Abstract : Delay Enhancement - Magnetic Resonance Imaging (DE-MRI) can be considered as the gold standard for the assessment of myocardial viability after myocardial infarction (MI). Around the infarcted areas that appear with hyper-enhanced signal, there is a peri-infarct border zone that may be an important arrhythmogenic substrate. The extent of this area is an independent predictor of post-MI mortality (1). However, it is difficult to separate peri-infarct border zones from infarct core or normal areas, because of their intermediate signal intensity. We propose a new automatic approach to detect this area, based on a modified Gaussian Mixture Model (GMM) and spatial-weighted fuzzy clustering.