Calibration apparatus for X-ray geometry
First Claim
1. Calibration apparatus for X-ray geometry, for use in conjunction with a portion of a patient'"'"'s body to be X-rayed, an X-ray source, and imaging means for forming an image, wherein said imaging means is at a given orientation and distance from said portion of a patient'"'"'s body, said apparatus comprising:
- a calibration ring adapted for being fastened to a portion of a patient'"'"'s body, said ring exhibiting a first degree of transparency to X-rays and being positioned such that one side of said calibration ring is proximate said X-ray source and the opposite side is distal thereto; and
encoding means incorporated in said ring, comprising a plurality of encoding units exhibiting a second degree of transparency to X-rays, different from said first degree, said encoding units being arranged in a predetermined configuration such that an essentially two-dimensional projected image, formed by said imaging means, of said calibration ring with said encoding means exhibits a pattern of contrasting intensity attributable to at least a portion of said encoding means incorporated in said proximate side of said calibration ring and at least a portion of said encoding means incorporated in said distal side, from which said orientation and distance can be determined uniquely.
1 Assignment
0 Petitions
Accused Products
Abstract
Calibration apparatus for X-ray geometry, for use in conjunction with a portion of a patient'"'"'s body to be X-rayed, an X-ray source, and imaging arrangement for forming an image, wherein the imaging arrangement is at a given orientation and distance from the portion of a patient'"'"'s body, comprises a calibration ring adapted for being fastened to a portion of a patient'"'"'s body, such as a patient'"'"'s head. The ring exhibits a first degree of transparency to X-rays. An encoding arrangement incorporated in the ring comprises a plurality of encoding units exhibiting a second degree of transparency to X-rays, different from the first degree, the encoding units being arranged in a predetermined configuration such that an essentially two-dimensional projected image, formed by the imaging arrangement, of the calibration ring with the encoding arrangement exhibits a pattern of contrasting intensity attributable to at least a portion of the encoding arrangement from which the orientation and distance can be determined uniquely.
98 Citations
21 Claims
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1. Calibration apparatus for X-ray geometry, for use in conjunction with a portion of a patient'"'"'s body to be X-rayed, an X-ray source, and imaging means for forming an image, wherein said imaging means is at a given orientation and distance from said portion of a patient'"'"'s body, said apparatus comprising:
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a calibration ring adapted for being fastened to a portion of a patient'"'"'s body, said ring exhibiting a first degree of transparency to X-rays and being positioned such that one side of said calibration ring is proximate said X-ray source and the opposite side is distal thereto; and encoding means incorporated in said ring, comprising a plurality of encoding units exhibiting a second degree of transparency to X-rays, different from said first degree, said encoding units being arranged in a predetermined configuration such that an essentially two-dimensional projected image, formed by said imaging means, of said calibration ring with said encoding means exhibits a pattern of contrasting intensity attributable to at least a portion of said encoding means incorporated in said proximate side of said calibration ring and at least a portion of said encoding means incorporated in said distal side, from which said orientation and distance can be determined uniquely. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. Calibration apparatus for use in conjunction with X-ray imaging for establishing correspondence between a three-dimensional object and its two dimensional projection image, said apparatus comprising a calibration ring associated with a portion of a the anatomy of a subject for X-ray examination by positioning said ring between an X-ray source and an imaging plane disposed on opposite sides thereof for forming a two-dimensional image including at least a portion of each of said opposite sides, said ring comprising:
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a carrier portion adapted for attachment to said subject; encoding means incorporated in said carrier portion of said calibration ring, said encoding means comprising a plurality of code word configurations formed of a substance having a different degree of transparency from that of said carrier portion, said code word configurations being arranged in a sequence separated by spaces along a circumferential path along said ring in a given sense in which such words are to be read, such that no code word occurs more than once and no code word forms a valid word when read in a sense opposite said given sense. - View Dependent Claims (9, 10)
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11. Calibration apparatus for use in conjunction with X-ray imaging for establishing correspondence between a three-dimensional object and its two dimensional projection image, said apparatus comprising a calibration ring associated with a portion of a the anatomy of a subject for X-ray examination by positioning said ring between an X-ray source and an imaging plane disposed on opposite sides thereof for forming a two-dimensional image including at least a portion of each of said opposite sides, said ring comprising:
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a carrier portion adapted for attachment to said subject; encoding means incorporated in said carrier portion of said calibration ring, said encoding means comprising a plurality of code word configurations formed of a substance for casting a calibration image inset two dimensional in contrast to that of said carrier portion, such that said correspondence can be established uniquely from a portion, less than the whole, of said calibration image. - View Dependent Claims (12, 13, 14)
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15. Calibration apparatus for X-ray geometry, for use in conjunction with a portion of a patient'"'"'s body to be X-rayed, an X-ray source, and imaging means for forming an image, wherein said imaging means is at a given orientation and distance from said portion of a patient'"'"'s body, said apparatus comprising:
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a calibration ring adapted for being fastened to a portion of a patient'"'"'s body, said ring exhibiting a first degree of transparency to X-rays; and encoding means incorporated in said ring, comprising a plurality of encoding units exhibiting a second degree of transparency to X-rays, different from said first degree, said encoding units being arranged in a predetermined configuration such that an essentially two-dimensional projected image, formed by said imaging means, of said calibration ring with said encoding means exhibits a pattern of contrasting intensity attributable to at least a portion of said encoding means from which said orientation and distance can be determined uniquely, wherein said predetermined configuration is in the form of a code of groups of units forming words and spaces therebetween in a sequence along the circumferential dimension of said calibration ring. - View Dependent Claims (16, 17, 18, 19, 20)
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21. Calibration apparatus for use in conjunction with X-ray imaging for establishing correspondence between a three-dimensional object and its two dimensional projection image, said apparatus comprising a calibration ring associated with a portion of a the anatomy of a subject for X-ray examination, said ring comprising:
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a carrier portion adapted for attachment to said subject; encoding means incorporated in said carrier portion of said calibration ring, said encoding means comprising a plurality of code word configurations formed of a substance having a different degree of transparency from that of said carrier portion, said code word configurations being arranged in a sequence separated by spaces along a circumferential path along said ring in a given sense in which such words are to be read, such that no code word occurs more than once and no code word forms a valid word when read in a sense opposite said given sense, said substance of which said code word configurations are formed being relatively opaque to X-rays, said carrier portion being made of a substance relatively transparent to X-rays, and said code word configurations being formed of ball-bearing-like metallic balls.
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Specification