A HIGH-FIELD MAGNETIC-RESONANCE-IMAGING STUDY OF EXPERIMENTAL VASOGENIC BRAIN EDEMA AND ITS RESPONSE TO AVS - 1,2-BIS(NICOTINAMIDO)-PROPANE

We clearly represented brain structures of rats and permitted a rapid assessment of water gradient of the brain edema by cortical freezing u tilizing a high-field (7T) proton magnetic resonance imaging (MRI). Th e typical time course of vasogenic edema and the efficacy of AVS;1,2-b is (nicotinamide)-propane upon the edema were presented. Twelve rats w ith edema induced by cortical freezing were divided into two groups; o ne group of animals received 0.5 ml of physiological saline with 100 m g (/kg) AVS every eight hours intraperitoneally. The other group of un treated animals received only saline. One three, six, 12, and 24 hours after lesion production, the profiles of edema fluid spreading and th e maximum signal intensity (MI) of some regions of interest (ROI) were assessed by T2 weighted images (TE = 70 ms, TR = 3500 ms). One hour a fter lesion production in the untreated group, a low heterogeneous int ensity area was seen mainly in the primarily injured cortex. Two hours later, the margin of the lesion gradually increased in intensity and MI of ROIs around the lesion also gradually increased. Twenty-four h a fter lesion production edema extended contralaterally via corpus callo sum. AVS reduced edema fluid spreading beginning from about six hours after lesion production. The MIs of the AVS treated group were signifi cantly lower than in the untreated group (p < 0.01). We conclude that sequential observation of edema using MRI is a quite practical techniq ue for evaluation of the efficacy of any therapeutic agent.