Age-related T2 relaxation times at 3 Tesla as a biomarker of infratentorial brain maturation.

Abstract

The purpose of this study was to examine age-related, infratentorial changes in T2 relaxation times during infancy and childhood using routine MRI data at 3 Tesla. One hundred patients (0-199months) without signal abnormalities on conventional MRI were retrospectively selected from our pool of pediatric MRI examinations. T2 maps based on our routinely acquired triple-echo turbo spin-echo (TSE) sequence were created. Based on their clinical symptoms, the children were divided into 43 controls and 57 diseased children with different clinical diseases. T2 relaxation times were measured in 15 infratentorial brain regions (medullary pyramid, ventral and dorsal pons, middle cerebellar peduncle, dentate nucleus, medial and lateral cerebellar hemisphere each on both sides, and in the cerebellar vermis) investigating age-related changes. Secondly, this study examined whether those changes in T2 values differed between healthy and diseased children. Age significantly reduced T2 relaxation time in all infratentorial brain regions (p<0.05). With increasing age, the T2 relaxation times decreased continuously, faster in the first 9months and slower thereafter. Overall, controls did not differ significantly from diseased children (p>0.05) apart from the dentate nucleus and cerebellar hemispheres in terms of rapid decline (larger in controls) and the right dorsal pons and left pyramid in terms of slow decline (larger in diseased children). In both groups, the later slow decline was almost negligible. Using T2 maps, it was possible to determine age-related T2 relaxation times in the different infratentorial brain regions in this preliminary study. Between neurologically healthy controls and diseased children, no significant differences in T2 relaxation times could be found overall in the studied regions.