System and method for image reconstruction for helical cone beam computed tomography with factorized redundancy weighting
AssigneesToshiba Medical Systems Corporation, Kabushiki Kaisha Toshiba
InventorsSatoru NAKANISHI, Aleksandr Zamyatin
Life of this patent
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Abstract
A method and system for computed tomography were weighted data is used to reconstruct an image. The apparatus includes an x-ray source producing a cone-beam of x-rays, an x-ray detector disposed to receive x-rays from the x-ray source, a data collection unit, and a processing unit for processing the data using a weighting function using contributions from fan-beam and cone-beam weighting functions. The apparatus can produce images with reduced artifacts.
Claims16
A computed-tomography apparatus, comprising:
- an x-ray source;
- an x-ray detector disposed to receive x-rays from said x-ray source;
- a data collection unit;
- a processing unit for processing said data using a weighting function given as
- w
- CB
-
- (
- β
- ,
- γ
- ,
- v
- )
- =
- u
- FB
-
- (
- β
- )
- ·
- u
- CB
-
- (
- v
- ,
- γ
- )
- ∑
- n
- =
- -
- N
- N
-
- (
- u
- FB
-
- (
- β
- n
-
- (
- β
- ,
- γ
- )
- )
- ·
- u
- CB
-
- (
- v
- n
- )
- )
- where β is a projection angle of said x-rays, γ is a fan angle of said x-rays, and ν is a detector coordinate parallel to axis of rotation of said x-ray source.
A computed tomography method, comprising:
- exposing a subject to x-rays from an x-ray source;
- collecting data;
- weighting said data using
- w
- CB
-
- (
- β
- ,
- γ
- ,
- v
- )
- =
- u
- FB
-
- (
- β
- )
- ·
- u
- CB
-
- (
- v
- ,
- γ
- )
- ∑
- n
- =
- -
- N
- N
-
- (
- u
- FB
-
- (
- β
- n
-
- (
- β
- ,
- γ
- )
- )
- ·
- u
- CB
-
- (
- v
- n
- )
- )
- where β is a projection angle of said x-rays, γ is a fan angle of said x-rays, and ν is a detector coordinate parallel to axis of rotation of said x-ray source;
- and
- reconstructing an image of said subject using said weighted data.
A computer-readable medium containing instructions that may be executed by a computer to perform a method comprising:
- collecting data associated with exposing a subject to x-rays from an x-ray source;
- weighting said data using
- w
- CB
-
- (
- β
- ,
- γ
- ,
- v
- )
- =
- u
- FB
-
- (
- β
- )
- ·
- u
- CB
-
- (
- v
- ,
- γ
- )
- ∑
- n
- =
- -
- N
- N
-
- (
- u
- FB
-
- (
- β
- n
-
- (
- β
- ,
- γ
- )
- )
- ·
- u
- CB
-
- (
- v
- n
- )
- )
- where β is a projection angle of said x-rays, γ is a fan angle of said x-rays, and ν is a detector coordinate parallel to axis of rotation of said x-ray source;
- and
- reconstructing an image of said subject using said weighted data.
A computed-tomography apparatus, comprising:
- an x-ray source;
- an x-ray detector disposed to receive x-rays from said x-ray source;
- a data collection unit;
- and
- a reconstruction unit for reconstructing a CT image based on said data and a weighting value obtained by using a function uFB(β), depending on a projection angle and a function uCB(ν, γ) depending on a fan angle and cone angle,
- where β is a projection angle of said x-rays, γ is a fan angle of said x-rays, and ν is a cone angle.
Dependencies are inferred from the claim text.