Evidence of Rapid Ongoing Brain Development Beyond 2 Years of Age Detected by Fiber Tracking

• Published in: American journal of neuroradiology : AJNR Vol. 29; no. 7; pp. 1261 - 1265
• Main Authors: Ding, X.-Q, Sun, Y, Braass, H, Illies, T, Zeumer, H, Lanfermann, H, Fiehler, J
• Format: Journal Article
• Language: English
• Published: Oak Brook, IL Am Soc Neuroradiology 01-08-2008; American Society of Neuroradiology
• Subjects: Adolescent; Adult; Biological and medical sciences; Brain - growth & development; Child; Child, Preschool; Cohort Studies; Corpus Callosum - growth & development; Diffusion Magnetic Resonance Imaging - methods; Female; Human viral diseases; Humans; Image Enhancement - methods; Image Processing, Computer-Assisted - methods; Imaging, Three-Dimensional - methods; Infant; Infectious diseases; Investigative techniques, diagnostic techniques (general aspects); Male; Mathematical Computing; Medical sciences; Nerve Fibers, Myelinated - ultrastructure; Nervous system; Pediatrics; Radiodiagnosis. Nmr imagery. Nmr spectrometry; Reference Values; Software; Viral diseases; Viral diseases of the lymphoid tissue and the blood. Aids; Nervous system diseases; Tracking; Radiodiagnosis; Central nervous system; Encephalon
• ISSN: 0195-6108; 1936-959X
• DOI: 10.3174/ajnr.A1097

Development of callosal fibers is important for psychomotor and cognitive functions. We hypothesized that brain maturation changes are detectable beyond 2 years of age by using diffusion tensor imaging (DTI) of the corpus callosum (CC).
T2 and fractional anisotropy (FA) maps of the brain of 55 healthy subjects between 0.2 and 39 years of age were obtained. Quantitative T2 and FA values were measured at the genu and splenium of the CC (gCC and sCC). Fiber tracking, volumetric determination, and the fiber density calculations of the CC were related to age. A paired t test was used for significant differences between the values at the gCC and sCC.
T2 relaxation times at gCC and sCC decrease fast in the first months of life and very little after 2 years of age. The FAgCC increases until 5 years of age and remains nearly constant thereafter; it showed a significant increase from 0 to 2 years versus 2-5 years, whereas there was no difference in the other age groups. FAsCC values showed no significant changes after 2 years of age. The fiber density of the CC shows a tendency of inverse age dependence from childhood to adulthood.
Rapid ongoing changes in brain maturation (increase in FAgCC) are detectable until 5 years of age. DTI reveals more information about brain maturation than T2 relaxometry.