The use of functional magnetic resonance imaging and MR tractography for neuropsychiatirc studies of cognitive functions

5. Summary Although conventiona! MR imaging techniques play a crucia! role in the examination of the centra!nervous system (CNS), these techniques can not give any information about functiona! properties of the brain tissue. Besides conventional MRl techniques, however, there are some MR methods enabling evaluation of these functiona! properties. These methods include functiona! magnetic resonance imaging (!MRl), diffusion-weigbted imaging (DWI) or diffusion tensor imaging (DTI), and voxel based morphometry (VBM). fMRI is a method monitoring the activity of the individua! parts of the brain duriog specific tasks and thus c1arifying their functions. fMRI has become the method of choice especia!ly in neurosurgica! procedures plarming, when it is necessary to know the relative location of the pathological lesion and to localize functiona!ly important areas of the cerebra! cortex, and thereby to reduce the risk of damage associated with the neurosurgical operations. DWI and DT[ are very important methods that may be used to assess the severity of cerebra! ischemia and the integrity ofwhite matter tracts based on diffusion properties ofthe brain tissue. Voxel·based morphometry (VBM) is an objective method and fuHy automated whole brain structura! ana! ysis. Neuropathological changes in the brain tissue of..