The Magnetic Resonance Imaging (MRI) of the brain with diffusion is a painless and simple procedure that provides excellent images of the brain and brain stem. There are many indications for MRI Brain with diffusion and including early identification of ischemic stroke, differentiation of acute from chronic stroke, differentiation of acute stroke from other stroke mimics, differentiation of epidermoid cyst from an arachnoid cyst, differentiation of abscess from necrotic tumours, assessment of cortical lesions in Creutzfeldt-Jakob disease (CJD), differentiation of herpes encephalitis from diffuse temporal gliomas, assessment of the extent of diffuse axonal injury, grading of diffuse gliomas and meningiomas, assessment of active demyelination, grading of prostate lesions (see PIRADS), differentiation between cholesteatoma and otitis media among others.