Susceptibility induced gray-white matter MRI contrast in the human brain

▶ Myelin is responsible for MRI phase contrast between cortical gray and white matter. ▶ Iron concentration is lower in the frontal cortex than in frontal white matter. ▶ Iron concentration is higher in the occipital cortex than in occipital white matter. ▶ Myelin content and iron are negatively correlated within white matter regions.