Studying neuroanatomy using MRI

The study of neuroanatomy using imaging enables key insights into how our brains function, are shaped by genes and environment, and change with development, aging, and disease. Developments in MRI acquisition, image processing, and data modelling have been key to these advances. However, MRI provides an indirect measurement of the biological signals we aim to investigate. Thus, artifacts and key questions of correct interpretation can confound the readouts provided by anatomical MRI. In this review we provide an overview of the methods for measuring macro- and mesoscopic structure and inferring microstructural properties; we also describe key artefacts and confounds that can lead to incorrect conclusions. Ultimately, we believe that, though methods need to improve and caution is required in its interpretation, structural MRI continues to have great promise in furthering our understanding of how the brain works

Steady-state MRI: Methods for neuroimaging

MRI pulse sequences that use regularly spaced trains of rapidly applied excitation pulses (every few milliseconds) are known as 'steady-state' sequences. Under these conditions, the magnetization evolves into a steady state that depends on tissue parameters such as T1, T2 and diffusion, as well as sequence parameters such as repetition time and flip angle. These sequences have attractive properties including high efficiency (in terms of signal-to-noise ratio) and flexible image contrast; they also create unique challenges due to the need to maintain the magnetization in the steady state and their complicated signal dependence. This article describes the primary types of steady-state sequences and their application to brain imaging. © 2011 Future Medicine Ltd