System and method for phase-contrast X-ray imaging using a multi-sector source grating
A differential phase contrast X-ray imaging system includes an X-ray illumination system, a beam splitter arranged in a radiation path of the X-ray illumination system, and a detection system arranged in a radiation path to detect X-rays after passing through the beam splitter.
1. A method for phase contrast imaging of an object using an interferometer comprising a multi-sector source grating, a beam-splitter grating, and an analyzer grating, wherein the object is positioned between the beam-splitter grating and the analyzer grating, the method comprising:
directing an X-ray beam onto the multi-sector source grating, wherein each sector of the multi-sector source grating is offset by a predetermined amount;
obtaining multiple images during a single exposure by translating the object or the interferometer, wherein the multiple images have a different interferometer phasing; and
combining the multiple images that were obtained to produce a phase contrast image of the object.
2. The method according to claim 1 , wherein the multi-sector source grating has greater than three different sectors.
3. The method according to claim 1 , wherein the multiple images are acquired at different angles through the object.
4. The method according to claim 1 , wherein the interferometer has a length about 1.8 m.
5. The method according to claim 1 , wherein the analyzer grating has a thickness of about several tens of centimeters.
6. The method according to claim 1 , wherein the multiple images are obtained using a line detector or a slot scan detector separated by about 1 cm that is positioned behind the analyzer grating.
7. The method according to claim 1 , wherein the multiple images of the object are obtained at angular increments of about 0.3°.
8. The method according to claim 1 , wherein the multiple images comprises four images and an angular range between the four images is about 0.9°.
9. The method according to claim 1 , wherein the analyzer grating comprises multiple glancing angle gratings stacked in order to cover a length of a detector.
10. A device for phase contrast imaging of an object comprising:
an interferometer comprising a multi-sector source grating, a beam-splitter grating, and an analyzer grating, wherein the object is positioned between the beam-splitter grating and the analyzer grating;
an X-ray source operable to direct an X-ray bean onto the multi-sector source grating, wherein each sector of the multi-sector source grating is offset by a predetermined amount;
a translation mechanism operable to translate the object or the interferometer;
a detector operable to obtain multiple images of the object during a single exposure; and
a processor operable to combine the multiple images that were obtained to produce a phase contrast image of the object.
11. The device according to claim 10 , wherein the multi-sector source grating has greater than three different sectors.
12. The device according to claim 10 , wherein the multiple images are acquired at different angles through the object.
13. The device according to claim 10 , wherein the interferometer has a length about 1.8 m.
14. The device according to claim 10 , wherein the analyzer grating has a thickness of about several tens of centimeters.
15. The device according to claim 10 , wherein the detector is a line detector or a slot scan detector and the multiple images are obtained using the line detector or the slot scan detector separated by about 1 cm that is positioned behind the analyzer grating.
16. The device according to claim 10 , wherein the multiple images of the object are obtained at angular increments of about 0.3°.
17. The device according to claim 10 , wherein the multiple images comprises four images and an angular range between the four images is about 0.9°.
18. The device according to claim 10 , wherein the analyzer grating comprises multiple glancing angle gratings stacked in order to cover a length of the detector.