Image reconstruction methods

• US 5,751,785 A
• Filed: 11/12/1996
• Issued: 05/12/1998
• Est. Priority Date: 01/25/1993
• Status: Expired due to Term

• Current Assignee: Airdrie Partners I LP
• Original Assignee: Cardiac Mariners, Inc. (NovaRay Medical, Inc.)
• Inventors: Wilent, deceased, John W., Fiekowsky, Peter J., Solomon, Edward G., Moorman, Jack W., Melen, Robert E., Skillicorn, Brian, Moorhouse, Abigail A.
• Primary Examiner(s): WONG, DON KITSUN
• Application Number:
  US08/753,263
• Time in Patent Office: 546 Days
• Field of Search: 378/4, 378/146, 378/901, 378/98.2, 378/98.5, 378/98.6
• US Class Current: 378/146
• CPC Class Codes: A61B 6/06 Diaphragms
• CPC Class Codes: A61B 6/12 Arrangements for detecting or locating foreign bodies
• CPC Class Codes: A61B 6/4028 resulting in acquisition of views from substantially different positions, e.g. EBCT
• CPC Class Codes: A61B 6/4042 K-edge filters
• CPC Class Codes: A61B 6/4241 using energy resolving detectors, e.g. photon counting
• CPC Class Codes: A61B 6/4488 Means for cooling A61B6/045 takes precedence
• CPC Class Codes: A61B 6/482 involving multiple energy imaging
• CPC Class Codes: A61B 90/39 Markers, e.g. radio-opaque or breast lesions markers
• CPC Class Codes: A61M 25/0108 using radio-opaque or ultrasound markers
• CPC Class Codes: G01T 1/20182 Modular detectors, e.g. tiled scintillators or tiled photodiodes stacked detectors G01T1/20181
• CPC Class Codes: G01T 1/20183 Arrangements for preventing or correcting crosstalk, e.g. optical or electrical arrangements for correcting crosstalk
• CPC Class Codes: G01T 1/20185 Coupling means between the photodiode and the scintillator, e.g. optical couplings using adhesives with wavelength-shifting fibres
• CPC Class Codes: G01T 1/202 the detector being a crystal
• CPC Class Codes: G01T 1/2971 using solid state detectors
• CPC Class Codes: G21K 1/025 using multiple collimators, e.g. Bucky screens; other devices for eliminating undesired or dispersed radiation
• CPC Class Codes: H01J 35/147 Spot size control
• CPC Class Codes: H01J 35/153 Spot position control
• CPC Class Codes: H05G 1/10 Power supply arrangements for feeding the X-ray tube supply circuits with converters in general H02M; supply circuits for emitters and amplifiers H04B1/16 - H04B1/1623
• CPC Class Codes: H05G 1/64 Circuit arrangements for X-ray apparatus incorporating image intensifiers
• CPC Class Codes: Y10S 378/901 Computer tomography program or processor

Abstract

An x-ray imaging system according to the present invention comprising a stepped scanning-beam x-ray source and a multi-detector array. The output of the multi-detector array is input to an image reconstruction engine which combines the outputs of the multiple detectors over selected steps of the x-ray beam to generate an x-ray image of the object. A collimating element, preferably in the form of a perforated grid containing an array of apertures, interposed between the x-ray source and an object to be x-rayed. A maneuverable positioner incorporating an x-ray sensitive marker allowing the determination of the precise position coordinates of the maneuverable positioner.

Claims

1. A method of imaging comprising:

generating a plurality of x-ray beams emanating from different locations on an x-ray source, the locations forming a pattern of rows on the x-ray source;

receiving x-rays that have passed through an object from each of the generated x-ray beams with an arrangement of detectors;

capturing information indicative of an x-ray absorbency of the object to be imaged from each detector for each x-ray beam;

obtaining imaging information about each image pixel in the object to be imaged by combining the information indicative of the x-ray absorbency of the object at each image pixel to be imaged from a plurality of detectors, the plurality of detectors each intersected by a line defined by a different location on the x-ray source and the image pixel for which imaging information is desired;

forming an image from the imaging information wherein the image comprises a plurality of rows of pixels, and wherein a number of pixels in at least one row of the plurality of rows of pixels is greater than the number of locations in at least one row of locations on the x-ray source.

2. The method of claim 1 wherein said step of generating comprises scanning an electron beam across an x-ray target and generating an x-ray beam at each of the different locations on the x-ray target.

3. The method of claim 1 wherein each image pixel lies on a same plane.

4. The method of claim 1 wherein the step of capturing information indicative of the x-ray absorbency of the object to be imaged by each detector from each x-ray beam comprises counting a number of x-ray photons received by each detector.

5. The method of claim 1 further comprising a step of passing the x-ray beams through an array of x-ray transmissive areas of a collimator prior to passing the x-ray beams through the object to be imaged.

6. The method of claim 5 wherein each of the x-ray transmissive areas comprise a longitudinal axis, each longitudinal axis intersecting the arrangement of detectors substantially at a center of the arrangement of detectors.

7. The method of claim 5 wherein the x-ray transmissive areas are substantially cylindrical in shape.

8. The method of claim 5 wherein the x-ray transmissive areas are substantially square in shape.

9. The method of claim 5 wherein the arrangement of detectors is arranged in a substantially pseudo-circular pattern.

10. The method of claim 5 wherein the imaging information is provided to a monitor for generating an image having an array of pixels.

11. The method of claim 10 wherein a ratio of a total number of x-ray transmissive areas to a total number of pixels is less than 1.

12. The method of claim 1 wherein the arrangement of detectors is arranged in a substantially pseudo-circular pattern.

13. A method of imaging comprising:

generating a plurality of x-ray beams emanating from a plurality of positions form an x-ray source, the positions forming a plurality of rows;

passing the plurality of x-ray beams through an object to be imaged;

detecting each x-ray beam of the plurality of x-ray beams with an arrangement of detectors;

generating a plurality of image pixels from the plurality of x-ray beams detected by the arrangement of detectors,

forming a representation of the object from the plurality of image pixels wherein the representation comprises a plurality of positions each of which represents an x-ray absorbency of the object at an image pixel of said plurality of image pixels, and wherein a number of positions in at least one row on the x-ray source is less than a number of positions in a row of the plurality of positions comprising said representation.

14. The method of claim 13 wherein said step of generating a plurality of x-ray beams comprises scanning an electron beam across an x-ray target and generating an x-ray beam at each of the plurality of positions on the x-ray target.

15. The method of claim 13 wherein each image pixel lies on a same plane.

16. The method of claim 13 further comprising a step of passing the plurality of x-ray beams through an array of x-ray transmissive areas of a collimator prior to passing the plurality of x-ray beams through the object to be imaged.

17. The method of claim 16 wherein each of the x-ray transmissive areas comprise a longitudinal axis, each longitudinal axis intersecting the arrangement of detectors substantially at a center of the arrangement of detectors.

18. The method of claim 16 wherein the representation is provided to a monitor for generating an image having an array of pixels.

19. The method of claim 18 wherein a ratio of a total number of x-ray transmissive areas to a total number of pixels in the array of pixels is less than 1.