CORRELATION BETWEEN HIGH-FIELD T2-WEIGHTED MR-IMAGING AND HISTOLOGY OF ISCHEMIC LESIONS IN GERBIL BRAIN

Global forebrain ischemia in the Mongolian gerbil is a common animal m odel for use in stroke research. We produced lesions of graded severit y in gerbil brains [after prescreening by MR imaging] by performing 6- minute bilateral carotid artery occlusions while monitoring pericrania l temperature with a temporalis muscle thermocouple probe and maintain ing the temperature at 32 degrees C, 36 degrees C, or 40 degrees C. Le sion severity was scored 4 days after occlusion from findings on spin- echo images acquired at 7 T and from histologic scores. Statistically significant correlation was observed between the MR imaging score and brain temperature and between the MR imaging score and the area of the CA region of the hippocampus measured by histology. In addition, beca use prescreening with MR imaging revealed abnormalities in the hippoca mpus of some of the animals, and these animals were rejected from the study, the statistical significance of the result could be strengthene d.