2-DIMENSIONAL H-1 SPECTROSCOPIC IMAGING FOR EVALUATING THE LOCAL METABOLIC RESPONSE TO FOCAL ISCHEMIA IN THE CONSCIOUS RAT

Two-dimensional H-1 spectroscopic imaging and magnetic resonance imaging were used to study focal ischemia induced by middle cerebral artery occlusion in rats. A water suppressing spin-echo sequence was used at 4.7 T. Phase encoding during the spin-echo delay (TE = 272 ms) yielded an 8 x 8 array of 35-mu-L voxels. The injured area of the brain had a higher lactate level and markedly lower N-acetyl aspartate, creatine and choline levels than did the non-ischemic regions. The spectroscopic imaging data clearly showed the localization of the infarct, which agreed well with both magnetic resonance imaging and the histological data obtained post-mortem. This study demonstrates the potential usefulness of combining magnetic resonance imaging and H-1 spectroscopic imaging for studying animal models of stroke, and indicates the suitability of the technique for further pharmacological approaches.