Functional MRI in clinical practice: a pictorial essay.

In clinical practice, functional magnetic resonance imaging (fMRI) is a valuable non-invasive tool particularly during preoperative work-up of brain tumour and epilepsy patients. In this pictorial essay, we review expected areas of eloquent cortical activation during the four major clinical paradigms, discuss pitfalls related to fMRI and look at clinical examples where fMRI was particularly valuable in preoperative planning.