Cluster analysis in kinetic modelling of the brain: a noninvasive alternative to arterial sampling. - Matthew G. Liptrot; Karen H. Adams; Lars Martiny; Lars H. Pinborg; Markus Nowak Lonsdale; Niels V. Olsen; Søren Holm; Claus Svarer; Gitte Moos Knudsen (NeuroImage, 2004)