Single photon emission computed tomography system

• US 6,504,157 B2
• Filed: 03/28/2002
• Issued: 01/07/2003
• Est. Priority Date: 04/14/1999
• Status: Expired due to Term

• Current Assignee: HighBrook Holdings, LLC
• Original Assignee: Jack E. Juhi
• Inventors: Juhi, Jack E.
• Primary Examiner(s): Hannaher, Constantine
• Assistant Examiner(s): Gabor, Otilia
• Application Number:
  US10/109,201
• Publication Number:
  US 20020171041A1
• Time in Patent Office: 285 Days
• Field of Search: 250/363.04, 250/363.03, 250/363.05, 250/363.08, 250/363.09, 250/363.1, 378/11
• US Class Current: 250/363.04
• CPC Class Codes: A61B 6/037 Emission tomography
• CPC Class Codes: G01T 1/1642 using a scintillation crystal and position sensing photodetector arrays, e.g. ANGER cameras

Abstract

A single photon emission computed tomography system produces multiple tomographic images of the type representing a three-dimensional distribution of a photon-emitting radioisotope. The system has a base including a patient support for supporting a patient such that a portion of the patient is located in a field of view. A longitudinal axis is defined through the field of view. A generally arcuate detector assembly is adjacent the field of view. The detector assembly extends generally arcuately at least partially about the field of view between a pair of ends. The ends are spaced apart so as to define an entry opening to the field of view. The detector assembly includes a plurality of photon-responsive detectors arranged along the arcuate detector assembly, with each detector being operable to detect if a photon strikes the detector. A generally arcuate photon-blocking member is positioned between the field of view and the detectors. The blocking member has a plurality of aperture slots defined therethrough at intervals along the member for passage of photons aligned with the aperture slots. A line of response for each of the detectors is defined from each detector through the nearest of the aperture slots. A displacement actuator moves the photon-blocking member relative to the detectors such that the aperture slots are displaced relative to the detectors and the lines of response are swept across at least a portion of the field of view.

Claims

1. A single photon emission computed tomography system for producing multiple tomographic images of the type representing a three-dimensional distribution of a photon-emitting radioisotope, said system comprising:

a base including a patient support for supporting a patient such that a portion of the patient is located in a field of view, a longitudinal axis being defined through the field of view;

a generally arcuate detector assembly adjacent to the field of view, said detector assembly extending generally arcuately at least partially about the field of view between a first end and a second end, said first and second ends being spaced apart so as to define an entry opening to the field of view, the detector assembly comprising a plurality of photon-responsive detectors arranged along the arcuate detector assembly, each detector being operable to detect if a photon strikes the detector;

a collimating assembly including at least two spaced apart collimating vanes of photon-attenuating material, each of said vanes being disposed between said detectors and the field of view;

a generally arcuate photon-blocking member disposed between the field of view and said detectors, said blocking member having a plurality of aperture slots defined therethrough at intervals along said member for passage of photons aligned with said aperture slots, a line of response for each of said detectors being defined from said detector through the nearest of said aperture slots; and

a displacement actuator operable to move said photon-blocking member relative to said detectors such that said aperture slots are displaced relative to said detectors and said lines of response are swept across at least a portion of the field of view.

2. The system according to claim 1, wherein said detectors each comprise an elongated strip with a central axis disposed generally parallel to the longitudinal axis, each of said detectors further including means to determine a position along the length of said elongated strip where a photon is detected.

3. The system according to claim 1, wherein said aperture slots are each generally parallel to the longitudinal axis.

4. The system according to claim 1, wherein said detector assembly extends over an arc of approximately 180 degrees.

5. The system according to claim 1, wherein said detector assembly extends over an arc between 180 and 360 degrees.

6. The system according to claim 1, wherein said detector assembly further comprises a housing for supporting said detectors, said housing being formed of photon attenuating material on the portions of the housing not directed toward the field of view.

7. The system according to claim 1, wherein said detectors and said photon-blocking member define concentric arcs.

8. The system according to claim 1, wherein each of said collimating vanes in said collimating assembly is in a plane generally perpendicular to the longitudinal axis.

9. The system according to claim 8, wherein said collimating vanes are disposed between said photon-blocking member and said detectors.

10. The system according to claim 1, wherein said collimating assembly further includes a radiolucent material disposed in the spaces between said collimating vanes.

11. The system according to claim 1, wherein the patient support supports the human patient such that a portion of the patient'"'"'s torso is located in a field of view, the patient'"'"'s torso extending generally vertically such that the patient'"'"'s head is substantially higher than the patient'"'"'s hips, the longitudinal axis being generally vertical.

12. The system according to claim 11, wherein said base comprises a chair-like structure having a generally horizontal bottom portion for supporting the patient'"'"'s hips and a generally vertical back portion of supporting the patient'"'"'s back.

13. The system according to claim 12, wherein said generally arcuate detector assembly is interconnected with said back portion of said base such that said assembly partially surrounds the patient'"'"'s torso when the patient is seated on said bottom portion.

14. A single photon emission computed tomography system for producing multiple tomographic images of the type representing a three-dimensional distribution of a photon-emitting radioisotope, said system comprising:

a base including a patient support for supporting a patient such that a portion of the patient is located in a field of view, a longitudinal axis being defined through the field of view;

a generally arcuate detector assembly adjacent to the field of view, said detector assembly extending generally arcuately at least partially about the field of view between a first end and a second end, said first and second ends being spaced apart so as to define an entry opening to the field of view, the detector assembly comprising a plurality of photon-responsive detectors arranged along the arcuate detector assembly, each detector being operable to detect if a photon strikes the detector;

a collimating assembly including at least two spaced apart collimating vanes of photon-attenuating material, each of said vanes being disposed between said detectors and the field of view;

a generally arcuate photon-blocking member disposed between the field of view and said detectors, said blocking member having a plurality of aperture slots defined therethrough at intervals along said member for passage of photons aligned with said aperture slots, a line of response for each of said detectors being defined from said detector through the nearest of said aperture slots; and

a displacement actuator operable to move said detectors relative to said photon-blocking member such that said detectors are displaced relative to said aperture slots and said lines of response are swept across at least a portion of the field of view.

15. The system according to claim 14, wherein said detectors each comprise an elongated strip with a central axis disposed generally parallel to the longitudinal axis, each of said detectors further including means to determine a position along the length of said elongated strip where a photon is detected.

16. The system according to claim 14, wherein said aperture slots are each generally parallel to the longitudinal axis.

17. The system according to claim 14, wherein said detector assembly extends over an arc of approximately 180 degrees.

18. The system according to claim 14, wherein said detector assembly extends over an arc between 180 and 360 degrees.

19. The system according to claim 14, wherein said detector assembly further comprises a housing for supporting said detectors, said housing being formed of photon attenuating material on the portions of the housing not directed toward the field of view.

20. The system according to claim 14, wherein said detectors and said photon-blocking member define concentric arcs.

21. The system according to claim 20, wherein each of said vanes is in a plane generally perpendicular to the longitudinal axis.

22. The system according to claim 21, wherein said collimating vanes are disposed between said photon-blocking member and said detectors.

23. The system according to claim 14, wherein said collimating assembly further comprises a radiolucent material disposed in the spaces between said vanes.

24. The system according to claim 16, wherein the patient support supports the human patient such that a portion of the patient'"'"'s torso is located in a field of view, the patient'"'"'s torso extending generally vertically such that the patient'"'"'s head is substantially higher than the patient'"'"'s hips, the longitudinal axis being generally vertical.

25. The system according to claim 24, wherein said base comprises a chair-like structure having a generally horizontal bottom portion for supporting the patient'"'"'s hips and a generally vertical back portion of supporting the patient'"'"'s back.

26. The system according to claim 25, wherein said generally arcuate detector assembly is interconnected with said back portion of said base such that said assembly partially surrounds the patient'"'"'s torso when the patient is seated on said bottom portion.