MRI is an important medical diagnosis tool for the detection of tumors in brain as it provides the detailed information associated to the anatomical structures of the brain.MR images helps the radiologist to find the presence of abnormal cell growths or tissues (if any) which we call as tumors. The MRI image analysis is performed under the sequence of operations such as Image Acquistion, Preprocessing, Feature Extraction, Feature Reduction and Image Classification. In this paper, an effort was put to review the existing MRI image processing techniques used in the brain tumor detection and their performances are studied.