System and method for estimating a quantity of interest of a dynamic artery/tissue/vein system
AssigneeOlea Medical
InventorFabrice Pautot
Life of this patent
Estimating the term…
Abstract
The invention relates to a system and a method for estimating a quantity of interest of a dynamic artery/tissue/vein system of an elementary volume—referred to as a voxel—of an organ based on medical images according to the methods referred to as oSVD or cSVD. The invention discloses two embodiments which are distinguished by the execution time necessary in order to produce the estimate of said quantity of interest and enable a therapeutic diagnosis including in an emergency situation.
Claims14
A method implemented by a processing unit of a medical imaging analysis system for producing an estimate of a haemodynamic parameter in a dynamic artery/tissue/vein system, on the basis of experimental intensity signals S(t), wherein the method comprises:
- obtaining a signal S(t), wherein said signal S(t) represents the evolution of a voxel of interest of a plurality of voxels over time t, wherein the plurality of voxels constitute elementary volumes of an organ;
- deriving, from the signal S(t), a concentration curve c for the voxel of interest;
- performing, by the processing unit, a step for breaking down a convolution matrix A canonically into singular values in the form A=U·S·VT
- where S≡diag(σ1, . . . , σL) is the diagonal matrix of singular values classified by increasing order,
- VT is the transpose of a matrix V, and
- V=(vij) and U=(uij) are two unitary and real square matrices of dimension L×L, L≧N, N being a defined number of samples, A and c respectively having dimensions L×L and L×1;
- performing, by the processing unit, at least one iterative step for:
- producing a pseudo-inverse Ã1−1 of A, in the form Ã1−1=V·Wl·UT, where UT designates the transpose of U, and where
- W
- l
- =
- diag
- (
- 0
- ,
- …
-
- ,
- 0
- ︸
- l
- ,
- 1
- /
- σ
- l
- +
- 1
- ,
- …
-
- ,
- 1
- /
- σ
- L
- )
-
- 0
- <
- l
- ≤
- L
- ;
-
- producing dl=Ã−1·c;
- performing, by the processing unit, a step for producing the estimate of the haemodynamic parameter on the basis of an estimate of a quantity of interest {circumflex over (d)}=dlF produced with the iteration lF, where {circumflex over (d)} has dimensions L×1, and lF is positive and less than or equal to L;
- producing, by the processing unit, the estimate of the haemodynamic parameter in a format suitable for display on a man-machine interface;
- and
- displaying, on the man-machine interface, an illustration of the estimate.
A method implemented by a processing unit of a medical imaging analysis system for producing an estimate of a haemodynamic parameter in a dynamic artery/tissue/vein system, on the basis of experimental intensity signals S(t), wherein the method comprises:
- obtaining a signal S(t), wherein said signal S(t) represents the evolution of a voxel of interest of a plurality of voxels over time t, wherein the plurality of voxels constitute elementary volumes of an organ;
- deriving, from the signal S(t), a concentration curve c for the voxel of interest;
- performing, by the processing unit, a step for breaking down a convolution matrix A canonically into singular values in the form A=U·S·VT
- where S=diag(σ1, . . . , σL) is the diagonal matrix of positive singular values classified by increasing order,
- VT is the transpose of a matrix V, and
- V=(vij) and U=(uij) are two unitary and real square matrices of dimension L×L, L≧N, N being a defined number of samples, A and c respectively having dimensions L×L and L×1;
- performing, by the processing unit, at least one iterative step in order with the iteration 0<l≦L to calculate the L components dl(i), i=1,L of the vector dl by
- d
- l
-
- (
- i
- )
- =
- d
- l
- -
- 1
-
- (
- i
- )
- -
- v
- il
- σ
- l
-
- ∑
- j
- =
- 1
- N
-
- c
- j
- ·
- u
- jl
- ,
- where dl-1(i), i=1,L are the components of the vector dl-1 obtained with the preceding iteration;
- prior to each step for producing-d1, performing, by the processing unit, the verification of a regularisation condition consisting of the calculation an oscillation index OIl, said regularisation condition being met as soon as OIlF≦POI, where POI is a sole predetermined value, said method being interrupted with the iteration lF as soon as said condition is met;
- performing, by the processing unit, a step for producing the estimate of the haemodynamic parameter on the basis of an estimate of a quantity of interest {circumflex over (d)}=dlF with the iteration lF being strictly positive and less than or equal to L, where {circumflex over (d)} has dimensions L×1;
- producing, by the processing unit, the estimate of the haemodynamic parameter in a format suitable for display on a man-machine interface;
- and
- displaying, on the man-machine interface, an illustration of the estimate.
Dependencies are inferred from the claim text.