The substantia nigra is a brain structure located in the mesencephalon (midbrain), that plays an important role in reward, addiction, and movement. It is an area of pigmented cells in the midbrain which is responsible for producing the neurotransmitter dopamine. The aim of this study is to characterize the Substantia nigra in Schizophrenia, Parkinson, and Epilepsy diseases by means of MRI and depict the changes in substantia nigra dimensions using T2 weighted imaging as well as to characterize the Pons, Putamen, Lateral Ventricles and Temporal lobes.