An introduction to functional magnetic resonance imaging

BACKGROUND - Functional magnetic resonance imaging (fMRI) is a promising tool for understanding structure/function relationships in the brain. This technique can be used to map sensorimotor and cognitive processing noninvasively within single subjects. REVIEW SUMMARY - This review provides an overview of the physiological underpinnings of fMRI; the execution of a fMRI experiment, including design of the behavioral paradigm, image acquisition, and analysis of the data; and examples of fMRI data from motor and cognitive studies of normal adults and people with neurological disease. We discuss problems with fMRI, such as temporal resolution and movement artifacts, and a few important technical issues in functional neuroimaging, such as the subtraction methodology, functional localization, and statistical analysis. CONCLUSIONS - With the high spatial resolution of fMRI and its noninvasive nature, involving no radiation exposure, it promises to provide detailed knowledge of functional neuroanatomy of human sensorimotor and cognitive processes. Two areas in which application of research using fMRI to clinical neurology seems particularly likely to have an impact in the short term are in epilepsy and stroke recovery. However, current studies of fMRI require careful attention to design and analysis procedures. In particular, fMRI studies are limited by temporal resolution, susceptibility to movement artifacts, and inadequate statistical models.