Perfusion Quantification using Gaussian Process Deconvolution

Irene Klærke Andersen, Informatics and Mathematical Modelling, Technical University of Denmark
Anna Szymkowiak Have, Informatics and Mathematical Modelling, Technical University of Denmark
Carl Edward Rasmussen, Gatsby Computational Neuroscience Unit, UCL
Lars G. Hanson, Danish Research Centre for Magnetic Resonance
Jacob R. Marstrand, Danish Research Centre for Magnetic Resonance
Henrik B. W. Larsson, Danish Research Centre for Magnetic Resonance
Lars Kai Hansen, Informatics and Mathematical Modelling, Technical University of Denmark

The quantification of perfusion using dynamic susceptibility contrast MR imaging requires deconvolution to obtain the residual impulse-response function (IRF). Here, a method using a Gaussian process for deconvolution, GPD, is proposed. The fact that the IRF is smooth is incorporated as a constraint in the method. The GPD method, which automatically estimates the noise level in each voxel, has the advantage that model parameters are optimized automatically. The GPD is compared to singular value decomposition (SVD) using a common threshold for the singular values and to SVD using a threshold optimized according to the noise level in each voxel. The comparison is carried out using artificial data as well as using data from healthy volunteers. It is shown that GPD is comparable to SVD variable optimized threshold when determining the maximum of the IRF, which is directly related to the perfusion. GPD provides a better estimate of the entire IRF. As the signal to noise ratio increases or the time resolution of the measurements increases, GPD is shown to be superior to SVD. This is also found for large distribution volumes.

Magnetic Resonance in Medicine, 48:351-361, Wiley (2002).

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