Imaging the rapidly developing brain: Current challenges for MRI studies in the first five years of life

Abstract

Rapid and widespread changes in brain anatomy and physiology in the first five years of life present substantial challenges for developmental structural, functional, and diffusion MRI studies. One persistent challenge is that methods best suited to earlier developmental stages are suboptimal for later stages, which engenders a trade-off between using different, but age-appropriate, methods for different developmental stages or identical methods across stages. Both options have potential benefits, but also biases, as pipelines for each developmental stage can be matched on methods or the age-appropriateness of methods, but not both. This review describes the data acquisition, processing, and analysis challenges that introduce these potential biases and attempts to elucidate decisions and make recommendations that would optimize developmental comparisons.

Keywords: Brain; Child; Development; Infant; MRI; Neuroimaging.

Fig. 1

Sample structural MRI images depicting brain growth during (A) early and (B) later development. Each quandrant shows brain images from a child at two developmental stages as collected longitudinally. Please note the substantial anatomical changes during early development, especially in the first year of life, compared to later development.

Fig. 2

Factors that may introduce bias when scanning children at different developmental stages between birth and age five.

Fig. 3

Abbreviated hypothetical decision tree. For multiple stages of a developmental study, investigators must choose between age-appropriate methods (pink) or methods that are identical across developmental stages (blue), exponentially increasing the number of pipeline permutations. Please note that we have limited pipeline permutations here to four stages and binary options (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article).