Diffusion MRI studies of experimental animal models and patients with stroke

Purpose This overview summarises the diffusion magnetic resonance imaging ( MRI) results both from the experimental animal model studies and clinical i nvestigations in acute cerebral ischemic stroke. Data Sources An English literature searched using MEDLINE (1990-1997). Study Selection Over. 80 papers and reviews published in the last eight yea rs and our partial results were selected. Results and Conclusions magnetic resonance imaging (DWI) nas been extensive ly used to study acute cerebral ischemia both in experimental animal models and in patients. DWI yields signal intensity contrast modulated by water m olecular self-diffusion. By recording a series of DWI with different amplit udes of the displacement encoding gradient, the apparent diffusion coeffici ent (ADO) can be quantitatively mapped. DWI combined with quantitative ADC: mapping can provide earlier and more precise evaluation of the ischemic zo nes. However, the biophysical mechanisms behind the decreased ADC in acute cerebral ischemia are still not fully understood.