CN104434148A - Control method of X-ray photographing system - Google Patents

Abstract

The invention relates to a control method of an X-ray photographing system. The control method includes the steps of obtaining rack information and obtaining the scope of a plane of a flat panel detector; according to the rack information, calculating a radiation field generated by X-rays on the plane of the flat panel detector through a beam-defining clipper; when the radiation field exceeds the scope of the plane of the flat panel detector, adjusting at least one parameter of the width or the height of the radiation field so as to enable the adjusted radiation field to be smaller than or equal to the scope of the plane of the flat panel detector; and transmitting the adjusted parameter to the beam-defining clipper. By means of the control method, the X-ray photographing system can automatically solve the problem that the radiation field exceeds the scope of the plane of the flat panel detector in the X-ray photographing.

Description

A kind of control method of X-ray shooting system

Technical field

The present invention relates to X-ray shooting system, particularly a kind of control method of X-ray shooting system.

Background technology

The essence of X-ray is that a kind of wavelength is very short but can penetrate the ray of human body, and being applied in is exactly medically medical X-ray camera chain, is called for short X-ray shooting system, is also one of large imaging device of medical science six.X-ray shooting system is conventional equipment and the necessary equipment of hospital radiological department and orthopaedics.So far, kind and the output of X-ray shooting system all have greatly increased in medical X-ray imaging technical development, and current high frequency, digitized, multi-functional X-ray camera chain have become the main flow in market.

The rack construction of a kind of X-ray shooting system shown in Figure 1, mainly comprise and crossbeam 1, radiography bed 2, flat panel detector (Flat Detector are installed, FD) 3, column 4, moving guide rail 5, the suspension arm 6 that can stretch up and down and bulb 7, wherein: column 4 is generally fixed on the floor (face, place, floor is horizontal plane o) of machine room, it is provided with flat panel detector 3, bulb 7 also has the beam-defining clipper 8 in order to control X-ray, bulb 7 is connected with suspension arm 6 by tube stand 9.

The operation principle of above-mentioned X-ray shooting system is: patient lies on radiography bed 2, relative position between adjustment bulb 7 and flat panel detector 3 is to enter detected state, make patient's lesions position be in bulb 7 send on the bulb focus 10 of the X-ray position suitable with flat panel detector 3 receiving surface, like this from bulb 7 penetrate X-ray through beam-defining clipper 8 regulate behind ray open country (described ray open country and x-ray bombardment scope) pass patient's lesions position beat on flat panel detector 3 plane, the receiving panel of flat panel detector 3 receives X-ray, and at the upper image generating lesions position of work station (computer) after digital processing, thus doctor can provide a diagnostic result.

X-ray can produce ionizing radiation, and clinical carrying out can cause absorption of human body X-ray to a certain degree when X-ray checks, x-ray bombardment amount is larger, irradiation time is longer, larger to the infringement of human body.Therefore, in order to reduce the X-ray amount that patient absorbs as far as possible, ray open country can be avoided to exceed the range of receiving of flat panel detector 3 when carrying out X-ray as far as possible.

In addition, ray open country is controlled also to be to roentgendosis be controlled the consideration in known scope in the range of receiving of flat panel detector 3: receive because the roentgendosis received by flat panel detector 3 can all be received panel, and have certain clinical meaning to the lesions position image formed, and the part roentgendosis exceeding the range of receiving of flat panel detector 3 cannot be received and can cause ray contamination to patient or external environment, cause the out of control of radiation range, thus, when ray open country exceeds flat panel detector range of receiving, forbid exposure, need to control ray open country, allow exposure again.

The control method of a kind of X-ray shooting system of prior art, as shown in Figure 2, comprises the steps, the ray open country occurred during to solve X-ray exceeds the problem of flat panel detector range of receiving:

Step S100, forbids exposure.

Namely described forbidding expose, and forbids carrying out X-ray when ray open country exceeds flat panel detector range of receiving.

Step S101, the wild size of Non-follow control ray, to make ray wild in the range of receiving of flat panel detector.

The wild size of described Non-follow control ray can be specifically as under type: a kind of mode is, at user interface (the User Interface of X-ray shooting system, UI) the upper relative position selecting alignment thereof to regulate flat panel detector and beam-defining clipper, then it is wild in flat panel detector range of receiving to adjust ray; Another kind of mode is on UI interface, select the preset value of ray open country, and adjustment ray is wild in flat panel detector range of receiving; Another mode directly manually regulates beam-defining clipper, and the wild scope of modulation ray is in flat panel detector range of receiving.

If ray open country still exceeds flat panel detector range of receiving, repeat step S101, if ray open country does not exceed flat panel detector range of receiving, then perform step S102.

Step S102, allows exposure.

Namely described permission exposure, proceeds X-ray when ray open country does not exceed flat panel detector range of receiving.

The control method of above-mentioned X-ray shooting system at least comprises following defect:

The only non-automatic adjustment carrying out ray open country by manual mode, owing to manually adjusting the limitation of the mode of ray open country by prior art, the adjustment of ray open country inaccuracy, only control by experience or intuition, the problem repeatedly adjusted may be caused, control mode is more coarse, and service efficiency is low.

Repeatedly adjust in the process of ray open country and X-ray shooting system, patient's waiting time can be added, increase the risk that patient accepts extra ionizing radiation amount.

The mode that prior art manually adjusts ray open country is controlled by experience or intuition, Parameters variation when source image distance may be caused to wait other frames to run, other error and precision problems of causing frame to be run.

Summary of the invention

The technical problem that technical solution of the present invention solves is, in X-ray process, how to make system automatically prevent ray open country from exceeding the problem of flat panel detector range of receiving.

In order to solve the problems of the technologies described above, technical solution of the present invention provides a kind of control method of X-ray shooting system, and described X-ray shooting system comprises frame, and described frame comprises the bulb launching X-ray and the flat panel detector receiving described X-ray, comprising:

Obtain frame information, and obtain the scope of flat panel detector plane;

According to described frame information, calculate the ray open country that X-ray is produced in described flat panel detector plane by beam-defining clipper;

When described ray open country exceedes the scope of flat panel detector plane, adjust at least one parameter in the wild width of described ray or height, with the scope making the open country of the ray after adjustment be less than or equal to flat panel detector plane;

Parameter after adjustment is sent to described beam-defining clipper.

Optionally, the scope of described flat panel detector plane and ray wild respectively with its apex coordinate definition in shape.

Optionally, described frame information comprises the width 2w of flat panel detector plane _fDwith height 2h _fD, the shape of described flat panel detector plane is rectangle;

The described scope obtaining flat panel detector plane comprises:

Using described flat panel detector planar central as initial point, set up flat panel detector plane coordinate system;

Record the summit P of flat panel detector plane respectively ₁to P ₄for (-w _fD, h _fD), (w _fD, h _fD), (w _fD,-h _fD) and (-w _fD,-h _fD).

Optionally, described frame information comprises the anglec of rotation of bulb focus and the angle of inclination of flat panel detector;

The shape of described ray open country is rectangle, and the described ray open country produced in described flat panel detector plane by beam-defining clipper according to described frame information calculating X-ray is comprised:

Using bulb focus as initial point, set up focus three-dimensional system of coordinate;

The summit P of recording ray open country respectively _1Dto P _4Dinitial coordinate under described focus three-dimensional system of coordinate;

The summit P of ray open country is obtained according to the anglec of rotation of bulb focus and described initial coordinate _1Dto P _4Drotational coordinates under described focus three-dimensional system of coordinate;

Based on described rotational coordinates, by the summit P of ray open country _1Dto P _4Dthe plane projecting to flat panel detector along directions of rays obtains the summit P of ray open country _1Dto P _4Dplane coordinates;

The summit P of ray open country is obtained according to the angle of inclination of flat panel detector and described plane coordinates _1Dto P _4Dtrue coordinate.

Optionally, described focus three-dimensional coordinate is xyz coordinate system; This xyz coordinate system is with bulb focus for initial point, and x-axis is parallel with directions of rays or overlap, z-axis and horizontal plane, and xy plane is parallel to horizontal plane.

Optionally, described frame information also comprises the wild width 2w of initial ray, and initial ray wild height 2h and source image are apart from s, the summit P of ray open country _1Dto P _4Dinitial coordinate under described focus three-dimensional system of coordinate is respectively: P ₁₀(-s ,-w, h), P ₂₀(-s, w, h), P ₃₀(-s, w ,-h) and P ₄₀(-s ,-w ,-h).

Optionally, described frame information also comprise beam-defining clipper relative to the anglec of rotation C of x-axis, bulb focus relative to the anglec of rotation RVA of z-axis, bulb focus relative to the anglec of rotation RHA of y-axis, the summit P of ray open country _1Dto P _4Drotational coordinates under described focus three-dimensional system of coordinate is respectively: P _1F, P _2F, P _3Fand P _4F, order:

$\left[\begin{array}{c}{P}_{10}\\ P_{20}\\ P_{30}\\ P_{40}\end{array}\right]=\begin{array}{c}\left[\begin{array}{cccc}-s& -w& h& 1\\ -s& w& h& 1\\ -s& w& -h& 1\\ -s& -w& -h& 1\end{array}\right]\end{array},$

P _1F, P _2F, P _4Fand P _4Fmeet:

${\left[\begin{array}{c}{P}_{1F}\\ P_{2F}\\ P_{3F}\\ P_{4F}\end{array}\right]}^T=T_{\mathrm{RVA}}\·T_{\mathrm{RHA}}\·T_C\·{\left[\begin{array}{c}{P}_{10}\\ P_{20}\\ P_{30}\\ P_{40}\end{array}\right]}^T,$

Wherein, T _rVAfor the spin matrix relevant to described anglec of rotation RVA, T _rHAfor the spin matrix relevant to described anglec of rotation RHA, T _cfor the spin matrix relevant to described anglec of rotation C, have:

$T_{\mathrm{RVA}}=\left[\begin{array}{cccc}\cos \mathrm{RVA}& -\sin \mathrm{RVA}& 0& 0\\ \sin \mathrm{RVA}& \cos \mathrm{RVA}& 0& 0\\ 0& 0& 1& 0\\ 0& 0& 0& 1\end{array}\right];$

$T_{\mathrm{RHA}}=\left[\begin{array}{cccc}\cos \mathrm{RHA}& 0& \sin \mathrm{RHA}& 0\\ 0& 1& 0& 0\\ -\sin \mathrm{RHA}& 0& \cos \mathrm{RHA}& 0\\ 0& 0& 0& 1\end{array}\right];$

$T_C=\left[\begin{array}{cccc}1& 0& 0& 0\\ 1& \cos C& -\sin C& 0\\ 0& \sin C& \cos C& 0\\ 0& 0& 0& 1\end{array}\right].$

Optionally, the summit P of ray open country _1Dto P _4Dplane coordinates be respectively: P _1B, P _2B, P _3Band P _4Bif, P _nF=(x _nF, y _nF, z _nF), then:

$P_{\mathrm{nB}}=(x_{\mathrm{nF}},-\frac{y_{\mathrm{nF}}}{x_{\mathrm{nF}}/s},\frac{z_{\mathrm{nF}}}{x_{\mathrm{nF}}/s});$

Wherein, n=1 ~ 4.

Optionally, described frame information also comprises flat panel detector to the angle of inclination T relative to y-axis, the summit P of ray open country _1Dto P _4Dtrue coordinate P _1d, P _2d, P _3dand P _4dmeet:

${\left[\begin{array}{c}{P}_{1d}\\ P_{2d}\\ P_{3d}\\ P_{4d}\end{array}\right]}^T=T_T\·{\left[\begin{array}{c}{P}_{1B}\\ P_{2B}\\ P_{3B}\\ P_{4B}\end{array}\right]}^T,$

Wherein, T _tfor the spin matrix closed with described angle of inclination T-phase, have:

$T_T=\left[\begin{array}{cccc}\cos T& 0& \sin T& 0\\ 0& 1& 0& 0\\ -\sin T& 0& \cos T& 0\\ 0& 0& 0& 1\end{array}\right].$

Optionally, the control method of described X-ray shooting system also comprises:

As the summit P of ray open country _1Dto P _4Din have at least a summit to fall into outside described flat panel detector plane, then judge that described ray open country exceedes the scope of flat panel detector plane.

Optionally, the described ray open country produced in described flat panel detector plane by beam-defining clipper according to described frame information calculating bulb focus is also comprised: by the summit P under focus three-dimensional system of coordinate _1Dto P _4Dtrue coordinate be converted to true coordinate under flat panel detector plane coordinate system;

The described summit P when ray open country _1Dto P _4Din have at least a summit to fall into outside described flat panel detector plane, then judge that the scope that described ray open country exceedes flat panel detector plane comprises:

Obtain the summit P under flat panel detector plane coordinate system ₁to P ₄coordinate and summit P _1Dto P _4Dcoordinate;

Connect Vertex P successively ₁to P ₄to form a square range;

Judge summit P _1Dto P _4Dwhether exceed described square range.

Optionally, described flat panel detector plane coordinates is y ' z ' coordinate system, and this y ' z ' coordinate system is with flat panel detector center for initial point, and y ' axle is parallel with y-axis or overlap, and z ' axle is that z-axis rotates angle of inclination T-shaped one-tenth relative to y-axis.

Optionally, described frame information also to comprise under flat panel detector plane coordinate system bulb focus relative to the relative coordinate (y at flat panel detector center ₀, z ₀);

The summit P of ray open country _1Dto P _4Dtrue coordinate under flat panel detector plane coordinate system meets:

If P _nd=(x _nd, y _nd, z _nd), then:

P _nd’＝(y _nd＋y ₀，z _nd＋z ₀)；

Wherein, n=1 ~ 4; P _1d, P _2d, P _3dand P _4dbe followed successively by the summit P of the ray open country obtained according to angle of inclination and the described plane coordinates of flat panel detector _1Dto P _4Dtrue coordinate, P _1d', P _2d', P _3d' and P _4d' be followed successively by the summit P of ray open country _1Dto P _4Dtrue coordinate under flat panel detector plane coordinate system.

Optionally, at least one parameter in the wild width of the described ray of described adjustment or height comprises:

Keep source image apart from parameter constant;

Alignment thereof when bulb focus and flat panel detector center is middle alignment, directly adjusts at least one parameter in the wild width of described ray or height;

Alignment thereof when bulb focus and flat panel detector center is upper alignment or lower alignment: the alignment thereof first arranging described bulb focus and flat panel detector center is middle alignment, then adjusts at least one parameter in the wild width of described ray or height; Or, keep the alignment thereof at described bulb focus and flat panel detector center constant, adjust at least one parameter in the wild width of described ray or height.

Optionally, described source image is apart from obtaining in the following way:

If source image distance is s, the coordinate points S under acquisition focus three-dimensional system of coordinate between bulb focus and flat panel detector center ₁=[-s 00 1];

According to the anglec of rotation and the coordinate points S of bulb focus ₁obtain the point of rotation coordinate S between bulb focus and flat panel detector center _1F, S _1Fmeet S _1F ^t=T _rVAt _rHAt _cs ₁ ^t;

Based on point of rotation coordinate S _1F, in the plane described point of rotation being projected to flat panel detector along directions of rays and the planar point coordinate obtained between bulb focus and flat panel detector center wherein, x _sF, y _sFand z _sFby being obtained point of rotation coordinate S _1Fcoordinate figure;

True point coordinates S between bulb focus and flat panel detector center is obtained according to the angle of inclination of flat panel detector and described planar point coordinate _1s, S _1smeet S _1s=T _ts _1B;

Based on described true point coordinates S _1scan obtain described source image apart from s is:

$s=\sqrt{{(x_0-x_{1S})}^2+{(y_0-y_{1S})}^2+{(z_0-z_{1s})}^2};$

Wherein, x ₀, y ₀and z ₀for bulb focus under three-dimensional system of coordinate is relative to the relative coordinate values at flat panel detector center, x _1s, y _1sand z _1sfor described true point coordinates S _1scoordinate figure, described three-dimensional coordinate is xy ' z ' coordinate system, and this xy ' z ' coordinate system for initial point, comprises x-axis, y ' axle and z ' axle with bulb focus, and wherein, y ' axle and z ' axle form described flat panel detector plane coordinate system.

Optionally, the control method of described X-ray shooting system also comprises:

Connect the summit of flat panel detector plane successively to form the first polygon;

Connect the summit of ray open country successively to form the second polygon;

When described first polygon and the second polygon exist intersection point, then judge that described ray open country exceedes the scope of flat panel detector plane;

The polygon that the area that ray open country after adjustment is formed for described intersection point and the wild summit in shape of the first polygon inner rays is maximum.

Optionally, described polygon is tetragon.

The beneficial effect of technical solution of the present invention at least comprises:

Technical solution of the present invention, when ray open country exceeds flat panel detector range of receiving, regulates the wild size of ray automatically, makes ray open country remain in the range of receiving of flat panel detector, can automatically prevent ray open country from exceeding flat panel detector range of receiving; The time that patient is checked can either be reduced, reduce the probability that patient accepts extra ionizing radiation amount, additionally reduce the operating procedure of operation technician or doctor, improve clinical position efficiency.

In possibility, automatically calculate in the wild step whether beyond the range of receiving of flat panel detector of ray according to frame information, by setting up the technological means of flat panel detector plane coordinate system and focus three-dimensional system of coordinate respectively, the accurate apex coordinate of acquisition flat panel detector plane and the apex coordinate of ray open country, utilize above-mentioned apex coordinate to define flat panel detector planar range and ray respectively wild, accurately calculate and judge ray open country whether beyond the range of receiving of flat panel detector.Compared to the control model of the manual adjustments ray open country of prior art, technical solution of the present invention is with summit definition flat panel detector planar range and ray open country, the data source of control method is better than prior art, whether ray open country is exceeded flat panel detector planar range from the acquisition of scope, relatively all by data precision of scope.Further, technical solution of the present invention also uses the spin matrix relevant to rack status to carry out the process of above-mentioned data source, has good reality simulation and precision.

In possibility, the zone of reasonableness of the ray open country after the adjustment of technical solution of the present invention gained be according to adjustment before ray intersection point that is wild and flat panel detector planar range set, adjustment number of times can be reduced, realize Systematical control accurately, avoid unnecessary regulating step, simplify the control procedure of X-ray, have very large contribution for clinical position.

Technical solution of the present invention gives a kind of account form of source image distance, can beam-defining clipper be more accurately instructed to run, to control its plumbous leaf motion, system is made not change current source image distance when adjustment ray is wild automatically, meet degree of accuracy and the reasonability of the adjustment of ray open country, in the process of adjustment ray open country, ensure that the accuracy that frame is run.

Accompanying drawing explanation

Fig. 1 is a kind of structural representation of X-ray shooting system frame;

Fig. 2 is the control method schematic flow sheet of a kind of X-ray shooting system of prior art;

Fig. 3 is the control method schematic flow sheet that technical solution of the present invention provides a kind of X-ray shooting system;

Fig. 4 is technical solution of the present invention beam-defining clipper and flat panel detector plane relative position schematic diagram;

Fig. 5 to turn clockwise 90 ° the rack construction schematic diagram formed in Fig. 1 plane for bulb in the X-ray shooting system shown in Fig. 1;

Fig. 6 for bulb in the X-ray shooting system shown in Fig. 1 Fig. 1 plane be rotated counterclockwise 90 ° formed rack construction schematic diagrams;

Fig. 7, based on Fig. 4, is the flat panel detector plane coordinate system schematic diagram set up according to flat panel detector plane;

Fig. 8 is a kind of schematic flow sheet obtaining the wild each apex coordinate value of ray of technical solution of the present invention;

Fig. 9, based on Fig. 4, is the focus three-dimensional system of coordinate schematic diagram set up according to bulb focus;

Figure 10 is by the schematic diagram of next spot projection of focus three-dimensional system of coordinate xyz to flat panel detector plane;

Figure 11 is the schematic diagram that ray open country projects the situation 10 of flat panel detector plane;

Figure 12 is the schematic diagram that ray open country projects the situation 11 of flat panel detector plane;

Figure 13 is the schematic diagram that ray open country projects the situation 12 of flat panel detector plane;

Figure 14 is the schematic diagram that ray open country projects the situation 20 of flat panel detector plane;

Figure 15 is the schematic diagram that ray open country projects the situation 21 of flat panel detector plane;

Figure 16 is the schematic diagram that ray open country projects the situation 22 of flat panel detector plane;

Figure 17 is the schematic diagram that ray open country projects the situation 23 of flat panel detector plane;

Figure 18 is the schematic diagram that ray open country projects the situation 24 of flat panel detector plane;

Figure 19 is the schematic diagram that ray open country projects the situation 25 of flat panel detector plane;

A kind of schematic flow sheet adjusting ray open country that Figure 20 provides for technical solution of the present invention;

Figure 21 is the situation schematic diagram that in application examples, ray open country projects flat panel detector plane.

Detailed description of the invention

In order to the range of receiving that can automatically prevent ray open country from exceeding flat panel detector plane in X-ray process, to instruct X-ray shooting system to run better, present embodiments provide a kind of control method of X-ray shooting system, as shown in Figure 3, comprising:

Step S200, obtains frame information.

In this step, the frame of X-ray shooting system comprises the bulb launching X-ray and the flat panel detector receiving described X-ray, and its concrete structure can with reference to prior art, and the present embodiment is not construed as limiting the frame of X-ray shooting system.

The concept of described frame information can do wide in range understanding: can think described frame information at each circuit of X-ray process mid frame, all kinds of operation informations that sense node exported or produced; The frame intrinsic information of the record such as frame description, operation instruction or service manual, also can think described frame information; In the present embodiment, frame information is divided into two category informations, and a kind of is the direct frame information that directly can acquire from frame intrinsic information or operation information, and another kind needs from the above-mentioned frame information that can directly obtain by calculating the indirect frame information obtained.

In the present embodiment, the frame information in step S200 comprises and calculates described flat panel detector plane and ray open country and regulating in the wild process of ray the relevant information kept needed for other operational factors of frame, and the frame information spinner related to will comprise:

1, the geometry of flat panel detector plane geometric shape and ray open country.

Flat panel detector plane geometric shape is relevant with the intrinsic parameter of frame with the geometry of ray open country, is considered as the known and frame information that can directly obtain.The geometry of both the present embodiment acquiescences is rectangle.

2, flat panel detector plane width and height, and the width of initial ray open country and height.

Here, described width be highly all a relative concept, the relative position schematic diagram of beam-defining clipper 8 as shown in Figure 4 and flat panel detector 3 plane, the length of the side 31 of flat panel detector 3 plane can be set as width, the length of opposite side 32 is height, and in the ray open country 80 that beam-defining clipper 8 is formed, the length of the side 81 of ray open country 80 is width, the length of opposite side 82 is height.

General, because X-ray shooting system is when entering operation, the width of ray open country and may be highly a front end of run time numerical value, also may be numerical value during chassis initialization, thus the present embodiment thinks that the width of ray open country when entering operation and height are known and the frame information that can directly obtain, by the width of ray open country when entering operation and the width and the height that are highly called initial ray open country.

And the width of flat panel detector plane is relevant to the intrinsic parameter of flat panel detector with height, be considered as the known and frame information that can directly obtain.

3, the anglec of rotation of bulb focus and the angle of inclination of flat panel detector.

The anglec of rotation of bulb focus is that frame bulb focus in running is moved with bulb the deviation angle of the directions of rays produced, and the angle of inclination of flat panel detector is the angle departing from initialized flat panel detector plane that frame controls tilted flat detector and formed in running.

The anglec of rotation of bulb focus and the angle of inclination of flat panel detector are considered as the known and frame information that can directly obtain.

4, the anglec of rotation (being also the anglec of rotation of ray open country) of beam-defining clipper.

The anglec of rotation of beam-defining clipper mainly refers to the angle controlling the wild diffracted ray direction of ray and rotate in frame running.The anglec of rotation of beam-defining clipper is considered as the known and frame information that can directly obtain.

5, source image distance.

X-ray shooting system run duration, source image is very important data message apart from (SID, Source Image Distance).The ray that source image sends apart from information definition bulb is to the distance of detector plane, namely with bulb focus be starting point, distance along X-ray to flat panel detector plane, control accuracy due to source image distance directly determines the precision of image magnification ratio, the wild area of X-ray and accumulated dose rate three parameters, in the control method of the X-ray shooting system of the present embodiment, obtain accurate source image apart from information and in the wild process of adjustment ray keeping system source image apart from constant be necessary.

Source image belongs to above-mentioned indirect frame information apart from information in the present embodiment process.

6, the relative distance information at bulb focus and flat panel detector center.

The relative distance information at bulb focus and flat panel detector center, for frame, can directly obtain in frame running, is considered as the known and frame information that can directly obtain.

Continue with reference to figure 3, the control method of the present embodiment X-ray shooting system also comprises:

Step S201, based on described frame information, obtains the scope of flat panel detector plane.

Step S202, according to described frame information, calculates the ray open country that X-ray is produced in described flat panel detector plane by beam-defining clipper.

It should be noted that, step S201 and step S202 does not have sequencing.The main purpose of step S201 and step S202 is the scope and the ray open country that obtain flat panel detector plane respectively.The thinking of the present embodiment is by described frame information, calculates the positional information on each summit of flat panel detector plane and the positional information on the wild each summit of ray, obtains scope and the ray open country of flat panel detector plane with the positional information on each summit.Thus, the scope of described flat panel detector plane and ray wild respectively with its vertex position information definition geometrically.

Concrete, the present embodiment weighs above-mentioned vertex position information with apex coordinate.Can consider that the same coordinate system is put on the summit of ray open country and flat panel detector planar top point obtains its coordinate figure, also can calculate based on simplification and consider, set up focus three-dimensional system of coordinate and flat panel detector plane coordinate system respectively, to obtain apex coordinate value and the flat panel detector planar top point coordinates value of the ray open country under focus three-dimensional system of coordinate.

It should be noted that, the foundation of focus three-dimensional system of coordinate and flat panel detector plane coordinate system is all based on rack construction.Rack construction is as shown in Figure 5 and Figure 6 similar with the rack construction of Fig. 1:

By vertical flat plate detector 3 plane and the direction setting parallel with horizontal plane o is first direction (x), the positive direction of first direction (x) is vertical flat plate detector 3 plane and points to the direction of bulb 7.

Be second direction (y) by the direction setting all parallel with horizontal plane o with flat panel detector 3 plane, the positive direction of second direction (y) is just to described flat panel detector 3 plane and level direction to the right.

To be parallel to flat panel detector 3 plane and the direction setting vertical with horizontal plane o is third direction (z), the positive direction of third direction (z) is direction perpendicular to horizontal plane o and straight up.

The present embodiment is that the mode by setting up focus three-dimensional system of coordinate and flat panel detector plane coordinate system realizes step S201 and step S202:

In step s 201, width and the elevation information of the flat panel detector plane in frame information can be utilized, and based on flat panel detector plane geometric shape, directly obtain the coordinate figure on each summit of flat panel detector plane at described flat panel detector plane coordinate system.Wherein, flat panel detector plane coordinate system can be the two-dimensional coordinate system relevant with the angle of inclination of flat panel detector plane, y ' z ' the coordinate system that if it is is initial point with flat panel detector center, in y ' z ' coordinate system, y ' direction of principal axis is second direction, z ' direction of principal axis is relevant with described angle of inclination with the angle of third direction, usually, the angle of flat panel detector plane when described angle of inclination refers to that current flat panel detector plane departs from initialization, thus, the angle of z ' direction of principal axis and third direction can be described angle of inclination.

Due in the present embodiment, flat panel detector plane geometric shape is rectangle, thus can perform following steps, to obtain the scope of flat panel detector plane in step S201:

Composition graphs 7, using described flat panel detector 3 planar central as initial point o ', sets up flat panel detector plane coordinate system y ' z ';

Width 31 based on frame information middle plateform detector plane is 2w _fD, height 32 is 2h _fDinformation, record the summit P of flat panel detector plane respectively ₁for (-w _fD, h _fD), summit P ₂for (w _fD, h _fD), summit P ₃for (w _fD,-h _fD), summit P ₄for (-w _fD,-h _fD).

Certainly, in other embodiments, described flat panel detector plane coordinate system also can be the three-dimensional system of coordinate relevant with the angle of inclination of flat panel detector plane, it can be set as the x ' y ' z ' coordinate system that is initial point with flat panel detector center, in x ' y ' z ' coordinate system, angle between x ' direction of principal axis to described first direction relevant with described angle of inclination (general x ' direction of principal axis is equal with described angle of inclination with the angle between described first direction), y ' direction of principal axis is second direction, and z ' direction of principal axis is relevant with described angle of inclination to the angle of third direction.Like this, the vertex point coordinate information of above-mentioned flat panel detector plane is exactly also need to increase x ' number of axle certificate, because x ' axle is perpendicular to y ' z ' plane and using flat panel detector planar central as initial point, therefore under x ' y ' z ' coordinate system, and the summit P of flat panel detector plane ₁for (0 ,-w _fD, h _fD), summit P ₂for (0, w _fD, h _fD), summit P ₃for (0, w _fD,-h _fD), summit P ₄for (0 ,-w _fD,-h _fD).The present embodiment, in order to for simplicity, ignores x ' number of axle certificate, and directly using flat panel detector plane coordinate system as two-dimensional coordinate system.

In step S202, the information at the anglec of rotation of bulb focus in frame information and the angle of inclination of flat panel detector can be utilized, and based on the geometry of ray open country, in described focus three-dimensional system of coordinate, directly obtain the coordinate figure on the wild each summit of ray.Wherein, the three-dimensional system of coordinate that focus three-dimensional system of coordinate is is initial point with bulb focus, if focus three-dimensional coordinate is xyz coordinate system, in xyz coordinate system, x-axis direction is first direction, and y-axis direction is second direction, and z-axis direction is third direction.

Under described focus three-dimensional system of coordinate, the present embodiment asks for each apex coordinate of ray open country by different conditions when decomposing frame operation, and each apex coordinate of striked ray open country refers to each apex coordinate of the ray open country be radiated in flat panel detector plane.Analyze from frame running:

When frame just enters initial launch, each apex coordinate of described ray open country is known; Here, each apex coordinate of ray open country during frame initial launch is recorded as initial coordinate, initial coordinate can be the wild apex coordinate value of front ray when once running, ray wild apex coordinate value when also can be chassis initialization.

When frame enters operation, the wild anglec of rotation under focus three-dimensional system of coordinate of ray may be adjusted, in conjunction with focus three-dimensional system of coordinate defined above, can think that now the anglec of rotation of ray open country comprises three kinds of situations: the first, rotating bulb makes the wild directions of rays of ray offset around y-axis, the second, rotates bulb and the wild directions of rays of ray is offset around z-axis, the third, rotate beam-defining clipper and make ray wild around x-axis skew certainly.

The offset data of the first situation and the second situation can be known from the focus angle frame information, and the offset data in the third situation can be known from the anglec of rotation of the beam-defining clipper frame information.

In above-mentioned three kinds of situations, because directions of rays rotates change or the wild spinning of ray, ray open country is caused to rotate under focus three-dimensional system of coordinate, its each apex coordinate also there occurs change from initial coordinate, and the present embodiment is recorded as rotational coordinates by each apex coordinate of the ray open country that the above-mentioned anglec of rotation affects.

In addition, consider after processing initial coordinate according to the above-mentioned anglec of rotation, the rotational coordinates on the wild each summit of ray is the coordinate figure under focus three-dimensional system of coordinate.Owing to needing that wild for the ray under focus three-dimensional system of coordinate each apex coordinate is transformed into flat panel detector plane coordinate system, therefore, the rotational coordinates on each summit of ray open country is also needed to project in flat panel detector plane along directions of rays, the present embodiment is called plane coordinates by projecting to each apex coordinate of ray open country in flat panel detector plane, note now, the coordinate of plane coordinates institute foundation is xy ' z coordinate system, and project to flat panel detector plane be initialize time (angle of inclination is 0 °) flat panel detector plane, described xy ' z coordinate system comprises x-axis, y ' axle and z-axis, and its initial point is bulb focus.

In addition, according to frame information, flat panel detector may also have certain angle of inclination in frame running, therefore, need to utilize the angle of inclination of frame information middle plateform detector to do extra process to the wild coordinate of ray, and export each apex coordinate value of final gained ray open country.Wild for the ray finally exported each apex coordinate is called true coordinate, note now, the coordinate of true coordinate institute foundation is xy ' z ' coordinate system, to project to flat panel detector plane be the flat panel detector plane having certain angle of inclination, described xy'z ' coordinate system comprises x-axis, y ' axle and z ' axle, and its initial point is bulb focus.

Based on above-mentioned analysis, can the flow chart shown in reference diagram 8, the implementation procedure of step S202 comprises the steps:

Step S300, using bulb focus as initial point, sets up focus three-dimensional system of coordinate.

Can specifically marked bulb focus 10 and focus three-dimensional system of coordinate xyz by reference diagram 9, Fig. 9.

Step S301, the respectively initial coordinate of each summit under described focus three-dimensional system of coordinate of recording ray open country.

The width 2w of initial ray open country in frame information and height 2h, source image can be utilized apart from s to define the summit P of four of ray open country _1D, summit P _2D, summit P _3D, summit P _4Dinitial coordinate P under described focus three-dimensional system of coordinate ₁₀, P ₂₀, P ₃₀and P ₄₀.Wherein, source image is the frame information indirectly acquired apart from s.

The initial coordinate under focus three-dimensional system of coordinate can be obtained: P ₁₀(-s ,-w, h), P ₂₀(-s, w, h), P ₃₀(-s, w ,-h) and P ₄₀(-s ,-w ,-h).

The summit P of source image distance s and ray open country is illustrated in Fig. 9 _1D, summit P _2D, summit P _3D, summit P _4D.

Step S302, obtains the rotational coordinates of each summit under described focus three-dimensional system of coordinate of ray open country according to the anglec of rotation of bulb focus and described initial coordinate.

Four summits (i.e. summit P of ray open country can be obtained further according to the rotation angle information of bulb focus in described frame information and the rotation angle information of beam-defining clipper _1D, summit P _2D, summit P _3D, summit P _4D) rotational coordinates under described focus three-dimensional system of coordinate.

If beam-defining clipper relative to the anglec of rotation of x-axis be C, bulb focus relative to the anglec of rotation of z-axis be RVA, bulb focus is RHA relative to the anglec of rotation of y-axis, the summit P of ray open country _1D, summit P _2D, summit P _3D, summit P _4Drotational coordinates under described focus three-dimensional system of coordinate is respectively: P _1F, P _2F, P _3Fand P _4F, order:

$\left[\begin{array}{c}{P}_{10}\\ P_{20}\\ P_{30}\\ P_{40}\end{array}\right]=\left[\begin{array}{cccc}-s& -w& h& 1\\ -s& w& h& 1\\ -s& w& -h& 1\\ -s& -w& -h& 1\end{array}\right],$

P _1F, P _2F, P _3Fand P _4Fmeet:

${\left[\begin{array}{c}{P}_{1F}\\ P_{2F}\\ P_{3F}\\ P_{4F}\end{array}\right]}^T=T_{\mathrm{RVA}}\·T_{\mathrm{RHA}}\·T_C\·{\left[\begin{array}{c}{P}_{10}\\ P_{20}\\ P_{30}\\ P_{40}\end{array}\right]}^T---\left(1\right)$

Wherein, T _rVAfor the spin matrix relevant to described anglec of rotation RVA, T _rHAfor the spin matrix relevant to described anglec of rotation RHA, T _cfor the spin matrix relevant to described anglec of rotation C, have:

$T_{\mathrm{RVA}}=\left[\begin{array}{cccc}\cos \mathrm{RVA}& -\sin \mathrm{RVA}& 0& 0\\ \sin \mathrm{RVA}& \cos \mathrm{RVA}& 0& 0\\ 0& 0& 1& 0\\ 0& 0& 0& 1\end{array}\right];$

$T_{\mathrm{RHA}}=\left[\begin{array}{cccc}\cos \mathrm{RHA}& 0& \sin \mathrm{RHA}& 0\\ 0& 1& 0& 0\\ -\sin \mathrm{RHA}& 0& \cos \mathrm{RHA}& 0\\ 0& 0& 0& 1\end{array}\right];$

$T_C=\left[\begin{array}{cccc}1& 0& 0& 0\\ 1& \cos C& -\sin C& 0\\ 0& \sin C& \cos C& 0\\ 0& 0& 0& 1\end{array}\right].$

The wild summit P of ray can be obtained according to the above-mentioned formula (1) that solves _1D, summit P _2D, summit P _3D, summit P _4Drotational coordinates.

Step S303, based on described rotational coordinates, the plane each summit of ray open country being projected to flat panel detector along directions of rays obtains the plane coordinates on each summit of ray open country.

Can with reference to Figure 10, because bulb focus is s to the distance at the center of flat panel detector plane, namely try to achieve 1 P under xy'z coordinate system by following proportionate relationship ₀(x _f, y _f, z _f) projection coordinate P (x in flat panel detector plane _b, y _b, z _b), wherein, x _b=-s:

$\frac{y_f}{x_f}=\frac{y_b}{-s},y_b=-\frac{y_f}{x_f/s};$

$\frac{z_f}{x_f}=\frac{z_b}{-s},z_b=-\frac{z_f}{x_f/s};$

Thus, projection coordinate P is

Based on above-mentioned principle, if the wild summit P of ray _1D, summit P _2D, summit P _3D, summit P _4Dplane coordinates be respectively: P _1B, P _2B, P _3Band P _4B, and establish the rotational coordinates P obtained by solving formula (1) _1Ffor (x _1F, y _1F, z _1F), P _2Ffor (x _2F, y _2F, z _2F), P _3Ffor (x _3F, y _3F, z _3F), P _4Ffor (x _4F, y _4F, z _4F), then:

P _1Bfor

P _2Bfor

P _3Bfor

P _4Bfor

Wherein, x _1F, x _2F, x _3F, x _4Fbe-s.

It should be noted that, in step S303, described flat panel detector plane does not have angle of inclination, and namely the angle of inclination of flat panel detector plane is 0 °.

Step S304, obtains the true coordinate on each summit of ray open country according to the angle of inclination of flat panel detector and described plane coordinates.

Step S304 considers that the influence factor at the angle of inclination of flat panel detector plane performs:

If frame information middle plateform detector is T relative to the angle of inclination of y-axis, the summit P of ray open country _1Dto P _4Dtrue coordinate P _1d, P _2d, P _3dand P _4dmeet:

${\left[\begin{array}{c}{P}_{1d}\\ P_{2d}\\ P_{3d}\\ P_{4d}\end{array}\right]}^T=T_T\·{\left[\begin{array}{c}{P}_{1B}\\ P_{2B}\\ P_{3B}\\ P_{4B}\end{array}\right]}^T---\left(2\right)$

In formula (2), T _tfor the spin matrix closed with described angle of inclination T-phase, have:

$T_T=\left[\begin{array}{cccc}\cos T& 0& \sin T& 0\\ 0& 1& 0& 0\\ -\sin T& 0& \cos T& 0\\ 0& 0& 0& 1\end{array}\right].$

It should be noted that, the angle of inclination T of the subscript " T " of matrix not in formula in above formula, but in matrix formula well known, the indications of the transposition of representing matrix.Not will be understood that angle of inclination T and other implications of subscript T meeting and the present embodiment definition producing matrix have the defect re-defined.

Solve formula (2), the summit P of ray open country can be obtained under xy ' z ' coordinate system _1D, summit P _2D, summit P _3D, summit P _4Dtrue coordinate value.

Continue with reference to figure 3, the control method of the present embodiment X-ray shooting system also comprises:

Step S203, when described ray open country exceedes the scope of flat panel detector plane, adjusts at least one parameter in the wild width of described ray or height, with the scope making the open country of the ray after adjustment be less than or equal to flat panel detector plane.

In fact, between step S202 (or step S201) and step S203, actual implying a kind ofly judges whether described ray open country exceedes the step of flat panel detector planar range, and this determining step can comprise and performs content as follows:

As the summit P of ray open country _1Dto P _4Din have at least a summit to fall into outside described flat panel detector plane, then judge that described ray open country exceedes the scope of flat panel detector plane.

Below give a kind of detailed process of determining step:

Obtain the summit P under flat panel detector plane coordinate system ₁to P ₄coordinate and summit P _1Dto P _4Dcoordinate;

Connect Vertex P successively ₁to P ₄to form a square range;

Judge summit P _1Dto P _4Dwhether exceed described square range.

Above-mentioned determining step is actual is compare each vertex position of ray open country and the process of each vertex position of flat panel detector, the true coordinate on the wild summit of ray obtained due to step S202 is the apex coordinate under three-dimensional system of coordinate (i.e. above-mentioned xy ' z ' coordinate system), can consider the true coordinate on summit each under three-dimensional system of coordinate to be transformed into the true coordinate on the wild each summit of ray under flat panel detector plane coordinate system, then the summit of the wild and flat panel detector plane of more above-mentioned ray further.Above-mentioned transformation process can perform in step S202, also can carry out in described determining step.

The relative distance information at bulb focus and flat panel detector center in frame information can be passed through, realize ray wild each summit true coordinate from three-dimensional system of coordinate to the conversion of flat panel detector plane coordinate system:

Above-mentioned by the relative distance information at bulb focus and flat panel detector center, to be converted under three-dimensional system of coordinate or flat panel detector plane coordinate system bulb focus relative to the relative co-ordinate information at flat panel detector center, if this relative coordinate is (x ₀, y ₀, z ₀) or (y ₀, z ₀);

If after the formula of solving (2), under three-dimensional system of coordinate, obtain the summit P of ray open country _1D, summit P _2D, summit P _3D, summit P _4Dp is respectively in the true coordinate value of flat panel detector plane _1d(x _1d, y _1d, z _1d), P _2d(x _2d, y _2d, z _2d), P _3d(x _3d, y _3d, z _3d) and P _4d(x _4d, y _4d, z _4d); The then summit P of ray open country _1Dto P _4Dtrue coordinate P under flat panel detector plane coordinate system _1d', P _2d', P _3d' and P _4d' meet:

P _1d' be (y _1d+ y ₀, z _1d+ z ₀);

P _2d' be (y _2d+ y ₀, z _2d+ z ₀);

P _3d' be (y _3d+ y ₀, z _3d+ z ₀);

P _4d' be (y _4d+ y ₀, z _4d+ z ₀).

If the result of above-mentioned determining step is the scope that described ray open country exceedes flat panel detector plane, then perform in step S203 the process of at least one the parameter adjusted in the wild width of described ray or height.At least one parameter in the wild width of the described ray of described adjustment or height specifically comprises:

Keep source image apart from parameter constant;

Alignment thereof when bulb focus and flat panel detector center is middle alignment, directly adjusts at least one parameter in the wild width of described ray or height.

Alignment thereof when bulb focus and flat panel detector center is upper alignment or lower alignment: the alignment thereof first arranging described bulb focus and flat panel detector center is middle alignment, then adjusts at least one parameter in the wild width of described ray or height; Or, keep the alignment thereof at described bulb focus and flat panel detector center constant, adjust at least one parameter in the wild width of described ray or height.

It should be noted that, above-mentioned middle alignment, upper alignment and lower alignment are three kinds of alignment thereof at bulb focus and flat panel detector center, wherein, middle alignment refers to that bulb focus is alignd along directions of rays with flat panel detector center, upper alignment refers to that bulb focus is a bit alignd along the top of directions of rays with flat panel detector center, and lower alignment refers to that bulb focus is a bit alignd along the bottom of directions of rays with flat panel detector center.Can think, the mode of described middle alignment can limit, and the mode of described upper alignment or lower alignment can be different according to system type.

Continue with reference to figure 3, the control method of the present embodiment X-ray shooting system also comprises:

Step S204, is sent to described beam-defining clipper by the parameter after adjustment.

The step S203 of the present embodiment and the principle that realizes of S204 are: when ray open country exceeds flat panel detector planar range, by adjusting at least one parameter in the width parameter of ray open country and height parameter, and keep frame source image apart from parameter constant; Width after adjustment and height and frame source image are issued beam-defining clipper apart from numerical value, and beam-defining clipper can, according to the wild width of the ray of specifying and height and source image apart from the motion of the plumbous leaf of numerical control, finally make ray open country meet the demands.

Can with reference to as follows about the example realizing the wild width parameter of adjustment ray or height parameter in step S203 and S204:

When during the alignment thereof of flat panel detector center and bulb focus is when alignment, only needing when ray open country exceeds dull and stereotyped scope is the width or highly of flat panel detector plane by the width of ray open country or High definition.And due to now flat panel detector center and the alignment of bulb focus center, y ₀=z ₀=0, the summit P of ray open country _1Dto P _4Dcoordinate figure under flat panel detector plane coordinate system is followed successively by (y _1d, z _1d), (y _2d, z _2d), (y _3d, z _3d), (y _4d, z _4d).For following three kinds of situations, to the adjustment process of ray open country be:

Situation 10: as shown in figure 11, according to above-mentioned coordinate figure, the summit P of ray open country _1Dto P _4Dthe summit P being in flat panel detector plane ₁to P ₄in the geometric ranges limited, therefore, the width parameter of ray open country is 2|y _1d|, the height parameter of ray open country is 2|z _1d|, meet 2|y _1d| be less than or equal to 2w _fD, 2|z _1d| be less than or equal to 2h _fD, do not need to adjust the width parameter of ray open country and height parameter.

Situation 11: as shown in figure 12, according to above-mentioned coordinate figure, the summit P of ray open country _1Dto P _4Dthe summit P being in flat panel detector plane ₁to P ₄outside the geometric ranges limited, the now width parameter 2|y of ray open country _1d| meet 2|y _1d| be greater than 2w _fD, the height parameter 2|z of ray open country _1d| meet 2|z _1d| be less than or equal to 2h _fD, need to adjust the width parameter of ray open country, make the width parameter after adjustment be 2w _fD, and the height parameter of ray open country remains 2|z _1d|.Wild four the summit P of ray after adjustment _1Dto P _4Dcoordinate be respectively: (-w _fD, z _1d), (w _fD, z _2d), (w _fD, z _3d), (-w _fD, z _4d).

Situation 12: as shown in figure 13, according to above-mentioned coordinate figure, the summit P of ray open country _1Dto P _4Dthe summit P being in flat panel detector plane ₁to P ₄outside the geometric ranges limited, the now width parameter 2|y of ray open country _1d| meet 2|y _1d| be less than or equal to 2w _fD, the height parameter 2|z of ray open country _1d| meet 2|z _1d| be greater than 2h _fD, need to adjust the height parameter of ray open country, make the height parameter after adjustment be 2h _fD, and the width parameter of ray open country remains 2|y _1d|.Wild four the summit P of ray after adjustment _1Dto P _4Dcoordinate be respectively: (y _1d, h _fD), (y _2d, h _fD), (y _3d,-h _fD), (y _4d,-h _fD).

When the alignment thereof of flat panel detector center and bulb focus is non-middle alignment (namely comprising above-mentioned upper alignment and lower alignment), and due to now flat panel detector center and bulb focus center and non-alignment, y ₀and z ₀at least one be not equal to 0, the summit P of ray open country _1Dto P _4Dcoordinate figure under flat panel detector plane coordinate system is followed successively by (y _1d+ y ₀, z _1d+ z ₀), (y _2d+ y ₀, z _2d+ z ₀), (y _3d+ y ₀, z _3d+ z ₀), (y _4d+ y ₀, z _4d+ z ₀).For following several situation, to the adjustment process of ray open country be:

Situation 20: as shown in figure 14, ray open country does not shine in flat panel detector plane completely, now direct the width parameter of ray open country and height parameter is adjusted to 0.Wild four the summit P of ray after adjustment _1Dto P _4Dcoordinate be respectively: (0,0), (0,0), (0,0), (0,0).

Situation 21: as shown in figure 15, summit P _1Dand summit P _4Dbe in the summit P of flat panel detector plane ₁to P ₄outside the geometric ranges limited, namely the width segments of ray open country exceeds the side (side, lower edge of Figure 15 middle plateform detector plane) of flat panel detector plane, now should adjust the width parameter of ray open country, eliminate and exceed part, the width parameter after adjustment is | y _1d|+w _fD-| y ₀|, height parameter is 2|z _1d|.Wild four the summit P of ray after adjustment _1Dto P _4Dcoordinate be respectively: (-w _fD, z _1d+ z ₀), (y _2d+ y ₀, z _2d+ z ₀), (y _3d+ y ₀, z _3d+ z ₀), (-w _fD, z _4d+ z ₀).

Situation 22: based on situation 21, the summit P of ray open country _1Dto P _4Din as shown in figure 16, summit P _2Dand summit P _3Dbe in the summit P of flat panel detector plane ₁to P ₄outside the geometric ranges limited, namely the width segments of ray open country exceeds the opposite side (side, upper edge of Figure 16 middle plateform detector plane) of flat panel detector plane, now based on the adjustment mode of situation 21, the width parameter of ray open country should be adjusted, elimination exceeds part, and the width parameter after adjustment is | y _1d|+w _fD-| y ₀|, height parameter is 2|z _1d|.Wild four the summit P of ray after adjustment _1Dto P _4Dcoordinate be respectively: (y _1d+ y ₀, z _1d+ z ₀), (w _fD, z _2d+ z ₀), (w _fD, z _3d+ z ₀), (y _4d+ y ₀, z _4d+ z ₀).

Situation 23: as shown in figure 17, summit P _1Dand summit P _2Dbe in the summit P of flat panel detector plane ₁to P ₄outside the geometric ranges limited, namely the height component of ray open country exceeds the side (the left margin side of Figure 17 middle plateform detector plane) of flat panel detector plane, the height parameter that now should adjust ray open country exceeds part to eliminate, and the width parameter after adjustment is 2|y _1d|, height parameter is | z _1d|+h _fd-| z ₀|.Wild four the summit P of ray after adjustment _1Dto P _4Dcoordinate be respectively: (y _1d+ y ₀, h _fD), (y _2d+ y ₀, h _fD), (y _3d+ y ₀, z _3d+ z ₀), (y _4d+ y ₀, z _4d+ z ₀).

Situation 24: as shown in figure 18, summit P _3Dand summit P _4Dbe in the summit P of flat panel detector plane ₁to P ₄outside the geometric ranges limited, namely the height component of ray open country exceeds the side (the right of Figure 18 middle plateform detector plane is along side) of flat panel detector plane, the height parameter that now should adjust ray open country exceeds part to eliminate, based on the adjustment mode of situation 23, the width parameter after adjustment is 2|y _1d|, height parameter is | z _1d|+h _fD-| z ₀|.Wild four the summit P of ray after adjustment _1Dto P _4Dcoordinate be respectively: (y _1d+ y ₀, z _1d+ z ₀), (y _2d+ y ₀, z _2d+ z ₀), (y _3d+ y ₀,-h _fD), (y _4d+ y ₀,-h _fD).

Situation 25 to situation 28: for the wild height component of ray and width segments all exceed flat panel detector plane, this exists following four kinds of situations respectively, is corresponding in turn to situation 25 to situation 28:

The wild summit P of ray _1D, summit P _2Dand summit P _4Dbe in the summit P of flat panel detector plane ₁to P ₄outside the geometric ranges limited, ray open country exceedes flat panel detector plane left lower side as shown in figure 19 along side; Now need all to adjust the width parameter of ray open country and height parameter.Wild four the summit P of ray after adjustment _1Dto P _4Dcoordinate be respectively: (-w _fD, h _fD), (y _2d+ y ₀, h _fD), (y _3d+ y ₀, z _3d+ z ₀), (-w _fD, z _4d+ z ₀).

The wild summit P of ray _1D, summit P _2Dand summit P _3Dbe in the summit P of flat panel detector plane ₁to P ₄outside the geometric ranges limited, ray open country exceedes flat panel detector plane left edge side as shown in figure 19; Now need all to adjust the width parameter of ray open country and height parameter.Wild four the summit P of ray after adjustment _1Dto P _4Dcoordinate be respectively: (y _1d+ y ₀, h _fD), (w _fD, h _fD), (w _fD, z _3d+ z ₀), (y _4d+ y ₀, z _4d+ z ₀).

The wild summit P of ray _1D, summit P _3Dand summit P _4Dbe in the summit P of flat panel detector plane ₁to P ₄outside the geometric ranges limited, ray open country exceedes side, edge, flat panel detector plane bottom right as shown in figure 19; Now need all to adjust the width parameter of ray open country and height parameter.Wild four the summit P of ray after adjustment _1Dto P _4Dcoordinate be respectively: (-w _fD, z _1d+ z ₀), (y _2d+ y ₀, z _2d+ z ₀), (y _3d+ y ₀,-h _fD), (-w _fD,-h _fD).

The wild summit P of ray _2D, summit P _3Dand summit P _4Dbe in the summit P of flat panel detector plane ₁to P ₄outside the geometric ranges limited, ray open country as shown in figure 19, exceedes flat panel detector plane top right-hand side along side; Now need all to adjust the width parameter of ray open country and height parameter.Wild four the summit P of ray after adjustment _1Dto P _4Dcoordinate be respectively: (y _1d+ y ₀, z _1d+ z ₀), (w _fD, z _2d+ z ₀), (w _fD,-h _fD), (y _4d+ y ₀,-h _fD).

The ray illustrated in Figure 19 wild 80 is situation 25, namely exceedes flat panel detector plane left lower side along side.

In situation 25 to situation 28, the width parameter of the ray open country after adjustment is | y _1d|+w _fD-| y ₀|, height parameter is | z _1d|+h _fD-| z ₀|.

In the example of the wild parameter of above-mentioned adjustment ray, it should be noted that:

1, the summit P of known rays open country _1Dto P _4Dtrue coordinate under flat panel detector plane coordinate system is P _1d' (y _1d+ y ₀, z _1d+ z ₀), P _2d' (y _2d+ y ₀, z _2d+ z ₀), P _3d' (y _3d+ y ₀, z _3d+ z ₀), P _4d' (y _4d+ y ₀, z _4d+ z ₀), but because of the geometry of the ray open country of the present embodiment be rectangle, therefore y _1d, y _2d, y _3d, y _4dabsolute value equal, be 1/2nd, z of the width of ray open country _1d, z _2d, z _3d, z _4dabsolute value equal, be 1/2nd of the height of ray open country.Here, 2|y is selected _1d| be the width parameter of ray open country, select 2|z _1d| be the height parameter of ray open country.

2, when ray open country exceeds dull and stereotyped scope, width or the height parameter of adjustment ray open country are not limited to the width parameter or the height parameter that the width parameter exceeded or height parameter are defined as flat panel detector plane, general according to clinical demand, can free setting Tuning function or resize ratio, in the scope only needing the wild scope of the ray after by adjustment to be limited to flat panel detector plane or equal the scope of flat panel detector plane.

Adjust the mode of ray open country when non-middle alignment 3, for situation 20 to situation 28, be not limited to the above-mentioned direct adjustment to width parameter and height parameter; Can also when ray open country exceed dull and stereotyped scope, the mode first by aliging from the UI interface selection of X-ray shooting system; After centering, if ray open country still exceeds flat panel detector planar range, then with reference to the mode adjusting ray open country under alignment condition in given by situation 10 to 12, width parameter and height parameter directly can be adjusted.

According to above-mentioned analysis, the present embodiment additionally provides a kind of mode of more pervasive adjustment ray open country, and when described ray open country exceedes the scope of flat panel detector plane, as shown in figure 20, step S203 comprises execution following steps:

Step S400, connects the summit of flat panel detector plane successively to form the first polygon;

Step S401, connects the summit of ray open country successively to form the second polygon;

Step S402, obtains described first polygon and the second polygonal intersection point;

Step S403, the maximum polygon of the area formed on wild to described intersection point and the first polygon inner rays summit is in shape wild as the ray after described adjustment.

Due in the present embodiment, described first polygon and Second Edge shape are rectangle, and the application examples first of step S400 to S403 can with reference to Figure 21:

If beam-defining clipper 8 has certain anglec of rotation relative to suspension, (this anglec of rotation is relevant relative to the anglec of rotation C of x-axis with the present embodiment beam-defining clipper, the two all can think the anglec of rotation obtained relative to different reference substance or reference axis that a spinning movement of beam-defining clipper 8 obtains), then ray is wild also there will be situation as shown in figure 21 in the projection of flat panel detector plane:

In Figure 21, the alignment thereof of flat panel detector and bulb focus is middle alignment, and beam-defining clipper 8 has certain anglec of rotation relative to suspension, and namely there is certain angle of inclination ray open country relative to flat panel detector plane.Now can adjust ray open country according to the process of step S400 to S403:

Suppose after step S400 to S402, the four edges of ray open country with the intersection point of dull and stereotyped four edges is:

By clockwise from summit P _1Dwith summit P _2Dthe side formed starts, and makes intersection point be respectively d1 to d8.

Step S403 is performed further: according to summit P based on intersection point d1 to d8 ₁with summit P ₂, summit P can be asked ₁with summit P ₂form the first linear equation of side; According to summit P _1Dwith summit P _2D, summit P can be asked _1Dwith summit P _2Dform the second linear equation of side, the first linear equation described in simultaneous and the second linear equation can obtain the coordinate of intersection point d1, and the rest may be inferred can obtain the coordinate of intersection point d2 to d8.

Solving each point coordinates of complete d1 to d8, only need to choose in these 8 all rectangles formed, the maximum rectangle of area is wild as the ray after adjustment, and the width parameter of the ray open country after adjustment is the width value of selected rectangle, and height parameter is the height value of selected rectangle.And four the summit P of ray open country after adjustment _1Dto P _4Dcoordinate figure be the coordinate figure of selected rectangle four points, be the numerical value solved.

From the step S200 to S204 of the present embodiment, whether the present embodiment obtains the scope of flat panel detector plane by step S201 and S202 and ray is wild, by the scope known ray open country of the scope and ray open country that compare flat panel detector plane beyond dull and stereotyped range of receiving; And when exceeding flat panel detector scope in ray open country, perform step S203 and S204, process with situation ray open country being exceeded to flat panel detector scope, wherein, step S203 and S204 is mainly based on following thinking:

Under keeping X-ray shooting system alignment thereof that the prerequisite of (described alignment thereof comprises the upper alignment between bulb focus and flat panel detector, middle alignment and lower alignment) is set, reduce width or the height of ray open country, it is made to narrow down in the scope of flat panel detector, then the width after adjustment and height and source image are issued beam-defining clipper apart from data, beam-defining clipper will, according to the wild width of the ray that receives and height and source image apart from the motion of the plumbous leaf of Data Control limiter of speed, finally make the ray open country after adjustment meet the demands.

Only from above-mentioned steps S200 to S204, technical solution of the present invention utilizes the frame information of X-ray shooting system, makes system automatic decision ray open country whether become possibility beyond dull and stereotyped range of receiving; And, the calculating of flat panel detector planar range and ray open country and indirectly frame information are based on the information directly acquired from frame intrinsic information or operation information, the source of these information is true, and the error of calculation is controlled to a certain extent, and reliability and accuracy rate are all very high.

Those of ordinary skill in the art, based on foregoing, should implement technical solution of the present invention and apply.But on the basis of this area notification technique, be understandable that, the present embodiment is sent to the parameter of limiter of speed except the width parameter after adjustment and height parameter, also comprises source image apart from parameter.

In the implementation process of technical solution of the present invention, be using source image apart from parameter as the frame information that can ask, be changeless in the process of step S200 to S204.Obtaining accurate source image distance parameter in frame running, and in the control procedure of step S200 to S204, keep the source image of frame apart from parameter constant, is highly significant.

The method for solving of source image distance has a lot.Will be understood that, in prior art, any one solves the mode of source image distance is all feasible at the present embodiment.Especially, the present embodiment also provides a kind of mode solving source image distance, specifically comprises the steps:

If source image distance is s, the coordinate points S under acquisition focus three-dimensional system of coordinate between bulb focus and flat panel detector center ₁=[-s 00 1];

According to the anglec of rotation and the coordinate points S of bulb focus ₁obtain the point of rotation coordinate S between bulb focus and flat panel detector center _1F, S _1Fmeet S _1F ^t=T _rVAt _rHAt _cs ₁ ^t;

Based on point of rotation coordinate S _1F, in the plane described point of rotation being projected to flat panel detector along directions of rays and the planar point coordinate obtained between bulb focus and flat panel detector center wherein, x _sF, y _sFand z _sFfor point of rotation coordinate S _1Fcoordinate figure;

True point coordinates S between bulb focus and flat panel detector center is obtained according to the angle of inclination of flat panel detector and described planar point coordinate _1s, S _1smeet S _1s=T _ts _1B;

Based on described true point coordinates S _1scan obtain described source image apart from s is:

$s=\sqrt{{(x_0-x_{1S})}^2+{(y_0-y_{1S})}^2+{(z_0-z_{1s})}^2};$

Wherein, x ₀, y ₀and z ₀for bulb focus under three-dimensional system of coordinate (xy ' z ' coordinate system) is relative to the relative coordinate values at flat panel detector center, x _1s, y _1sand z _1sfor true point coordinates S _1scoordinate figure.

The source image that the present embodiment provides possesses higher feasibility and precision apart from the mode that solves of parameter, can perform, further increase the operational efficiency of frame while execution step S200 to S204.

Although the present invention with preferred embodiment openly as above; but it is not for limiting the present invention; any those skilled in the art without departing from the spirit and scope of the present invention; the Method and Technology content of above-mentioned announcement can be utilized to make possible variation and amendment to technical solution of the present invention; therefore; every content not departing from technical solution of the present invention; the any simple modification done above embodiment according to technical spirit of the present invention, equivalent variations and modification, all belong to the protection domain of technical solution of the present invention.

Claims (17)

1. a control method for X-ray shooting system, described X-ray shooting system comprises frame, and described frame comprises the bulb launching X-ray and the flat panel detector receiving described X-ray, it is characterized in that, comprising:

Obtain frame information, and obtain the scope of flat panel detector plane;

According to described frame information, calculate the ray open country that X-ray is produced in described flat panel detector plane by beam-defining clipper;

When described ray open country exceedes the scope of flat panel detector plane, adjust at least one parameter in the wild width of described ray or height, with the scope making the open country of the ray after adjustment be less than or equal to flat panel detector plane;

Parameter after adjustment is sent to described beam-defining clipper.

2. the control method of X-ray shooting system as claimed in claim 1, is characterized in that, the scope of described flat panel detector plane and ray wild respectively with its apex coordinate definition in shape.

3. the control method of X-ray shooting system as claimed in claim 2, it is characterized in that, described frame information comprises the width 2w of flat panel detector plane _fDwith height 2h _fD, the shape of described flat panel detector plane is rectangle;

The described scope obtaining flat panel detector plane comprises:

Using described flat panel detector planar central as initial point, set up flat panel detector plane coordinate system;

Record the summit P of flat panel detector plane respectively ₁to P ₄for (-w _fD, h _fD), (w _fD, h _fD), (w _fD,-h _fD) and (-w _fD,-h _fD).

4. the control method of X-ray shooting system as claimed in claim 2, it is characterized in that, described frame information comprises the anglec of rotation of bulb focus and the angle of inclination of flat panel detector;

The shape of described ray open country is rectangle, and the described ray open country produced in described flat panel detector plane by beam-defining clipper according to described frame information calculating X-ray is comprised:

Using bulb focus as initial point, set up focus three-dimensional system of coordinate;

The summit P of recording ray open country respectively _1Dto P _4Dinitial coordinate under described focus three-dimensional system of coordinate;

The summit P of ray open country is obtained according to the anglec of rotation of bulb focus and described initial coordinate _1Dto P _4Drotational coordinates under described focus three-dimensional system of coordinate;

Based on described rotational coordinates, by the summit P of ray open country _1Dto P _4Dthe plane projecting to flat panel detector along directions of rays obtains the summit P of ray open country _1Dto P _4Dplane coordinates;

The summit P of ray open country is obtained according to the angle of inclination of flat panel detector and described plane coordinates _1Dto P _4Dtrue coordinate.

5. the control method of X-ray shooting system as claimed in claim 4, it is characterized in that, described focus three-dimensional coordinate is xyz coordinate system; This xyz coordinate system is with bulb focus for initial point, and x-axis is parallel with directions of rays or overlap, z-axis and horizontal plane, and xy plane is parallel to horizontal plane.

6. the control method of X-ray shooting system as claimed in claim 5, is characterized in that, described frame information also comprises the wild width 2w of initial ray, and initial ray wild height 2h and source image are apart from s, the summit P of ray open country _1Dto P _4Dinitial coordinate under described focus three-dimensional system of coordinate is respectively: P ₁₀(-s ,-w, h), P ₂₀(-s, w, h), P ₃₀(-s, w ,-h) and P ₄₀(-s ,-w ,-h).

7. the control method of X-ray shooting system as claimed in claim 6, it is characterized in that, described frame information also comprise beam-defining clipper relative to the anglec of rotation C of x-axis, bulb focus relative to the anglec of rotation RVA of z-axis, bulb focus relative to the anglec of rotation RHA of y-axis, the summit P of ray open country _1Dto P _4Drotational coordinates under described focus three-dimensional system of coordinate is respectively: P _1F, P _2F, P _3Fand P _4F, order:

$\left[\begin{array}{c}{P}_{10}\\ P_{20}\\ P_{30}\\ P_{40}\end{array}\right]=\left[\begin{array}{cccc}-s& -w& h& 1\\ -s& w& h& 1\\ -s& w& -h& 1\\ -s& -w& -h& 1\end{array}\right],$

P _1F, P _2F, P _3Fand P _4Fmeet:

${\left[\begin{array}{c}{P}_{1F}\\ P_{2F}\\ P_{3F}\\ P_{4F}\end{array}\right]}^T=T_{\mathrm{RVA}}\·T_{\mathrm{RHA}}\·T_C\·{\left[\begin{array}{c}{P}_{10}\\ P_{20}\\ P_{30}\\ P_{40}\end{array}\right]}^T,$

Wherein, T _rVAfor the spin matrix relevant to described anglec of rotation RVA, T _rHAfor the spin matrix relevant to described anglec of rotation RHA, T _cfor the spin matrix relevant to described anglec of rotation C, have:

$T_{\mathrm{RVA}}=\left[\begin{array}{cccc}\cos \mathrm{RVA}& -\sin \mathrm{RVA}& 0& 0\\ \sin \mathrm{RVA}& \cos \mathrm{RVA}& 0& 0\\ 0& 0& 1& 0\\ 0& 0& 0& 1\end{array}\right];$

$T_{\mathrm{RHA}}=\left[\begin{array}{cccc}\cos \mathrm{RHA}& 0& \sin \mathrm{RHA}& 0\\ 0& 1& 0& 0\\ -\sin \mathrm{RHA}& 0& \cos \mathrm{RHA}& 0\\ 0& 0& 0& 1\end{array}\right];$

$T_C=\left[\begin{array}{cccc}1& 0& 0& 0\\ 1& \cos C& -\sin C& 0\\ 0& \sin C& \cos C& 0\\ 0& 0& 0& 1\end{array}\right].$

8. the control method of X-ray shooting system as claimed in claim 7, is characterized in that, the summit P of ray open country _1Dto P _4Dplane coordinates be respectively: P _1B, P _2B, P _3Band P _4Bif, P _nF=(x _nF, y _nF, z _nF), then:

$P_{\mathrm{nB}}=(x_{\mathrm{nF}},-\frac{y_{\mathrm{nF}}}{x_{\mathrm{nF}}/s},\frac{z_{\mathrm{nF}}}{x_{\mathrm{nF}}/s});$

Wherein, n=1 ~ 4.

9. the control method of X-ray shooting system as claimed in claim 8, it is characterized in that, described frame information also comprises flat panel detector to the angle of inclination T relative to y-axis, the summit P of ray open country _1Dto P _4Dtrue coordinate P _1d, P _2d, P _3dand P _4dmeet:

${\left[\begin{array}{c}{P}_{1d}\\ P_{2d}\\ P_{3d}\\ P_{4d}\end{array}\right]}^T{=T}_T\·{\left[\begin{array}{c}{P}_{1B}\\ P_{2B}\\ P_{3B}\\ P_{4B}\end{array}\right]}^T,$

Wherein, T _tfor the spin matrix closed with described angle of inclination T-phase, have:

$T_T=\left[\begin{array}{cccc}\cos T& 0& \sin T& 0\\ 0& 1& 0& 0\\ -\sin T& 0& \cos T& 0\\ 0& 0& 0& 1\end{array}\right].$

10. the control method of X-ray shooting system as claimed in claim 4, is characterized in that, also comprise:

As the summit P of ray open country _1Dto P _4Din have at least a summit to fall into outside described flat panel detector plane, then judge that described ray open country exceedes the scope of flat panel detector plane.

The control method of 11. X-ray shooting systems as claimed in claim 10, it is characterized in that, the described ray open country produced in described flat panel detector plane by beam-defining clipper according to described frame information calculating bulb focus is also comprised: by the summit P under focus three-dimensional system of coordinate _1Dto P _4Dtrue coordinate be converted to true coordinate under flat panel detector plane coordinate system;

The described summit P when ray open country _1Dto P _4Din have at least a summit to fall into outside described flat panel detector plane, then judge that the scope that described ray open country exceedes flat panel detector plane comprises:

Obtain the summit P under flat panel detector plane coordinate system ₁to P ₄coordinate and summit P _1Dto P _4Dcoordinate;

Connect Vertex P successively ₁to P ₄to form a square range;

Judge summit P _1Dto P _4Dwhether exceed described square range.

The control method of 12. X-ray shooting systems as described in any one of claim 3 or 11, it is characterized in that, described flat panel detector plane coordinates is y ' z ' coordinate system, this y ' z ' coordinate system with flat panel detector center for initial point, y ' axle is parallel with y-axis or overlap, and z ' axle is that z-axis rotates angle of inclination T-shaped one-tenth relative to y-axis.

The control method of 13. X-ray shooting systems as claimed in claim 11, is characterized in that, described frame information also to comprise under flat panel detector plane coordinate system bulb focus relative to the relative coordinate (y at flat panel detector center ₀, z ₀);

The summit P of ray open country _1Dto P _4Dtrue coordinate under flat panel detector plane coordinate system meets:

If P _nd=(x _nd, y _nd, z _nd), then:

P _nd’=(y _nd+y ₀，z _nd+z ₀)；

Wherein, n=1 ~ 4; P _1d, P _2d, P _3dand P _4dbe followed successively by the summit P of the ray open country obtained according to angle of inclination and the described plane coordinates of flat panel detector _1Dto P _4Dtrue coordinate, P _1d', P _2d', P _3d' and P _4d' be followed successively by the summit P of ray open country _1Dto P _4Dtrue coordinate under flat panel detector plane coordinate system.

The control method of 14. X-ray shooting systems as claimed in claim 1, is characterized in that, at least one parameter in the wild width of the described ray of described adjustment or height comprises:

Keep source image apart from parameter constant;

Alignment thereof when bulb focus and flat panel detector center is middle alignment, directly adjusts at least one parameter in the wild width of described ray or height;

Alignment thereof when bulb focus and flat panel detector center is upper alignment or lower alignment: the alignment thereof first arranging described bulb focus and flat panel detector center is middle alignment, then adjusts at least one parameter in the wild width of described ray or height; Or, keep the alignment thereof at described bulb focus and flat panel detector center constant, adjust at least one parameter in the wild width of described ray or height.

The control method of 15. X-ray shooting systems as claimed in claim 9, is characterized in that, described source image is apart from obtaining in the following way:

If source image distance is s, the coordinate points S under acquisition focus three-dimensional system of coordinate between bulb focus and flat panel detector center ₁=[-s 00 1];

According to the anglec of rotation and the coordinate points S of bulb focus ₁obtain the point of rotation coordinate S between bulb focus and flat panel detector center _1F, S _1Fmeet S _1F ^t=T _rVAt _rHAt _cs ₁ ^t;

Based on point of rotation coordinate S _1F, in the plane described point of rotation being projected to flat panel detector along directions of rays and the planar point coordinate obtained between bulb focus and flat panel detector center wherein, x _sF, y _sFand z _sFby being obtained point of rotation coordinate S _1Fcoordinate figure;

True point coordinates S between bulb focus and flat panel detector center is obtained according to the angle of inclination of flat panel detector and described planar point coordinate _1s, S _1smeet S _1s=T _ts _1B;

Based on described true point coordinates S _1scan obtain described source image apart from s is:

$s=\sqrt{{(x_0-x_{1S})}^2+{(y_0-y_{1S})}^2+{(z_0-z_{1s})}^2};$

Wherein, x ₀, y ₀and z ₀for bulb focus under three-dimensional system of coordinate is relative to the relative coordinate values at flat panel detector center, x _1s, y _1sand z _1sfor described true point coordinates S _1scoordinate figure, described three-dimensional coordinate is xy ' z ' coordinate system, and this xy ' z ' coordinate system for initial point, comprises x-axis, y ' axle and z ' axle with bulb focus, and wherein, y ' axle and z ' axle form described flat panel detector plane coordinate system.

The control method of 16. X-ray shooting systems as claimed in claim 2, is characterized in that, also comprise:

Connect the summit of flat panel detector plane successively to form the first polygon;

Connect the summit of ray open country successively to form the second polygon;

When described first polygon and the second polygon exist intersection point, then judge that described ray open country exceedes the scope of flat panel detector plane;

The polygon that the area that ray open country after adjustment is formed for described intersection point and the wild summit in shape of the first polygon inner rays is maximum.

The control method of 17. X-ray shooting systems as claimed in claim 16, it is characterized in that, described polygon is tetragon.