Adaptive iterative bone correction in computerized tomography

1. A method of performing bone correction on a computerized tomography (CT) image, comprising:

A. generating a reconstructed CT image of a bone-containing portion of a patient's body, the reconstructed CT image including a bone region corresponding to the bone-containing portion;

B. determining characteristics of the bone region of the image, wherein the bone region characteristics include at least one of a bone density value d and a bone area value s; and

C. performing a bone correction procedure on the image, the bone correction procedure being performed at a gain that is determined based on the bone region characteristics

wherein, if the bone region characteristics fall within a first threshold region of a grid having a first axis representative of the bone density value d and a second axis representative of the bone area value s, the gain in step C is a first gain setting of zero;

wherein, if the bone region characteristics fall within a second threshold region of the grid, the gain in step C is a second gain setting of one;

wherein, if the bone region characteristics do not fall within the first threshold region of the grid nor the second threshold region of the grid, the gain in step C is a third gain setting that is between zero and one;

wherein the first, second and third gain settings are determined based on a relationship between (a) an intersection value of the bone density value d and the bone area value s and (b) the first and second threshold regions;

wherein the first threshold region is defined by an area of the grid enclosed by a first threshold bond density value d 1 and a first threshold bone area value s 1 ;

wherein the second threshold region is an area of the grid defined by a ratio of a second threshold bone density value d 2 and a second threshold bone area value s 2 ;

wherein the third gain setting is determined based on the distance between an intersection point A of the determined bone density value d and the determined bone area value s and each of the first threshold region and the second threshold region;

wherein the third gain setting is determined according to the equation:

G 3 =D 2 /( D 1 +D 2) ;

where D 1 is the distance between the intersection point A and the second threshold region and D 2 is the distance between the intersection point A and the first threshold region; and

wherein the value of G 3 ranges from zero to one.

2. The method of claim 1 , wherein the value of D 1 is

D

1

=



d

+

α

⁢

⁢

s

-

γ



1

+

α

2

;

determine according to the equation:

where γ represents the y-intercept of a boundary of the second threshold region and α represents a scaling factor for normalizing the ration between the units of bone density and bone area of the grid.

3. The method of claim 2 , wherein the value of D 2 is determined according to the equation:

D

2

=

{

α

⁡

(

s

-

s

1

)

if

⁢

⁢

d

<

d

1

d

-

d

1

if

⁢

⁢

s

<

s

⁢

1

α

2

⁡

(

s

-

s

1

)

2

+

(

d

-

d

1

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Otherwise

.

4. A method of performing bone correction on a computerized tomography (CT) image, comprising:

A. generating a reconstructed CT image of a bone-containing portion of a patient's body, the reconstructed CT image including a bone region corresponding to the bone-containing portion;

B. determining at least one of a bone density value d and a bone area value s of the bone region of the image; and

C. performing a bone correction procedure on the image, the bone correction procedure being performed at a gain that is determined based on at least one of the bone density value d and the bone are value s of the bone region of the image;

wherein (a) if one of the bone density value d is greater than a predetermined bone density value d 1 and the bone area value s is greater than a predetermined bone area value s 1 , the gain is set to a first value greater than 0, and (b) if the bone density value d and the bone area value s satisfy the equation:

d+αs−γ> 0,

where α is a scalar value and γ is the y-intercept of the line formed by the equation, then the gain is set to a second value of 1.

5. A method of performing bone correction on a computerized tomography (CT) image comprising:

A. generating a reconstructed CT image of a bone-containing portion of a patient's body, the reconstructed CT image including a bone region corresponding to the bone-containing portion;

B. determining at least one of a bone density value d and a bone area value s of the bone region of the image; and

C. performing a bone correction procedure on the image, the bone correction procedure being performed at a gain that is determined based on at least one of the bone density value d and the bone area value s of the bone region of the image;

wherein, (a) if one of the bone density value d is greater than a predetermined bone density value d 1 and the bone area value s is greater than a predetermined bone area value s 1 , the gain is set to a first value greater than 0; (b) if the bone density value d is less than the predetermined bone density d 1 and the bone area value s is less than the predetermined bone area value s 1 , the gain is set to a second value of 0; and (c) if the bone density value d and the bone area value s satisfy the equation:

d+αs−γ> 0,

where α is a scalar value and γ is the y-intercept of the line formed by the equation, then the gain is set to a third value of 1.