Apparatus and Method for the Processing of Perfusion Images
AssigneeKoninklijke Philips Electronic, N.V.
InventorsJurgen Weese, Georg Rose
Life of this patent
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Abstract
The invention relates to an apparatus and a method for the reconstruction of time-dependent cross-sectional images and may be applied for example in perfusion imaging in the vessel system (2) of a patient. According to the method, projections pij are generated from a number M of different directions d and at different times tij. Moreover, the time-dependent intensity function I(x,t) of the reconstructed volume is approximated by a predetermined model function I*(a(x),t), wherein the unknown parameter vector a(x) is estimated for each voxel x. This estimation may be done using the update functions of known reconstruction algorithms like ART for at least N projections pij in each iteration step.
Claims19
An image processing apparatus (1) for the reconstruction of time-dependent representations I(x,t) of an object (2), comprising
- an approximation module with memory storing the N-dimensional parameter vector a(x) of a predetermined parametric model function I*(a(x),t) that approximates the function I(x,t);
- an input module for the reception of a set of projections pij of the object (2) generated at times tij, and
- an estimation module that is adapted to estimate the parameter vector a(x) with the help of said projections pij.
An X-ray examination system, comprising
- a rotational X-ray apparatus (3) for generating X-ray projections pij of an object (2) from different directions;
- an image processing apparatus (1) coupled to the X-ray apparatus (3) and adapted to estimate based on said projections pij the N-dimensional parameter vector a(x) of a predetermined model function I*(a(x),t) that approximates the representation I(x,t) of the object (2).
A method for the reconstruction of time-dependent representations of an object (2), comprising the following steps:
- approximation of the function I(x,t) which describes the representations by a predetermined parametric model function I*(a(x),t);
- and
- estimation of the N-dimensional parameter vector a(x) with the help of a set of projections pij of the object (2) generated at times tij.
An X-ray system suitable for determining a 3D dynamic process in an object (2), the system comprising
- an x-ray source and an x-ray detector placed at opposite positions with respect to an examination space and simultaneously rotatable around said examination space for generating a plurality of x-ray projections;
- a data processing unit for deriving from said plurality of x-ray projections a map of the time dependent 3D dynamic process in the object (2);
- whereby the 3D dynamic process is approximated by a predetermined model with a limited set of parameters;
- whereby the data processing unit is arranged to estimate parameters in said limited set of parameters out of data in the x-ray projections.
Dependencies are inferred from the claim text.