Comparison of five cluster validity indices performance in brain [ F]FET-PET image segmentation using k-means.

Purpose: Dynamic [ F]fluoro-ethyl-L-tyrosine positron emission tomography ([ F]FET-PET) is used to identify tumor lesions for radiotherapy treatment planning, to differentiate glioma recurrence from radiation necrosis and to classify gliomas grading. To segment different regions in the brain k-means cluster analysis can be used. The main disadvantage of k-means is that the number of clusters must be pre-defined.