[MR spectroscopy in acute brain infarction: differentiation of infarcted and non-infarcted areas]

Two cases of brain infarction were studied using multivoxel proton MR spectroscopy (MRS). MRS of both cases clearly demonstrated an increased level of lactate and decreased N-acetylaspartate (NAA), resulting in a high lactate/NAA ratio (LNR). Case 1 without thrombolysis therapy revealed that the area where LNR was less than 1.0 did not develop to infarction. This was also confirmed by MRS of case 2, who received an interventional reperfusion 4 hours after onset. In acute stags of brain infarction, on LNR greater than 1.0 on H-MRS may predict the margin of the infarcted region. Elevation of lactate in the non-infarcted cerebral hemisphere has not been reported before, and farther evaluation is necessary.