Spatial sequenced backscatter portal

• US 8,300,763 B2
• Filed: 07/22/2010
• Issued: 10/30/2012
• Est. Priority Date: 07/24/2009
• Status: Active Grant

• Current Assignee: American Science and Engineering Incorporated (OSI Systems Incorporated)
• Original Assignee: Nucsafe, Inc.
• Inventors: Shedlock, Daniel
• Primary Examiner(s): THOMAS, COURTNEY D
• Application Number:
  US12/841,401
• Publication Number:
  US 20110019799A1
• Time in Patent Office: 831 Days
• Field of Search: 378/57, 378/62, 378/86, 378/87, 382/131
• US Class Current: 378/57
• CPC Class Codes: G01N 2223/419 computed tomograph
• CPC Class Codes: G01N 23/046 using tomography, e.g. computed tomography [CT]

Abstract

Systems and methods for scanning an object in an inspection space are disclosed. The systems and methods generally incorporate spatially separated and sequenced Compton x-ray backscatter imaging techniques in a plurality of perspective planes. Such processes as time-gating detectors, weighting scintillation detections, and preferentially accepting signals that originate from a point that is substantially orthogonal to a radiation detector and at least partially shielding out signals that do not originate from a point substantially orthogonal to the detector may be used to enhance the data acquisition process.

Claims

1. A method for scanning an object in an inspection space comprising:

(a) scanning the object from a first perspective that is substantially orthogonal to a first plane starting at a first entry point in the inspection space that is adjacent a first edge of the inspection space to establish a first scan line trace of the object from the first perspective;

(b) scanning the object from a second perspective that is substantially orthogonal to a second plane that is adjacent to but not co-planar with the first plane, starting at a second entry point on the second plane that is adjacent a second edge between the first plane and the second plane, to establish a second scan line trace of the object from the second perspective;

(c) providing relative motion between the object and the first scan line trace and the second scan line trace; and

(d) repeating step (a), step (b), and step (c) at least once such that the repetition of step (a) produces a first two-dimensional image of the object comprising multiple first image scan lines from the first perspective and step (b) produces a second two-dimensional image of the object comprising multiple second image scan lines from the second perspective.

2. The method of claim 1 wherein step (a) and step (b) are initiated at approximately the same time.

3. The method of claim 1 wherein the first plane is substantially orthogonal to the second plane.

4. The method of claim 1 further comprising:

(e) scanning the object from a third perspective that is substantially orthogonal to a third plane that is adjacent to but not co-planar with the second plane, starting at a third entry point on the third plane that is adjacent a third edge between the second plane and the third plane, to establish a third scan line trace of the object from the third perspective, wherein step (a), step (b) and step (e) are initiated at approximately the same time;

(f) providing relative motion between the object and the third scan line trace; and

(g) repeating step (e) and step (f) at least once concurrently with repeating step (a), step (b) and step (c) such that step (e) produces a third two-dimensional image of the object comprising multiple third image scan lines from the third perspective.

5. The method of claim 1 further comprising time gating of scintillation detections during at least one step selected from the group consisting of step (a) and step (b).

6. The method of claim 1 further comprising weighting of scintillation detections during at least one step selected from the group consisting of step (a) and step (b).

7. The method of claim 1 wherein at least one step selected from the group consisting of step (a) and step (b) further comprises ortho-enhancing the scanning.

8. A method for scanning an object in an inspection space comprising:

(a) scanning the object from a first perspective that is substantially orthogonal to a first plane starting at a first entry point adjacent a first edge of the inspection space to establish a first scan line trace of the object from the first perspective;

(b) scanning the object from a second perspective that is substantially orthogonal to a second plane where the second perspective is opposed to the first perspective, starting the scanning at a second entry point on the second plane that is diagonally opposed across the inspection space from the first entry point, to establish a second scan line trace of the object from the second perspective, wherein step (a) and step (b) are initiated at approximately the same time;

(c) providing relative motion between the object and the first scan line trace and the second scan line trace; and

(d) repeating step (a), step (b), and step (c) at least once such that the repetition of step (a) produces a first two-dimensional image of the object comprising multiple first image scan lines from the first perspective and step (b) produces a second two-dimensional image of the object comprising multiple second image scan lines from the second perspective.

9. The method of claim 8 wherein the second perspective is diametrically-opposed to the first perspective.

10. The method of claim 8 further comprising a step of time gating of scintillation detections during at least one step selected from the group consisting of step (a) and step (b).

11. The method of claim 8 further comprising weighting of scintillation detections during at least one step selected from the group consisting of step (a) and step (b).

12. The method of claim 8 wherein at least one step selected from the group consisting of step (a) and step (b) further comprises ortho-enhancing the scanning.