الفهرس 
Overview of Imaging in Multiple SclerosisOnly 14 pages are availabe for public view
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Abstract
Enrolled in this study were 49 patients (21 females & 28 males). Patients were divided into two groups; RRMS (n= 33) & SPMS (n=16). All patients underwent thorough history taking, full clinical examination as well as conventional MR examination & MR spectroscopy. The purpose of this study was to shed light on the role of MRI in MS and studying the changes in different metabolites in different clinical forms of the disease. MRI can demonstrate macroscopic lesions associated with multiple sclerosis with high sensitivity, but lesions on standard T2WI lack specificity for underlying pathological process such as inflammation, demyelination, axonal loss or gliosis. Proton magnetic resonance spectroscopy (MRS) can complement MRI in the assessment of patients with MS by defining metabolic changes occurring within and outside T2 visible lesions (NAWM).When considering all lesions together, regardless of the clinical form, acute or chronic, there are significant reductions of NAA/Cr & NAA/Cho and a significant elevation of Ins/Cr as compared with control group(the findings are more pronounced in SPMS group than RRMS group. We did not find any significant difference between the metabolites ratios in acute lesions of both forms. However, in chronic lesions NAA/Cr & NAA/Cho were significantly lower in SPMS than in RRMS. Decreases in NAA are not restricted to T2 visible lesions but extend to NAWM. We found significant reductions of NAA/Cr & NAA/Cho as compared with control group in the NAWM of both forms (NAA/Cr was significantly reduced in SPMS than in RRMS). In this study, DAWM showed lower ratios than NAWM and higher ratios than plaques. It could represent a different injured tissue type in MS. Attention to this subtle tissue on imaging may provide additional information. The use of metabolic ratios has the disadvantage of always being reliant on two variables of unknown concentration. The concentration of the Cr is not definitely proved to be stable. We found a reduction of Cr in acute lesions (7/21), chronic lesions (7/69), and in NAWM (2/118). In 21/118 voxel of NAWM Cr was elevated. Thus, an absolute quantification is essential for an adequate description of metabolic changes in MS to avoid a false interpretation. Our study showed that even lesions with the same T1 hypointensity in patients with MS are not metabolically equivalent which do not represent a unique type of pathologic finding but rather varying stage, types, or activities. Although the data reported in the literature have shown a variety of results, it may be premature to arrive at a consensus regarding the ultimate role of MRS. This may be a result of the heterogeneous nature of the disease. However, if any case has a problem in its course, MRS is a very valuable tool to monitor the changes in the course of the disease. It could help in expectation of the prognosis particularly by studying the changes in the NAWM or even the gray matter of the patients.