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 utilizing a high-field (7T) proton magnetic resonance imaging (MRI). The typical time course of vasogenic edema and the efficacy of AVS; 1,2-bis (nicotinamide)-propane upon the edema were presented. Twelve rats with edema induced by cortical freezing were divided into two groups; one group of animals received 0.5 ml of physiological saline with 100 mg (/kg) AVS every eight hours intraperitoneally. The other group of untreated animals received only saline. One three, six, 12, and 24 hours after lesion production, the profiles of edema fluid spreading and the maximum signal intensity (MI) of some regions of interest (ROI) were assessed by T2 weighted images (TE = 70 ms, TR = 3500 ms). One hour after lesion production in the untreated group, a low heterogeneous intensity 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 after lesion production edema extended contralaterally via corpus callosum. AVS reduced edema fluid spreading beginning from about six hours after lesion production. The MIs of the AVS treated group were significantly lower than in the untreated group (p < 0.01). We conclude that sequential observation of edema using MRI is a quite practical technique for evaluation of the efficacy of any therapeutic agent.