ABSTRACT
The most widely used brain imaging modalities are magnetic resonance images (MRI), functional-MRI (fMRI) and diffusion tensor images (DTI). MRI depends on the response of magnetic fields in generating digital images that provide structural information about brain noninvasively. Compared to the computed tomography (CT), MRI has been mainly used for in vivo imaging of the brain due to higher image contrast in soft tissues. Unlike CT, MRI does not use X-ray for imaging so there is no risk of radiation exposure. MRI produces images based on the spin-lattice relaxation time (T1), the spin-spin relaxation time (T2) and the proton density (ρ) [39]. The widely used T1and T2-weighted imaging weight the contribution of one component and minimize the effect of the other two. The T1-weighted MRI is more often used in anatomical studies compared to the T2-weighted MRI. Structural images you are seeing are most likely T1-weighted MRI.
