MRI/DTI scan will be performed at CIRC, NUS. Prior to the scan, all patients will be briefed of the test procedure and safety aspects. A medically-trained physician will be on standby throughout the procedure. All participants will be scanned on a 3-T GE scanner using a standard radiofrequency head coil. Head motion was minimized by foam padding and forehead-restraining straps. A T1-weighted high-resolution scan and a set of axial fluid attenuated inversion recovery images will be acquired. T1-weighted and fluid attenuated inversion recovery images will be realigned and spatially normalized into images of isotropic voxel size implemented in Matlab. Each session will last approximate 1 hour including set-up time.