Visual enhancement of interval changes using temporal subtraction, convolving, and non-rigid transformation field mapping

• US 8,229,189 B2
• Filed: 02/08/2008
• Issued: 07/24/2012
• Est. Priority Date: 02/09/2007
• Status: Active Grant

• Current Assignee: Agfa Nv (Agfa-Gevaert N.V.)
• Original Assignee: AGFA Healthcare NV (Agfa-Gevaert N.V.)
• Inventors: Seghers, Dieter, Dewaele, Piet, Suetens, Paul
• Primary Examiner(s): Johnston, Phillip A
• Assistant Examiner(s): PURINTON, BROOKE J
• Application Number:
  US12/028,255
• Publication Number:
  US 20080193001A1
• Time in Patent Office: 1,628 Days
• Field of Search: 382/276, 382/131, 382/294, 382/128, 382/130, 382/132, 382/279, 382/181, 382/190
• US Class Current: 382/128
• CPC Class Codes: G06T 2207/30061 Lung
• CPC Class Codes: G06T 7/0016 involving temporal comparison
• CPC Class Codes: G06T 7/254 involving subtraction of images
• CPC Class Codes: G06T 7/35 using statistical methods

Abstract

Method to bring out a temporal difference between corresponding structures in a reference image R and a floating image F by convolving the reference image R and the floating image F with a window function H_w to generate R_w and F_w, applying a non-rigid transformation resulting in a transformation field g(r_R) mapping every location r_R to a corresponding location r_F in the floating image F and generating a subtraction image by performing subtraction R_w(r)−F_w(g(r)) wherein r represents a voxel (x, y, z) in reference image R.

Claims

1. A method to bring out a temporal difference between corresponding structures in a reference image R and a floating image F, the method comprising:

convolving said reference image R with a window function H_w to generate R_w,

convolving said floating image F with the same window function H_w to generate F_w,

applying a non-rigid transformation resulting in a transformation field g(r_R) mapping every location r_R to a corresponding location r_F in the floating image F,

generating a subtraction image by performing subtraction R_W(r)−

F_w(g(r)) wherein r represents a voxel (x, y, z) in the reference image R.

2. A method according to claim 1 wherein said window function is an averaging function.

3. A method according to claim 2 wherein the size of said window function is related to the dimensions of said structure.

4. A method according to claim 1 wherein the size of said window function is related to the dimensions of said structure.

5. A computer software product for bringing out a temporal difference between corresponding structures in a reference image R and a floating image F, the product comprising a non-transitory computer-readable medium in which program instructions are stored, which instructions, when read by a computer, cause the computer to:

convolve said reference image R with a window function H_w to generate R_w,

convolve said floating image F with the same window function H_w to generate F_w,

apply a non-rigid transformation resulting in a transformation field g(r_R) mapping every location r_R to a corresponding location r_F in the floating image F, and

generate a subtraction image by performing subtraction R_W(r)−

F_w(g(r)) wherein r represents a voxel (x, y, z) in reference image R.

10. A product according to claim 5 wherein said window function is an averaging function.

11. A product according to claim 10 wherein the size of said window function is related to the dimensions of said structure.

12. A product according to claim 5 wherein the size of said window function is related to the dimensions of said structure.

6. A computer executing a software product for bringing out a temporal difference between corresponding structures in a reference image R and a floating image F, the computer:

convolving said reference image R with a window function H_w to generate R_w,

convolving said floating image F with the same window function H_w to generate F_w,

applying a non-rigid transformation resulting in a transformation field g(r_R) mapping every location r_R to a corresponding location r_F in the floating image F, and

generating and displaying a subtraction image on a display device of the computer by performing subtraction R_W(r)−

F_w(g(r)) wherein r represents a voxel (x, y, z) in reference image R.

7. A computer according to claim 6 wherein said window function is an averaging function.

8. A computer according to claim 7 wherein the size of said window function is related to the dimensions of said structure.

9. A computer according to claim 6 wherein the size of said window function is related to the dimensions of said structure.