LOCALIZED Q-SPACE IMAGING OF THE MOUSE-BRAIN

Localized q-space imaging was used to obtain water displacement profil es from mouse brain. These profiles take the form of unidirectional di ffusive displacement probability distributions. Two groups of mice wer e studied, a normal group and a group in which surgery had been perfor med to produce a unilateral reduction in the supply of blood to the fo rebrain, q-Space measurements were made both in vivo and postmortem, T he displacement profiles were characterized using the summary paramete r prob[d < 10], which is the proportion of water molecules that underg o a net diffusive displacement that is less than +/-10 mu m, during th e diffusion period (50 ms). The range of prob[d < 10] values in the no rmal group was 0.71 to 0.77 in vivo compared with 0.78 to 0.87 in the impaired hemisphere of the surgically treated group, An increase in pr ob[d < 10] occurred postmortem to yield values in the range 0.79 to 0. 81 and 0.80 to 0.89 in the normal and surgically treated group, respec tively, These observations are consistent with the diffusion-weighted image intensity changes that occur after a period of ischemia.