MYELINATION OF THE BRAIN IN MRI - A STAGING SYSTEM

In a retrospective study 516 cranial MRI examinations of children aged 1 month to 14 years were reevaluated for myelination. An objective st aging system for the assessment of the degree of myelination was desig ned, based on the characteristic patterns of myelin-typical signal whi ch develop in the course of brain maturation. Thus myelination can be estimated using only routine MRI examinations; no additional measureme nts of signal intensities are necessary. In order to obtain detailed i nformation, ten regions of the brain are ranked separately, with compa risons of the T1- and T2-weighted images for each region. The applicat ion of the staging system to the case material revealed typical age ra nges for the stages, and retarded myelination in some children. In mos t cases the observed retardation affected several regions but never th e whole brain. Such delays can only be detected by separate assessment of the degree of myelination in each region of the brain.