Point spread function radial component implementation in Joseph's forward projector
AssigneeSiemens Medical Solutions USA, Inc.
InventorsMichael E. Casey, Vladimir Y. Panin
Life of this patent
Estimating the term…
Abstract
Point spread function (PSF) radial filtering in a line of response space. Modeling a radial component, R, of a point spread filter as a function of at least a radial projection index ρ, a radial image space coordinate r, and an azimuth θ. The index ρ is characterized by an asymmetrical Gaussian distribution having where σleft(r) and σright(r) derived from point source measurements, and an adjustment σJ(r, θ) estimated from point source sinogram by Josephs' projector.
Claims3
In a nuclear medicine (NM) imaging system, a method performed by a hardware processor for point spread function radial filtering in a line of response space, the method comprising:
- modeling, utilizing a hardware processor, a radial component, R, of a point spread filter as a function of at least a radial projection index ρ, a radial image space coordinate r, and an azimuth θ as:
- R
-
- (
- ρ
- ;
- r
- ,
- θ
- )
- =
- exp
-
- (
- -
- (
- ρ
- -
- ρ
- 0
-
- (
- r
- )
- )
- 2
- 2
-
-
- σ
- ρ
- 2
-
- (
- ρ
- ;
- r
- ,
- θ
- )
- )
-
-
- where
-
- :
- σ
- ρ
-
- (
- ρ
- )
- =
- {
- σ
- left
- 2
-
- (
- r
- )
- -
- σ
- J
- 2
-
- (
- r
- ,
- θ
- )
- ,
- ρ
- <
- ρ
- 0
-
- (
- r
- )
- σ
- right
- 2
-
- (
- r
- )
- -
- σ
- J
- 2
-
- (
- r
- ,
- θ
- )
- ,
- ρ
- ≥
- ρ
- 0
-
- (
- r
- )
- ,
- where σleft(r) and σright(r) are derived from point source measurements,
- where σJ(r, θ) is estimated from point source sinogram by Josephs' projector,
- wherein when θ=0,σJ(r, θ) has a smallest values, and when θ=45°,σJ(r, θ) has a largest values, so that the radial component R is dependent on the azimuth θ, and
- reconstructing a nuclear image using the radial component.
A nuclear medicine imaging system, including a hardware processor, comprising:
- a point spread function filter comprising a radial component, R, as a function of at least a radial projection index ρ, a radial image space coordinate r, and an azimuth θ as:
- R
-
- (
- ρ
- ;
- r
- ,
- θ
- )
- =
- exp
-
- (
- -
- (
- ρ
- -
- ρ
- 0
-
- (
- r
- )
- )
- 2
- 2
-
-
- σ
- ρ
- 2
-
- (
- ρ
- ;
- r
- ,
- θ
- )
- )
-
-
- where
-
- :
- σ
- ρ
-
- (
- ρ
- )
- =
- {
- σ
- left
- 2
-
- (
- r
- )
- -
- σ
- J
- 2
-
- (
- r
- ,
- θ
- )
- ,
- ρ
- <
- ρ
- 0
-
- (
- r
- )
- σ
- right
- 2
-
- (
- r
- )
- -
- σ
- J
- 2
-
- (
- r
- ,
- θ
- )
- ,
- ρ
- ≥
- ρ
- 0
-
- (
- r
- )
- ,
- where σleft(r) and σright(r) are derived from point source measurements,
- where σJ(r, θ) is estimated from point source sinogram by Josephs' projector,
- wherein when θ=0, σJ(r, θ) has a smallest values, and when θ=45°, σJ(r, θ) has a largest values, so that the radial component R is dependent on the azimuth θ, and
- reconstructing a nuclear image using the radial component.
In a nuclear medicine (NM) imaging system comprising a data processing system, a computer program product for point spread function radial filtering in a line of response space, the system comprising:
- a non-transitory computer-readable recording medium for storing a computer program that executed on a computer, the program comprising the steps of:
- modeling a radial component, R, of a point spread filter as a function of at least a radial projection index ρ, a radial image space coordinate r, and an azimuth θ as:
- R
-
- (
- ρ
- ;
- r
- ,
- θ
- )
- =
- exp
-
- (
- -
- (
- ρ
- -
- ρ
- 0
-
- (
- r
- )
- )
- 2
- 2
-
-
- σ
- ρ
- 2
-
- (
- ρ
- ;
- r
- ,
- θ
- )
- )
-
-
- where
-
- :
- σ
- ρ
-
- (
- ρ
- )
- =
- {
- σ
- left
- 2
-
- (
- r
- )
- -
- σ
- J
- 2
-
- (
- r
- ,
- θ
- )
- ,
- ρ
- <
- ρ
- 0
-
- (
- r
- )
- σ
- right
- 2
-
- (
- r
- )
- -
- σ
- J
- 2
-
- (
- r
- ,
- θ
- )
- ,
- ρ
- ≥
- ρ
- 0
-
- (
- r
- )
- ,
- where σhd left(r) and σright(r) are derived from point source measurements,
- where σJ(r, θ) is estimated from point source sinogram by Josephs' projector,
- wherein when θ=0,σJ(r, θ) has a smallest values, and when θ=45°, σJ(r, θ) has a largest values, so that the radial component R is dependent on the azimuth θ, and
- reconstructing a nuclear image using the radial component.
Dependencies are inferred from the claim text.