Comparison of accelerated 3-D spiral chemical shift imaging and single-voxel spectroscopy at 3T in the pediatric age group

Pediatr Radiol. 2015 Aug;45(9):1417-22. doi: 10.1007/s00247-015-3311-2. Epub 2015 Apr 1.

Abstract

Single-voxel spectroscopy (SVS) is usually used in the pediatric population when a short acquisition time is crucial. To overcome the long acquisition time of 3-D phase-encoded chemical shift imaging (CSI) and lack of spatial coverage of single-voxel spectroscopy, efficient encoding schemes using spiral k-space trajectories have been successfully deployed, enabling acquisition of volumetric CSI in <5 min. We assessed feasibility of using 3-D spiral CSI sequence routinely in pediatric clinical settings by comparing its reconstructed spectra against SVS spectra. Volumetric spiral CSI obtained spectra from 2-cc isotropic voxels over a 16×16×10-cm region. SVS acquisition encoded a 3.4-cc (1.5-mm) isotropic voxel. Acquisition time was 3 min for every technique. Data were gathered prospectively from 11 random pediatric patients. Spectra from left basal ganglia were obtained using both techniques and were processed with post-processing software. The following metabolite ratios were calculated: N-acetylaspartate/creatine (NAA/Cr), choline/creatine (Cho/Cr), lactate/creatine (Lac/Cr) and N-acetylapartate/choline (NAA/Cho). We collected data on 11 children ages 4 days to 10 years. In 10/11 cases, spectral quality of both methods was acceptable. Considering 10/11 cases, we found a statistically significant difference between SVS and 3-D spiral CSI for all three ratios. However, this difference was fixed and was probably caused by a fixed bias. This means that 3-D spiral CSI can be used instead of SVS by removing the mean difference between the methods for each ratio. Accelerated 3-D CSI is feasible in pediatric patients and can potentially substitute for SVS.

Publication types

  • Comparative Study
  • Evaluation Study

MeSH terms

  • Biomarkers / metabolism
  • Brain / anatomy & histology
  • Brain / metabolism*
  • Child
  • Child, Preschool
  • Female
  • Humans
  • Image Interpretation, Computer-Assisted / methods*
  • Imaging, Three-Dimensional / methods*
  • Infant
  • Infant, Newborn
  • Magnetic Resonance Imaging / methods*
  • Magnetic Resonance Spectroscopy / methods*
  • Male
  • Molecular Imaging / methods*
  • Reproducibility of Results
  • Sensitivity and Specificity

Substances

  • Biomarkers