Quantitative evaluation of cerebral metabolites and cerebral blood flow in patients with carotid stenosis

Abstract

We examined the metabolic and hemodynamic status of patients with severe carotid stenosis and evaluated the effectiveness of carotid endarterectomy (CEA) by comparing pre- and post-operative results of quantitative proton magnetic resonance spectroscopy (1H-MRS) and single-photon emission computed tomography (SPECT). Quantitative 1H-MRS and SPECT were performed in 17 patients with severe carotid stenosis before CEA; in 10 patients the examinations were repeated after CEA. There was a significant correlation between the degree of internal carotid artery (ICA) stenosis and the N-acetyl-aspartate (NAA) concentration, and between CBFand NAA in the basal ganglia. In 10 of the 17 patients (58.8%) we noted a decrease of NAA on 1H-MRS. After CEA in these patients, NAA was significantly increased, and in 7 of 8 patients whose pre-operative SPECT had indicated impairment of cerebral vasoreactivity, it was improved. Quantitative 1H-MRS and CBF measurements can indicate the severity of metabolic and hemodynamic impairment in patients with severe carotid stenosis, and can help to assess the effectiveness of CEA.