@MASTERSTHESIS\{IMM2006-04449,
    author       = "B. Bodvarsson and M. M{\o}rkebjerg",
    title        = "Analysis of Dynamic {PET} Data",
    year         = "2006",
    school       = "Informatics and Mathematical Modelling, Technical University of Denmark, {DTU}",
    address      = "Richard Petersens Plads, Building 321, {DK-}2800 Kgs. Lyngby",
    type         = "",
    note         = "Supervised by Lars Kai Hansen, {IMM}.",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/4449-full.html",
    abstract     = "In dynamic positron emission tomography (PET) an artery sampling is needed for assessment and validation of parameters in kinetic models. The sampling can be uncomfortable and painful for the patient and technically demanding for the personnel performing the sampling. Noninvasive estimation of the artery time activity curve (TAC) is thus very useful, since the sampling then can be avoided.

Methods are tested on simulated data which is an approximation to {PET} data. The results from the simulated data are used to quantify how will the different methods perform and to illustrate their limitations. The methods are then used on real {PET} data, and the estimated TACs are compared to the sampled artery {TAC}.

Non-negative matrix factorization (NMF) and independent component analysis (ICA) show the best results with correlations around 0.95 with the artery sampled {TAC}. However, the scaling of the resulting components is lost in the deconvolution so a rescaling scheme is used to get the correct scale in the results. A factor is calculated to solve this scaling problem. The peaks found in the {NMF} and {ICA} components are higher than the ones found by the other methods.

The {ICA} and the {NMF} results are very similar when applied to real {PET} data. Therefore, the {NMF} is chosen as the most appropriate method as it is more stable and not as complicated as the {ICA}."
}