Children, especially within the first few years of development, experience rapid and considerable changes of the macro- and microstructure of the brain. These changes include rapid growth of the brain tissue, myelination patterns and white matter connectivity alterations, and cerebral blood flow changes. Although age-related alterations of the corresponding imaging biomarkers are well-described for elderly populations, no comprehensive age-related normal data are available for healthy children across the whole age spectrum. However, such normal data are clinically needed to better identify disease-related differences, especially in the context of rapid development during early childhood. With this study, we sought to determine comprehensive reference values for age-dependent changes of these parameters in healthy children across the whole spectrum of childhood.
Briefly, using an atlas-based automatic analysis approach of arterial spin-labeling (ASL) and diffusion-weighted MR imaging (DWI) of 100 healthy children, age-related normal values for regional CBF, apparent diffusion coefficient (ADC), and volume were determined for the cerebral cortex, hippocampus, thalamus, caudate nucleus, putamen, globus pallidus, amygdala, and nucleus accumbens. All gray matter structures grew rapidly before the age of 10 years and then plateaued or slightly declined thereafter. The ADC of all structures decreased with age, with the most rapid changes occurring prior to the age of 5. With the exception of the globus pallidus, CBF increased rather linearly with age.
We hope that this normal data will help us to diagnose pathologic image-based changes at an early time point, which might help to improve understanding of diseases and advance personalized medicine. Within this context, we have already successfully used this normal data to investigate the long-term effects of chemotherapy and radiotherapy on brain development in children with brain tumors.1
Currently, we are working on projects related to epilepsy, headaches, and migraines, as well as Moyamoya disease. The possibilities of using these normal data to investigate effects of other diseases on brain development are myriad, especially because ASL and DWI sequences are well-established and widely available in clinical practice, and they also provide quantitative measurements.