High Angular Resolution Diffusion Imaging (HARDI)

This article covers the young history of high angular resolution diffusion imaging (HARDI), from basic diffusion principles and diffusion tensor imaging (DTI) to q ‐space imaging, advanced modeling, and high‐order reconstruction techniques. HARDI has opened up new perspectives to noninvasively measure microstructural features and study white matter connectivity using HARDI‐based fiber tractography. HARDI is thus at the heart of modern neuroscience research and several clinical applications.