• Purpose: To prospectively determine hemodynamic changes in the NAWM of patients with RR-MS comparing with normal healthy individuals by using dynamic susceptibility contrast material-enhanced perfusion magnetic resonance imaging.

• Methods: This study was a single-center, comparative cross-sectional study, recruited 46 consecutive male patients between April 2024 to October 2024. cMR imaging and DCSE T2*-weighted MR imaging were performed in 23 male patients with relapsing remitting multiple sclerosis- and 23 healthy control cases. Absolute cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT) were determined in different regions of the brain including the periventricular white matter and NAWM at the level of the centrum semiovale, as well as the thalamus and caudate nuclei as NAGMr, mean levels are then used to compare perfusion measures between patients with RR-MS patients and control individuals.

• Results: We applied our study on 46 patients, was divided into two groups: Cases Group (n=23) and Control Group (n=23), mean age 31.87±6.13 with the same inclusion and exclusion criteria . The 23 cases was classified according the disease duration as we found that 73.9% of our patients were diagnosed as MS from > 5 years.

• Conclusion Comparison between CBV , CBF values in Patients Group and Control Group in different regions showing a highly statistically significant highest mean value of patients group compared to control group with p-value (p<0.001). while we found that there is no statistically significant difference between MTT measurements in patients' group and control group with p-value (p>0.05)