SYSTEM AND METHOD FOR COMPACT LAMINOGRAPHY UTILIZING MICROFOCUS TRANSMISSION X-RAY SOURCE AND VARIABLE MAGNIFICATION X-RAY DETECTOR

Abstract

An x-ray computed laminography imaging system includes a transmission x-ray source configured to generate x-rays, at least some of the x-rays propagate along an x-ray propagation axis through a region of interest of an object. The system further includes a stage assembly configured to rotate the object about a rotation axis extending through the region of interest. The system further includes at least one x-ray detector configured to intercept at least some of the x-rays propagating along the x-ray propagation axis. The at least one x-ray detector includes a scintillator, at least one optical lens, and two-dimensional pixelated imaging circuitry. The scintillator has a thickness that is substantially parallel to the x-ray propagation axis and the at least one optical lens is configured to receive visible light from the scintillator and to focus the visible light into a two-dimensional image. The at least one optical lens has a depth of focus, and the thickness of the scintillator is in a range of 1 to 20 times the depth of focus.

Description

Claims

1. An x-ray computed laminography imaging system configured to generate a transmission image of a region of interest of an object, the system comprising: a transmission x-ray source configured to generate x-rays at an x-ray source focal spot, at least some of the x-rays propagating along an x-ray propagation axis extending from the x-ray source focal spot through the region of interest of the object;a stage assembly comprising at least one rotation stage configured to rotate the object about a rotation axis extending through the region of interest, the rotation axis at an angle relative to a normal to the x-ray propagation axis in a range of 10 degrees to 60 degrees;at least one x-ray detector configured to intercept at least some of the x-rays propagating along the x-ray propagation axis, the at least one x-ray detector comprising at least one optical subsystem and a two-dimensional pixelated imaging circuitry comprising an imaging area configured to receive a two-dimensional image from the at least one optical subsystem, the at least one optical subsystem comprising: a scintillator having a thickness that is substantially parallel to the x-ray propagation axis, the scintillator configured to generate visible light in response to x-rays impinging the scintillator; andat least one optical lens configured to receive the visible light from the scintillator and to focus the visible light into the two-dimensional image, the at least one optical lens having a depth of focus, the thickness of the scintillator in a range of 1 to 20 times the depth of focus.

2. The system of claim 1, wherein the thickness of the scintillator is in a range of 1 to 5 times the depth of focus.

3. The system of claim 1, wherein the at least one optical lens comprises an objective lens configured to receive at least a portion of the visible light from the scintillator and to focus the two-dimensional image on the imaging area of the imaging circuitry.

4. The system of claim 1, wherein the at least one optical lens comprises an objective lens configured to receive at least a portion of the visible light from the scintillator and a tube lens configured to receive at least a portion of the visible light from the objective lens, the tube lens configured to focus the two-dimensional image on the imaging area of the imaging circuitry.

5. The system of claim 1, wherein the at least one optical subsystem comprises: a first optical subsystem comprising a first scintillator and at least one first optical lens configured to be translated into position to intercept the x-rays and to provide a first optical attribute for the two-dimensional image at the imaging area; anda second optical subsystem comprising a second scintillator and at least one second optical lens configured to be translated into position to intercept the x-rays and to provide a second optical attribute for the two-dimensional image at the imaging area, the second optical attribute different from the first optical attribute.

6. The system of claim 5, wherein the first and second optical attributes are optical magnifications.

7. The system of claim 5, wherein the first and second optical attributes are numerical apertures.

8. The system of claim 1, further comprising at least one linear translation stage configured to move the object relative to the rotation axis.

9. The system of claim 1, further comprising a gantry on which the x-ray source and the at least one x-ray detector are mounted, the gantry configured to rotate the x-ray source and the at least one x-ray detector about a rotation pivot point at an intersection of the x-ray propagation axis and the rotation axis.

10. The system of claim 9, wherein the gantry is configured to adjust an angle of the x-ray propagation axis relative to the rotation axis.

11. The system of claim 1, further comprising at least one source stage configured to translate the x-ray source relative to the object and relative to the at least one x-ray detector to adjust a magnification of the two-dimensional image relative to the region of interest.

12. The system of claim 11, wherein the at least one source stage is further configured to adjust an angle of the x-ray propagation axis relative to the rotation axis.

13. The system of claim 1, further comprising at least one detector stage configured to translate the at least one x-ray detector relative to the object and relative to the at least one x-ray source to adjust a magnification of the two-dimensional image relative to the region of interest.

14. The system of claim 13, wherein the at least one detector stage is further configured to adjust an angle of the x-ray propagation axis relative to the rotation axis.

15. The system of claim 1, wherein the at least one x-ray detector further comprises a second x-ray detector configured to be moved in place of the at least one optical subsystem and the two-dimensional pixelated imaging circuitry, such that the second x-ray detector is receives the x-rays instead of the at least one optical subsystem and the two-dimensional pixelated imaging circuitry.

16. The system of claim 15, wherein the second x-ray detector is selected from a group consisting of: an energy discriminating flat panel detector, an amorphous selenium detector, and a photon counting detector.

17. The system of claim 1, wherein the stage assembly further comprises at least one linear translation stage mounted to the at least one rotation stage.

18. The system of claim 17, wherein the stage assembly further comprises a support configured to hold the object, the support substantially transparent to a substantial fraction of the x-rays.

19. The system of claim 1, further comprising a gantry on which the x-ray source and the at least one x-ray detector are mounted, the gantry configured to rotate the x-ray source and the at least one x-ray detector about a rotation pivot point at an intersection of the x-ray propagation axis and the rotation axis.

20. The system of claim 19, wherein the gantry is configured to adjust an angle of the x-ray propagation axis relative to the rotation axis.

21. A method of generating at least one two-dimensional image of a region of interest of an object, the method comprising: emitting diverging x-rays from an x-ray source focal spot;propagating at least some of the x-rays along an x-ray propagation axis through the region of interest of the object;positioning the object at a plurality of rotational positions by rotating the object about a rotation axis extending through the region of interest, the rotation axis at an angle relative to a normal of the x-ray propagation axis in a range of 10 degrees to 60 degrees; andfor one or more of the rotational positions of the object, detecting x-rays that have propagated through the region of interest.

22. The method of claim 21, wherein said detecting comprises: impinging at least some of the x-rays that have propagated through the region of interest onto a scintillator having a thickness that is substantially parallel to the x-ray propagation axis;using the scintillator to generate visible light in response to the x-rays impinging the scintillator;guiding the visible light, using an optical assembly, at a two-dimensional pixelated imaging area of imaging circuitry; andgenerating, using the imaging circuitry, the two-dimensional image of the region of interest.

23. The method of claim 22, wherein said detecting further comprises moving a flat panel and/or photon counting detector in place of the scintillator and the optical assembly and impinging at least some of the x-rays that have propagated through the region of interest onto the flat panel and/or photon counting detector.

24. The method of claim 22, wherein said detecting further comprises moving a second scintillator and a second optical assembly in place of the scintillator and the optical assembly and impinging at least some of the x-rays that have propagated through the region of interest onto the second scintillator, using the second scintillator to generate visible light in response to the x-rays impinging the second scintillator, and guiding the visible light, using the second optical assembly, at the two-dimensional pixelated imaging area of the imaging circuitry.

25. The method of claim 24, wherein the optical assembly has a first depth of focus, the thickness of the scintillator in a range of 1 to 20 times the first depth of focus, and the second optical assembly having a second depth of focus, a second thickness of the second scintillator substantially equal to an integer multiple of the second depth of focus, the second depth of focus different from the first depth of focus.

26. The method of claim 25, wherein the thickness of the scintillator is in a range of 1 to 5 times the first depth of focus.

27. The method of claim 22, wherein the optical assembly comprises at least one optical lens or a magnifying fiber optic plate.