Clinical Significance of Diffusion-weighted Magnetic Resonance Imaging on Treatment Efficacy in MS Patients With Acute Attacks.

Introduction: Despite various imaging methods, the accurate diagnosis of numerous neurodegenerative diseases remains controversial. Using advanced imaging techniques, like diffusion-weighted imaging, can help the early detection of Multiple Sclerosis (MS) and evaluation of the treatment efficacy in these patients. Methods: In total, 24 MS patients with acute attack and 30 healthy subjects were considered in our study. Region of Interest (ROI) was defined for acute and chronic plaques and Normal-Appearing White Matter (NAWM) in the patients' group. In the normal group, ROI only was mapped in the white matter in the same regions of the patient. All MS patients were receiving Methylprednisolone for 3 to 5 days. The rate of clinical disability in these patients was also evaluated based on the Expanded Disability Status Scale (EDSS) index. Finally evaluate changes of ADC values of plaques and NAWM before and after treatment. Results: The Apparent Diffusion Coefficient (ADC) values of acute plaques, the ADC values of NAWM, the number of enhancement in T1w, and EDSS values suggested a significant difference after treatment compared to before treatment. However, the ADC values of chronic plaques revealed no significant difference after treatment. There was a significant positive correlation between the difference in EDSS values before and after treatment. Conclusion: The study results demonstrated that using diffusion technique and ADC values analysis is a proper non-invasive method for MS diagnosis and evaluating treatment efficacy in these patients. Highlights: The obtained results suggested that the mean ADC for acute plaques and normal white matter significantly decreased after methylprednisolone treatment.Our study indicated a strong correlation between variations in EDSS, the mean ADC for acute plaques, and normal white matter.The collected results indicated that the number of enhanced plaques decreased after treatment. Besides, there was a positive correlation between its variations and EDSS. Plain Language Summary: Multiple Sclerosis (MS) is a common inflammatory disorder of the central nervous system that could result in physical and mental disabilities in patients. Disease progression usually manifests as a series of attacks. Although there is no proven cure for MS, different treatment strategies aim to modify the cause of the disease, manage its symptoms, and prevent and postpone disability. The most common therapy in acute attacks is using corticosteroid drugs. In addition to the treatment, evaluating the success rate of treatment was also challenging. Historically, clinical assessments method (e.g. EDSS) have been used as the baseline for measuring the therapy's efficiency. Several supplementary methods, including imaging techniques, are introduced to address this issue. Conventional MRI imaging with injection has been widely accepted to assess the treatment. However, because of the modest sensitivity of conventional MRI to detect subtle pathological changes, there is a poor correlation between its findings and patients' disability. This study moved from conventional MRI to advanced techniques, such as DWI and its quantitative index named ADC value. This technique can provide information about microstructural changes in MS patients. This method does not require injection, so there are no probable adverse effects and lower scan time. This study emphasizes changes in ADC value and EDSS before and after treatment with methylprednisolone. Our results suggested s that ADC values and EDSS after treatment are significantly different from their typical values. ADC values can be used as a biomarker to evaluate treatment efficiency, yet it is not objective enough to use it alone. So, the combination of DWI imaging with conventional methods might be beneficial in assessing treatment efficiency in MS patients.