Background and purpose: The human allocortex is different from the isocortex in neuroglial cytoarchitecture. The purpose of this study was to compare metabolic data of the allocortex with those of the isocortex by using localized proton MR spectroscopy.
Methods: Short-TE stimulated-echo acquisition mode proton MR spectroscopy (TR/TE = 3000/30) was applied to the allocortex of the temporal lobe and isocortex of the parietal or frontal lobe in 30 healthy children (19 boys and 11 girls, 3-14 years old). Peak intensities of N-acetylaspartate (NAA), choline-containing compounds (Cho), and myo-inositol (mI) relative to creatine and phosphocreatine (Cr) were calculated. Metabolic data from the investigated regions were compared.
Results: NAA/Cr was significantly lower in the allocortex than in the isocortex of the parietal or frontal lobe: 1.05 +/- 0.12 (n = 33) vs. 1.36 +/- 0.10 (n = 28) or 1.32 +/- 0.10 (n = 12), respectively. Cho/Cr and mI/Cr were significantly higher in the allocortex than in the isocortex: 0.84 +/- 0.11 vs. 0.56 +/- 0.06 or 0.75 +/- 0.10; 0.78 +/- 0.15 vs. 0.54 +/- 0.08 or 0.66 +/- 0.09, respectively. In the isocortex, NAA/Cr was not different but Cho/Cr and mI/Cr were significantly higher in the frontal cortex than in the parietal cortex.
Conclusion: Clear metabolic differences were observed between the allocortex and isocortex.