Chronological Changes of the Signal Intensities of White Matter on the FLAIR Images of Infants

To assess the pattern of chronological change for the signal intensities of white matter on the FLAIR images of infants. FLAIR, T1- and T2-weighted images of 119 infants (newborn to 24 months age) were obtained by using a 1.5 T MRI machine. From these images, the signal intensities of 9 different white matter regions were compared to those of the adjacent gray matter and the signal intensities of each image were scored from 1 to 5. The FLAIR images show high signal intensity for the cerebellar peduncle and posterior limb of the internal capsule at birth, but changed to low signal intensities in 2 to 3 months. The low signal intensities of the occipital-, parietal-, and frontal deep white matter and subcortical white matter changed to high signal intensities in 2 months, and they returned to low signal intensities in 10, 11, 12 and 19 months, respectively. The signal intensity of the white matter of infants showed peculiar chronologic changes on the FLAIR images. This knowledge could be helpful for the differentiation of normal white matter development and the lesions that mimic white matter disease in infants