Method of and system for extracting 3D bag images from continuously reconstructed 2D image slices in computed tomography

• US 7,327,853 B2
• Filed: 06/09/2004
• Issued: 02/05/2008
• Est. Priority Date: 06/09/2004
• Status: Active Grant

• Current Assignee: Analogic Corporation
• Original Assignee: Analogic Corporation
• Inventors: Shokrollahi, Nima, Aiyer, Anuradha, Srinivasan, Govindarajan T., Subramanian, Chitra, Crawford, Carl R., Ying, Zhengrong
• Primary Examiner(s): Mehta; Bhavesh M
• Assistant Examiner(s): KIM, CHONG R
• Application Number:
  US10/864,619
• Publication Number:
  US 20050276468A1
• Time in Patent Office: 1,336 Days
• Field of Search: None
• US Class Current: 382/100
• CPC Class Codes: G01T 1/2985 In depth localisation, e.g. using positron emitters; Tomographic imaging (longitudinal and transverse section imaging; apparatus for radiation diagnosis sequentially in different planes, steroscopic radiation diagnosis); using external radiation sources A61B6/02
• CPC Class Codes: G01V 5/224 Multiple energy techniques using one type of radiation, e.g. X-rays of different energies
• CPC Class Codes: G01V 5/226 using tomography
• CPC Class Codes: G06T 2207/10081 Computed x-ray tomography [CT]
• CPC Class Codes: G06T 2207/30112 Baggage; Luggage; Suitcase
• CPC Class Codes: G06T 7/11 Region-based segmentation
• CPC Class Codes: G06T 7/136 involving thresholding
• CPC Class Codes: G06V 10/457 by analysing connectivity, e.g. edge linking, connected component analysis or slices
• CPC Class Codes: G06V 2201/05 Recognition of patterns representing particular kinds of hidden objects, e.g. weapons, explosives, drugs
• CPC Class Codes: G06V 2201/12 Acquisition of 3D measurements of objects

Abstract

A method of and a system for extracting 3D bag images from continuously reconstructed 2D image slices are provided. The method detects the boundaries of baggage in the reconstructed images, and provides better flexibilities for threat detection and displaying. The method comprises detecting starting and ending slices using multiple slices, counting bag slices, splitting 3D bag images when maximum number of slices of a 3D bag image is reached, and creating overlapping slices for the split 3D bag images.

Claims

1. A method of extracting 3D bag images from continuously reconstructed 2D CT image slices comprising:

A. Detecting a starting slice from a series of N_s1+N_s2 slices, further comprising;

A1. Computing slice energy for each 2D CT image slice;

A2. Thresholding slices into high energy slices and low energy slices;

A3. Counting the number of high energy slices until a predetermined number of high energy slices are achieved within an N_s1 number of slices;

A4. Counting the number of high energy slices in the last N_s2 slices; and

A5. Using and checking a starting slice criterion to determine whether a starting slice has been detected;

B. Counting bag slices;

C. Splitting 3D bag images, if necessary; and

D. Detecting an ending slice.

2. The method of claim 1, wherein step A5 includes a condition that the number of high energy slices in the first N_s1 slices is no greater than a pre-defined threshold.

3. The method of claim 1, wherein step A5 includes a condition that the number of high energy slices in the last N_s2 slices is no less than a pre-defined threshold.

4. A method of extracting 3D bag images from continuously reconstructed 2D CT image slices comprising:

A. Detecting a starting slice;

B. Counting bag slices;

C. Splitting 3D bag images, if necessary; and

further including;

C1. Generating more than one 3D bag image when the number of slices of a 3D bag image is greater than a pre-defined threshold; and

D. Detecting an ending slice.

5. A method of extracting 3D bag images from continuously reconstructed 2D CT image slices comprising:

A. Detecting a starting slice;

B. Counting bag slices;

C. Splitting 3D bag images if necessary, and

D. Detecting an ending slice from a series of N_d1+N_d2 slices, Step D further comprising;

D1. Computing slice energy for each 2D CT image slice;

D2. Thresholding slices into high energy slices and low energy slices;

D3. Counting the number of high energy slices until a predetermined number of high energy slices are achieved within an N_e1 number of slices;

D4. Counting the number of high energy slices in the last N_e2 slices; and

D5. Using and checking an ending slice criterion to determine whether an ending slice has been detected.

6. The method of claim 5, wherein any two consecutive 3D bag images of the split multiple 3D bag images have overlapping slices.

7. The method of claim 6, wherein step D5 includes a condition that the number of high energy slices in the first N_e1 slices is no less than a pre-defined threshold.

8. The method of claim 6, wherein step D5 includes a condition that the number of high energy slices in the last N_e2 slices is no greater than a pre-defined threshold.

9. A system for extracting 3D bag images from continuously reconstructed 2D CT image slices comprising:

A. A starting slice detector wherein the starting slice detector constructed and arranged so as to detect a starting slice from a series of N_s1+N_s2 slices, the starting slice detector further comprising;

A1. A module constructed and arranged so as to compute slice energy for each 2D CT image slice;

A2. A module constructed and arranged so as to threshold slices into high energy slices and low energy slices;

A3. A module constructed and arranged so as to count the number of high energy slices in the first N_s1 slice;

A4. A module constructed and arranged so as to count the number of high energy slices in the last N_s2 slice; and

A5. A module constructed and arranged so as to use a starting slice criterion to determine whether a starting slice has been detected;

B. Bag slice counter;

C. 3D bag image splitter;

D. An ending slice detector; and

E. An overlapping slice buffer.

10. A system for extracting 3D bag images from continuously reconstructed 2D CT image slices comprising:

A. A starting slice detector;

B. Bag slice counter;

C. 3D bag image splitter;

wherein said 3D bag image splitter may generate more than one 3D bag image when the number of slices of a 3D bag image is greater than a pre-defined threshold;

D. An ending slice detector; and

E. An overlapping slice buffer.

11. The system of claim 10, wherein said generated more than one 3D bag images may contain overlapping slices.

12. The system of claim 11, wherein said overlapping slices may be obtained from the overlapping slice buffer.

13. A system for extracting 3D bag images from continuously reconstructed 2D CT image slices comprising;

A. A starting slice detector;

B. Bag slice counter;

C. 3D bag image splitter;

D. An ending slice detector;

said ending slice detector may detect the last slice of N_e1+N_e2 slices as an ending slice, comprising;

D1. A module constructed and arranged to compute slice energy;

D2. A module constructed and arranged to threshold slices into high energy slices and low energy slices;

D3. A module constructed and arranged to count the number of high energy slices in the first N_e1 slice;

D4. A module constructed and arranged to count the number of high energy slices in the last N_e2 slice;

D5. A module constructed and arranged to check ending slice criterion; and

E. An overlapping slice buffer.