Functional Magnetic Resonance Studies of Brain Activation

Recent advances in functional magnetic resonance imaging (fMRI), have stimulated considerable interest in applying this noninvasive approach to investigate the human brain. From early investigations of the visual and the motor system, applications of fMRI have matured to the demonstration of subtle activations associated with complex neurological tasks involving language, memory, and other higher brain functions. On the other hand, it is clear that current enthusiasm for fMRI must be tempered with the realization that interpretation of findings entails a number of assumptions about image contrast mechanisms which necessitate a more pragmatic assessment of what is actually being measured and how to compare the results to those of more established functional imaging techniques like positron emission tomography. Metabolic changes associated with neuronal activation can now be measured by functional magnetic resonance spectroscopy (fMRS) and functional magnetic resonance spectroscopic imaging (fMRSI). Comination of these approaches with fMRI may help to provide a more complete picture of vascular and metabolic mechanisms associated with brain function.