Method and system of automated X-ray positioning and collimation control on hand and foot scan
An automation method is disclosed for an X-ray tube scanner having an X-ray tube and an X-ray detector. The method allows the X-ray tube scanner to detect the X-ray detector's plane with an object to be imaged placed on the X-ray detector; determine a boundary box of the object to be imaged on the X-ray detector; determine the object's center position and orientation on the X-ray detector's plane; transfer the object's center position from the object's coordinate system to the X-ray tube's coordinate system; and estimate the X-ray tube control parameters for aligning the X-ray field emitted from the X-ray tube's collimator to the object's center position and the object's orientation on the X-ray detector.
1. A method for X-ray tube scanner automation, wherein the X-ray tube scanner comprises an X-ray tube and an X-ray detector, the method comprising:
acquiring, by a three-dimensional camera that includes a camera coordinate system, a three-dimensional image of an object placed on the X-ray detector, the X-ray detector including an X-ray detector coordinate system;
identifying the X-ray detector's plane in the three-dimensional image;
generating a boundary box of the object on the X-ray detector, the boundary box comprising four corner points;
determining the object's center position and orientation on the X-ray detector's plane;
transferring the four corner points of the boundary box from the camera coordinate system to the X-ray detector coordinate system;
calculating a transformation function from an object coordinate system to the X-ray detector coordinate system using one in-plane rotation and in-plane translation and the object's center position and orientation;
transferring, using the transformation function, the object's center position from the object's coordinate system to a coordinate system of the X-ray tube; and
estimating X-ray tube control parameters for aligning an X-ray field emitted from a center of a collimator of the X-ray tube to the object's center position in the coordinate system of the X-ray tube.
2. The method of claim 1 , wherein the X-ray tube scanner determining the boundary box of the object to be imaged on the X-ray detector comprises:
receiving image data representing a first image of the object to be imaged using the X-ray tube to form a second image;
detecting a plurality of positions of respective predetermined features in the first image;
determining the boundary box of an imaging area of the object to be imaged on the basis of the detected positions; and
controlling one or more parameters of the X-ray tube on the basis of the determined boundary box.
3. The method of claim 2 , further comprising:
determining an object size and/or an object orientation of the object to be imaged on the basis of the detected positions.
4. The method of claim 3 , further comprising:
determining the object orientation on the basis of an angle of a line intersecting two or more of the detected positions; and
orienting the boundary box of the imaging area of the object to correspond with the object orientation.
5. The method of claim 1 , wherein the X-ray tube control parameters comprise a position of the X-ray tube and/or one or more collimator settings of the collimator of the X-ray tube.
6. An X-ray tube scanner system comprising:
an X-ray tube including a coordinate system;
a three-dimensional camera that includes a camera coordinate system;
an X-ray detector that includes an X-ray detector coordinate system; and
a system controller, wherein the system controller comprising a processor, and a non-transitory computer readable medium storing computer program instructions for operating the X-ray tube scanner,
wherein the computer program instructions when executed by the processor cause the processor to perform operations comprising:
acquiring using the three-dimensional camera a three-dimensional image of an object placed on the X-ray detector;
detecting the X-ray detector's plane in the three-dimensional image;
generating a boundary box of the object to be imaged on the X-ray detector, the boundary box comprising four corner points;
determining the object's center position and orientation on the X-ray detector's plane;
transferring the four corner points of the boundary box from the camera coordinate system to the X-ray detector's coordinate system;
calculating a transformation function from an object coordinate system to the X-ray detector coordinate system using one in-plane rotation and in-plane translation and the object's center position and orientation;
transferring, using the transformation function, the object's center position from the object's coordinate system to the X-ray tube's coordinate system; and
estimating X-ray tube control parameters for aligning an X-ray field emitted from the X-ray tube's collimator to the object's center position in the coordinate system of the X-ray tube.
7. The X-ray tube scanner system of claim 6 , wherein the X-ray tube scanner determining the boundary box of the object to be imaged on the X-ray detector comprises:
receiving image data representing a first image of the object to be imaged using the X-ray tube to form a second image;
detecting a plurality of positions of respective predetermined features in the first image;
determining the boundary box of an imaging area of the object to be imaged on the basis of the detected positions; and
controlling one or more parameters of the X-ray tube on the basis of the determined boundary box.
8. The X-ray tube scanner system of claim 7 , wherein the operation performed by the processor further comprising:
determining an object size and/or an object orientation of the object to be imaged on the basis of the detected positions.
9. The X-ray tube scanner system of claim 8 , wherein the operation performed by the processor further comprising:
determining the object orientation on the basis of an angle of a line intersecting two or more of the detected positions; and
orienting the boundary box of the imaging area of the object to correspond with the object orientation.
10. The X-ray tube scanner system of claim 6 , wherein the X-ray tube control parameters comprise a position of the X-ray tube and/or one or more collimator settings of the collimator of the X-ray tube.
11. A non-transitory computer readable medium storing computer program instructions for X-ray tube scanner automation, wherein the X-ray tube scanner comprising an X-ray tube and an X-ray detector, the computer program instructions when executed by a processor cause the processor to perform operations comprising:
acquiring, by a three-dimensional camera that includes a camera coordinate system, a three-dimensional image of an object placed on the X-ray detector that includes an X-ray detector coordinate system;
identifying the X-ray detector's plane in the three-dimensional image;
generating a boundary box of the object on the X-ray detector, the boundary box comprising four corner points;
determining the object's center position and orientation on the X-ray detector's plane;
transferring the four corner points of the boundary box from the camera coordinate system to the X-ray detector's coordinate system;
calculating a transformation function from an object coordinate system to the X-ray detector coordinate system using one in-plane rotation and in-plane translation and the object's center position and orientation;
transferring, using the transformation function, the object's center position from the object's coordinate system to a coordinate system of the X-ray tube; and
estimating X-ray tube control parameters for aligning an X-ray field emitted from a center of a collimator of the X-ray tube to the object's center position in the coordinate system of the X-ray tube.
12. The non-transitory computer readable medium of claim 11 , wherein the X-ray tube scanner determining the boundary box of the object to be imaged on the X-ray detector comprises:
receiving image data representing a first image of the object to be imaged using the X-ray tube to form a second image;
detecting a plurality of positions of respective predetermined features in the first image;
determining the boundary box of an imaging area of the object to be imaged on the basis of the detected positions; and
controlling one or more parameters of the X-ray tube on the basis of the determined boundary box.
13. The non-transitory computer readable medium of claim 12 , further comprising:
determining an object size and/or an object orientation of the object to be imaged on the basis of the detected positions.
14. The non-transitory computer readable medium of claim 13 , further comprising:
determining the object orientation on the basis of an angle of a line intersecting two or more of the detected positions; and
orienting the boundary box of the imaging area of the object to correspond with the object orientation.
15. The non-transitory computer readable medium of claim 11 , wherein the X-ray tube control parameters comprise a position of the X-ray tube and/or one or more collimator settings of the collimator of the X-ray tube.