-Non-invasive and accurate differentiation of brain mass lesions are important for determining the correct treatment plan and in some cases, may avoid the necessity of performing a biopsy. Now MRI is being currently used to determine the tumor nature and extent that is helpful in planning surgery and radiotherapy, even for post therapy monitoring for tumor recurrence or progression. 30-90% MRI can correctly diagnose intracranial space occupying lesions of various types. It is clinically very important to differentiate brain infections from brain tumors, as their plan of management is completely different