CORRELATION OF SEQUENTIAL MAGNETIC-RESONANCE-IMAGING OF EXPERIMENTAL BRAIN ISCHEMIA WITH HISTOLOGIC-CHANGES IN GERBILS

RATIONAL AND OBJECTIVES. To characterize Gd-DTPA-enhanced T1-weighted images (Gd-T1WI) in the acute phase of cerebral ischemia, sequential m agnetic resonance images of 84 Mongolian gerbils with occlusion of the left common carotid artery were evaluated. METHODS. Twelve gerbils we re used for each group, among which the occlusion time (5-180 minutes, permanent) varied. Histopathologic changes developing within the firs t 2 weeks were compared with patterns on T2-weighted images and Gd-T1W I on a 7.05-Tesla system. RESULTS. Although T2-weighted images and Gd- T1WI both demonstrated abnormal findings as early as 3 hours after occ lusion, Gd-T1WI demonstrated more definite abnormalities with shorter occlusion than T2-weighted images (especially when there were only mil d histologic changes). The earliest changes were an abnormal enhanceme nt around and within the lateral ventricles in temporary occlusions; t his was not demonstrated in permanent occlusions. CONCLUSIONS. Magneti c resonance images using Gd-DTPA demonstrated abnormal permeability wi thin 3 hours after occlusion, and the pattern is correlated with inten sity of ischemia.