CN101011250A - Focus detector arrangement for generating phase-contrast X-ray images and method for this - Google Patents

Abstract

A focus-detector arrangement and an X-ray apparatus for generating projective or tomographic phase contrast recordings of a subject are disclosed. In at least one embodiment, the focus-detector arrangement includes a radiation source with a focus, arranged on a first side of the subject, for generating a fan-shaped or conical beam of rays; at least one X-ray optical grating arranged in the beam path, with at least one phase grating arranged on the opposite second side of the subject in the beam path generating an interference pattern of the X-radiation preferably, in a particular energy range; and an analysis-detector system which detects at least the interference pattern generated by the phase grating in respect of its phase shift with position resolution. According to at least one embodiment of the invention, at least one X-ray optical grating including bars which are free from overhangs form shadows in the beam path of the fan-shaped or conical beam of rays.

Description

The focus-detector arrangement that is used to produce the phase-contrast photo of X-ray equipment

Technical field

The present invention relates to a kind of focus-detector arrangement of phase-contrast photo that is used to produce projection or tomography of X-ray equipment, it has: be arranged on and check that having of object first side is used to produce the radiation source of the focus of fan-shaped or conical beam, the phase grating that in ray path, is provided with in the second relative side of checking object, this phase grating produces a radiating conoscope image of predetermined power zone internal X-ray at X ray, and the analyzing and testing system, this analyzing and testing system differentiates ground, position at least and detects the conoscope image that is produced by phase grating at phase shift.

Background technology

The focus-detector arrangement that this class is used to produce the phase-contrast photo of the projection of checking object or tomography is known.For example can be referring to European patent application EP 1447046A1 and the formerly not disclosed German patent application that has file number 102006017290.6,102006015358.8,102006017291.4,102006015356.1 and 102006015355.3.

For by ionizing ray, especially come imaging by X ray, mainly can consider two effects that when material is passed in radiation, occur, that is, and by checking the radiating absorption and the phase shift of object.Also known, it is much better than to the absorption of the significant reaction comparison ray of the thickness of passing through material and the minute differences aspect the composition to pass the phase shift that takes place when checking object at ray under many circumstances.The strong respectively basically row of the size of these two kinds of effects ground depends on the lotus charge number of radiating energy and institute's transmission material.

Must analyze by the phase shift of checking that object causes in order to carry out this phase-contrast-radiography or phase-contrast-tomography.At this, similar with X-ray radiography and x-ray tomography radiography, not only can make the projected image of phase shift, perhaps can also calculate a plurality of projected images that the tomography of phase shift is represented.

Can not directly determine the phase place of X ray ripple, and can only be by determining with the benchmark interference of wave.With respect to reference wave or can measure and be combined into the photo of projection and tomography with respect to the phase shift of adjacent ray by the grating that adopts interferometer.The document that the measuring method of relevant interferometer can be quoted with reference to the front.In these methods, check object with relevant X ray transmission, guide X ray by having the grating with suitable cycle of the wavelength of ray subsequently, produce conoscope image thus, this conoscope image depends on the phase shift that produces in checking subject.Analysis and detection device by back connection (on the time subsequently) is measured this conoscope image, can differentiate ground, position thus and determine phase shift.Also known, this type of phase grating is for example made by etching rectangular configuration from silicon wafer.

The system that is used for different phase-contrast radiographies or phase-contrast tomography so far is at the parallel-beam geometry design.Showed already, in this type systematic, only could be embodied as picture satisfactorily near the zone axle, and along with segment angle that increases gradually towards the detector edge direction and bevel angle, imaging effect worse and worse.

Wish that for the medical diagnosis and the harmless examination of materials X-ray equipment that is adopted is of compact construction.For example source, phase-contrast optical-mechanical system and detector are at an inlet internal rotation in computed tomograph (CT), and the diameter of this inlet is for the system aspects reason and because centrifugal force is restricted.In addition, the opening of medicine CT system is determined by patient's size and required human engineering.This size appends to a greatest length on the ray path of differential phase contrast imaging system.On the other hand, it is enough big that want in the visual field, so that reach rational scanning.This requires to adopt wide fan-shaped or conical beam.Also provide similar state and consideration at X-ray equipment that is used for projection print or C shape shelf system.

Summary of the invention

Technical problem to be solved by this invention is, a kind of focus-detector arrangement that improves imaging in all marginal areas away from the zone of axis or detector system is provided.

The inventor recognizes, become the reason of aberration to be towards the detector edge direction is local at least when phase-contrast is taken, grizzly bar (Gitterstege) increases along with the distance with the center with respect to the orientation of directions of rays and has an increasing angles gradually in the edge region in traditional plane grating.Based on usually＞the high relatively photon energy of 20keV in grating (exactly, not only in phase grating but also in analyzing grating) reaches at grizzly bar height and the empty wide form ratio of grid greater than 10: 1 scopes.The grating height of phase grating is analyzed the grating height of grating even is also increased byer force along with the roughly linear growth of photon energy, and this causes great form ratio under the high photon energy condition of medical diagnosis and nondestructive material detection.If adopt ray path with wideer fan-shaped or angle of taper, then this grating with big form ratio causes occlusion effect, and this occlusion effect influences the refraction effect of phase grating especially consumingly and analyzes grating towards wide-angle more that is towards the scanning effect of detector edge direction.

If avoid this negative effect, then must correspondingly construct grating, this grating will be avoided shade to form or avoid outstanding curtain ( berhang) with respect to the radiation direction of institute's useful to irradiation of rays.

This for example blocking can be avoided along each directions of rays orientation by grizzly bar being designed to its side.Also there is such probability, that is, grizzly bar is designed to trapezoidal, make only on the little position of grating, to occur blocking.Correspondingly also can select to avoid the waveform profile that blocks.Especially favourable can be, the waveform that grating can also have grizzly bar changes, and this variation had not been that steep side prevents when moving towards and blocks.

In addition, also can adopt traditional raster, if this grating is circularly around the bending of radiation source focus with vertical side.At this, radially the grizzly bar of aligned orientation extends perpendicular to unfolded spherical surface of institute or cylindrical surface ground.

This bending of grating can for example produce by tightening accordingly, perhaps also by the grating of a bending is realized as the separating surface between two different air pressure or the hydraulic chamber, wherein, at edge side supporting is set.The differential phase control methods not only needs the phase grating of cylindrical section or ball collar form when fan-shaped and conical beam shape, and because the concentric detector that the formation of concentric conoscope image also needs the concentric analysis grating of cylindrical section or ball collar form and also has cylindrical section or ball collar form in case of necessity.This means technical difficulty.For this reason, the inventor advises widely, according to geometric known conditions, grizzly bar height (Steghoehe) or the grating cycle with phase grating is adjusted into alone or in combination, makes the radial distance of phase grating and analysis and detection device equal desirable talbot distance (Talbot-Abstand).

Be also noted that following situation in principle:

Through stochastic process from laboratory x-ray source (for example X-ray tube, secondary target, plasma source, radioactive source) and also from first to the traditional synchrotron radiation source of third generation emission x-ray photon.Therefore, the X-radiation of being launched itself does not have spatial coherence.But worked as viewing angle enough hour, the radiation of x-ray source is as realizing in phase-contrast radiography and phase-contrast tomography or any interference experiment coherent radiation in the space, under described viewing angle, for observer, object, grating or detector manifest described radiation source.Enumerate so-called spatial coherence length L as the space of weighing an abduction x-ray source or the parameter of lateral coherence _c:

$L_c=\mathrm{\λ}\frac{a}{s}.$

Wherein, λ is a wavelength, and s is horizontal radiation source size, and a is the distance of radiation source and point of observation.Some author also is called spatial coherence length with half of numerical value as defined above.Accurate numerical value is accessory; Importantly, (laterally) size of the spatial dimension that should interfere mutually with the ray that therefrom sends is compared coherence length L _cWant big.

Coherent radiation can be interpreted as such radiation on the meaning of present patent application, that is, this radiation causes forming conoscope image in the given geometry of X ray optical grating and under the situation of determining deviation.Certainly, described spatial coherence and and then spatial coherence length always determine by three numerical value (wavelength, radiation source size and viewing distance).Practical situation is simply to conceptive as " relevant X-radiation ", " relevant x-ray radiation source " or " being used to produce the point source of relevant X-radiation " etc. on the meaning of compact expression way.These simply are based on, and the wavelength of X-radiation or ENERGY E are on the one hand by checking the transmission capacity that object is desired and limiting by available frequency spectrum in the laboratory x-ray source on the other hand in this purposes of discussing.To be subjected to certain restriction apart from a being used for nondestructive material check or medical diagnosis between radiation source and the point of observation.Therefore, in most cases radiation source size s is unique degree of freedom, even the relation of radiation source size and tube power has tight boundary.

Requirement little or the point-like radiation source is caused, and the intensity that can adopt is also less relatively.Therefore, also advise, adopt an x-ray source with large-area relatively focus and in focus and check in the ray path between the object and adopt an X ray optical absorption grating, a so-called source grating in order to improve intensity.Large-area focus allows to adopt bigger and and then the stronger x-ray source of power.The narrow gap of source grating or grid sky are used for the desired spatial coherence of ray that keeps all to penetrate from same slit.Gap width must satisfy the numerical value requirement for lateral radiation Source size s that draws from equation (1).Photon from the slit of source grating to the slit according to:

g ₀/g ₂＝l/d (2)

Suitably make source grating cycle g ₀With conoscope image cycle g ₂And source grating G ₀With phase grating G ₁Between distance 1 and phase grating G ₁With between the conoscope image apart from d universal time coordinated mutually, can realize at least the maximum of stationary field and minima in the correct stack aspect the intensity.In the simple expression way of present patent application, adopt the notion of " approximate coherent radiation " or " approximate coherent source " therewith relatively.

Radiation in time or longitudinally coherence is that monochromaticity with X-radiation or x-ray radiation source occurs.The X-radiation of characteristic line has enough monochromaticity and coherence length in time for the purposes majority of discussing at this.Connect monochromator the preceding or the grizzly bar height selective reaonance energy by phase grating also can or quicken to filter out the frequency spectrum enough narrow spectrum region and and then satisfied requirement to time dependent coherence length in this device synchronously from the retardance transmitted spectrum.

According to these basic thoughts, inventor's suggestion improves the focus-detector arrangement that is used for X-ray equipment, and this device is used to produce the projection of inspection object or the phase-contrast photo of tomography, and its composition is as follows at least:

-be arranged on and check that having of object first side is used to produce the radiation source of the focus of fan-shaped or conical beam,

-at least one X ray optical grating that in ray path, is provided with, at least one phase grating that in ray path, is provided with in the second relative side of checking object wherein, this phase grating produce one X-radiation, preferably at the radiating conoscope image of predetermined power zone internal X-ray, and

-analyzing and testing system, this analyzing and testing system differentiate ground, position at least and detect the conoscope image that is produced by phase grating at phase shift.

Be that according to improvements of the present invention at least one X ray optical grating has in the ray path of described fan-shaped or conical beam not by the grizzly bar that blocks the outstanding curtain that forms.That is to say, this grating has in each upper edge, position directions of rays aims at localized grizzly bar and grid sky, transitional region between grizzly bar and the grid sky appears in actual separately directions of rays transition ground, feasible edge, and its method is that the transition seamed edge is parallel to directions of rays and extends.

This design example is as realizing by following manner, promptly, X ray optical grating is designed at least in one first sectional plane round the focus bending, wherein, this at least one X ray optical grating can preferably have the constant radius of curvature round focus in described first sectional plane.

In addition, described X ray optical grating also can be designed as one with vertical second sectional plane of first sectional plane in round the focus bending.At this, also preferably adopt identical radius of curvature round focus.Reach thus, each position of described X ray optical grating all has the identical distance round focus, that is extends on the spherical surface of focus at one.

According to a special design of the present invention, the grizzly bar of described X ray optical grating only has radially towards in focus the rising and the side of decline.

This a kind of bending of grating for example can be tightened the separating surface that produces or can also be used as between two different air pressure or the hydraulic chamber by the grating with a bending accordingly and be realized, wherein, at edge side supporting is set.

At described focus-detector arrangement, especially in a kind of exemplary design scheme of phase grating, the bending of described phase grating in a plane is by forcing to reach tightening between at least three, preferred four supporting members.Wherein, a described at least supporting member can point-like or wire abut on this phase grating.If these supporting members are provided with mutually with staggering, then can be according to being applied to the pressure on the supporting member and reaching bending in one or more planes according to the flexibility of grating.Thus, can make the grating that manufactures plane formula originally crooked in the way you want.Also there is such probability in principle, that is, changes (for example in the CT system, being occurred) gravity and centrifugal force that the ground compensation may exist to the pressure on the supporting member by Accommodation.

According to another embodiment suggestion, described X ray optical grating is that separating surface and the desired bending that reaches at least one plane of described grating between at least two different air pressure zones at least additionally forced to realize by the pressure reduction between two different air pressure zones.At this, can also change by pressure influences bending.It is pointed out that in addition that at least the side at grating can also adopt liquid to replace gas.

In another different substantially design, suggestion replaces all crooked grating with plane X ray optics grating, and wherein, basic thought according to the present invention is designed to grizzly bar can not block.This for example can reach by corresponding orientation or the shaped design to grizzly bar.

But also be appreciated that, the grating that can adopt surperficial bidimensional bending within the scope of the invention with have along the combination of the plane grating of the grizzly bar of directions of rays orientation.

According to the present invention, the grizzly bar of described grating is at least one sectional plane, radially aim at the focus orientation in case of necessity in two orthogonal sectional planes.

Suggestion in addition, the grizzly bar of described X ray optical grating has a kind of sine-shaped height change at least roughly along ray path at least one sectional plane or described first sectional plane.

On the other hand, the grizzly bar of described phase grating also can have a kind of sinusoidal or swash shape or trapezoid height change along ray path in two orthogonal sectional planes.This design is especially favourable when adopting in two planes fan-shaped unfolded beam.

In addition, according to extension to inventive concept, for the bending of adjusting grating surface with adjust thus to the given influence of the talbot distance of phase grating and in order to adapt with the given geometrical relationship in the focus-detector arrangement, inventor's suggestion, about the development length of described phase grating, this phase grating presents different distance to described analyzing and testing system.

At this, for the grizzly bar that makes talbot distance be adapted to the described phase grating of different distance of described analyzing and testing system can have different grizzly bar length.For the grizzly bar that makes talbot distance be adapted to the described phase grating of different distance of described analyzing and testing system also can have the different grating cycles.Similarly also can adopt above-mentioned two kinds of combination of features.

With the design of such scheme differently, advise a kind of equidistant focus-detector arrangement, wherein about the development length of described phase grating, this phase grating is identical to the distance of described analyzing and testing system.

At this, be adapted to the same distance of described analyzing and testing system in order to make talbot distance, the grizzly bar of described phase grating can have identical grizzly bar length when having different grizzly bar height.For the sake of clarity be noted that grizzly bar height and grizzly bar equal in length when grizzly bar is vertical.

According to another kind design, be adapted to the same distance of described analyzing and testing system in order to make talbot distance, the grizzly bar of described phase grating can present the different grating cycles when having identical grizzly bar height with different grizzly bar length.Last-mentioned these combination of features also are possible.

Suggestion in addition, following following geometrical relationship aspect the meansigma methods of radial distance from the focus to the phase grating and radial distance at least from focus to the analyzing and testing system:

$g_2=\frac{1}{2}\&CenterDot;\frac{r_2}{{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="A20071000793500301.png"\; state="\{\{state\}\}">r</figure-callout>}}_1}\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="g"\; filenames="A20071000793500301.png"\; state="\{\{state\}\}">g</figure-callout>}}_1,$

Wherein:

r ₁=focus is to the radial distance of phase grating;

r ₂=focus is to the radial distance of analyzing and testing system;

g ₁=phase grating G ₁Cycle;

g ₂The interior analysis grating G of=analyzing and testing system ₂Cycle.

The inventor also advises, keeps following geometrical relationship in the beam that utilizes fan out carries out focus-detector arrangement that phase-contrast measures:

${\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="A20071000793500301.png"\; state="\{\{state\}\}">r</figure-callout>}}_1>\frac{{{\mathrm{<figure-callout\; id="1"\; label="g"\; filenames="A20071000793500301.png"\; state="\{\{state\}\}">g</figure-callout>}}_1}^2}{2\mathrm{\&lambda;}},$

Wherein:

r ₁=focus is to the radial distance of phase grating;

g ₁=phase grating G ₁Cycle;

The wavelength of the energy of the X-radiation of λ=considered.

Should keep following geometrical relationship in addition:

$r_2-{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="A20071000793500301.png"\; state="\{\{state\}\}">r</figure-callout>}}_1=d_m=(m-\frac{1}{2})\&CenterDot;\frac{{{\mathrm{<figure-callout\; id="1"\; label="g"\; filenames="A20071000793500301.png"\; state="\{\{state\}\}">g</figure-callout>}}_1}^2}{4\&CenterDot;\mathrm{\&lambda;}},$

Wherein:

r ₁=focus is to the radial distance of phase grating;

r ₂=focus is to the radial distance of analyzing and testing system;

g ₁=phase grating G ₁Cycle;

d _m=phase grating is to the distance of analyzing and testing system;

The wavelength of the energy of the X-radiation of λ=considered.

To observe following geometrical relationship in addition:

$2\mathrm{\&Theta;}>\frac{\mathrm{\&Delta;\&alpha;}}{2},$

Wherein:

Θ=half refraction angle of first ordinal number (Ordnung) of observed X-radiation on phase grating has Θ=arcsin (λ/2g ₁);

Δ α=according to Δ α=arc (g ₁/ r ₁) the bevel angle of phase grating;

g ₁=phase grating G ₁Cycle;

r ₁=focus is to the radial distance of phase grating;

The energy wavelength of the X-radiation of λ=observed.

Focus-detector arrangement described above can be provided with one basically and be designed to the focus of point-like as far as possible.At this advantageously, present very clear and definite geometrical relationship.But the dosage power of maximum is not enough to implement CT examination with such system usually when focal spot size is minimum, because sweep time is oversize.

Advise at this that in order to reach high dosage power described focus-detector arrangement for example is provided with focus and source grating that is used to produce indivedual coherent ray beams that is additionally provided between focus and the inspection object of planar structure.But it should be appreciated that under the situation that does not deviate from inventive concept, do not have the source grating and the focus shape (for example many focuses) that produces approximate coherent ray also is considered as having the effect that is equal to.

A kind of like this focus-detector arrangement also belongs to scope of the present invention, promptly, in this focus-detector arrangement, the analyzing and testing system design is the combination with the analysis grating of settling the X-radiation average phase that is used for determining each detector element particular energy the preceding to move along directions of rays of the detector of differentiating the position.At this, the detector of analyzing and testing system has round the analysis grating of the curvature of focus and/or analyzing and testing system and has curvature round focus.

In addition, described analyzing and testing system design is for differentiating the detector of position, and wherein detector element has the internal structure that the average phase that is applicable to the X-radiation of determining each detector element moves.The detector of analyzing and testing system also can have preferred with the curvature of constant radius round described focus in this scheme.

In embodiment according to the suggestion of the another kind of focus-detector arrangement of the present invention, focus to the distance of checking object with respect to the inspection object for the distance of analyzing and testing system design must little (1/2x-1/10x) until very little (＜1/10x).Reach corresponding amplification effect thus.

Inventive principle of the present invention for example can be applied in the X ray computer tomographic system that the x-ray system of the phase-contrast photo that is used for producing projection, the X ray C shape shelf system or be used to that is used to produce the phase-contrast photo of projection or tomography produce the phase-contrast photo of tomography.

Description of drawings

By means of preferred implementation illustrated in the accompanying drawings the present invention is elaborated below, wherein only described for understanding the feature of wanting required for the present invention.At this, adopted following Reference numeral: 1: computer-tomographic system; 2: the first X-ray tubes; 3: the first detectors; 4: the second X-ray tubes; 5: the second detectors; 6: holster shell; 7: the patient; 8: patient's bed; 9: system's axle; 10: control and computing unit; 11: memorizer; 12: axis; 13: conoscope image; 14: grizzly bar; 15: the grid sky; 16: supporting member; 17: sealing member; 18: supporting force; 19: window; 20.1,20.2: chamber half one; D ₁: detector; D: spacing; d _m: talbot distance; E: energy; E _x: detector element; F ₁: focus; G ₀: the source grating; G ₁: phase grating; G ₂: analyze grating; g ₀, g ₁, g ₂: the cycle of grating line; h ₀, h ₁, h ₂: the height of grizzly bar; I: intensity; L: distance; N: refractive index; P: sample; Prg _n: program; r ₁: focus is to the radial distance of phase grating; r ₂: focus is to the radial distance of analyzing and testing system; S _i: X ray; X, y, z: Cartesian coordinate; x _G: the side-play amount of analyzing grating; Θ: have Θ=arcsin (λ/2g ₁) phase grating on half refraction angle of first ordinal number of the X-radiation considered; Δ α: according to Δ α=arc (g ₁/ r ₁) the coning angle in phase grating cycle; λ: the wavelength of the X-radiation energy of being considered;  _Ij: the relative phase between the detector element moves;  x: at detector element E _xOn phase shift.In the accompanying drawing:

Fig. 1 represents to have phase grating, analyzes grating and is used to represent the schematic diagram of focus-detector system of the detector of interference with longitudinal section;

Fig. 2 represents that depending on of selected detector element analyze the Strength Changes curve of grating with respect to the relative position of conoscope image;

The longitudinal section that Fig. 3 represents that active grating, phase grating are set and analyzes the focus-detector system of grating;

Fig. 4 represents to have the point-like focus, crooked phase grating and analyze grating, comprise the longitudinal section of focus-detector arrangement of the detection faces of concentric bending with one heart;

Fig. 5 represents to have the point-like focus, the plane phase grating, analyze the longitudinal section of the focus-detector arrangement of grating and detector, but grizzly bar is radially directed;

Fig. 6 represents the embodiment by the grating of four supporting member bendings;

Fig. 7 represents to apply different pressures and the embodiment of crooked grating by the pressure chamber that both sides are provided with;

Fig. 8 represents to have the X ray computer tomographic system of focus-detector of the present invention system with 3-D view;

Fig. 9 is with the refraction and the talbot distance of the X ray of graphic representation on phase grating.

The specific embodiment

In order to understand the present invention better, the phase-contrast basic principle of measurement is described below by Fig. 1 to 3.Make following basic explanation: institute's drawings attached is not the standard view for this reason, but will enumerate basic structure and the effect of being set forth.Transverse axis extends with respect to the longitudinal axis (optical axis).Angle is exaggerative thus illustrates.Though when conoscope image is maximum that is with first talbot distance, locate the purpose that described analysis grating adopts described method just, especially may spatially will be separated from each other out some for the reason of teaching and depict conoscope image and analyze grating.Therefore, parameter d and r ₂Not only relate to conoscope image, and relate to the analysis grating.

Fig. 1 shows from the coherent radiation of point-like radiation source or passes through the approximate relevant radiation that the source grating produces, and sample P is passed in these radiation, wherein, phase shift occurs after passing inspection object P.Passing grating G ₁The time produce a conoscope image of expressing by gray shade, this conoscope image is by means of grating G ₂At detector D subsequently ₁With and detector element on cause the different radiant intensity of each detector element, wherein, form a conoscope image with so-called talbot distance.

For example, can observe detector element E _iWith analysis grating G ₂Relative position x _GRelation and intensity I (E _i(x _G)) as relative position x _GAbout the function of intensity I, obtain a kind of thus shown in figure 2 at this detector element E _iThe sinusoidal of intensity I change curve.If according to side-play amount x _GRecord is corresponding to each detector element E _iOr E _jMeasured radiant intensity I, then function I (E for the different detector element that finally between focus and each detector element, forms spatial X-ray beam _i(x _G)) and I (E _j(x _G)) be proximate.From these functions, can determine that corresponding to each detector element the relative phase between phase shift  and the detector element moves  _Ij

Therefore, measure the phase shift of determining every ray for every in space ray by three times of utilizing the analysis grating that is provided with of staggering respectively to carry out at least, therefrom or can when the X ray that carries out projection is taken, directly calculate the pixel value of projection print, perhaps can carry out generating the projection that its pixel value is equivalent to phase shift when CT (computer tomography) is checked, make therefrom can calculate that those shares of measured phase shift belong to checks intravital those elementary volume, volume elements of object by means of known reproducting method own.Therefore therefrom calculate faultage image or volume data, they can differentiate the influence at the phase shift of X-radiation of object that the reflection of ground, position checked.Owing to check the minute differences of object aspect composition phase shift is applied intense influence, therefore can to itself relatively materials similar, especially soft tissue is described out extremely in detail and the intensive volume data of contrast.

This by means of repeatedly displacement the analysis grating and the measurement of the radiant intensity on the detector element after analyzing grating caused the scheme of passing the X ray phase shift of checking object and detecting, must implement at least three measurements under the condition that analyze grating moving with the fractional part in grating cycle respectively to every beam X-ray bundle.

Also there is following probability in principle, promptly, cancel this alanysis grating and replace the detector that adopts enough fine structures, wherein avoided in this case because the dose losses that the absorption in the grizzly bar of analysis grating causes and just can determine phase shift in the observed ray by carrying out unique one-shot measurement.

Need adopt relevant radiation in order to measure phase-contrast.This radiation for example can be by the point-like focus or as approximate relevant radiating the structure generation by source grating the focus of face structure after or the corresponding grating type that is used for imitated this class grating by the focus on an anode.

A kind of like this passing through in the face structure focal point F ₁The scheme that the source grating of back produces the field of approximate coherent radiation schematically shows in Fig. 3.A kind of like this design is because the dosage power of high Gong utilization also is applicable to the CT system.All grating G shown in the figure in principle ₀, G ₁With G ₂Can be by replacing according to not shading of the present invention or the few grating of shading.

The focal point F of representing its maximum development length with s ₁Be positioned at the first grating G ₀Before.From source grating G ₀The approximate relevant X ray that sends is represented with S1 to S4.This grating G ₀Cycle g with grating line ₀And the height h of grizzly bar ₀Correspondingly, grating G ₁And G ₂Be provided with height h ₁Or h ₂And cycle g ₁Or g ₂In order to realize the functional requirement of phase measurement, grating G ₀With G ₁Between apart from l and grating G ₁With G ₂Between to have definite proportionate relationship each other apart from d.At this, following relation is set up:

${\mathrm{<figure-callout\; id="0"\; label="g"\; filenames="A20071000793500301.png"\; state="\{\{state\}\}">g</figure-callout>}}_0=g_2\frac{1}{d}.$

Has detector element E ₁To E _nDetector D ₁With analysis grating G ₂Distance be accessory.At this, should be with the grizzly bar height h of phase grating ₁Be chosen to, will satisfy following formula according to the wavelength of being considered that is the X-radiation energy of being considered and at grating material separately:

${\mathrm{<figure-callout\; id="1"\; label="h"\; filenames="A20071000793500301.png"\; state="\{\{state\}\}">h</figure-callout>}}_1=\frac{\mathrm{\&lambda;}}{2(n-1)}.$

At this, n represents the refractive index of grating material, and λ indicates to measure the wavelength of the X ray of phase shift.Can also observe, above the equation mentioned only strictly be applicable to the parallel-beam geometry, and when adopting the fan beam geometry, must correspondingly adjust.

Produce between the position of staying for grizzly bar and the extensive sky of grating and effectively absorb difference, analyze the height h of grating at the Transmission X x radiation x ₂Must be enough, so that differentiate the intensity distributions of gathering conoscope image and further date processing reached easily by position resolution and intensity/gray value.

Usually with grating G ₀To G ₂The groove direction be chosen as, make the grating line of existing grating and the existing bar structure of detector element extended in parallel to each other.Further advantageously, grating line is parallel or directed perpendicular to the system axle ground in the rotation focus-detector system shown in this, but this is optional.

In Fig. 3, can see represented grating and fan ray or the fan beam that goes out more accurately, can see thus, the ray S that tilts to extend _iCause blocking in grizzly bar edge.But with respect to obvious design De Genggao of interval of grid strip or grating cycle, that is form makes the effect that forms shade also show more obviously when departing from optical axis slightly than bigger at grizzly bar in fact.The degree of ray fan is partly obviously bigger than situation about schematically expressing among Fig. 3 in addition.Occur thus, big fan-shaped or bevel angle and big form than the time in the marginal area of flat traditional raster during high X ray energy since the principle that the occlusion effect that shows is more and more doughtily measured phase-contrast almost do not prove effective.

For fear of this problem, advise now that according to the present invention at least one grating structure causes like this, it has in fan-shaped or conical beam ray path not by the grizzly bar that blocks the outstanding curtain that constitutes.This for example can realize by following described two kinds of different substantially embodiments and the combination of these two kinds of schemes in case of necessity:

Crooked grating:

Advise a kind of in one embodiment by the point-like focal point F according to the present invention ₁, have a curved raster G of radially directed grizzly bar 14 ₁And G ₂And crooked detector D ₁The X ray optical system, as in Fig. 4, exemplarily illustrating.At this, grating G ₁And G ₂The center of curvature to be positioned in the radiation source focus on the optical axis 12, at this be focal point F ₁In, that is radius of curvature r ₁, r ₂Equal the radiation source focal point F respectively ₁With each grating G ₁And G ₂Between distance.In this X ray optical system, the phase grating G of shooting line allotter effect not only ₁And play the amplitude grating G of analyzer effect ₂All be crooked and all centering on same focus.Grating G ₁And G ₂Can be at one or two plane inner bending.Can avoid occlusion effect by this X ray optical system of forming by curved raster, and this occlusion effect otherwise in known smooth grating, occur according to big bevel angle.These gratings are bent to, make that the center of crooked grating is in the focus of radiation source on a cylinder or spherical surface.

It is pointed out that according to source grating that exists in case of necessity of the design of the focus-detector system among Fig. 3 and also can have corresponding curved surface and along the grizzly bar of directions of rays orientation.

In order to set up stationary field, must satisfy the relation between the bevel angle of refraction angle 2 Θ of following first ordinal number reflection and phase grating cycle Δ α according to conical beam or fan beam geometry:

2Θ＞Δα/2，

Wherein, Θ=arcsin (λ/2g ₁) and Δ α=arc (g ₁/ r ₁), g ₁Corresponding to phase grating G ₁Cycle, and r ₁Corresponding to phase grating G ₁Radius of curvature, this radius equals radiation source to grating G ₁Distance.Check object in order to reach transmission, for for necessary wavelength λ in the radiography, phase grating G ₁Cycle g ₁Usually be in the scope of a plurality of micron number magnitudes, but according to radiation source-phase grating apart from phase grating G ₁Cycle g ₁Also can be either large or small.

Each has the periodic grating that requires and can be used as the ray allotter in principle, is to reflect the intensity of injecting of high share but adopt the advantage of the phase grating with the π that suddenlys change mutually.In order to obtain the π of sudden change mutually corresponding to the resonant energy E of wavelength X, that is at the refraction ordinal number for+1 with reached maximum intensity at-1 o'clock, by means of following formula phase grating G is described ₁Height h ₁:

$h=\frac{\mathrm{\&lambda;}}{2\mathrm{\&delta;}},$

Wherein, δ is the truly amount of subduing of the refractive index of grating material.

For low photon energy, advise for example aluminum, silicon, diamond or plastics for the grizzly bar that the material by the low number of nuclear charges constitutes.For high photon energy, advise for example combination of chromium, nickel, molybdenum, tantalum, tungsten, platinum, gold, lead, uranium or these elements for the grizzly bar that the material by the higher number of nuclear charges constitutes.Can reach the needed π that suddenlys change mutually by more small grizzly bar height in the end described these materials, and this more small grizzly bar height can be made more easily and not too can aim at ray.

For fear of unnecessary loss of strength, can select a kind of carrier material/wafer, for example silicon wafer or plastic carrier with as far as possible little mass-absorption coefficient.

It is 1: 1 the grid sky and the width ratio of grizzly bar that described grating should have, so that reach+and maximum intensity during 1 and-1 refraction ordinal number; Different ratios is favourable to different refraction ordinal numbers.

Usually the shape of grating is a rectangle, but other shape also effectively and influence about the intensity distributions of difference refraction ordinal number.Intensity at rectangular raster shape time+1 and-1 refraction ordinal number is about 85% of primary ray.By the sinusoidal raster shape, except insignificant absorption loss water+intensity approximate 100% of 1 and-1 refraction ordinal number.

The horizontal cycle of stationary field is half of cycle of phase grating in the parallel-beam geometry:

$g_2=\frac{1}{2}{\mathrm{<figure-callout\; id="1"\; label="g"\; filenames="A20071000793500301.png"\; state="\{\{state\}\}">g</figure-callout>}}_1.$

Standing wave forms along optical axis, and this is known as the talbot effect already.The shortest in d ₁, so-called first talbot distance (contrast of interference fringe that is stationary field show maximum) there depends on wavelength and grating cycle g ₁And can approximate representation as follows:

${\mathrm{<figure-callout\; id="1"\; label="d"\; filenames="A20071000793500301.png"\; state="\{\{state\}\}">d</figure-callout>}}_1=\frac{1}{2}\frac{{{\mathrm{<figure-callout\; id="1"\; label="g"\; filenames="A20071000793500301.png"\; state="\{\{state\}\}">g</figure-callout>}}_1}^2}{4\mathrm{\&lambda;}}.$

The horizontal cycle of horizontal standing wave is also depended on the distance in source when taper or fan beam geometry.The projection geometry that it is regarded as increasing in first is similar in the horizontal cycle of the first talbot distance standing internal wave field is there:

$g_2=\frac{1}{2}\&CenterDot;\frac{r_2}{{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="A20071000793500301.png"\; state="\{\{state\}\}">r</figure-callout>}}_1}\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="g"\; filenames="A20071000793500301.png"\; state="\{\{state\}\}">g</figure-callout>}}_1.$

The adjusting of this stationary field and phase place are subjected to the influence by the phase shift of phase place object introducing.Has the imaging that the detector of enough resolution can be depicted the feature of stationary field and reflect described object thus in principle.For this reason, its resolution must be on the big order of magnitude in stationary field cycle or is better.This class scheme is introduced to some extent in patent application DE102006017290 and DE102006017291.4 and also can be applied to this.If can not use such detector, can adopt then that (preferably in first talbot distance) has enough Analysis of Resolution gratings in the stationary field position.Scan this analysis grating by standing wave, determine phase place, amplitude and the skew of sinusoidal Strength Changes curve along identical talbot ordinal number.

At least must take three measurement points for this handling procedure, wherein grating moved cycle g ₂Fractional part, preferably with g ₂/ 3 amount of separation move.This in practice scanning is with g ₂/ 4 or littler step-length width according to four steps or more multistep realize suddenly.Ideally must implement around the source to rotatablely move for this scanning.But little sweep length also allows the linear scanning across optical axis.

In this embodiment, advise, analyze grating G ₂, the amplitude grating of being also referred to as presents a kind of curved raster shape of radially locating grizzly bar that has.The plumb line on curved raster surface should be in the focus of source and optical axis intersection, that is radius of curvature equal between source and the grating apart from r ₂Therefore, grating has the shape of cylindrical section and have the arcual shape of ball under two-dimensional case under one-dimensional case, wherein on the focus that is centered close to source point or x-ray source of the axis of cylinder or ball.The amplitude grating that plays the analyzer effect equally can centering to described source.Analyzing grating can be in one or two plane and phase grating G ₁Shape as one man crooked.Shape by the grating bending makes grizzly bar radially directed and can avoid at the occlusion effect of straight grating in big bevel angle situation.

Detector, for example CCD directly are placed in and analyze after the grating.The pixel resolution of detector is determined position resolution, by this position resolution to the object imaging.But do not need opposite with described transmission method differentiated interference fringe by detector itself when adopting the analysis grating.At this, this analysis grating by fine-resolution is finished.In addition, when taper or fan-shaped geometry, utilize to enlarge effect, and the detector that therefore utilizes lower position resolution to object with high position resolution imaging.

In order to make phase grating play refraction grating or ray allotter and can produce a conoscope image after phase grating, the X-radiation of injecting on phase grating must satisfy coherence's requirement.At least two adjacent grizzly bars that must formation coherently shine phase grating.That is to say that lateral coherence length must be at least grating cycle g ₁The order of magnitude.Except viewing distance and wavelength, source parameter, the lateral dimension decision coherence length of focus especially.

For example advise two kinds in the technology shown in Fig. 6 and 7 for the circular one dimension bending of grating:

(i) Fig. 6 represents to have the rectangular raster G of uniform thickness substrate/wafer ₁, except grizzly bar, grating also by means of four supporting members 16 on four supporting-lines (the viewgraph of cross-section invading the exterior at Fig. 6 shows 4 supporting-points) by staggering and the power 18 of relativity is bent.Be not subjected to the external force effect and only bear a constant moment by applying the grating/wafer part of load between two internal support lines symmetrically.Obtain the grating of a fixed radius of curvature that is the cylindrical bending of one dimension thus.

(ii) show another kind of embodiment at Fig. 7 invading the exterior, wherein, rectangular raster G ₁Or wafer by sealing member 17 be positioned at hermetically have two chambers, half one 20.1 and 20.2 and the cross section of window 19 be on orthogonal pressure chamber or the vacuum chamber.Two smooth and designs in parallel to each other in opposed limit.Other limit has the circular contour of expectation.At grating G ₁Both sides applied pressure difference this grating is pressed into desirable circular bend shape.Obtain a kind of grating of cylindrical section form of one dimension bending thus.Although in order to ensure have grating bending equably under the anisotropic flexible characteristics situation at grating, the crystallization main shaft of grizzly bar and substrate ((100) in silicon and (010) orientation) should be parallel to pressure chamber or supporting-line ground is directed.For fear of edge effect, grating is compared enough big with the circular development length of this grating perpendicular to the planar size of drawing in these two kinds of warp architecture configurations.

In order to make the globulate bending of grating bidimensional ground, grating is positioned on the pressure or vacuum chamber of a circle.Go up grating by the sealing of leakproof ground at the framework (chamber edge) of circle.This grating is pressed into the shape that is the ball collar shape of desirable bidimensional circular bend in the both sides of grating applied pressure difference.

For the application in radiology, it is crooked that detector needs not to be.Area detector also can satisfy these functions.But the detector that preferably has the crooked outline shape for the application in CT.

Also it is pointed out that as the medium that in pressure chamber, produces pressure and except gas, also can adopt liquid.Similarly also can only adopt a chamber half one 20.2, condition is to have set up the negative pressure for external atmosphere pressure in this chamber half one.

Plane grating with inclination grizzly bar:

As shown in Fig. 5, also advise a kind of plane grating G that has according to another embodiment ₁And G ₂, but have the X ray optical system of the structure of radial directed.At this, the localized source focal point F that is centered close on the optical axis of grating ₁In.Grating G ₁And G ₂With respect to location, symmetrical ground, wherein grizzly bar and grid are empty aims at the capable focus (Strichfokus) of x-ray source or puts focus.The phase grating G of shooting line allotter effect in this X ray optical system ₁With the amplitude grating G that plays the analyzer effect ₂Aspect grizzly bar 14 directed, all aim at same focal point F ₁Not only can realize the one-dimensional grating structure by this way, and can realize the two-dimensional grating structure, and can avoid to pass through the occlusion effect that the plane grating under bigger bevel angle produces by this grizzly bar and the empty X ray optical system of forming of grid by appropriate orientation.

Size with this embodiment of plane grating is followed above-mentioned basic principle for curved raster.But curved raster shows as strict theoretic difference with the difference with plane grating of inclination grizzly bar.The advantage on yet this embodiment possesses skills in having the ray path of medium bevel angle.

The advantage that above-mentioned grating has is, can cancel in order to reach a certain definite round-shaped and measure of taking or at least can be just enough by bending slightly.

The inclined orientation of grizzly bar and grid sky for example reaches by following two etching processes in the grating:

(i) in plasma or dry etch process by wafer is tilted with respect to the electric field of plasma.

(ii) when wet-chemical etching by light-operated corrosiveness.For this reason, in the first step, start defective (Startdefekte) by means of on structure plan, being provided with the photoetching technique definition in the corrosion of the KOH on the front wafer surface.In second step, on front wafer surface, adopt the HF corrosion and use IR (IR=infrared ray) light simultaneously from the rear side irradiate wafer.At this, can utilize in the adulterated silicon of weak n and control corrosiveness by electric cave (hole).Can in the adulterated silicon of n, control the generation in electric cave by input IR light.Because silicon is transmissive for IR, so can shine from the wafer rear side.Direction of illumination and described by the control of the corrosive in advance startup defective of KOH the direction or the shape of corrosive hole or grid sky.

Because the inclination of grizzly bar, thus unequal along the grizzly bar length of directions of rays, but different according to the distance of distance optical axis, although grizzly bar height (the vertical height for the grating face) is identical.This causes, and grating only provides the phase shift of accurate π corresponding to definite wavelength in several little zones.Therefore, in the design of optimizing, the corrosion control to described grid sky should be become, make that grizzly bar length is uniform along directions of rays on entire wafer.The auxiliary corrosion process of the top light of mentioning provides this probability.If adopt other corrosion processes that does not have this control probability, then Xia Mian polishing process is feasible another kind of scheme, can adjust the height of grizzly bar by this polishing process.

Because this may be slight curving when the grizzly bar height is identical when constant talbot distance for the beam shape of fan-shaped or taper, X ray stationary field.When the exemplary value considered along the optical axis talbot distance, this difference slightly can be ignored in first ordinal number.But considering that more in depth the time grid cycle is along with the variation with the variable in distance of optical axis provides such probability according to the top equation of mentioning that is used for talbot distance, that is, stationary field is oriented in the plane or itself and actual range of analyzing grating or analyzing and testing device is adapted or stationary field is adjusted on this detector.

That is, can explain out basically three kinds make the X ray optical grating be adapted to the scheme of given geometrical condition: the grizzly bar length of grating can change, and the curvature of grating can be adjusted and the cycle of grating can change.Be noted that for the sake of clarity grizzly bar height and grizzly bar length equate when grizzly bar is vertical.

In order to obtain adjustable length grizzly bar, for grizzly bar, adopt a kind of longitudinal section of bending.That is in order to compensate to the variation distance of analyzing grating, can be according to the length that the requirement of grating surface is changed grizzly bar.At this, for example make the bigger grizzly bar of distance at grating center obtain a vertical height littler than the grizzly bar at grating center.On the whole surface of grating, be identical about the grizzly bar length of directions of rays that is the ray stroke by grizzly bar thus.All grizzly bars all are adapted to the identical wavelength of X-radiation by this way.This can reach by polishing process on technology, as known in optics industry, has adopted this polishing process before being carved into the grid cavitation corrosion on the silicon wafer.But also there are overcompensation or under-compensated probability that grizzly bar is tilted.

If obtained crooked talbot cross section by the conical beam geometry: for fear of necessity to crooked absorption cross-section, can be in same vertical plane, exactly in the plane of absorption grating, adjust all talbot distance.For this reason, changed in the grating cycle in described vertical plane continuously, make the talbot distance that is caused always and best not only in first method of approximation, be equivalent to objective plane.Because talbot distance depends on the grating cycle, this means that the grating cycle is as progressively being adjusted with the distance function of optical axis.

Thus, also can coordinating mutually with the different wave length of X-radiation among a small circle with interferometer.For this measure of the talbot distance of processing variation, when presenting identical shaped grating during the cycle, inventor's suggestion is partly for the described phase grating of different wavelength regulation.Therefore, problem to be solved by this invention is that the striped of amplitude peak always appears in the same plane.Because talbot distance depends on wavelength, this means, according to adjusting described phase grating corresponding to different wavelength with the distance of optical axis.For corresponding to different oscillation wavelengths, so grizzly bar has different length.This requirement has the grizzly bar of definite longitudinal section, and definite longitudinal section can reach by the grating surface that for example is used for optical lens is polished.

In Fig. 9, express the diagrammatic of this problem and represent, wherein, use S _iRepresent single ray, and at phase grating G ₁Express afterwards with the first talbot distance d ₁+ 1 and the refraction of-1 ordinal number.Should observe following geometrical relationship formula 2 Θ＞Δ α/2 at this,

Wherein, Θ=arcsin (λ/2g ₁) be illustrated in X ray S observed on the phase grating _iHalf refraction angle of first ordinal number, Δ α represents the (g according to Δ α=arc ₁/ r ₁) the bevel angle of phase grating, g ₁Be phase grating G ₁Cycle, r ₁Be the radial distance of focus, and λ is the wavelength of the energy of observed X ray to phase grating.

Now advantageously, when phase-contrast radiography and tomography, from the bigger available visual field, help imaging by the grating of bending or the grizzly bar of inclined orientation.Can realize better dose efficiency thus and diagnose fast and analyze.

Optical-mechanical system described in microradiograph and tomography allows, and object not only directly is positioned at before or after the phase grating, and near radiation source.This can realize the geometry of an amplification, and the geometry of this amplification especially allows under the condition of differential phase contrast imaging little object to be amplified when Non-Destructive Testing.Need no longer thus to make that desirable resolution adapts on detector resolution and the optics.The substitute is, the amplification of projection geometries has reduced about the necessary detector resolution of magnification factor.

This exemplary illustration relates generally to phase grating, still the consideration of structure and size design is also migrated to basically and analyzes on grating and the source grating.As described, the cycle of analysis grating can directly draw from phase grating.With meaning that resonance energy is coordinated mutually on do not exist and crucially adjust the empty degree of depth (thickness of the absorbing structure) problem of grid, but absorbing structure must have enough thickness, greater than three times of absorption length, or preferably thicker.In addition, to select to have the material (for example: Ta, W, Pt, Au, Pb, U) of high as far as possible mass-absorption coefficient for desirable resonance energy.As described, can there be different size design rules in the design size situation of looking phase grating for the shape of analyzing grating.For fear of unnecessary loss of strength, should select to have the carrier material of as far as possible little mass-absorption coefficient.

Unsheltered structure form also is favourable for the grating of source.Can be designed as curved raster equally or have the grating of inclination grizzly bar.Also can adopt source in principle therewith relatively that is have the anode of grating shape structure of the transmitting site of X-radiation with ribbon anode.Cycle can draw from described lever ratio (Hebelverh  ltnis).The ratio of empty width of grid and grill width is advantageously between 1: 10 to 1: 1.The quantity of grid sky advantageously between 1 to about 20 scope.With meaning that resonance energy is coordinated mutually on do not exist and crucially adjust the empty degree of depth (thickness of the absorbing structure) problem of grid, but absorbing structure must have enough thickness, that is to say, the thickness of absorbing structure is greater than three times of absorption length.In addition, to select to have the material (for example: Ta, W, Pt, Au, Pb, U) of high as far as possible mass-absorption coefficient for desirable resonance energy.For fear of unnecessary loss of strength, the carrier material that carrier material should approach and should select to have as far as possible little mass-absorption coefficient.

In Fig. 8 also exemplary and typically for other x-ray systems, be particularly useful for producing projected phase contrast photo x-ray system and for C shape bar assembly expressed have focus-detector of the present invention system and the complete computer-tomographic system that is used to implement the inventive method.The figure shows computer-tomographic system 1, it has the X-ray tube 2 that has on the frame that is not shown specifically that is placed in the holster shell 6 and the first focus-detector system of opposed detector 3.In the ray path of this first focus-detector system 2,3, settled one according to the optical-mechanical system shown in Fig. 1 to 3, made in the ray path of the first focus-detector system, to move describedly to be positioned at the patient 7 on patient's bed that can move along optical axis 9 and there it to be scanned.By the control that control and computing unit 10 are implemented the CT system, in this control and computing unit 10, in memorizer 11, stored program Prg ₁To Prg _n, these programs are used for implementing described above according to method of the present invention and from the measured phase shift reconstruction corresponding computed tomography images relevant with ray.

Selectively, as the replacement scheme of a unique focus-detector system, also one second focus-detector system can settled in holster shell.X-ray tube 4 that this second focus-detector system illustrates in Fig. 8 by a dotted line and detector 5 expressions.

At least there is one according to grating of the present invention in the focus-detector system, wherein in the grating medium, produces the optical grating construction that is used for detected phase contrast photo by ultrasonic standing wave.

In another expansion design of focus-detector system, also can constitute grating by the grating medium, wherein, be configured for the optical grating construction of X-radiation by means of the ultrasound wave stationary field.

What also need to remark additionally is, by shown focus-detector system not only can the measured X x radiation x phase shift, and so in addition focus-detector system is applicable to that also traditional measurement is to the absorption of ray and be used to rebuild corresponding absorption image.Need, also can generate the absorption and the phase-contrast photo of combination.

Self-evident, without departing from the present invention, above-mentioned feature of the present invention not only can be used for the combination enumerated respectively, and is applicable to other combinations or occasion separately.

Claims (37)

1. One kind be used for produce checking object (7, the focus-detector arrangement (F of the X-ray equipment of the phase-contrast photo of projection P) or tomography ₁, D), its composition is as follows at least:

   Check that having of object first side is used to produce fan-shaped or conical beam (S 1.1. be arranged on _i) focus (F ₁) radiation source (2),

   1.2. the X ray optical grating (G that at least one is provided with in ray path ₀, G ₁, G ₂), wherein, at least one check object (7, the phase grating (G that second relative side P) is provided with in ray path ₁), it is the radiating conoscope image of predetermined power zone internal X-ray the preferred of X-radiation that this phase grating produces one, and

   1.3. (the G of analyzing and testing system ₂, D ₁), this analyzing and testing system differentiates ground, position at least and detects by phase grating (G at phase shift ₁) conoscope image that produces,

   It is characterized in that,

   1.4. at least one X ray optical grating (G ₀, G ₁, G ₂) have at described fan-shaped or conical beam (S _i) ray path in do not form the grizzly bar of the outstanding curtain that blocks.
2. 2. according to the described focus-detector arrangement of claim 1, it is characterized in that described at least one X ray optical grating (G ₀, G ₁, G ₂) be designed in first sectional plane round focus (F ₁) bending.
3. 3. according to the described focus-detector arrangement of claim 2, it is characterized in that described at least one X ray optical grating (G ₀, G ₁, G ₂) in described first sectional plane, have round focus (F ₁) radius of curvature (r ₁).
4. 4. according to claim 2 or 3 described focus-detector arrangements, it is characterized in that described at least one X ray optical grating (G ₀, G ₁, G ₂) be designed to vertical second sectional plane of first sectional plane in round focus (F ₁) bending.
5. 5. according to the described focus-detector arrangement of claim 4, it is characterized in that described at least one X ray optical grating (G ₀, G ₁, G ₂) in described second sectional plane, have round focus (F ₁) radius of curvature (r ₀, r ₁, r ₂).
6. 6. according to each described focus-detector arrangement in the claim 1 to 5, it is characterized in that described at least one X ray optical grating (G ₀, G ₁, G ₂) grizzly bar (14) only have and radially aim at focus (F ₁) rising and the side of decline.
7. 7. according to the described focus-detector arrangement of claim 6, it is characterized in that described at least one X ray optical grating (G ₀, G ₁, G ₂) each grizzly bar (14) have perpendicular to described beam (S _i) the end face of transmitted ray orientation.
8. 8. according to each described focus-detector arrangement in the claim 2 to 7, it is characterized in that described at least one X ray optical grating (G ₀, G ₁, G ₂) bending in a plane is by forcing to reach tightening between at least three, preferred four supporting members (16).
9. 9. according to the described focus-detector arrangement of claim 8, it is characterized in that, abut in to a described at least supporting member (16) point-like described at least one X ray optical grating (G ₀, G ₁, G ₂) on.
10. 10. according to claim 8 or 9 described focus-detector arrangements, it is characterized in that, abut in to a described at least supporting member (16) wire described at least one X ray optical grating (G ₀, G ₁, G ₂) on.
11. 11. according to each described focus-detector arrangement in the claim 2 to 10, it is characterized in that,

    11.1 described at least one X ray optical grating (G ₀, G ₁, G ₂) be at least two separating surfaces between the different air pressure zone, and

    11.2 described at least one X ray optical grating (G ₀, G ₁, G ₂) at least one plane desirable bending at least additionally force to realize by the pressure reduction between two different air pressure zones.
12. 12., it is characterized in that described at least one X ray optical grating (G according to the described focus-detector arrangement of claim 1 ₀, G ₁, G ₂) be planar structure generally.
13. 13., it is characterized in that described at least one X ray optical grating (G according to the described focus-detector arrangement of claim 12 ₀, G ₁, G ₂) grizzly bar (14) at least one sectional plane, radially aim at focus (F ₁) orientation.
14. 14., it is characterized in that described at least one X ray optical grating (G according to the described focus-detector arrangement of claim 13 ₀, G ₁, G ₂) grizzly bar (14) three-dimensionally radially aim at focus (F ₁) orientation.
15. 15., it is characterized in that described at least one X ray optical grating (G according to each or 12 described focus-detector arrangements in the claim 1 to 5 ₀, G ₁, G ₂) grizzly bar at least one sectional plane or described first sectional plane, have a kind of sine-shaped height change at least roughly along ray path.
16. 16., it is characterized in that described at least one X ray optical grating (G according to the described focus-detector arrangement of claim 15 ₀, G ₁, G ₂) grizzly bar in two orthogonal sectional planes, have a kind of sinusoidal or swash shape or trapezoid height change along ray path.
17. 17. according to each described focus-detector arrangement in the claim 1 to 16, it is characterized in that, at least one X ray optical grating (G ₀, G ₁, G ₂) development length on, this at least one X ray optical grating (G ₀, G ₁, G ₂) to the described analyzing and testing (G of system ₂, D ₁) present different distance.
18. 18. according to the described focus-detector arrangement of claim 17, it is characterized in that, in order to make talbot distance (d _m) be adapted to the described analyzing and testing (G of system ₂, D ₁) the described phase grating (G of different distance ₁) grizzly bar have different grizzly bar length.
19. 19. according to each described focus-detector arrangement in the claim 16 to 18, it is characterized in that, in order to make talbot distance (d _m) be adapted to the described analyzing and testing (G of system ₂, D ₁) the described phase grating (G of different distance ₁) grizzly bar have different grating cycle (g ₁).
20. 20. according to each described focus-detector arrangement in the claim 1 to 16, it is characterized in that, at described phase grating (G ₁) development length on, this phase grating (G ₁) to the described analyzing and testing (G of system ₂, D ₁) distance identical.
21. 21. according to the described focus-detector arrangement of claim 20, it is characterized in that, in order to make talbot distance (d _m) be adapted to the described analyzing and testing (G of system ₂, D ₁) same distance, described phase grating (G ₁) grizzly bar when having different grizzly bar height, present identical grizzly bar length.
22. 22. according to the described focus-detector arrangement of claim 20, it is characterized in that, in order to make talbot distance (d _m) be adapted to the described analyzing and testing (G of system ₂, D ₁) same distance, described phase grating (G ₁) grizzly bar when having identical grizzly bar height, present different grating cycle (g with different grizzly bar length ₁).
23. 23. according to each described focus-detector arrangement in the claim 1 to 22, it is characterized in that, at least from focus (F ₁) to phase grating (G ₁) radial distance and from focus (F ₁) to (G of analyzing and testing system ₂, D ₁) the meansigma methods aspect of radial distance follow following geometrical relationship:

    $g_2=\frac{1}{2}\&CenterDot;\frac{r_2}{r_1}\&CenterDot;g_1,$

    Wherein:

    r ₁=focus is to the radial distance of phase grating;

    r ₂=focus is to the radial distance of analyzing and testing system;

    g ₁=phase grating (G ₁) cycle;

    g ₂The cycle of=analyzing and testing system.
24. 24. according to each described focus-detector arrangement in the claim 1 to 23, it is characterized in that, keep following geometrical relationship:

    $r_1>\frac{{g_1}^2}{2\mathrm{\&lambda;}},$

    Wherein:

    r ₁=focus is to the radial distance of phase grating;

    g ₁=phase grating (G ₁) cycle;

    The wavelength of the X-radiation energy of λ=considered.
25. 25. according to each described focus-detector arrangement in the claim 1 to 24, it is characterized in that, keep following geometrical relationship:

    $r_2-r_1=d=\frac{1}{2}\&CenterDot;\frac{{g_1}^2}{4\&CenterDot;\mathrm{\&lambda;}},$

    Wherein:

    r ₁=focus is to the radial distance of phase grating;

    r ₂=focus is to the radial distance of analyzing and testing system;

    g ₁=phase grating (G ₁) cycle;

    The d=phase grating is to the distance of analyzing and testing system;

    The wavelength of the X-radiation energy of λ=considered.
26. 26. according to each described focus-detector arrangement in the claim 1 to 24, it is characterized in that, keep following geometrical relationship:

    2Θ＞Δα/2，

    Wherein:

    Θ=half refraction angle of first ordinal number of observed X ray on phase grating has Θ=arcsin (λ/2g ₁);

    Δ α=according to Δ α=arc (g ₁/ r ₁) the bevel angle of phase grating;

    g ₁=phase grating (G ₁) cycle;

    r ₁=focus is to the radial distance of phase grating;

    The wavelength of the X-radiation energy of λ=observed.
27. 27., it is characterized in that described focus (F according to each described focus-detector arrangement in the claim 1 to 26 ₁) be designed to point-like substantially.
28. 28., it is characterized in that, at focus (F according to each described focus-detector arrangement in the claim 1 to 26 ₁) with check object (7, settle the source grating (G that is used to produce approximate relevant ray beam between P) ₀).
29. 29. according to the described focus-detector arrangement of claim 28, it is characterized in that described analyzing and testing system design is to have the single file of detector element of a plurality of definite systemic resolutions or multi-row detector and settle along directions of rays to be used to differentiate the analysis grating (G that ground, position determines that the average phase of X-radiation of the particular energy of each detector element moves the preceding ₂) combination.
30. 30., it is characterized in that the detector of described analyzing and testing system has around described focus (F according to the described focus-detector arrangement of claim 29 ₁) curvature.
31. 31., it is characterized in that the described analyzing and testing (G of system according to claim 29 or 30 described focus-detector arrangements ₂, D ₁) analysis grating (G ₂) have a radius of curvature (r around described focus ₂).
32. 32., it is characterized in that the described analyzing and testing (G of system according to each described focus-detector arrangement in the claim 1 to 31 ₂, D ₁) be designed to have the detector element (E of a plurality of definite systemic resolutions _X) single file or multi-row detector, wherein, at least a portion detector element (E _X) have and determine each detector element (E with being applicable to the resolution position _X) the average phase of X-radiation of the particular energy internal structure of moving.
33. 33., it is characterized in that the described analyzing and testing (G of system according to the described focus-detector arrangement of claim 32 ₂, D ₁) detector (D ₁) have around described focus (F ₁) radius of curvature (r ₂), it is identical that the preferred curvature radius keeps.
34. 34., it is characterized in that focus (F according to each described focus-detector arrangement in the claim 1 to 33 ₁) arrive (G of analyzing and testing system to the distance of checking object (P) with respect to inspection object (P) ₂, D ₁) distance and Yan Yaoxiao (1/2x-1/10x) until very little (＜1/10x).
35. 35. an x-ray system that is used to produce the phase-contrast photo of projection is characterized in that described x-ray system has according to each described focus-detector arrangement in the aforesaid right requirement 1 to 34.
36. 36. an X ray C shape shelf system that is used to produce the phase-contrast photo of projection or tomography is characterized in that, described X ray C shape shelf system has according to each described focus-detector arrangement in the aforesaid right requirement 1 to 34.
37. 37. an X ray computer tomographic system that is used to produce the phase-contrast photo of tomography is characterized in that described X ray computer tomographic system has according to each described focus-detector arrangement in the aforesaid right requirement 1 to 34.

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