MR assessment of normal brain development in neonates and infants: comparative study of T1- 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 human brains.

METHODS

T1- and diffusion-weighted images were obtained in 32 children without neurological abnormalities or growth retardation. The ages at which signal intensity changes of white matter on T1-weighted images and diffusional anisotropy appeared were compared.

RESULTS

In the optic radiation, diffusional anisotropy was observed in neonates < 1 month old, whereas signal intensity became high after 1 month old. In the frontal lobe, diffusional anisotropy began to appear after 1 month of age, but signal intensity became high after 6 months of age. These visual findings were confirmed statistically by quantitative analysis using signal intensity ratios and anisotropic ratios. Similar findings were observed in the external capsule and the genu of the corpus callosum.

CONCLUSION

In conclusion, diffusional anisotropy is a sensitive indicator of brain maturation in neonates and infants and precedes signal intensity change on T1-weighted images.