MR ASSESSMENT OF NORMAL BRAIN-DEVELOPMENT IN NEONATES AND INFANTS - COMPARATIVE-STUDY OF T1-WEIGHTED AND DIFFUSION-WEIGHTED IMAGES

Purpose: This study was designed to compare the sensitivity of T1- and diffusion-weighted images for the assessment of brain maturation in h uman brains. Methods: T1- and diffusion-weighted images were obtained in 32 children without neurological abnormalities or growth retardatio n. The ages at which signal intensity changes of white matter on T1-we ighted images and diffusional anisotropy appeared were compared. Resul ts: In the optic radiation, diffusional anisotropy was observed in neo nates <1 month old, whereas signal intensity became high after 1 month old. In the frontal lobe, diffusional anisotropy began to appear afte r 1 month of age, but signal intensity became high after 6 months of a ge. These visual findings were confirmed statistically by quantitative analysis using signal intensity ratios and anisotropic ratios. Simila r findings were observed in the external capsule and the genu of the c orpus callosum. Conclusion: In conclusion, diffusional anisotropy is a sensitive indicator of brain maturation in neonates and infants and p recedes signal intensity change on T1-weighted images.