Multivoxel MR spectroscopy in acute ischemic stroke: comparison to the stroke protocol MRI.

BACKGROUND AND PURPOSE Few patients with stroke have been imaged with MR spectroscopy (MRS) within the first few hours after onset. We compared data from current MRI protocols to MRS in subjects with ischemic stroke. METHODS MRS was incorporated into the standard clinical MRI stroke protocol for subjects <24 hours after onset. MRI and clinical correlates for the metabolic data from MRS were sought. RESULTS One hundred thirty-six MRS voxels from 32 subjects were analyzed. Lactate preceded the appearance of the lesion on diffusion-weighted imaging in some voxels but in others lagged behind it. Current protocols may predict up to 41% of the variance of MRS metabolites. Serum glucose concentration and time to maximum partially predicted the concentration of all major metabolites. CONCLUSIONS MRS may be helpful in acute stroke, especially for lactate detection when perfusion-weighted imaging is unavailable. Current MRI protocols do provide surrogate markers for some indices of metabolic activity.