System and method for decomposed temporal filtering for X-ray guided intervention application

1. A computer implemented method of temporally filtering medical images during a fluoroscopy guided intervention procedure, the method performed by said computer comprising the steps of:

providing a mask image and a fluoroscopy intervention image acquired at a current time during a medical intervention procedure;

forming a subtraction image by subtracting said mask image from said intervention image;

calculating a motion image of a moving structure in said subtraction image;

forming a residual image by subtracting said motion image from said subtraction image;

temporally filtering said residual image with a filtered image from a previous time; and

adding said motion image to said temporally filtered residual image.

2. The method of claim 1 , further comprising normalizing a contrast of the mask image and the intervention image, before forming said subtraction image.

3. The method of claim 2 , wherein said contrast is normalized by calculating a log of each said image.

4. The method of claim 1 , wherein said moving structure comprises a guide wire being inserted into a blood vessel during said medical intervention procedure.

5. The method of claim 1 , wherein calculating a motion image comprises calculating an image that minimizes an objective function that includes a mutual information of the subtraction image and the intervention image.

6. The method of claim 5 , wherein said mutual information is of the form MI(I sub,t (x,y)−I mov,t (x,y), I t (x,y)−I mov,t (x,y)), wherein (x,y) is a pixel location, I mov,t (x,y) is said motion image, I sub,t (x,y) is said subtraction image, and I t (x,y) is said intervention image.

7. The method of claim 5 , wherein said objective function being minimized includes term proportional to a square of said motion image.

8. The method of claim 6 , wherein said mutual information is of the form

M

⁢

⁢

I

⁡

(

N

1

,

N

2

)

=

∑

k

⁢



E

⁡

(

f

k

⁡

(

N

1

)

,

g

k

⁡

(

N

2

)

)

-

E

⁡

(

f

k

⁡

(

N

1

)

)

·

E

⁡

(

g

k

⁡

(

N

2

)

)



2

,

where f k (N 1 )=N 1 K , g k (N 2 )=N 2 k and N 1 , N 2 represent the first and second arguments of said mutual information, respectively.

9. The method of claim 1 , further comprising calculating a motion consistent image

I

~

mov

,

t

⁡

(

x

,

y

)

=

arg

⁢

min

I

~

mov

,

t

⁡

(



I

~

mov

,

t

⁡

(

x

,

y

)

-

I

mov

,

t

⁡

(

x

,

y

)



2

+

λ

⁢



I

~

mov

,

t

⁡

(

x

,

y

)

-

I

~

mov

,

t

⁡

(

x

,

y

)



2

)

,

that constrains said motion image to be substantially constant if said moving structure is not moving, wherein λ is a constant set to 0 when ∥I mov,t (x, y)−Ĩ mov,t-1 (x, y)∥>ε, wherein ε is a threshold for motion detection.

10. The method of claim 1 , wherein said temporal filtering takes the form I t (x,y)=wI t-1 (x,y)+(1−w)(I sub,t (x,y)−I mov,t (x,y)), wherein (x,y) is a pixel location, I mov,t (x,y) is said motion image, I sub,t (x,y) is said subtraction image, I t-1 (x,y) is the filtered image from a previous time, and w is a predetermined weighting factor.

11. A computer implemented method of temporally filtering medical images during a fluoroscopy guided intervention procedure, the method performed by said computer comprising the steps of:

providing a fluoroscopy intervention image of a blood vessel acquired at a current time during a medical intervention procedure and a subtraction image of said blood vessel;

calculating a motion image that minimizes an objective function that includes a mutual information of the subtraction image and the intervention image, wherein said mutual information is of the form MI(I sub,t (x,y)−I mov,t (x,y), I t (x,y)−I mov,t (x,y)), wherein (x,y) is a pixel location, I mov,t (x,y) is said motion image, I sub,t (x,y) is said subtraction image, and I t (x,y) is said intervention image;

forming a residual image by subtracting said motion image from said subtraction image; and

temporally filtering said residual image with a filtered image from a previous time.

12. The method of claim 11 , wherein providing said subtraction image comprises providing a mask image and forming said subtraction image by subtracting said mask image from said intervention image, wherein said mask image is provided before said intervention by injecting a contrast media into said blood vessel and acquiring an image of said highlighted vessels.

13. The method of claim 11 , further comprising adding said motion image to said temporally filtered residual image.

14. A non-transitory program storage device readable by a computer, tangibly embodying a program of instructions executable by the computer to perform the method steps for temporally filtering medical images during a fluoroscopy guided intervention procedure, the method comprising the steps of:

providing a mask image and a fluoroscopy intervention image acquired at a current time during a medical intervention procedure;

forming a subtraction image by subtracting said mask image from said intervention image;

calculating a motion image of a moving structure in said subtraction image;

forming a residual image by subtracting said motion image from said subtraction image;

temporally filtering said residual image with a filtered image from a previous time; and

adding said motion image to said temporally filtered residual image.

15. The computer readable program storage device of claim 14 , the method further comprising normalizing a contrast of the mask image and the intervention image, before forming said subtraction image.

16. The computer readable program storage device of claim 15 , wherein said contrast is normalized by calculating a log of each said image.

17. The computer readable program storage device of claim 14 , wherein said moving structure comprises a guide wire being inserted into a blood vessel during said medical intervention procedure.

18. The computer readable program storage device of claim 14 , wherein calculating a motion image comprises calculating an image that minimizes an objective function that includes a mutual information of the subtraction image and the intervention image.

19. The computer readable program storage device of claim 18 , wherein said mutual information is of the form MI(I sub,t (x,y)−I mov,t (x,y)−I mov,t (x,y)), wherein (x,y) is a pixel location, I mov,t (x,y) is said motion image, I sub,t (x,y) is said subtraction image, and I t (x,y) is said intervention image.

20. The computer readable program storage device of claim 18 , wherein said objective function being minimized includes term proportional to a square of said motion image.

21. The computer readable program storage device of claim 19 , wherein said mutual information is of the form

M

⁢

⁢

I

⁡

(

N

1

,

N

2

)

=

∑

k

⁢



E

⁡

(

f

k

⁡

(

N

1

)

,

g

k

⁡

(

N

2

)

)

-

E

⁡

(

f

k

⁡

(

N

1

)

)

·

E

⁡

(

g

k

⁡

(

N

2

)

)



2

,

where f k (N 1 )=N 1 K , g k (N 2 )=N 2 k and N 1 , N 2 represent the first and second arguments of said mutual information, respectively.

22. The computer readable program storage device of claim 14 , the method further comprising calculating a motion consistent image

I

~

mov

,

t

⁡

(

x

,

y

)

=

arg

⁢

min

I

~

mov

,

t

⁡

(



I

~

mov

,

t

⁡

(

x

,

y

)

-

I

mov

,

t

⁡

(

x

,

y

)



2

+

λ

⁢



I

~

mov

,

t

⁡

(

x

,

y

)

-

I

~

mov

,

t

-

1

⁡

(

x

,

y

)



2

)

,

that constrains said motion image to be substantially constant if said moving structure is not moving, wherein λ is a constant set to 0 when ∥I mov,t (x, y)−Ĩ mov,t-1 (X, y)∥>ε, wherein ε is a threshold for motion detection.

23. The computer readable program storage device of claim 14 , wherein said temporal filtering takes the form I t (x,y)=wI t-1 (x,y)+(1−w)(I sub,t (x,y)−I mov,t (x,y)), wherein (x,y) is a pixel location. I mov,t (x,y) is said motion image, I sub,t (x,y) is said subtraction image, I t-1 (x,y) is the filtered image from a previous time, and w is a predetermined weighting factor.