Electroporation (EP), the permeabilization of cellular membrane by externally applied voltage pulses, has shown its potential as treatment for cancer when combined with chemotherapeutic agents (electrochemotherapy) and genes (gene electrotransfer). Imaging biomarkers for EP based treatments are therefore needed for monitoring the response both during medical procedures and follow-up. In this paper we focus on diffusion weighted magnetic resonance imaging (DW-MRI) as a non-invasive and quantitative tool for detection of electroporation of brain tissue. We discuss the impact of issues such as joule heating, tissue perfusion, cell morphology on the DW-MRI measurement. We conclude that DW-MRI may potentially be used for direct detection of induced membrane permeabilization, but a number of fundamental challenges need to be dealt with.