GB2527505A

GB2527505A - X-ray imaging method and apparatus

Info

Publication number: GB2527505A
Application number: GB1411002.7A
Authority: GB
Inventors: Roy Peter Peers-Smith
Original assignee: Kirintec Ltd
Current assignee: Kirintec Ltd
Priority date: 2014-06-20
Filing date: 2014-06-20
Publication date: 2015-12-30
Also published as: GB201411002D0

Abstract

A method for use in the X-ray imaging of an item 10 comprises positioning an electrically conductive X-ray transmissive material mesh screen 12 over and around the item and using an X-ray based imaging system to produce an image of the item, the mesh material screen 12 being located between the item and the X-ray based imaging system, transmitter 26 and receiver 28. The mesh screen 12 may comprise a woven fabric cover 16 such as a blanket with conductive strands and may be put over a frame 14 to form an enclosed space 18. Opaque markers 24 may be included on the mesh to provide a position reference for regions of interest 10a on the item. The mesh screen acts to reduce interference in the image by filtering out unwanted scatter and stray reflections and may produce a sharper x-ray image.

Description

X-Ray Imaging Method and Apparatus This invention relates to a method and apparatus for use in the examination or imaging of items using X-ray or the like technology.

Where suspect packages are found, for example in locations to which the public have access such as airports and railway stations, there is often a need to examine those packages in situ to ascertain whether or not their contents represent a risk to the public. Manual inspection of such packages carries the risk that if the package contains an explosive device, the person undertaking the inspection and those close by are exposed to considerable risks. Rather than undertake a manual inspection, there are occasions where a physical inspection may be undertaken using, for example, a remotely operated device. However, this requires the presence of specialist equipment and specially trained operators.

Rather than undertake manual or physical inspections of such package, it may be preferred to use X-ray equipment to produce an image of the contents of the package to ascertain whether or not the package contents represent such a risk.

X-ray equipment has been in use in undertaking inspections of packages or the like for many years, and whilst its use has been successful, one issue with the use of X-ray based inspection equipment is that the images produced by the equipment can be difficult to interpret. The images tend to include a number of spurious shadows and sharp edges of an item can appear significantly blurred in the image. Consequently, there is a risk of misinterpretation of the X-ray images with the risk that contents that could represent a risk are not identified.

Even where X-ray based techniques are used to successfully identify the presence of an element which could represent a risk, determination of the precise location of the element within the package as a whole is difficult, and so subsequent procedures used to destroy or render safe the item may be longer and more complex than could be the case where the location of the item is well defined.

Whilst in the description hereinbefore reference is made to packages found in public spaces, the techniques described herein may be used in a wide range of other applications. For example, the techniques may be used in the inspection, for example routine inspection, of larger packages, crates or boxes, for example in transit through ports or airports, or on-board vehicles. Indeed, the techniques may be used on vehicles, to identify the presence of suspect items located thereon or therein.

Furthermore, whilst the description hereinbefore refers to the identification of packages whose contents may represent a risk to the safety of the public, the techniques of the invention may be used in the inspection for the presence of, for example, illegal drugs or objects being smuggled into a country, or in a number of other applications.

It is an object of the invention, therefore, to provide a method and apparatus for use in the inspection or imaging of items by X-ray in which at least some of the disadvantages with the techniques outlined hereinbefore are overcome or are of reduced effect.

References herein to items should be interpreted to cover any of the alternatives set out hereinbefore and the like, or other objects to be imaged.

According to one aspect of the invention there is provided a method for use in the X-ray imaging of an item comprising the steps of: positioning an electrically conductive X-ray transmissive material mesh over and around the item; and using an X-ray based imaging system to produce an image of the item, the mesh material being located between the item and components of the X-ray based imaging system.

It has been found that the location of an electrically conductive mesh material between the X-ray based imaging equipment and an item to be imaged results in the production of a clearer, sharper X-ray image of the item. As a result, the contents of the item can be ascertained with a greater degree of accuracy. Consequently, the risk of relevant contents of the item being misidentified or missed is reduced.

It is thought that the mesh serves as a filter removing or reducing, for example, low power X-ray reflections, scattered X-rays from interactions with the item, and other interference from the X-ray image, thereby resulting in the production of the clearer, sharper image.

The electrically conductive material mesh may comprise, for example, a woven polymer fabric, the fabric being composed of strands each of which carries a metallic material coating. Alternatively, the mesh may be of non-woven form, formed of randomly orientated strands each of which carries a metallic material coating. By way of example, the metallic material coating may comprise a copper coating. However, this represents just one possibility of a wide range of suitable materials. The electrically conductive mesh material could comprise, for example, thin metallic strands One suitable mesh material is Aaronia X-Dream (rtm). However, it will be appreciated that this represents just one example of a suitable material, and the invention is not restricted in this regard.

The mesh may take the form of, for example, a blanket to be positioned over the item.

Alternatively, the mesh may be adapted to be supported by a frame to define an enclosure to be positioned, in use, around the item.

The mesh may be provided with an array of markers which are opaque to the X-ray based imaging system. Where the mesh is adapted to be supported by a frame, then the mesh conveniently defines a series of side walls, each of which is provided with an array of such markers. It will be appreciated that in such an arrangement, the image produced by the X-ray based imaging system will include both the image of the item and the markers. As the positional relationship between the imaging system and the markers may be known, it will be appreciated that triangulation methods may be used to identify the location of elements of the contents of the item as viewed in by the imaging system. Consequently, if it is felt that further procedures should be undertaken to render safe such elements, the procedures can be accurately targeted minimising risk, enhancing the efficiency with which such procedures can be undertaken and avoiding unnecessary interference of parts of the item remote from the elements of concern.

By way of example, the markers could comprise metallic material discs of the like attached to the mesh in predetermined positions.

According to another aspect of the invention there is provided an apparatus for use in the method defined hereinbefore, the apparatus comprising a screen of an electrically conductive, X-ray transmissive material mesh to be positioned, in use, over and around the item to be inspected.

The screen may take the form of, for example, a blanket to be positioned over the item.

Alternatively, the screen may be adapted to be supported by a frame to define an enclosure to be positioned, in use, around the item.

The screen may be provided with an array of markers which are opaque to the X-ray based imaging system. Where the screen is adapted to be supported by a frame, then the screen conveniently defines a series of side walls, each of which is provided with an array of such markers.

The material of the screen may comprise, for example, a woven polymer fabric, the fabric being composed of strands each of which carries a metallic material coating.

Alternatively, it may take the form of a non-woven polymer material comprising substantially randomly orientated polymer strands carrying a metallic material coating.

By way of example, the metallic material coating may comprise a copper coating.

However, this represents just one possibility of a wide range of suitable materials. The material could alternatively comprise, for example, thin metallic strands woven together to form the mesh.

As mentioned above, one suitable mesh material is Aaronia X-Dream (rtm). However, it will be appreciated that this represents just one example of a suitable material, and the invention is not restricted in this regard.

The invention will further be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a diagram illustrating an apparatus in accordance with an embodiment of the invention employed in conducting the method of an aspect of the invention; Figure 2 is an enlargement illustrating part of the apparatus of Figure 1; and Figure 3 is another view illustrating part of the apparatus.

Referring to the accompanying drawings, an apparatus in accordance with an embodiment of the invention is illustrated. The apparatus is intended for use in the X-ray imaging of an item 10, in this case a box or the like located upon a floor surface.

However, the invention is suitable for use in a wide range of applications, and is not restricted in relation to the shape, position or size of an item to be imaged.

The apparatus of the illustrated embodiment of the invention comprises a screen 12 in the form of a supporting frame 14 over which a mesh material cover 16 is positioned, the cover 16 being supported by the frame 14 to define an enclosed space 18. The screen 12 is erected and positioned around the item 10 such that the item 10 is located within the enclosed space 18. In the illustrated embodiment the space 18 is of generally cube shaped form. However, this represents just one of many suitable shapes. The frame 14 and cover 16 may be integrated with one another. For example, they may take a pop-up type form, or may be arranged to be erected by a telescoping and/or folding operation.

The cover 16 is formed from an electrically conductive mesh material 20 (see Figure 2) comprising a series of strands 22 which are woven together. Each strand 22 is of polymer material form and is provided with a thin metallic material coating. The coating may be applied to the strands before the strands are woven together to form the fabric material 20 of the cover 16. Alternatively, the strands 22 may be woven together to form the fabric of the cover 16, the woven fabric then having the metallic material coating applied thereto. Regardless as to which approach is taken to manufacture the material 20 of the cover 16, the material 20 is of electrically conductive form and is transmissive to at least part of the X-ray frequency band.

Whilst Figure 2 illustrates the material as being of woven form, it will be appreciated that it may alternatively be of non-woven form, for example comprising substantially randomly orientated strands of a polymer material, each strand carrying a metallic material coating. One example of a material suitable for use in the cover is Aaronia X-Dream (rim) available from Aaronia AG. However, this represents just one example of a suitable material, and a wide range of other materials may be used without departing from the scope of the invention.

As illustrated, metallic material discs or markers 24 are secured to the cover 16. The markers 24 are opaque to X-rays.

In use, therefore, the screen 12 is assembled and positioned over and around the item 10. An X-ray imaging transmitter 26 of an X-ray imaging system is positioned to one side of the screen 12 and the associated receiver 28 is positioned to an opposing side of the screen so that X-rays transmitted from the transmitter 26 pass through the screen 12 into the space 18 where they interact with the item 10. Depending upon the nature of the item 10, some of the X-rays will pass through the item 10, passing through the screen 12 to be received by the receiver 28. Where the interaction between the X-rays and parts of the item results in the incident X-rays being absorbed, then the intensity of the X-rays received by the receiver 28 imaging that part of the item will be reduced. The variations in the intensity of the X-rays incident upon the receiver 28 give rise to the generation of an image providing information regarding the materials and/or contents of the item 10.

The interaction between the X-rays and parts of the item 10 may result in the X-rays being scattered, for example, elastic and/or inelastic scattering may occur, and such scattering can negatively impact upon the clarity of the image, for example resulting in the generation of shadows and in blurring of the image. By the use of the screen 12, such relatively low power scattered rays must pass through the screen 12 before they are incident upon the receiver 28, and the electrically conductive nature of the screen 12 serves to attenuate the relatively low power scattered and reflected rays with the result that they do not negatively impact upon the clarity of the image, or such impacts are of reduced effect. As a result, therefore, the formation of undesired shadows and blurring of the image is reduced.

If it is determined that the item 10 includes an element iDa thought to be of concern in that it appears to contain an explosive device or comprises a material which requires further investigation, then the location of the element ba can be ascertained, relative to the screen 12, as the markers 24 which are opaque to the X-rays will appear on the image. The markers 24, as shown in Figure 3, form an array of a known pattern and with a known spacing between the markers 24. As the pattern of the markers 24 and their spacing is known, and the markers 24 are provided upon all of the walls of the cover 16, their presence on the image can be used to accurately ascertain the position of the element iDa by the use of appropriate triangulation techniques. In one arrangement, in order for such techniques to be used, it may be necessary to image the item 10 from two spaced apart locations or angles. However, with appropriate, preferably computer based, imaging techniques, the precise location of the element ba may be determined whilst imaging from a single location or from locations that are very closely spaced, with the result that the location may be determined using a single transmitter 26 in a single location and a single receiver 28 in a single location.

Whilst in the arrangement described hereinbefore the screen 12 is intended to be supported by the frame 14 or the like, the invention is also applicable to arrangements in which the screen 12 is intended to be positioned or draped directly over the item. In such an arrangement the screen 12 will take the form of a blanket or the like.

It will be appreciated that whilst certain specific embodiments of the invention are described hereinbefore, a wide range of modifications and alterations may be made thereto without departing from the scope of the invention as defined by the appended claims.

Claims

CLAIMS: 1. A method for use in the X-ray inspection of an item, the method comprising the steps of: positioning an electrically conductive X-ray transmissive material mesh screen over and around the item; and using an X-ray based imaging system to produce an image of the item, the mesh material screen being located between the item and a component of the X-ray based imaging system.
2. A method according to Claim 1, wherein the electrically conductive material mesh screen comprises a polymer fabric, the fabric being composed of strands each of which carries a metallic material coating.
3. A method according to Claim 2, wherein the metallic material coating comprises a copper coating.
4. A method according to Claim 2 or Claim 3, wherein the mesh screen material is of woven form.
5. A method according to Claim 2 or Claim 3, wherein the mesh screen material is of non-woven form.
6. A method according to Claim 1, wherein the electrically conductive mesh material comprises thin metallic strands woven together to form the mesh.
7. A method according to any of the preceding claims, wherein the mesh takes the form of a blanket to be positioned over the item.
8. A method according to any of Claims ito 6, wherein the mesh is adapted to be supported by a frame to define an enclosure to be positioned, in use, around the item.
9. A method according to any of the preceding claims, wherein the mesh is provided with an array of markers which are opaque to the X-ray based imaging system.
10. A method according to Claim 9 wherein where the mesh screen is adapted to be supported by a frame, the mesh conveniently defines a series of side walls, each of which is provided with an array of the markers.
11. A method according to Claim 9 or Claim 10, wherein the markers comprise metallic material discs or the like attached to the mesh in predetermined positions.
12. An apparatus for use in the method of any of Claims 1 to 11, the apparatus comprising a screen of an electrically conductive, X-ray transmissive material mesh to be positioned, in use, over and around an item to be inspected.
13. An apparatus according to Claim 12, wherein the screen comprises a blanket to be positioned over the item.
14. An apparatus according to Claim 12, wherein the screen is adapted to be supported by a frame to define an enclosure to be positioned, in use, around the item.
15. An apparatus according to any of Claims 12 to 14, wherein the screen is provided with an array of markers which are opaque to the X-ray based imaging system.
16. An apparatus according to Claim 15, wherein where the screen is adapted to be supported by a frame, then the screen defines a series of side walls, each of which is provided with an array of the markers.
17. An apparatus according to Claim 15 or Claim 16, wherein the markers comprise metallic material discs or the like attached to the mesh in predetermined positions.
18. An apparatus according to any of Claims 12 to 17, wherein the material of the screen comprises a polymer fabric, the fabric being composed of strands each of which carries a metallic material coating.
19. An apparatus according to Claim 18, wherein the metallic material coating comprises a copper coating.
20. A method according to Claim 18 or Claim 19, wherein the mesh screen material is of woven form.
21. A method according to Claim 18 or Claim 19, wherein the mesh screen material is of non-woven form.
22. An apparatus according to any of Claims 12 to 17, wherein the material comprises thin metallic strands woven together to form the mesh.