decay to imaging results.But cannot correct the distortion of detector and scatter artefacts.
In sum, the bearing calibration of moment detector can be divided into off-line calibration method and on-line calibration method two class.Off-line calibration method is namely before scanning testing sample, first special auxiliary die body imaging is obtained to the correction parameter of system, then machinery adjustment carried out to system or the correction parameter of trying to achieve is updated in image reconstruction program, ensureing that system maintains static afterwards, carry out testing sample test.On-line calibration is the information utilizing testing sample, carrys out the method for the correction parameter of anti-pushing system.
The advantage of off-line calibration is to adopt special auxiliary die body, can obtain the control information that system is whole; Defect is, corrects and gathers on two process times separate, and correction coefficient may, because reason partial failures such as time, temperature, frame for movements, cause image quality to decline.In system that on-line calibration method especially frequently adjusts at mechanical instability system, high-resolution, needs etc., there is advantage; But because the geological information of testing sample is unknown, be therefore difficult to obtain whole correction parameters.
The object of the invention is to, by the auxiliary die body of particular design, itself and testing sample are together detected.After preliminary imaging, adopt figure segmentation and recognizer, auxiliary die body is separated with object under test.Die body imaging data and the known contrast of actual geometric properties will be assisted, on the basis of off-line correction, after secondary correction is carried out to system, again carry out imaging, thus improve quality and the precision of imaging.
Summary of the invention
The object of the invention is to overcome prior art Problems existing, a kind of X-ray detector calibration steps based on auxiliary die body is provided.
For realizing above-mentioned technical purpose, reach above-mentioned technique effect, the present invention is achieved through the following technical solutions:
Based on an X-ray detector for auxiliary die body, include the auxiliary die body together carrying out with testing sample detecting.
Further, the nylon buckles that described auxiliary die body comprises upper and lower end face refers to band and nylon buckles wrist strap, be around in respectively nylon buckles refer to be with and nylon buckles wrist strap on using flexible wire, and be arranged on nylon buckles refer to be with nylon buckles wrist strap between multiple standard density modules, described standard density module forms an entirety by the mode of binding, and described standard density module refers to be with by carbon fiber band and nylon buckles and nylon buckles wrist strap engages.
Based on an X-ray detector calibration steps for auxiliary die body, by auxiliary die body, auxiliary die body and testing sample are together detected.After preliminary imaging, adopt figure segmentation and recognizer, die body and object under test are separated, by die body imaging data and the known contrast of actual geometric properties, on the basis of off-line correction, after secondary correction is carried out to system, again carry out imaging, specifically comprise the following steps:
Step 1, acquisition sky adopt image, gather the response without detector array under X-ray;
Step 2, obtain sky and to expose to the sun image, without the flat field image of object-exposing under X-ray;
Step 3, obtain correction parameter, carry out computing according to result, obtain the first time correction parameter and drift value of detector;
Step 4, patient scan, patient, when preparation room, brings medical correction die body, after 10 nylon buckles wrist straps are fastened wrist, adjusts 1 nylon buckles and refers to be with position, and finger band is buckled in little finger of toe root, then enter shielding house and prepare to check;
Step 5, preliminary images are rebuild, and after patient has been scanned, use correction parameter for the first time to carry out image reconstruction, obtain comprising die body and patient information preliminary reconstruction image;
Step 6, image characteristics extraction, carry out feature extraction to preliminary reconstruction image, dividing processing, obtains the image of die body portion;
Step 7, die body correct, and compare measured value and the theoretical value of detector on motif position, obtain the correction value of segment detector gain calibration parameter, then according to the dependency relation between detector, the anti-correction value pushing away the gain calibration parameter of whole detector;
Step 8, correction parameter correction, according to the shape facility of die body portion image and the true form of die body, obtain the correction value of segment detector geometric correction parameter, in the dependency relation according to sensitive detection parts, the anti-correction value pushing away the geometric correction parameter of whole detector;
Step 9, second time image reconstruction, will obtain the correction value of all correction parameters.Use revised correction parameter, initial data is processed, carry out second time image reconstruction;
Step 10, result export, and after having rebuild, result exported, for doctor and patient's reference, single pass flow process terminates, and carry out next patient or the detection of other testing sample then jumps to step 1 item and jumps to step 1.
Further, the theoretical calculation formula for pixel response each on this detector is as follows:
, wherein α is the attenuation quotient of die body A, relevant to x-ray photon energy, and δ is constant is-1000, and the pad value of water is made zero, and ε is the drift value of detector, due to die body density
known, so theoretical explorer response value can be calculated
, after theoretical value and actual acquisition value are compared process, new correction coefficient can be obtained.
Further, the method comprises the gain calibration parameters revision to detector and the geometric correction parameters revision to detector.
Further, in described step 4 and step 5, during testing sample non-patient, the setting position of auxiliary die body is be fixed on the one near conveyer belt, near detector, on testing sample among three.
The invention has the beneficial effects as follows:
1, by using special small-sized auxiliary die body, can when checking, on-line correction parameter detector, improves precision and the accuracy of image result, can revise equipment calibration parameter, to ensure the ageing of correction parameter while collection patient information.Meanwhile, because this die body uses when patient gathers simultaneously, do not affect the service life of equipment.Simultaneously according to correction situation, rationally can judge the opportunity of carrying out off-line correction, strengthen the interval of twice offline correction process, reduce the workload of off-line correction, improve service life and the effectiveness of equipment.
2, by rebuilding, revise the method for correction parameter, thus promote secondary reconstruction precision.
3, the present invention not only can revise the gain calibration parameter of detector, also can revise the geometric correction parameter of detector.Meanwhile, the present invention does not need to increase temperature sensor after detector, to check temperature field situation.Reduce further cost and manufacture difficulty.
Accompanying drawing explanation
Fig. 1 is common digital X ray detector structural representation;
Fig. 2 is a kind of medical auxiliary die body structural representation in the present invention;
Fig. 3 is FB(flow block) of the present invention.
Number in the figure illustrate: 1, nylon buckles refer to band, 2,11, using flexible wire, 3,4,5,6,7,8,9, standard density module, 10, nylon buckles wrist strap, 11, using flexible wire, 12, non-crystalline silicon array, 13, row drive plate, 14, scintillator layers, 15, integrated circuit reads plate.
Detailed description of the invention
Below with reference to the accompanying drawings and in conjunction with the embodiments, describe the present invention in detail.
Based on an X-ray detector for auxiliary die body, it is characterized in that, include the auxiliary die body together carrying out with testing sample detecting.
With reference to shown in Fig. 2, the nylon buckles that described auxiliary die body comprises upper and lower end face refers to band 1 and nylon buckles wrist strap 10, be around in nylon buckles respectively and refer to using flexible wire 2 on band 1 and nylon buckles wrist strap 10 and using flexible wire 11, and be arranged on multiple standard density modules that nylon buckles refers between band 1 and nylon buckles wrist strap 10, the present embodiment is provided with seven, label is in Fig. 23 to 9, described standard density module forms an entirety by the mode of binding, by carbon fiber band and 1 nylon buckles, described standard density module refers to that band 1 and nylon buckles wrist strap 10 engage; Refer to band 1 and nylon buckles wrist strap 10 settle using flexible wire 2 and using flexible wire 11 at nylon buckles, bring the metal scattering of X-ray, enable the correction parameter of secondary correction carry out correction to a certain degree to scatter artefacts; Two tinsels when being imagings surround the diameter that annular can embody patients wrist and finger, are that body structures rebuilds, provide auxiliary parameter.
With reference to shown in Fig. 3, a kind of X-ray detector calibration steps based on auxiliary die body, is characterized in that, by auxiliary die body, auxiliary die body and testing sample is together detected.After preliminary imaging, adopt figure segmentation and recognizer, die body and object under test are separated, by die body imaging data and the known contrast of actual geometric properties, on the basis of off-line correction, after secondary correction is carried out to system, again carry out imaging, specifically comprise the following steps:
Step 1, acquisition sky adopt image, gather the response without detector array under X-ray;
Step 2, obtain sky and to expose to the sun image, without the flat field image of object-exposing under X-ray;
Step 3, obtain correction parameter, carry out computing according to result, obtain the first time correction parameter and drift value of detector;
Step 4, patient scan, patient, when preparation room, brings medical correction die body, after 10 nylon buckles wrist straps are fastened wrist, adjust 1 nylon buckles and refer to be with position, and finger band is buckled in little finger of toe root, then enter shielding house to prepare to check, wrist and refer to mainly carpal joint and articulations digitorum manus, muscle and fat less, by calculating the size of wire rings after imaging, effectively instead can release patient articular's size, hand size and skeleton density situation, accelerate to rebuild the speed calculated, promote the precision of images;
Step 5, preliminary images are rebuild, and after patient has been scanned, use correction parameter for the first time to carry out image reconstruction, obtain comprising die body and patient information preliminary reconstruction image;
Step 6, image characteristics extraction, carry out feature extraction to preliminary reconstruction image, dividing processing, obtains the image of die body portion;
Step 7, die body correct, and compare measured value and the theoretical value of detector on motif position, obtain the correction value of segment detector gain calibration parameter, then according to the dependency relation between detector, the anti-correction value pushing away the gain calibration parameter of whole detector;
Step 8, correction parameter correction, according to the shape facility of die body portion image and the true form of die body, obtain the correction value of segment detector geometric correction parameter, in the dependency relation according to sensitive detection parts, the anti-correction value pushing away the geometric correction parameter of whole detector;
Step 9, second time image reconstruction, will obtain the correction value of all correction parameters, use revised correction parameter, process initial data, carry out second time image reconstruction;
Step 10, result export, and after having rebuild, result exported, for doctor and patient's reference, single pass flow process terminates, and carry out next patient or the detection of other testing sample then jumps to step 1 item and jumps to step 1.
Theoretical calculation formula for pixel response each on this detector is as follows:
, wherein α is the attenuation quotient of die body A, relevant to x-ray photon energy, and δ is constant is-1000, and the pad value of water is made zero, and ε is the drift value of detector, due to die body density
known, so theoretical explorer response value can be calculated
, after theoretical value and actual acquisition value are compared process, new correction coefficient can be obtained.
The method comprises the gain calibration parameters revision to detector and the geometric correction parameters revision to detector.
In described step 4 and step 5, during testing sample non-patient, the setting position of auxiliary die body is be fixed on the one near conveyer belt, near detector, on testing sample among three.
The foregoing is only the preferred embodiments of the present invention, be not limited to the present invention, for a person skilled in the art, the present invention can have various modifications and variations.Within the spirit and principles in the present invention all, any amendment done, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.
Claims (8)
1. based on an X-ray detector for auxiliary die body, it is characterized in that, include the auxiliary die body together carrying out with testing sample detecting.
2. the X-ray detector based on auxiliary die body according to claim 1, it is characterized in that, the nylon buckles that described auxiliary die body comprises upper and lower end face refers to be with (1) and nylon buckles wrist strap (10), be around in nylon buckles respectively to refer to be with the using flexible wire (2 on (1) and nylon buckles wrist strap (10), 11), and be arranged on nylon buckles and refer to be with the multiple standard density modules between (1) and nylon buckles wrist strap (10), described standard density module forms an entirety by the mode of binding, described standard density module refers to be with (1) and nylon buckles wrist strap (10) to engage by carbon fiber band and (1) nylon buckles.
3. based on an X-ray detector calibration steps for auxiliary die body, it is characterized in that, by auxiliary die body, auxiliary die body and testing sample are together detected.
4., after preliminary imaging, adopt figure segmentation and recognizer, die body and object under test are separated, by die body imaging data and the known contrast of actual geometric properties, on the basis of off-line correction, after secondary correction is carried out to system, again carry out imaging, specifically comprise the following steps:
Step 1, acquisition sky adopt image, gather the response without detector array under X-ray;
Step 2, obtain sky and to expose to the sun image, without the flat field image of object-exposing under X-ray;
Step 3, obtain correction parameter, carry out computing according to result, obtain the first time correction parameter and drift value of detector;
Step 4, patient scan, patient, when preparation room, brings medical correction die body, after 10 nylon buckles wrist straps are fastened wrist, adjusts 1 nylon buckles and refers to be with position, and finger band is buckled in little finger of toe root, then enter shielding house and prepare to check;
Step 5, preliminary images are rebuild, and after patient has been scanned, use correction parameter for the first time to carry out image reconstruction, obtain comprising die body and patient information preliminary reconstruction image;
Step 6, image characteristics extraction, carry out feature extraction to preliminary reconstruction image, dividing processing, obtains the image of die body portion;
Step 7, die body correct, and compare measured value and the theoretical value of detector on motif position, obtain the correction value of segment detector gain calibration parameter, then according to the dependency relation between detector, the anti-correction value pushing away the gain calibration parameter of whole detector;
Step 8, correction parameter correction, according to the shape facility of die body portion image and the true form of die body, obtain the correction value of segment detector geometric correction parameter, in the dependency relation according to sensitive detection parts, the anti-correction value pushing away the geometric correction parameter of whole detector;
Step 9, second time image reconstruction, will obtain the correction value of all correction parameters.
5. use revised correction parameter, initial data is processed, carries out second time image reconstruction;
Step 10, result export, after having rebuild, by result export, for doctor and patient's reference, single pass flow process terminates, carry out next patient or other testing sample detection then jump to step 1.
6. the X-ray detector calibration steps based on auxiliary die body according to claim 3, is characterized in that, the theoretical calculation formula for pixel response each on this detector is as follows:
, wherein α is the attenuation quotient of die body A, relevant to x-ray photon energy, and δ is constant is-1000, and the pad value of water is made zero, and ε is the drift value of detector, due to die body density
known, so theoretical explorer response value can be calculated
, after theoretical value and actual acquisition value are compared process, new correction coefficient can be obtained.
7. the X-ray detector calibration steps based on auxiliary die body according to claim 3, is characterized in that, the method comprises the gain calibration parameters revision to detector and the geometric correction parameters revision to detector.
8. the X-ray detector calibration steps based on auxiliary die body according to claim 3, it is characterized in that, in described step 4 and step 5, during testing sample non-patient, the setting position of auxiliary die body is be fixed on the one near conveyer belt, near detector, on testing sample among three.
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| CN201410563078.4A CN104306008B (en) | 2014-10-22 | A kind of X-ray detector calibration steps based on auxiliary die body |
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| CN201410563078.4A CN104306008B (en) | 2014-10-22 | A kind of X-ray detector calibration steps based on auxiliary die body |
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| CN104306008A true CN104306008A (en) | 2015-01-28 |
| CN104306008B CN104306008B (en) | 2017-01-04 |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104898159A (en) * | 2015-05-13 | 2015-09-09 | 中国科学院苏州生物医学工程技术研究所 | Calibration method of energy resolution CT detector |
| CN105943067A (en) * | 2016-06-06 | 2016-09-21 | 辽宁开普医疗系统有限公司 | X-ray quality comparison evaluation device and method |
| CN108056785A (en) * | 2017-12-04 | 2018-05-22 | 上海奕瑞光电子科技股份有限公司 | A kind of update method of flat panel detector gain calibration template |
| CN111855709A (en) * | 2020-07-27 | 2020-10-30 | 湖北航天技术研究院计量测试技术研究所 | Imaging correction method of microfocus X-ray detector |
| CN113017657A (en) * | 2021-03-08 | 2021-06-25 | 中国计量科学研究院 | Method for calibrating projection area of dual-energy X-ray bone densitometer and die body |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1331571A (en) * | 1998-11-02 | 2002-01-16 | 模拟技术公司 | Appts. and method for calibrating detectors in compound tomography scanner |
| CN103315765A (en) * | 2012-03-21 | 2013-09-25 | 西门子公司 | Patient couch |
| DE102012215991A1 (en) * | 2012-09-10 | 2014-03-13 | Siemens Aktiengesellschaft | Checking the picture quality of recordings made by a recording system |
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1331571A (en) * | 1998-11-02 | 2002-01-16 | 模拟技术公司 | Appts. and method for calibrating detectors in compound tomography scanner |
| CN103315765A (en) * | 2012-03-21 | 2013-09-25 | 西门子公司 | Patient couch |
| DE102012215991A1 (en) * | 2012-09-10 | 2014-03-13 | Siemens Aktiengesellschaft | Checking the picture quality of recordings made by a recording system |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104898159A (en) * | 2015-05-13 | 2015-09-09 | 中国科学院苏州生物医学工程技术研究所 | Calibration method of energy resolution CT detector |
| CN104898159B (en) * | 2015-05-13 | 2017-11-03 | 中国科学院苏州生物医学工程技术研究所 | A kind of calibration method of energy resolution CT detectors |
| CN105943067A (en) * | 2016-06-06 | 2016-09-21 | 辽宁开普医疗系统有限公司 | X-ray quality comparison evaluation device and method |
| CN105943067B (en) * | 2016-06-06 | 2018-11-20 | 辽宁开普医疗系统有限公司 | A kind of X-ray quality versus assessment device and method |
| CN108056785A (en) * | 2017-12-04 | 2018-05-22 | 上海奕瑞光电子科技股份有限公司 | A kind of update method of flat panel detector gain calibration template |
| CN108056785B (en) * | 2017-12-04 | 2021-05-07 | 上海奕瑞光电子科技股份有限公司 | Updating method of gain correction template of flat panel detector |
| CN111855709A (en) * | 2020-07-27 | 2020-10-30 | 湖北航天技术研究院计量测试技术研究所 | Imaging correction method of microfocus X-ray detector |
| CN111855709B (en) * | 2020-07-27 | 2023-03-24 | 湖北航天技术研究院计量测试技术研究所 | Imaging correction method of microfocus X-ray detector |
| CN113017657A (en) * | 2021-03-08 | 2021-06-25 | 中国计量科学研究院 | Method for calibrating projection area of dual-energy X-ray bone densitometer and die body |
| CN113017657B (en) * | 2021-03-08 | 2022-09-16 | 中国计量科学研究院 | Method for calibrating projection area of dual-energy X-ray bone densitometer and die body |
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