Abstract: The present invention relates to a method for estimating perfusion indices (PI) in a mammal (200), e.g. a human. Data (DAT, DAT?) representative of a contrast agent concentration as a function of time of an injected contrast agent is obtained from a medical imaging system (100). Perfusion indices (PI) are found by applying a parametric model (PM) for capillary transit time distributions as a function of time, and a minorize-maximization (MM) type procedure, such as an expectation-maximization (EM) type procedure, with regularization. The minorize-maximization type procedure has an exact analytical expression for the variance of an observation error of the contrast agent (C?) in a non-linear observation model for the contrast agent concentration used in the maximization step. Clinical tests performed for 7 patients show improved MTT mapping as compared to singular value decomposition (SVD), and reduced sensitivity to delay.

Abstract: The present invention relates to a method for generating a risk map indicating predicted voxel-by-voxel probability of tissue infarction for a set of voxels, the method comprising the steps of, receiving for each voxel a first value (x) corresponding to a set of tissue marker values and generating the risk map, using a statistical model based on data from a group of subjects, and a stochastic variable, wherein the statistical model also comprises a second value (zi), being based on the stochastic variable, such as the second value modelling non-measured values. The invention may be seen as advantageous since it acknowledges subject variability in probability of tissue infarction on a voxel-by-voxel basis by taking non-measured values into account, which in turn may enable providing more reliable estimates of probability of infarction.

Abstract: The present invention relates to a method for estimating perfusion indices (PI) in a mammal (200), e.g. a human. Data (DAT, DAT?) representative of a contrast agent concentration as a function of time of an injected contrast agent is obtained from a medical imaging system (100). Perfusion indices(PI) are found by applying a parametric model (PM) for capillary transit time distributions as a function of time, and a minorize-maximization (MM) type procedure, such as an expectation-maximization (EM) type procedure, with regularization. The minorize-maximization type procedure has an exact analytical expression for the variance of an observation error of the contrast agent (C?) in a non-linear observation model for the contrast agent concentration used in the maximization step. Clinical tests performed for 7 patients show improved MTT mapping as compared to singular value decomposition (SVD), and reduced sensitivity to delay.

Abstract: The present invention relates to a method for generating a risk map indicating predicted voxel-by-voxel probability of tissue infarction for a set of voxels, the method comprising the steps of, receiving for each voxel a first value (x) corresponding to a set of tissue marker values and generating the risk map, using a statistical model based on data from a group of subjects, and a stochastic variable, wherein the statistical model also comprises a second value (zi), being based on the stochastic variable, such as the second value modelling non-measured values. The invention may be seen as advantageous since it acknowledges subject variability in probability of tissue infarction on a voxel-by-voxel basis by taking non-measured values into account, which in turn may enable providing more reliable estimates of probability of infarction.