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1. (WO2015171451) SYSTÈME ET PROCÉDÉ D'IMAGERIE PAR CONTRASTE DE PHASE DES RAYONS X
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METHOD Cross This application claims priority to and the benefit of the Provisional Patent Application having Serial May titled and Method for Imaging to Dan the entirety of which is incorporated by reference This application is also related to Patent Application Serial titled Phase Contrast imaging System and filed on January Patent Application titled and Method for Imaging on February Patent Application titled Field of View Grating interferometers for ray Phase Contrast Imaging and CT at High filed on February 2014 by Dan and Michael hereby incorporated by reference in their Field This disclosure relates to and more particularly to phase contrast imaging systems and illumination Background relies on the refraction of the passing through an Since for hard the refraction angles are in the radian the basic technique used for DPC imaging is to angularly filter with resolution the transmitted thus the angular beam deviations from refraction changes a conventional The angular filtering is done using optics such as crystals A fundamental advantage of DPC imaging is that it is sensitive to gradients in the measured object rather than to its bulk medical Imaging for refraction a contrast enhancing effect at tissue which enables the detection of soft tissues which are otherwise invisible in conventional The angle scattering occurring in soft tissue such as ligament or muscle has also a volume contrast enhancing Another benefit of DPC for medical imaging is that it can improve contrast and resolution at similar or lower dose than in conventional This is possible because DPC uses that are not absorbed by the body and because the soft tissue refraction coefficients decrease with energy much slower than the absorption in by using for DPC a spectrum with mean energy in the keV range the soft tissue dose is minimized while refraction strongly dominates over is also of for imaging and characterization in material in particular as concerns The structure and defects of materials ranging from to fiber to and to engineered can be probed on the micrometer scale using Some of the techniques used for can also be applied with Recently has gained attention in fusion energy where the capability of refraction based imaging to measure the density gradients an object can be used for the diagnostic of high density plasmas in confinement fusion and other high energy density physics Until research on DPC imaging has been dorse mostly at using crystal t he high intensity of the synchrotron compensates for the low efficiency than a hundredth of a of the crystal Although there are efforts to develop or to use narrow lines from conventional the crystal method has not yet entered the domain of practical It is thus of interest to develop more eff cient OPC methods and that can work with conventional medical or industrial A DPC method that can work conventional sources is the shearing in which optics such as gratings are used to angularly filter the refracted The Talbot interferometer includes first a a phase which divides through the Talbot effect the incoming beam into few wide The Talbot effect consists in a of the grating pattern by wave at periodic distances along the called Talbot with the grating the order of the and r for a phase shifting grating or for an absorption and rp2 a n phase The beamsplitter thus creates at the a fringe which changes shape with respect to the unperturbed pattern when a refractive object Is introduced in the The differential imaging consists thus in measuring the changes the fringe pattern by the with respect to the pattern without the To achieve angular sensitivity at hard the period g must be in the resulting a Talbot distance of a few tens of The fringe pattern can In principle be directl measured using a microscopic pixel This Is however quite For most practical the fringe pattern changes are converted into intensity on a macroscopic pixel by introducing an absorption grating placed behind the and having the period of the Talbot for such an interferometer to function with an extended spot a absorption grating is placed in front of the thus dividing it into an array of line The gratings are made by thin SI wafers or The absorption gratings are difficult to they are typically made by filling wit gold the gaps in regular transmission The shearing described above has demonstrated performance similar to the crystal method at energies a few tens of This method is however less useful at energies above a few tens of The reason is that it is difficult to fabricate absorption gr atings with the thickness required to block higher energy This is illustrated in 1A with a plot of the Au thickness needed for as a functio of the photon As several hundred depth gratings would be needed in the range of interest for clinical DPC Depending on the grating the present technological limit is around This limits the contrast of the grating shearing method for high energy as illustrated in by the fringe computed for an interferometer having 100 4 period Au analyzer grating throughout this specification we used for and optics calculations the P wave propagation code and the optics packaged Summary in accordance the present a method for phase contrast imaging of an using an interferometer comprising a source a and an analyser the object positioned between the grating analyzer grating is The method can comprise directing an beam onto the source wherein each sector of the source grating is offse by a predetermined obtaining multiple images during a single expose by translating the object or the wherein the multiple images have a different interferometer and combining the multiple images that obtained to produce a phase contrast image of the In accordance with the present a device for phase contrast imaging of an object is The device can comprise an interferometer comprising a source a and an analyzer wherein the object is positioned between the grating and the analyzer an source operable to direct an bean onto the source wherein each sector of the source grating is offset by a predetermined a translation mechanism operable to translate the object or the a detector operable to obtaining multiple images of the object during a single and a processor operable to combine the multiple images that were obtained to produce a phase contrast image of the in some the source grating has greater than three different In some the multiple images are acquired at different angles through the in some the interferometer has a length about some the analyzer grating has a thickness of about several tens of some the multiple images are obtained line slot scan detectors separated by about cm tha is positioned behind the analyzer In some an between the multiple images Is about In some an angular range between four images is about some the grating comprises multiple glancing angle grating stacked in order to a length of a incorporation by Reference The following references are incorporated by reference In their Alberto and Pekka from applications towards 58 Rnkenthai angle interferometers for phase contrast imaging at high 091108 Stutrnan Stayman Sie verdsen energy imaging using glancing angle grating Medical Imaging Physics of Medical 866814 er and Stutrnan energy phase using grating In print in Medical Physics 2014 and phase stepping in 094101 and mirror filtered grating INTERNATIONAL WORKSHOP ON AND NEUTRON PHASE IMAGING WITH Pro Brief Description of the Drawings The accompanying which are incorporated in and constitute a part of this illustrate embodiments of the disclosure together with the serve to explain the principles of the In the 1A and illustrate a layout of grating based phase contrast radiography and the illustrates the curve for obtained by scanning one of the gratings along Only small objects can be imaged and multiple successive exposures are required to obtain the 2A and 2B illustrate an example based on Stacked glancing angle interferometer gratings can be used to a long and narrow field of while object or the interferometer is Multiple closely spaced views through varying phase interferometers can be used to obtain the equivalent of the without the need for multiple The varying interferometer phasing can be achieved using a or this sketch the source 3A illustrates an example side view of scanning phase contrast mammography according to embodiments and 3B illustrates a top The and scatter images are simultaneously obtained in a single pass of the linear scanning To enable the oblique and projections required mammography the interferometer gantry can rotate on the support 4A and 4B illustrate an example scanning phase contrast radiography system for the in front view and according to For added tomosynthesis the scanning table can also rotate the 5 illustrates an example computer according to of the Embodiments Reference will now be made in detail to exemplary embodiments of the examples of which are illustrated in the accompanying Wherever the same reference numbers will be used throughout the drawings to refer to the same or like Notwithstanding that the numerical ranges and parameters setting forth broad scope of the disclosure are the numerical values set forth in the specific examples are reported as precisely as Any numerical inherently contains certain errors necessarily resulting from the standard deviation found in respective testing all ranges disclosed herein are to be understood to encompass any and ail subsumed for a range of than ca include any and between the minimum value of zero and the value of that any and all having a minimum value of equal to or greater than and a maximum value of equal to or less than 1 to in certain the numerical values as stated for the parameter can take on negative this the example value of range stated as that can assume negative of the present disclosure relate to the use of multiple grating Interferometers viewing each a separate slice through an to m phase contrast scanning radiography over a broad energy from to Embodiments of the present disclosure are a further advancement of our previous the Glancing Angle grating patent application and discloses a simple and economical method for radiography of large objects such the human Applications envisaged for embodiments of the present disclosure In medical where PC was shown to strongly enhance the visibility of soft such blood arterial brain micro and The systems described in accordance with embodiments of the present disclosure can work with energy and with high power and extended medical thus enabling radiography of tissues deep in the human in embodiments of the present disclosure can be used in the field of industrial testing and security where the disclosed systems be also scanning the object instead of the The imaging modalities for soft tissues are and while and ultrasound provide good soft tissue their spatial resolution is Conventional imaging on the other hand has good spatial but poor soft tissue contrast or based imaging grating interferometers has the potential to become a ne imaging offering higher soft tissue contrast and spatial resolution than that obtained with conventional attenuation based For recent analysis suggests that could enable the detection of tumors and lesions in soft which is not possible with other imaging phase contrast diagnostic of arterial plaque or of cartilage damage appears also There is thus a rapidly growing spectrum of possible medical applications of PC in there could be many powerful applications of in testing and material 1A and illustrate a layout of conventional grating based phase contrast The inset illustrates the curve for obtained by scanning one of the gratings along its Only small objects can be imaged and successive exposures are required to obtain the The Glancing Angle consists of three and having equal period and separated by equal and inclined at an typically in the range The of inclining the gratings is to increase their effective thickness from the normal incidence value tf to and thus achieve high interferometer fringe contrast or visibility over a broad energy exceeding 100 Multiple can be stacked and tiled to make large field of view imaging systems Our previous disclosures focused on phase contrast Computed Tomography While CT is a powerful technique for most of the as well as industrial and security imaging is still done in radiographic using plain D The advantages of radiography are low and high spatial resolution at clinically compatible breast radiography or mammography is the for breast cancer it Is thus of value to develop phase contrast radiography in addition to There are However several problems to be The area that needs to be covered in radiography 25x25 in and up to chest or abdomen larger than the grating area possible with present technology Combining tens of such gratings to cover an area of a few thousand cm2 is in practice and would also be Phase contrast imaging requires acquiring multiple images minimum of an object to produce the scatter Acquiring these Images in temporal succession through multiple as it Is usually is impractical for medical or industrial radiography because of potential in acquiring successive images implies having the whole in the field of covering a large area with which as above mentioned is difficult and The conventional grating interferometer poor fringe contrast at the high energies needed to Image thick body parts such as the head or legs 80 The extent of the FOV the direction perpendicular to the grating bars only a few cm for all grating Including the because of the effect of the narrow and deep grating openings curved gratings can be made to alleviate the vignetting but they are expensive and also do not solve the problem of imaging at high At low energies where normal incidence interferometers can it would still be advantageous to use the GAS order to improve the grating uniformity and reduce manufacturing For research grade gratings can be made with period of and with thickness of adequate for work up to high gratings are difficult to make have poor It much easier and of better quality to make the gratings with thickness and use in a GAI setup at 30s thus doubling their effective in some the combination of three or more is disclosed so as to low scanning phase contrast radiography systems for all of practical that do not require successive and that can image large objects with high resolution and clinically compatible dose and scanning embodiments consistent with the present teachings disclose the following The use of multiple closely spaced spatial views or chords through an having each different interferometer to obtain the contrast instead of multiple temporally separated images sequential The use of a line or slot scanning design to nearly Simultaneously acquire the multiple images needed for phase contrast thus alleviating the motion The use of multiple spatial views together with a line or slot scanning design to acquire phase contrast radiographs of large objects to several tens of cm by meters The use of having multiple sectors or active areas with lines shifted with a fraction of the grating period from sector to to obtain the multiple images needed for phase contrast without the need to scan one of the gratings or for successive The use of scanning for phase contrast radiography of large up to The use of scanning GAi interferometers in conjunction with Delay detectors or with photon counting for phase contrast mammography and radiography with low dose and The use of mirror or reflector filtered scanning GAi for phase contrast radiography with very high sensitivity and low shows a layout of conventional phase contrast lb shows a curve for 4 steps that is obtained by scan ning one of the gratings of 1A grating GO or grating along its the arrangement of only objects can be imaged and multiple successive exposures are required to obtain the curve of Conventional grating phase imaging works by placing the entire object in a tau normal incidence interferometer and then laterally scanning one of the gratings across its with N steps of size where G is the grating Successive images are acquired for each grating As shown in the conventional phase contrast radiography 100 operable to image an object 120 comprises an source a source grating GO a grating an analyser grating G2 and an area detector The source grating GO 110 is positioned between the ray source 105 and the grating The object 120 is positioned between the grating Gl 115 and the analyser grating G2 the area detector 130 is less than 10 cm on a This arrangement process produces a sinusoidal intensity oscillation in each pixel of the named as shown in The dc or mean value A of the ng curve produces the attenuation the amplitude of the modulation 8 the scatter and the phase shif Introduced by the object to the refraction image Since the curve is determined by t a minimum number of phase with three corresponding interferometer images are needed to obtain the ref raction and scatter images of the This method requires having the entire object in the interferometer field of For large such as the human this is because the typical grating size several by several In the grating field of view in the direction perpendicular to the grating bars in is limited to a few cm by the effect of the narrow and deep grating The method also requires acquiring multiple successive which requires a long measurement time several tens of seconds with a medical and also requires that the object does not move during this These constraints limit the practical usefulness of the conventional phase contrast imaging in particular for medical in the conventional normal incidence interferometer works only at low energy 2A illustrates an example phase contrast radiography based on Stacked gratings are used to image a long and narrow of while the object or the interferometer is Multiple closely spaced views through varying phase interferometers are used to obtain the equivalent of the without the need for multiple The varying interferometer phasing is achieved using a or which in is the source The source cars have a least two different As shown the example phase contrast radiography system according to which is operable to image an object 220 comprises an source a source grating GO a grating an analyzer grating G2 and a detector The source grating GO 210 is positioned between the source 205 and the grating The object 220 is positioned between the grating 215 and the analyser grating G2 some the analyser grating 225 can have a thickness of about several tens of The analyzer grating cars comprises multiple glancing angle grating stacked in order to cover a length of the detector The detector 230 can comprise multiple Time Delay CCD detectors or line The example arrangement as shown in 2A and 28 can in a cost effective ail of the above the exam ple closely spaced fan views or through the object are used In order to acquire the multiple images needed for phase contrast Each view has a different phasing of the obtained using a grating with multiple regions or sectors and each having differe t relative line as i For if four views are the relative phasing of the grating lines between sectors would be and where G is the grating Any of the three gratings can be in but the to manufacture in this way Is the small size source By scanning the fan views or slices across the object translating either the object or the multiple images having each a different interferometer phasing are acquired almost simultaneously only time lag being the distance between the adjacent views divided the which for a typical radiographic setup a fraction of a The images are acquired at different angles through the object and these images are then used to build the as shown in in this example the phase contrast radiography images acquired at slightly different angles through the object are For assuming a interferometer length of and line or slot scan detectors separated by 1 the angle between views is Assuming four one phase contrast projection would thus average the phase information over a angular Ours other studies of phase contrast rotational tomography in which acquired at slightly different angles are used for phase retrieval similar to 2 show however that such a small averaging is not significantly affecting the accuracy or quality of the refraction The attenuation and scatter images are even less affected this small angular embodiments of the present disclosure can use long and narrow slot or line scanning with ltiple gratings stacked in order to cover the length of the This will enable rad iography of large objects through linear scanning with a wide fan For produces for panoramic imaging mm by up to 440 mm long TDI CCDs or Time Delay integration is a technique for obtaining line scan images with very high ratio and consists in shifting the charge accumulated in the CCD synchronous with the object The TDi CCD works in essence as a continuous film Using such one could easily scan an object of the size of the human leg or one could use closely spaced rows of linear detectors such as photon counting Si or pixilated arrays This would also add energy resolution to the enabling to further increase its sensitivity and 3A illustrates an example side view of scanning phase contrast mammography according to embodiments and 38 illustrates a top The and scatter images are simultaneously obtained in a single pass of the linear scanning To enable the oblique and projections required in mammography the interferometer gantry can rotate on the support in this a tow energy mammography system 300 is disclosed that operates at low the layout is shown in 3a the low energy mammography system 300 comprises a patient supporting member 305 that is supported by a first base memberSlO and a second base member A scanning table 320 is positioned below the patient supporting member 305 and above the second base member The scanning table 320 is operable to rotate a rotation shaft 325 coupled to the second base member 3 5 and is abfed to be locked into a position using a rotation lock 330 coupled to the rotation shaft The table 320 is arranged below the patient supporting member 305 and comprises a Th gantry 330 comprises an source and a similar to that described above in relation to 2a and that is supported by an interferometrlc base As discussed in relation to 2a and the interferometrlc base 340 supports source gratings gratings analyzer gratings and a detector CCD this the breast which is the object being can be supported on either side by a pair of paddies The top of the gantry 330 be covered with cover With the patient lying prone on the patient supporting member 305 with an opening 375 for the this position is similar to the position used in stereotactic biopsy imaging The prone position allows also having the breast immersed in an index refraction matching fluid saline so a to remove the strong phase variation occurring for low energies at the Due to the geometry the estimated dose with such a system of the order of 1 and the scan time is only several As described a previous disclosure an mirror or other spectral filter can be added to the system to produce a spectrum which will further enhance the performance of the interferometers and Sower the 4A and 48 illustrate an example front and side view scanning phase contrast radiography system 400 for the according to The system 400 comprises a similar to that described above In relation to and and similar to that described above in relation to 3A and 3B that the GAI in 3A and 3B are in a horizontal the GAi of 4A and 48 is in a vertical The GAi comprises an source source gratings gratings analyser gratings and a detector CCD The patient being scanned positioned on a table 435 and the portion of the being scanned 430 positioned between the gratings 415 and the analyzer gratings For added tomosynthesis capability the scanning table also rotate around the in a high energy system is disclosed for radiography extremities or This embodiment uses a similar layout as for but with thicker more inclined gratings that can work at up to 140 kVp and with longer to several of scanning Such systems enable soft tissue diagnostic throughout the body at high similar to the way mammography enables detecting soft tissues abnormalities in the breast at low An example high application be for instance phase contrast diagnostic of unstable arterial Recent research shows that phase contrast cart discriminate very well between the arterial low density lipid and fibrous or calcified plaque Embodiments of the present disclosure are possible also for industrial or security phase contrast where wide and long such as luggage or helicopter can be scanned in the field of view of the In the systems depicted in 3A and and 4A and 4B using the system depicted in 2A and 2B can be operable to perform a method for phase contrast imaging of an object using an interferometer comprising a source a and an analyzer wherein the object is positioned between the and the analyzer The method can comprise directing an ray onto the source wherein each sector of the source grating is offset by predetermined obtaining multiple images during a single expose by translating the object or the wherein the multiple images have a different interferometer and combining the multiple images that were obtained to produce a phase contrast image of the The multiple images can be obtained using a line or slot scan detectors separated by about 1 cm that is positioned behind the analyzer The angle between the multiple images can be about or about The angular range between four Images be about about or about Other angles between the multiple images and other angular ranges between image can be used depending on the particular configuration of th imaging system The foregoing description is and variations in configuration and implementation can occur to persons skilled in the For the various illustrative logical and circuits described connection with the embodiments disclosed herein can be implemented or performed with a general purpose a digital signal processor an application specific integrated circuit a field programmable gate array or other programmable logic discrete gate or transistor discrete hardware or any combination thereof designed to perform the functions described A processor can be a in the the processor can be conventional or state A processor can also be as a combination of computing a combination of a DSP and a a plurality of one or more microprocessors in conjunction a DSP or any other such In one or more exemplary the functions described can be implemented or any combination For a software the techniques described herein can be implemented modules software and so that perform the functions described A module can be coupled to another module or a hardware by passing receiving or memory or the can be or transmitted using suitable means including message token network and the The software codes can he stored in memory units and executed by The unit can implemented within the processor or external to the in which case it can bs communicatively coupled to the processor via various means as is known in the For 5 illustrates an example of a hardware configuration for a computer device that can be used to perform one or more of the processes of the features described While illustrates various components contained in the computer device 5 illustrates one example of a computer device and additional components can be added and existing components can be The computer device 500 can be type of computer such as or mobile such as smart tablet cellular personal digital As illustrated in the computer device 500 can include one or more processors 502 of varying core configurations and clock The computer device 500 also include one or more memory devices 504 that serve as a main memory during the operation of the computer device For a copy of the software that supports the features can be stored in the one or more memory devices The computer device 500 can also include one or more peripheral interfaces such as computer for enabling interaction with and manipulation of the computer device The computer device 500 can also one or more network interfaces SOS for communicating via one or more such as Ethernet wireless or serial network for communicating over wired or wireless using The computer device 500 can also one or more storage device of varying physical dimensions and storage such as flash hard access for storing such as and program instructions for execution by the one or more processors the computer device 500 can include one or more software programs that enable the functionality of the features described The or more software programs can include Instructions that cause the one or more processors 502 to perform the processes described Copies of the one or software programs 512 can be stored the one or more memory devices 504 on in the one or more storage devices the data utilized by one or more software programs 512 can be stored in the one or more memory devices 504 on in the one or more storage devices In the computer device 500 can communicate with one or more other devices 514 via a network The one or more other devices 514 can be any types of devices as described The network 516 can be any type of such as a local area a a virtual private the an an a public switched telephone an a wireless and any combination The network can support communications using any of a variety of such as and the The network 516 can for a local area a area a virtual private the an an a public switched telephone an infrared a wireless and any combination The computer device 500 can include a variety of data stores and other memory and storage media as discussed These can reside in a variety of such as on a storage medium local to resident one or more of the computers or remote from any all of the across the In some information can reside in a network familiar to those skilled the any necessary files for performing the functions attributed to the or other network devices may he stored locally as the components of the computer device 500 as described above need not be enclosed within a single enclosure or located in close proximity to one Those skilled in the will appreciate that the componentry are examples as the computer device 500 can include any type of hardware including any necessary accompanying firmware or for performing the disclosed The computer device 500 can also be implemented in or in whole by circuit components or such as integrated circuits or gate arrays If implemented in the functions be stored on or transmitted over a medium as one or more instructions or media includes both computer storage media and communication media including any medium that facilitates transfer of a computer from one place to A storage media can be any available media that can be accessed a By way of and not such transitory media can comprise flash ROM or other optical disk magnetic disk storage or other magnetic storage or any other be used to carry or store desired code in the form of instructions or data structures and can be accessed by and as used includes laser optical floppy disk and disc where disks reproduce data while discs reproduce data optically connection Is properly termed a For if the software is from a or other remote source using a coaxial twisted digital subscriber or wireless technologies such as and then the coaxial fiber optic twisted or wireless technologies such as and microwave are included in the definition of Combinations of the above should also be included within the scope of While the teachings have described with reference to examples of the implementations those skilled the will be able to make various modifications to the described implementations without departing from the true spirit and The terms and descriptions used herein are set forth by way of only and are not meant as in although the processes have been described by the stages of the processes can be performed in a different order than illustrated or to the extent that the terms or variants thereof are used In the detailed such terms are intended to be inclusive in a manner similar to the term As used the terms or more of and one with respect to a listing of such for A and means A or A and unless specified the term should be interpreted as or the term or is Intended to mean either an indirect or direct if a first device couples to a second that connection can be through a direct or through an indirect connection via other and insufficientOCRQuality