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 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 obtaining a blood flow parameter. More particularly a method is presented wherein a first concentration curve is deconvolved with a second concentration curve and wherein a characteristic frequency is determined by an analysis in the frequency domain, the characteristic frequency being a frequency above which noise dominates the result of said deconvolution. A filter having the characteristic frequency is applied on the result of the deconvolution so as to disregard high frequency components, and the filtered result of the deconvolution is processed into a blood flow parameter. In an advantageous embodiment, the characteristic frequency may be dependent on a shape and/or width of an arterial input function and/or other parameters. The invention furthermore relates to a computer program product and a system for obtaining a blood flow parameter.