We have evaluated the performance of magnetic resonance proton exchange (Kex) imaging in vivo in characterization of gray matter, white matter as well as MS lesions. With informed consent, 10 control and 8 MS diagnosed subjects underwent a brain MRI on a 3T clinical-scanner. Kex maps were generated by pixel-wise ﬁtting of the omega plot constructed from four different saturation power (B1=1, 2, 3 & 4 µT). Kex values from gray matter (GM), white matter (WM) and lesions were calculated, and two-tailed paired Student’s T-test was used to classify each group. Kex was able to demarcates each region. The combined use of Kex mapping has potential to improve the early and speciﬁc diagnosis of MS.