Proton magnetic resonance spectroscopy in children with Moyamoya disease

Proton magnetic resonance spectroscopy (MRS) is an effective method to noninvasively investigate cerebral metabolism. The aim of this study was to evaluate cerebral metabolic changes in children with Moyamoya disease using proton MRS. A total of 11 patients under 15 years old were enrolled, whose main symptoms were transient ischemic attacks. In nine patients, the more and less affected hemispheres could be determined according to their symptoms and/or single-photon emission computed tomography (SPECT). A single voxel point resolved spectroscopy was performed in the frontal or parietal white matter bilaterally by using 1.5 Tesla MR system (repetition time 2000 ms and echo time 272 ms). Voxels were located within areas that were normal on T1- and T2-weighted MR imaging. Choline (Cho), creatine (Cre) and N-acetyl aspartate (NAA) were semiquantitated as a metabolite value using an external standard reference. Pre-operative Cho, Cre and NAA values were within respective normal ranges. No metabolite showed a significant difference between the more and less affected hemispheres. A total of six patients were examined before and after revascularization surgery on one side. Pre- and post-operative comparisons demonstrated that all three metabolites showed statistically significant increases following surgery. These results suggest that, although the mechanism of spectroscopic changes needs to be further investigated, proton MRS provides a valuable method to evaluate cerebral metabolism in children with Moyamoya disease.