A kind of method and device thereof that utilizes multipotency X ray compound-projection numeral compound imaging
Technical field
The present invention relates to digital X-ray image compound imaging application, relate in particular to a kind of synthetic method of multipotency X ray compound-projection digital image and device of utilizing.
Background technology
Because digital X-ray line photography (DR-Digital Radiography) has the following advantages with respect to film X-ray line photography: improve medical diagnosis on disease efficient and the radiation dose that reduces patient; And do not have environmental pollution, need not use film with and relevant chemical raw material.On overall, digital X-ray line photography is technical digital implementation and the digital image processing techniques utilized at traditional projection X-ray line photography.Digital X-ray line photography as a kind of be that it is made up of three parts usually: first is an X-ray source at projection X-ray line photography, comprise X-ray tube and relevant high voltage control circuit.Second portion is the X-line receiver, and two kinds of receive modes are arranged usually, and a kind of is that CCD (Charged-Coupled Devices) receives, and another kind is that quasiconductor dull and stereotyped (Flat Panel Detectors) receives.CCD (Charged-Coupled Devices) receptor at first converts the X-ray to visible light through a change-over panel (CsI) with it, and these visible lights just can be focused the CCD chip surface then, and absorb by it.The CCD chip is made up of one group of isolating semiconductor silicon integrating circuit or unit, and for example: the CCD chip of a 2.5x2.5cm can contain 1024x1024 circuit unit.To produce electronics after visible light is absorbed by the CCD chip surface and be stored on each unit, the power of light and electron number are directly proportional.These electronics can be read with the pattern of row output then.For the giant-screen receptor, need a point-device optical focusing lens that it is projected to the less CCD surface of relative area.Contain on the dull and stereotyped receptor of the quasiconductor surface and much independently accept the unit.Each unit can convert the X-ray of its acceptance to the signal of telecommunication, then these signals of telecommunication will be read with the mode of serial level and vertical line.The CCD receptor is relatively lower with the dull and stereotyped receptor cost of quasiconductor, but owing to it contains an optical focusing system, so its image resolution ratio and signal to noise ratio are lower, and volume is bigger.Third part is that data image signal is handled and pictorial display.For traditional film roentgenograph X art, digital X-ray line photography imaging has bigger dynamic indication range, and DR can make full use of the modern computer image processing techniques simultaneously, to realize best diagnosis effect.System is the basis with digital X-ray line photography, constantly develops the application technology that renewal in recent years: dual energy photography (Dual-energyRadiography), digital fault plane synthetic technology (Digital Tomosynthesis) or the like.Through these new The Application of Technology, make medical clinic applications more accurate.
The dual energy photography has been widely used in the angiography of X ray fluorescent screen.Because special electronics constraint efficiency should; The X ray absorption spectra of x-ray imaging agent material (like iodine, barium etc.) some energy section (~33keV) X-ray absorption coefficient of sudden change arranged, but the X-ray absorption coefficient of the tissue of human body does not have such sudden change in this energy section.The characteristics of utilizing these different X ray to absorb, we can produce two frame radioscopic images, and a frame is to be produced by the relative low-energy X-ray before the absorptance sudden change, and another frame then is to be produced by the relative high-energy X ray after the absorptance sudden change.Then this two frame of digital image is carried out weighted linear combination, just can get the radioscopic image that only contains contrast agent material.If contrast agent material only is contained in the blood of some blood vessel, we just can utilize it to diagnose the physiological function of blood vessel and near organ thereof.
Also have a kind of mode to be: in digital X-ray line photography imaging process, because different property (effective atomic number of soft tissue: Z=7.6, the effective atomic number of osseous tissue: Z=13) of the effective atomic number of interior soft tissue of human body and osseous tissue.(~50kVp) section, the X-gamma ray absorption coefficient is directly relevant with atomic number Z: with Z^3 proportional (mainly being photoelectric effect) low-yield.(~120kVp) section, X-gamma ray absorption coefficient and atomic number Z be pass (mainly being Compton effect) not and at high-energy.Be similar to double energy X-ray fluorescent screen angiography, we can produce two two field pictures, a frame be by low-yield relatively X-ray produce (~50kVp), another frame then be by relative high-energy X-ray produce (~120kVp).Then this two two field picture is carried out weighted linear combination, just can only be contained two frame radioscopic images of soft tissue (like the lung organ) or skeletal tissue's (like thoracic bone).
Although the dual energy method obtains in single projection imaging and should have, like X ray fluorescent screen angiography, it is also not accomplished in other imaging system, as aspect the digital fault plane compound imaging (DigitalTomosynthesis)." digital fault plane compound imaging " is a kind of new formation method.This technology and method will improve " contrast resolution " of image effectively, thereby can diagnose out the minor variations of the structure of matter effectively." fault plane compound imaging " is based on to blur and focusing on the projected image of fault plane with external structure, and the technology of preserving the projected image of the structure on the focusing surface.Up to the present, digital fault plane synthetic technology only utilizes the method for single energy to realize, and this technology is mainly used in the breast imaging system.Roundel is positioned at the focusing surface top, and square thing is arranged in focusing surface, and delta is positioned at the focusing surface below.When we with x-ray source when leftward position A moves to right positions B, the picture of X ray projection " A " and " B " also will change.In projection image " A ", the picture of left, middle and right is respectively " delta ", " square thing " and " roundel ".And in projection image " B ", the picture of left, middle and right is respectively " roundel ", " square thing " and " delta ".
Provided the image of these two projections, and the image of these two projections has been carried out simple linear, additive.We can see from the image of addition: being projected in the image after synthetic of roundel and delta, to be blured owing to be distributed in the left and right sides, and being projected in the image after synthetic of square thing is positioned at same position all the time and is retained.
The fault plane that the continuous development of Along with computer technology in recent years, traditional fault plane synthetic technology have been further expanded to numeral synthesizes.Adopt similar notion, when we move to position " B " with X-ray source from left-most position " A ", when " C " and " D " (right-most position), X ray projection imaging " A ", " B ", " C " and " D " also will change.We look like this four picture group to carry out translation and simple linear combination in various degree, just can obtain four new two field pictures.Every two field picture will keep the projection of the structure of certain specific fault plane, and blurs the projection of the structure of other aspect.Like this, finally we will obtain the image of the projection of a series of fault plane structures.These images can be used to clinical diagnosis these fault plane structure and characteristics thereof.The fault plane synthetic technology can make us see the structure that can't see in traditional projection imaging.
Because these advanced digital X-ray photography systems continue to bring out with technology, make that doctors can diagnose out the early stage pathological changes of patient more exactly clinically.Advantages such as these advanced digital X-ray photography systems compare with traditional CT simultaneously, can also keep relative less cost, and are easy to use, and X-radiation dosage is low.This patent invention will further develop these new techniques, with the fault plane formation method of the single energy that has the digital X-ray photography now and fault plane method for imaging and the equipment that equipment further develops multipotency.
Summary of the invention
The object of the present invention is to provide a kind of method and device thereof that utilizes multipotency X ray compound-projection numeral compound imaging; It is not enough to solve existing monoergic imaging technique definition effectively; Can not distinguish the problems such as structure of different tissues effectively, realize that the sensitivity and the degree of accuracy of diagnostic imaging significantly improves.
In order to solve the problems of the technologies described above, the present invention adopts following technical scheme:
A kind of method of utilizing multipotency X ray compound-projection numeral compound imaging is characterized in that in turn including the following steps:
The collection of A, projection image signal: adopt the X ray of n part different-energy to go out s part picture signal, n >=1, m >=1, s=n * m m different spatial projection respectively;
The pre-treatment of B, projected image: the projected image analogue signal is at first passed through signal amplifier and analog-digital converter, and the projected image analogue signal is amplified and converted data image signal to; Then data image signal is input to the digital picture pre-treating device; The digital picture pre-treating device is done compensation to the pixel cell sensitivity of each reception;
Synthesizing of C, projection digital picture: the digital picture of revising through the digital picture synthesizer, is utilized Digital Image Processing, synthesize a series of composite number word image;
The post processing of D, composite number word image: to satisfy the requirement of diagnosis;
The output of E, composite number word image: will handle the back image and export terminal unit to.
Preferably; Steps A adopts n part different-energy to carry out projection at other (m-1) individual different spaces projected position for the X ray that adopts n part different-energy earlier goes out n part image in a setting space position projection respectively again, i.e. projection produces s=n * m part image; N >=1, m >=1.
Preferred; Steps A goes out two parts of images in a setting space position projection respectively for adopting the X ray of two parts of different-energies earlier; Adopt two parts of different-energies to carry out projection at other (m-1) individual different spaces projected position again, i.e. projection produces s=2m part image, m >=1.
Preferably, steps A adopts the X ray of other (n-1) part different-energy to carry out projection respectively m position for the X ray that adopts a setting energy earlier goes out m part image m locus projection again, i.e. projection produces s=n * m part image, n >=1, m >=1.
Preferred, steps A adopts the X ray of another part different-energy to carry out projection m position for the X ray that adopts a setting energy earlier goes out m part image m locus projection again, i.e. projection produces s=2m part image, m >=1.
Preferably, the method that compensation is done in sensitivity to pixel cell among the step B is with a uniform X ray direct irradiation receptor, adjusts the gain of each pixel cell, makes from the picture signal of the same intensity of each pixel cell output.
Preferably, the digital picture pre-treating device also will be utilized the physical characteristic and the approximate hypothesis of scattered x-ray among the step B, scattered x-ray disturbed to received signal do correction.
Preferred, the method for correction is that scattered x-ray is evenly distributed on each regional area, and the decay of its scattering strength and each regional area X ray is proportional or proportional with the thickness of the tissue of the regional area that passes through.
Further, the digital picture pre-treating device also will be done the motion correction of projection digital picture among the step B, comprise the correction of human external motion to the image influence, to obtain the projection digital picture of moving displacement correction.
Preferably, the human external motion utilizes optical inductor people from location displacement body to being modified to of image influence, solves the displacement of human external structure relative motion.
Preferably, the human external motion is carried out Flame Image Process and image comparison to being modified to through the projected image to the human external feature structure of image influence, solves the displacement of human external structure relative motion.
Further, the digital picture pre-treating device also will be done the motion correction of projection digital picture among the step B, comprise the correction of inside of human body motion to the image influence, to obtain the projection digital picture of moving displacement correction.
Preferably; The inside of human body motion is to the cycle movement displacement that the signal that utilizes electrocardiograph is located inside of human body that is modified to of image influence; The signal of electrocardiograph can provide the periodic phase information of heartbeat; In identical phase place identical heartbeat displacement is arranged, solve the displacement of inside of human body relative motion.
Preferably; The inside of human body motion is carried out Flame Image Process and image comparison to being modified to through the projected image to the inside of human body structure of image influence; The relative motion of human organ border or shape of blood vessel characteristic defines inside of human body structure relative motion, solves the displacement of inside of human body structure relative motion.
Preferably; Among the step C synthesize earlier every same space angle but a fixed weighted linear combination is adopted in projection with different-energy earlier; To obtain the projection image of organ-/ tissue composition; Projection image with the organ-/ tissue of all projection angles makes up then, thereby produces one group of image that contains the fault plane structure of organ-/ tissue composition.
Preferably, among the step C synthesize earlier with one set the different angles of energy projection image synthesize, to obtain organizing the image of fault plane structure; Image with the formed fault plane of different-energy adopts weighting translation linear combination then, thereby obtains the image of organ-/ tissue composition fault plane structure.
Preferably, post processing comprises that the dynamic compression, dynamic image noise of digital picture reduce, image-region is selected among the step D, figure image intensifying, dynamic image show, obtains the image after a series of processing.
A kind of device that is used for realizing utilizing the method for multipotency X ray compound-projection numeral compound imaging like claim 1; It is characterized in that: comprise x-ray source and picture receiver; Picture receiver connects amplifier, analog-digital converter, digital projection picture pre-treating device, interim digital projection picture memorizer, Digital Image Processing and synthesizer, digital composograph preprocessor and digital composograph memorizer successively, and digital composograph memorizer connects final image display or computer network output.
Further; X-ray source connects x-ray source high-frequency and high-voltage control circuit and x-ray source position control circuit; Picture receiver connects the receptor control circuit, and x-ray source high-frequency and high-voltage control circuit, x-ray source position control circuit, receptor control circuit, Digital Image Processing and synthesizer, digital composograph preprocessor, digital composograph memorizer, final image display all connect terminal use's controller.
The present invention has following beneficial effect owing to adopted technique scheme:
The different X ray absorption characteristic that the present invention mainly combines the human body different tissues that X ray is had in the different energy section; Carrying out numeral with the digital picture of different spaces angle projection synthesizes; Finally obtain a series of high-contrasts, highly sensitive medical image; These images will comprise the surface information that is broken into of different material composition, can make the doctor diagnose the state of an illness more exactly.
The present invention is broken into scanning technique (CT-Computerized Tomography) with computer and compares, and has simple in structurely, and cost is low, and is easy to use, the advantage that X-radiation dosage is little.
The present invention can be applied to medical imaging, safety check appearance etc., also can method of the present invention be applied to the exploitation of breast machine and other specialized imaging of medical instruments.
Description of drawings
Below in conjunction with accompanying drawing the present invention is described further:
Fig. 1 utilizes the flow chart of the method for multipotency X ray compound-projection numeral compound imaging for the present invention is a kind of;
Fig. 2 utilizes the structured flowchart of multipotency X ray compound-projection numeral compound imaging device for the present invention is a kind of.
The specific embodiment
As shown in Figure 1, a kind of method of utilizing multipotency X ray compound-projection numeral compound imaging of the present invention in turn includes the following steps:
The collection of A, projection image signal: adopt the X ray of n part different-energy to go out s part picture signal, n >=1, m >=1, s=n * m m different spatial projection respectively.The collection of projection image signal can be adopted following method: adopt the X ray of n part different-energy to go out n part image in a setting space position projection respectively earlier; Adopt n part different-energy to carry out projection again at other (m-1) individual different spaces projected position; Be that projection produces s=n * m part image; N >=1, m >=1.Preferred; The collection of projection image signal goes out two parts of images in a setting space position projection respectively for adopting the X ray of two parts of different-energies earlier; Adopt two parts of different-energies to carry out projection at other (m-1) individual different spaces projected position again, i.e. projection produces s=2m part image, m >=1.The collection of projection image signal also can be adopted following method: adopt the X ray of a setting energy to go out m part image m locus projection earlier; Adopt the X ray of other (n-1) part different-energy to carry out projection m position respectively again; Be that projection produces s=n * m part image, n >=1, m >=1.Preferred, steps A adopts the X ray of another part different-energy to carry out projection m position for the X ray that adopts a setting energy earlier goes out m part image m locus projection again, i.e. projection produces s=2m part image, m >=1.Be the collection of multipotency and multi-angle space projection image, a kind of method is: we can adopt a fixed X ray energy (for example low-yield or high-energy) earlier and change the space angle projection to obtain one group of projected image; Change the X ray energy then, the complex phase of laying equal stress on space angle position together projection again obtains another group projected image.Another kind method is: we can adopt a fixed space angle to come to obtain two frame projected images with different X ray energy (for example low-yield and high-energy) projections earlier; Change the space angle position then, come to accomplish the projection of all space angles at last to obtain two frame projected images in addition and repeat identical X ray energy (low-yield and high-energy) projection.Similarly, we can replace dual energy with multipotency generally speaking.For example: adopt the X ray of 2 parts of different-energies to go out 2 parts of images the 1st fixed space position projection respectively earlier; Adopt the X ray of 2 parts of different-energies to go out 2 parts of images the 2nd different spatial projection respectively again; Adopt the X ray of 2 parts of different-energies to go out 2 parts of images the 3rd different spatial projection respectively again; Adopt the X ray of 2 parts of different-energies to go out 2 parts of images the 4th different spatial projection respectively again, obtain 8 parts of images altogether; 2 parts of x rays that energy is different, portion is a high-energy, portion is low-yield.Again for example: adopt high-octane X ray to go out 3 parts of images 3 fixed space position projections respectively earlier, adopt low-energy X ray to go out 3 parts of images in above-mentioned 3 different spatial projections respectively again, obtain 6 parts of different images.
The pre-treatment of B, projected image: the projected image analogue signal is at first passed through signal amplifier and analog-digital converter, and the projected image analogue signal is amplified and converted data image signal to; Then data image signal is input to the digital picture pre-treating device; The digital picture pre-treating device is done compensation to the pixel cell sensitivity of each reception and is revised and scattered x-ray disturbed to received signal and do correction.Because the human body imaging process need be accomplished in the regular hour, the motion of human organ tissue in the meantime is like human body respiration, heartbeat etc., all inevitable.And these athletic meeting produce wrong image information, thereby obtain wrong clinical diagnosis result.Here we will adopt the method for automatic digital picture correction to revise.Compensation correction is done in sensitivity to pixel cell: a kind of simple method is with a uniform X ray direct irradiation receptor, adjusts the gain of each pixel cell, makes from the picture signal of the same intensity of each pixel cell output.We will be according to the physical characteristic of X ray scattering simultaneously; Do correction with the X ray scattering is interferential to received signal; The method of revising is that scattered x-ray is evenly distributed on each regional area, and its scattering strength and each regional area X ray are decayed proportional or proportional with the thickness of the tissue of the regional area that passes through.The digital picture pre-treating device also will be done the motion correction of projection digital picture, comprise the human external motion correction correction that motion influences image with inside of human body to the image influence, to obtain the projection digital picture of moving displacement correction.The human external motion utilizes optical inductor people from location displacement body to being modified to of image influence, solves the displacement of human external structure relative motion.The human external motion also can solve the displacement of human external structure relative motion for carrying out Flame Image Process and image through the projected image to the human external structure relatively to the correction of image influence.The inside of human body motion is to the cycle movement displacement that the signal that utilizes electrocardiograph is located inside of human body that is modified to of image influence; The signal of electrocardiograph can provide the periodic phase information of heartbeat; In identical phase place identical heartbeat displacement is arranged, solve the displacement of inside of human body relative motion.The inside of human body motion also can be for carrying out Flame Image Process and image relatively to the correction of image influence through the projected image to the inside of human body structure; The relative motion of human organ border or shape of blood vessel characteristic defines inside of human body structure relative motion, solves the displacement of inside of human body structure relative motion.
Synthesizing of C, projection digital picture: the digital picture of revising through the digital picture synthesizer, is utilized Digital Image Processing, synthesize a series of composite number word image.The projection digital picture synthesize earlier every same space angle but a fixed weighted linear combination is adopted in projection with different-energy earlier; To obtain the projection image of organ-/ tissue composition; Projection image with the organ-/ tissue of all projection angles makes up then, thereby produces one group of image that contains the fault plane structure of organ-/ tissue composition.The synthetic of projection digital picture also can be for elder generation synthesizes the projection image of the different angles of a setting energy, to obtain organizing the image of fault plane structure; Image with the formed fault plane of different-energy adopts weighting translation linear combination then, thereby obtains the image of organ-/ tissue composition fault plane structure.
The post processing of D, composite number word image: composograph is handled through the digital picture preprocessor; Dynamic compression, dynamic image noise like digital picture reduces, image-region is selected, scheme image intensifying, dynamic image shows or the like; Obtain the image after a series of processing, to satisfy the requirement of diagnosis.
The output of E, composite number word image: will handle the back image and export terminal unit to.
As shown in Figure 2; Be a kind of device that is used to realize utilize the method for multipotency X ray compound-projection numeral compound imaging; Comprise x-ray source and picture receiver; Picture receiver connects amplifier, analog-digital converter (ADC), digital projection picture pre-treating device, interim digital projection picture memorizer, Digital Image Processing and synthesizer (DSP), digital composograph preprocessor and digital composograph memorizer successively, and digital composograph memorizer connects final image display or computer network output.X-ray source connects x-ray source high-frequency and high-voltage control circuit and x-ray source position control circuit; The digital picture receptor connects the receptor control circuit, and x-ray source high-frequency and high-voltage control circuit, x-ray source position control circuit, receptor control circuit, Digital Image Processing and synthesizer, digital composograph preprocessor, digital composograph memorizer, final image display all connect terminal use's controller.
The user can import instruction (parameter) to required x-ray source through " terminal use's controller ": 1) x-ray source high-frequency and high-voltage control circuit: monoergic or multipotency; KVp, mAs/mA, the x-ray source size is (like 0.1mm; 0.3mm or 0.6mm); 2) x-ray source position control circuit: single or a plurality of positions, rotational angle, rotation/translational velocity etc.Concrete gatherer process is such; After x-ray source receives these instructions; At first with a fixed X ray energy (for example 140kVp); Rotate radiographic source to form the space projection image of different angles, change X ray energy (for example 70kVp) then, repeat above-mentioned rotation again to form the space projection image of another group different angles.
In this process, the user can pass through " terminal use's controller ", and " accepter " imported instruction (parameter): begin/stop acquired signal, every frame projection image signal is gathered required time, picking rate or the like.The analog picture signal that receives will be through " signal amplifier ", is stored in " projection digital image memory " after " analog-digital converter " and " digital projection picture pre-treating device " temporarily.The user can import instruction (parameter) through " terminal use's controller " then: the image slices face degree of depth (cm); The fault plane number of plies (single or multiple lift face); And organ classification (lungs, skeleton), the digital picture that is stored in " digital projection picture memorizer " lining is synthesized.These synthetic completion in " Digital Image Processing and synthesizer ".The simplest a kind of synthetic method is: the set of digital images of all projections of will be a certain specific X ray energy (like the X ray of generation under the 140kVp high pressure) is carried out the processing of simple translation addition.In this building-up process, we can revise the motion of human body automatically.A kind of simple method is with respect to the do relative motion correction of displacement of first width of cloth projection image of the same space projected position with second width of cloth projection image.
Synthetic later picture signal will be outputed to " digital picture preprocessor ".The user can pass through " terminal use's controller ", and " preprocessor " imported instruction (parameter): the interested picture signal scope of composograph is gathered the required time with the zone." digital picture preprocessor " done corresponding processing with digital picture, selects (Image segmentation), figure image intensifying (Imageenhancement) or the like like dynamic compression (Dynamic compression), dynamic image noise reduction (Dynamicimage noise reduction), the image-region of digital picture.
At last the digital picture of handling well is stored in " digital image memory ".These digital pictures can show in high resolution display, or print, and output to computer network, or on the DVD, are provided with the back diagnosis and use.
More than be merely specific embodiment of the present invention; But technical characterictic of the present invention is not limited thereto, and any is the basis with the present invention, for realizing essentially identical technique effect; Done the ground simple change, be equal to replacement or modification etc., all be covered by among protection scope of the present invention.