Collimators, imaging devices, and methods for tracking and calibrating x-ray focus positions

A method for determining a focus position offset of an X-ray tube of an imaging device, wherein the method comprises:

• obtaining a first ray intensity distribution detected by an edge detection unit of a detector of the imaging device, wherein the imaging device includes an X-ray tube, a detector, and a collimator, and the collimator includes:
• an opening, and
• a protrusion, the protrusion being configured at at least one end of the opening and protruding into the opening, the opening having a plurality of opening widths along a first direction and a plurality of opening lengths along a second direction, and a first opening width corresponding to at least one end of the collimator in the second direction being smaller than a second opening width corresponding to a middle section of the collimator in the second direction,
• wherein the edge detection unit is located at an edge of the detector along the first direction, a size of the edge detection unit along the second direction corresponds to a size of the protrusion along the second direction, and the first ray intensity distribution corresponds to a first focus position of the X-ray tube;
• obtaining a second ray intensity distribution detected by the edge detection unit, wherein the second ray intensity distribution corresponds to a second focus position of the X-ray tube;
• and
• determining, based on the first ray intensity distribution and the second ray intensity distribution, the focus position offset that is between the first focus position and the second focus position of the X-ray tube.

A method for tracking a focus position of an X-ray tube of an imaging device, wherein the method comprises:

• obtaining a ray intensity distribution detected by an edge detection unit of a detector of the imaging device, wherein the imaging device includes an X-ray tube, a detector, and a collimator, the collimator includes:
• an opening, and
• a protrusion, the protrusion being configured at at least one end of the opening and protruding into the opening, the opening having a plurality of opening widths along a first direction and a plurality of opening lengths along a second direction, the plurality of opening widths including a first opening width and a second opening width, the first opening width corresponding to at least one end of the collimator in the second direction, the second opening width corresponding to a middle section of the collimator in the second direction, and the first opening width being smaller than the second opening width,
• wherein the edge detection unit is located at an edge of the detector along the first direction, a size of the edge detection unit along the second direction corresponds to a size of the protrusion along the second direction, and each ray intensity of the ray intensity distribution corresponds to a focus position of the X-ray tube;
• determining a first boundary intensity and a second boundary intensity of the ray intensity distribution;
• determining a relationship between the first boundary intensity and the second boundary intensity;
• and
• determining, by consulting a mapping table, the focus position of the X-ray tube based on the relationship between the first boundary intensity and the second boundary intensity, wherein the mapping table includes a correspondence relationship between focus positions and the relationship between the first boundary intensity and the second boundary intensity.

A system for tracking a focus position of an X-ray tube of an imaging device, wherein the system comprises:

• a storage device, configured to store a computer program;
• and
• a processor, configured to communicate with the storage device, when executing the computer program, causing the system to:
• obtain a ray intensity distribution detected by an edge detection unit of a detector of the imaging device, wherein the imaging device includes an X-ray tube, a detector and a collimator, the collimator includes:
• an opening, and
• a protrusion, the protrusion being configured at at least one end of the opening and protruding into the opening, the opening having a plurality of opening widths along a first direction and a plurality of opening lengths along a second direction, the plurality of opening widths including a first opening width and a second opening width, the first opening width corresponding to at least one end of the collimator in the second direction, the second opening width corresponding to a middle section of the collimator in the second direction, and the first opening width being smaller than the second opening width,
• wherein the edge detection unit is located at an edge of the detector along the first direction, a size of the edge detection unit along the second direction corresponds to a size of the protrusion along the second direction, and each ray intensity of the ray intensity distribution corresponds to a focus position of the X-ray tube;
• determine a first boundary intensity and a second boundary intensity of the ray intensity distribution;
• determine a relationship between the first boundary intensity and the second boundary intensity;
• and
• determine, by consulting a mapping table, the focus position of the X-ray tube based on the relationship between the first boundary intensity and the second boundary intensity, wherein the mapping table includes a correspondence relationship between focus positions and the relationship between the first boundary intensity and the second boundary intensity.

A calibration system for tracking a focus position of an imaging device, wherein the system comprises:

• a storage device, configured to store a computer program;
• and
• a processor, configured to communicate with the storage device, by executing the computer program, causing the system to:
• obtain a first detector response corresponding to a first focus position by scanning a reference object;
• obtain a second detector response corresponding to a second focus position by scanning a target object;
• determine, by consulting a correction table, a third detector response corresponding to the first focus position and a fourth detector response corresponding to the second focus position, wherein the correction table includes a correspondence relationship between focus positions and detector responses;
• calibrate the first detector response based on the third detector response and the fourth detector response;
• obtain image data corresponding to the target object based on the calibrated first detector response and the second detector response;
• and
• generate an image based on the image data.

A method for calibrating a focus position of an imaging device, wherein the method comprises:

• obtaining a first detector response corresponding to a first focus position by scanning a reference object;
• obtaining a second detector response corresponding to a second focus position by scanning a target object;
• determining, by consulting a correction table, a third detector response corresponding to the first focus position and a fourth detector response corresponding to the second focus position, wherein the correction table includes a correspondence relationship between focus positions and detector responses;
• calibrating the first detector response based on the third detector response and the fourth detector response;
• obtaining image data corresponding to the target object based on the calibrated first detector response and the second detector response;
• and
• generating an image based on the image data.