P-31 MR SPECTROSCOPY IN THE PREOPERATIVE EVALUATION OF SYMPTOMATIC UNILATERAL CAROTID-ARTERY STENOSIS

Purpose: The purpose of this study was to examine the potential of P-3 1-MRS (MR spectroscopy) in the pre- and postoperative evaluation of pa tients referred for endarterectomy. Material and Methods: Nine patient s with unilateral, hemodynamically significant stenosis in the region of the common carotid bifurcation were examined pre- and post operativ ely with CT, SPECT (regional cerebral blood flow), transcranial Dopple r, and duplex sonography, and they also underwent neuropsychologic inv estigation. Phosphorus-31 MRS of each hemisphere was pet-formed before and 27-148 days after surgery. The relative concentrations of phospho mono- and -diesters, inorganic phosphate, phosphocreatine, and ATP wer e estimated. Results: No definite changes in concentrations could be d etected for any of the metabolites. Conclusion: The lack of changes wa s probably due to well-functioning collaterals and to the partial volu me effect, whereby changes in a focal region are hidden when larger vo lumes are studied.