Proton MR Spectroscopy in leukodystrophies

Abstract

Objective: To analyze MR Spectroscopic findings and metabolite ratios in regions of abnormal signal in children with leukodystrophies. Methods: This prospective study was carried out on twenty-six children (17 males and 9 females); median age, 36 months ± 54 inter-quartile range. The imaging protocol included axial T1 and T2-weighted spin-echo and FLAIR images, and coronal and sagittal T2-weighted spin-echo images. 1H-MRSI was performed during the same session for all patients. Spectra were acquired from a volume of interest in the affected white matter and intravoxel (NAA/Cr, Cho/Cr, and Cho/NAA) ratios were calculated. Results: Spectroscopic analysis revealed abnormal (NAA/Cr, Cho/Cr, and Cho/NAA) ratios. Some were highly characteristic and specific as markedly elevated NAA resonance peak in cases with Canavan’s disease and significantly elevated lactate resonance peak in Leigh disease and MELAS syndrome. In the majority of cases, elevated Cho/Cr, decreased NAA/Cr and elevated Cho/NAA ratios were the dominant finding. One-way analysis of variance for the spectroscopic metabolite ratios revealed statistical significance (p < 0.0001). Conclusion: Proton MR Spectroscopy complementary to conventional MRI proved to be a valuable tool to establish the diagnosis of leukodystrophies.

Keywords

• Spectroscopy
• Leukodystrophies
• MRI