An X-ray beam collimator and a method of collimating X-ray beams from a plurality of X-ray emitters

Abstract

In chest imaging it is important to only image the lungs without exposing the thyroid gland or the abdominal organs, so the width of an X-ray beam is restricted so that the projection area matches the

Claims

1. An X-ray beam collimator for use with a plurality of X-ray emitters, the X-ray beam collimator comprising:a first plate comprising:a first hole; anda second hole, spaced from the first hole;a second plate disposed adjacent to, and in a plane parallel to, the first plate, the second plate movable relative to the first plate within the plane between a first position and a second position, the second plate comprising:a third hole located to at least partially overlap the first hole by a first amount when the second plate is in the first position, and by a second amount when the second plate is in the second position, thereby forming a first composite aperture of variable size; anda fourth hole spaced from the third hole, the fourth hole located to at least partially overlap the second hole by a third amount when the second plate is in the first position, and by a fourth amount when the second plate is in the second position, thereby forming a second composite aperture of variable size.

2. The X-ray beam collimator of claim 1, further comprising an actuator configured to move the second plate relative to first plate between the first and second positions.

3. The X-ray beam collimator of claim 2, wherein the actuator comprises a motor.

4. The X-ray bean collimator of claim 2 or claim 3, wherein the actuator is manually controllable.

5. The X-ray beam collimator of any preceding claim, wherein any one of the first, second, third and fourth holes has a quadrilateral shape.

6. The X-ray beam collimator of any preceding claim, wherein any one of the first, second, third and fourth holes is provided with a respective comer that is orientated in afirst direction, and wherein movement of the second plate between the first position and the second position is in the first direction.

7. The X-ray beam collimator of any preceding claim, in which any one of the first,second, third and fourth holes is provided with a respective corner that is orientated in a first direction, and wherein movement of the second plate between the first position and the second position is in a second direction different to the first direction.

8. The X-ray beam collimator of any preceding claim, wherein the first hole is larger than the second hole.

9. The X-ray beam collimator of any preceding claim, wherein the first hole is larger than the third hole.

10. The X-ray beam collimator of any preceding claim, wherein:the first plate comprises at least sixteen distinct holes, including the first hole and the second hole; andthe second plate comprises at least sixteen distinct further holes, including the third hole and the fourth hole, wherein each one of the at least sixteen distinct further holes is located to at least partially overlap with a respective one of the at least sixteen distinct holes by a respective first amount when the second plate is in the first position, and by a respective second amount when the second plate is in the second position, thereby forming sixteen respective composite apertures, each of variable size.

11. An X-ray system for collimating X-ray beams from a plurality of X-ray emitters, the X-ray system comprising:an X-ray beam collimator of any preceding claim;a first X-ray emitter arranged to emit a first beam of X-rays over the entire first composite aperture; anda second X-ray emitter arranged to emit a second beam of X-rays over the entire second composite aperture.

12. A method of collimating X-ray beams from a plurality of X-ray emitters, the method comprising the steps of:providing the X-ray beam collimator of any one of claims 1 to 10 having the second plate in the first position;5 providing a first X-ray emitter arranged to emit a first beam of X-rays over theentire first composite aperture;providing a second X-ray emitter arranged to emit a second beam of X-rays over the entire second composite aperture; andmoving the second plate relative to the first plate within the plane between the 10 first position and the second position.

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