X-ray imaging system and method

1. An X-ray imaging system, comprising:

an X-ray source configured to irradiate X-ray beams;

a first grating and a second grating arranged sequentially in an irradiation direction of the X-ray beams;

a detector arranged at downstream of the second grating in the irradiation direction of the X-ray beams; and

a controller and data processing device configured to control the X-ray source to irradiate the X-ray beams, to control the detector to receive X-ray beams passing through the first grating and the second grating to generate phase contrast information and/or dark field information, and to perform CT check on an object under check based on the phase contrast information and/or the dark field information to obtain a CT image, wherein the controller and data processing device is further configured to control the X-ray source and the detector to perform Digital Radiography (DR) scan on the object under check to obtain the phase contrast information and/or the dark field information, to determine a position of interest in the object under check based on the phase contrast information and/or the dark field information, and to perform CT scan at the position of interest in the object under check to obtain the CT image.

2. The X-ray imaging system of claim 1 , wherein the CT image obtained by performing CT scan at the position of interest in the object under check comprises at least one of a phase contrast image, a dark field image, an attenuation coefficient image, an atomic number image, or an electron density image.

3. The X-ray imaging system of claim 1 , wherein the CT scan comprises one of circle-orbit CT scan, spiral-orbit CT scan, or grating-based CT phase contrast scan.

4. The X-ray imaging system of claim 1 , further comprising a source grating arranged between the X-ray source and the first absorption grating, wherein the object under check undergoes scanning between the source grating and the first absorption grating.

5. The X-ray imaging system of claim 1 , wherein the X-ray source and the detector are interchangeable in position to form a reverse-geometrical grating-based imaging system.

6. The X-ray imaging system of claim 1 , wherein the detector comprises a linear array detector or a planar array detector.

7. The X-ray imaging system of claim 1 , wherein the first grating and the second grating each are an absorption grating and/or a phase grating.

8. The X-ray imaging system of claim 1 , wherein the first grating and the second grating each comprise a focusing grating, an arc-shaped grating or a polygonal-line shaped grating.

9. An X-ray imaging method, comprising steps of:

performing Digital Radiography (DR) scan on an object under check to obtain contrast information and/or dark field information;

determining a position of interest in the object under check based on the contrast information and/or the dark field information; and

performing CT scan at the position of interest in the object under check to obtain a CT image.

10. The method of claim 9 , wherein the step of determining a position of interest in the object under check based on the contrast information and/or the dark field information comprises:

deriving internal features of the object under check from the contrast information and/or the dark field information for the object under check; and

determining the position of interest based on the internal features if the internal features satisfy a predetermined condition.

11. The method of claim 9 , wherein the CT image obtained by performing CT scan at the position of interest in the object under check comprises at least one of a phase contrast image, a dark field image, an attenuation coefficient image, an atomic number image, or an electron density image.

12. The method of claim 9 , wherein the CT scan comprises one of circle-orbit CT scan, spiral-orbit CT scan, or grating-based CT phase contrast scan.

13. An X-ray imaging system, comprising:

an X-ray source configured to irradiate X-ray beams;

a first grating and a second grating arranged sequentially in an irradiation direction of the X-ray beams;

a detector arranged at downstream of the second grating in the irradiation direction of the X-ray beams; and

a controller and data processing device configured to control the X-ray source to irradiate the X-ray beams, to control the detector to receive X-ray beams passing through the first grating and the second grating to generate phase contrast information and/or dark field information, to generate a Digital Radiography (DR) image by scan without using the first and second gratings, and to determine whether the object under check contains a suspected article based on the DR image and also the phase contrast information and/or the dark field information,

wherein the controller and data processing device is further configured to:

determine a position of interest in the object under check based on the phase contrast information and/or the dark field information,

generate the DR image by scanning the position of interest in the object under check without using the first and second gratings, and

determine whether the object under check contains a suspected article based on the DR image obtained by scanning the position of interest.

14. An X-ray imaging system, comprising:

a first X-ray check device configured to obtain a Digital Radiography (DR) image of an object under check;

a second X-ray check device configured to obtain phase contrast information and/or dark field information of the object under check; and

a controller and data processing device configured to determine whether the object under check contains a suspected article based on the DR image and also the phase contrast information and/or the dark field information,

wherein the first X-ray check device configured to is further configured to:

determine a position of interest in the object under check based on the phase contrast information and/or the dark field information,

obtain the DR image of the object under check by scanning the position of interest in the object under check, and

determine whether the object under check contains a suspected article based on the DR image obtained by scanning the position of interest.

15. An X-ray imaging system, comprising:

a first X-ray CT device configured to obtain an X-ray CT image of an object under check;

a second X-ray CT device configured to obtain a phase contrast CT image and/or a dark field CT image of the object under check; and

a controller and data processing device configured to determine whether the object under check contains a suspected article based on the X-ray CT image and also the phase contrast CT image and/or the dark field CT image,

wherein the controller and data processing device is further configured to:

determine a position of interest in the object under check based on the phase contrast CT image and/or the dark field CT image,

obtain the X-ray CT image of the object under check by scanning the position of interest in the object under check, and

determine whether the object under check contains a suspected article based on the X-ray CT image obtained by scanning the position of interest.

16. An X-ray imaging system, comprising:

an X-ray check device configured to obtain a Digital Radiography (DR) image of an object under check;

an X-ray CT device configured to obtain a phase contrast CT image and/or a dark field CT image of the object under check; and

a controller and data processing device configured to determine whether the object under check contains a suspected article based on the DR image and also the phase contrast CT image and/or the dark field CT image,

wherein the controller and data processing device is further configured to:

determine a position of interest in the object under check based on the phase contrast CT image and/or the dark field CT image,

obtain the DR image of the object under check by scanning the position of interest in the object under check, and

determine whether the object under check contains a suspected article based on the DR image obtained by scanning the position of interest.

17. An X-ray imaging system, comprising:

an X-ray source configured to irradiate X-ray beams;

a first grating and a second grating arranged sequentially in an irradiation direction of the X-ray beams;

a detector arranged at downstream of the second grating in the irradiation direction of the X-ray beams; and

a controller and data processing device configured to control the X-ray source and the detector to perform CT scan on an object under check to obtain a CT image, and to control to use the first and second gratings based on information from the CT image to generate phase contrast information and/or dark field information of the object under check,

wherein the controller and data processing device is further configured to:

determine a position of interest in the object under check based on the phase contrast information and/or dark field information, and

perform CT scan at the position of interest in the object under check to obtain the CT image.