EFFECT OF MANNITOL ON FOCAL CEREBRAL-ISCHEMIA EVALUATED BY MAGNETIC-RESONANCE-IMAGING

We have evaluated the effect of mannitol on focal cerebral ischemia us ing T2-weighted magnetic resonance (MR) imaging and intravoxel incoher ent motion (IVIM) MR imaging. The left middle cerebral artery (MCA) wa s exposed via the transorbital approach in 20 adult cats and occluded just proximal to the origin of the perforating arteries. Seven cats in treatment group received mannitol (0.5 g/kg i.v.) at 0, 6,12 and 18 h ours after MCA occlusion. The other 13 cats received saline and served as controls. Sequential MR coronal images were obtained at 2, 4, 6, a nd 24 hours after MCA occlusion using a GE Signa (1.5 tesla) system. I VIM MR imaging demonstrated ischemic cerebral injury as a sharply dema rcated area at 2 hours after MCA occlusion in control group, while T2- weighted MR imaging failed to show clear evidence of the injury until 2-6 hours. At 24 hours after MCA occlusion, the infarcted area in the mannitol treatment group was 36.9 +/- 7.7% (S.E.M.) of the left hemisp here, as compared to 57.3 +/- 5.3% in control group (p < 0.05). Mannit ol has beneficial effect on ischemic injury.