Abstract 167

We have recently introduced Diffusion Tensor Images as a supplement to our MRI evaluation of the newborn infant. We have been able to identify a number of structures in the central white matter even in very young preterm infants. We performed nine examinations on seven mature and premature infants, chronological age was 5 to 159 days, gestational ages from 26.7 weeks to term, and in 5 healthy adult volunteers. Examinations were performed in a 1.5Tesla Siemens Vision scanner, using an echoplanar diffusion weighted sequence. Color-coded images according the diffusion tensor directions were calculated, ROIs (Regions of interest) were drawn and ADC (apparent diffusion coefficient) and FA (Fractional Anisotropy Index) calculated. In all children studied, we identified the posterior limb of the capsula interna, corpus callosum splenum and the optic radiation. The anterior limb of capsula interna, corpus callosum genu and capsula externa were also visible in nearly all children. In general, the appearance of the diffusion tensor images in children is very similar to the adults with regard to the central white matter tracts, while the subcortical white matter is practically not apparent in children, compared with the complex image we obtain from adults. As expected, the ADC is higher in children than in adults. FA is similar in children and adults. Diffusion tensor images give clear visual identification of a number of white matter structures, which in our children are only partially myelinated or unmyelinated. In conclusion, this is a new tool which potentially can identify white matter tract lesions, even in very young children.