Granted Patent B2

US 12,270,772 · App. 18/667,352 · Granted Apr 8, 2025

Inventor: Simon Archambault (St-Laurent, CA)

Assignee: Rapiscan Holdings, Inc.

G01N23/18G01N23/04G01N23/083G01N23/10G06T5/00G01N2223/04G01N2223/3308G01N2223/401G01N2223/643G01N2223/652G06T2207/10116

Abstract

Claims (31)

1. A method for detecting a presence of a material in an object, the method comprising:

obtaining X-ray image data of the object, wherein the X-ray image data comprises a plurality of pixels and wherein each pixel of the plurality of pixels has associated therewith an attenuation value and an effective atomic number (Z eff ) value;

for each pixel having said Z eff value greater than a threshold effective atomic number (Z eff -threshold), converting the Z eff value associated with the pixel to the Z eff -threshold, wherein the Z eff -threshold is representative of a target material;

for each pixel having said Z eff value less than a threshold effective atomic number (Z eff -threshold), not changing the Z eff value;

determining a maximum potential amount of the material present at each pixel based on at least one of the unchanged Z eff value and the converted Z eff value; and

displaying an image of the object showing a maximum potential amount of the target material present at each pixel based on at least one of the unchanged Z eff value and the converted Z eff value.

2. The method of claim 1 , further comprising, for each pixel having said Z eff value greater than said threshold effective atomic number (Z eff -threshold), applying a correction factor to the attenuation value associated with the pixel to generate a corrected attenuation value.

3. The method of claim 2 , wherein the correction factor is based on a difference between the Z eff at the pixel and the Z eff -threshold.

4. The method of claim 2 , further comprising obtaining the correction factor from a table comprising attenuation values and Z eff values for various material overlaps.

5. The method of claim 4 , wherein said various material overlaps comprise different combinations of overlapping organic and inorganic materials.

6. The method of claim 1 , further comprising acquiring the Z eff -threshold from a database, wherein the database comprises a plurality of values representative of Z eff -thresholds associated with different ones of said target material.

7. The method of claim 1 , wherein the target material is at least one of an organic material, an inorganic material, and aluminum.

8. The method of claim 1 , further comprising normalizing each pixel by correcting a detector offset value.

9. The method of claim 1 , further comprising normalizing each pixel by correcting a detector gain value.

10. The method of claim 1 , wherein pixels with a lower amount of the target material are lighter or less intensely colored than pixels with a higher amount of the target material.

11. A system for detecting a presence of a material in an object, the system comprising:

an x-ray scanning device for obtaining X-ray image data of the object, wherein the X-ray image data comprises a plurality of pixels and wherein each pixel of the plurality of pixels has associated therewith an attenuation value and an effective atomic number (Z eff ) value; and

at least one processor configured to:

convert, for each pixel having said Z eff value greater than a threshold effective atomic number (Z eff -threshold), the Z eff value associated with the pixel to the Z eff -threshold, wherein the Z eff -threshold is representative of a target material;

not change the Z eff value for each pixel having said Z eff value less than a threshold effective atomic number (Z eff -threshold);

determine a maximum potential amount of the material present at each pixel based on at least one of the unchanged Z eff value and the converted Z eff value; and

display an image of the object showing a maximum potential amount of the target material present at each pixel based on at least one of the unchanged Z eff value and the converted Z eff value.

12. The system of claim 11 wherein the at least one processor is further configured to apply a correction factor to the attenuation value associated with the pixel to generate a corrected attenuation value for each pixel having said Z eff value greater than said threshold effective atomic number (Z eff -threshold).

13. The system of claim 12 , wherein the correction factor is based on a difference between the Z eff at the pixel and the Z eff -threshold.

14. The system of claim 12 , wherein the at least one processor is further configured to obtain the correction factor from a table comprising attenuation values and Z eff values for various material overlaps.

15. The system of claim 14 , wherein said various material overlaps comprise different combinations of overlapping organic and inorganic materials.

16. The system of claim 11 , wherein the processor is further configured to acquire the Z eff -threshold from a database, wherein the database comprises a plurality of values representative of Z eff -thresholds associated with different ones of said target material.

17. The system of claim 11 , wherein the target material is at least one of an organic material, an inorganic material, and aluminum.

18. The system of claim 11 , wherein the processor is further configured to normalize each pixel by correcting a detector offset value.

19. The system of claim 11 , wherein the processor is further configured to normalize each pixel by correcting a detector gain value.

20. The system of claim 11 , wherein pixels with a lower amount of the target material are lighter or less intensely colored than pixels with a higher amount of the target material.

Assignments (3)

Continuity (2)

References Cited (390)