Predicting the pathological fate of focal cerebral ischemia using 1H-magnetic resonance spectroscopic imaging

To clarify regional difference in H-1 magnetic resonance spectral changes in the acute stage of focal cerebral ischemia, and to assess whether any correlation exists between spectral changes in acute stage and pathological outcome in the chronic stage, we measured the non-volume selected H-1-MRSI serially in the acute stage of focal ischemia in rat brain and correlated histopathological findings. The focal ischemia was induced by intraluminal MCA thread occlusion. After induction of focal ischemia, H-1-MR Spectroscopic Images (MRSI) were taken serially up to 10 h after the occlusion. NAA in the peri-ischemic area was maintained. On the other hand, the decline of NAA in the ischemic lesion was linear and drastic during the first 10 h after MCA occlusion, and the rates of decline of NAA concentrations up to 10 h after induction of ischemia, calculated with linear regression, were 0.44 m mol/kg/h in the ischemic core and 0.29 m mol/kg/h in the ischemic rim (p < 0.05). Lactate accumulated significantly in all three areas. Decreasing depth of NAA during the acute stage of cerebral ischemia identifies the formation of the ischemic core and can be used as a predictor for histological outcome. (C) 2003 Elsevier Science B.V. All rights reserved.