Abstracts

Rationale: Neurometabolic diseases such as creatine synthesis or transport disorders may present as epilepsy and require magnetic resonance spectroscopy (MRS) for diagnostic screening. Basal ganglia are sensitive loci to detect metabolic disorders. We sought to establish a pediatric normative database for single voxel basal ganglia MRS. Methods: A retrospective analysis was conducted of clinical and imaging data of children who received MRS at our institution. Each patient was rated by a neurologist blinded to imaging data, and neuroradiologist blinded to clinical data, for normal neurological status and structural imaging, respectively. Peak heights of N-acetyl aspartate (NAA), creatine (Cre), choline (Cho), were measured at 35 ms (short TE) and 288 ms (long TE) echo times via single voxel MRS. Short TE was 35 ms and long TE was adjusted to 288 ms for all studies. Peak height ratios of NAA/Cre and NAA/Cho were calculated. Results: 282 children had spectra acquired from the basal ganglia; 204 had both short and long TE data. Of these, 47(ages 4 mos to 21.2 y; mean 57 months) were classified as both normal on clinical and radiographic scales. Values derived are shown in the TABLE. Conclusions: NAA/Cre and Cho/Cre ratios were derived from a normal pediatric population studied with single voxel basal ganglia MRS. Ratios using long TE spectra were NAA/Cre 2.33±0.31 and Cho/Cre 1.39±0.20. This data may serve as a reference point for interpretation of MRS.