Magnetic resonance spectroscopy in multiple sclerosis diagnosis

PURPOSE :Relapsing remitting MS (RRMS) is the most common type of MS seen in demyelinating disease. We aimed to evaluate the MR spectroscopic changes of acute and chronic plaques and normal appearing white matter in RRMS patients.MATERIALS AND METHOD:49 RRMS cases and 20 control subjects were included in the study. The RRMS was diagnosed by clinical features, neurologic examination, CSF findings, electrophysiologic tests and MRI findings. Axial T1-weighted, T2-weighted, FLAIR, sagittal T2-weighted and post-contrast axial, sagittal, coronal T1-weighted images were obtained. MRS examinations were obtained with short and long TE (TE:35 and 135 msec). Statistical evaluations were performed by Kruskal Wallias and Mann-Whitney U test.RESULTS:MRS with TE 135 showed significantly decreased NAA/Cho, NAA/Cr ratios and NAA, Cho, Cr levels and significantly increased Cho/Cr ratio in comprasion with the control group. MRS of the acute plaques group showed significantly increased Cho/Cr ratio, and significantly decreased NAA/Cho, NAA/Cr ratios. MRS of chronic plaques demonstrated significantly decreased NAA, Cho, Cr levels and NAA/Cho, NAA/Cr ratios and significantly increased Cho/Cr ratio.Low signal intensity lesions on T1-weighted images showed significantly decreased NAA, Cho, Cr levels and NAA/Cho, NAA/Cr ratios on MRS with TE 135 msec. mI/Cr ratio of these lesions was significantly higher on MRS with TE 35 msec compared to control group. Isointens lesions showed significantly decreased NAA, Cho, Cr levels and NAA/Cho, NAA/Cr ratios whereas Cho/Cr ratio is significantly increased.CONCLUSION:MRS is found to be helpful in determination of lesion age and specifications. MRS is found to be contributary to MRI in diagnosis and follow-up of MS patients. MRS elucidate the locations where new lesions may develop, earlier than the MRI .