Brain MRI Segmentation and Lesions Detection by EM Algorithm

In Multiple Sclerosis, pathological changes in the brain results in deviations in signal intensity on Magnetic Resonance Images (MRI). Quantitative analysis of these changes and their correlation with clinical finding provides important information for diagnosis. This constitutes the objective of our work. A new approach is developed. After the enhancement of images contrast and the brain extraction by mathematical morphology algorithm, we proceed to the brain segmentation. Our approach is based on building statistical model from data itself, for normal brain MRI and including clustering tissue type. Then we detect signal abnormalities (MS lesions) as a rejection class containing voxels that are not explained by the built model. We validate the method on MR images of Multiple Sclerosis patients by comparing its results with those of human expert segmentation.

Authors:

• Mounira Rouaïnia
• Mohamed Salah Medjram
• Noureddine Doghmane

Keywords:

• EM algorithm
• Magnetic Resonance Imaging
• Mathematical morphology
• Markov random model.

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