IN-VIVO VISUALIZATION OF MYELIN WATER IN BRAIN BY MAGNETIC-RESONANCE

We exploit the intrinsic difference in magnetic resonance spin-spin re laxation time, T-2, between water associated with myelin sheaths and w ater in other central nervous system tissue in order to measure myelin water content within any region of an image or to generate indirectly a myelin map of the brain. In normal volunteers, myelin water maps gi ve the expected myelin distribution. In multiple sclerosis patients, l esions exhibit different myelin water contents providing insight into the demyelination process unavailable from conventional magnetic reson ance images. In vivo myelin measurement has important applications in the clinical management of multiple sclerosis and other white matter d iseases.