Academia Sinica Logo

Less is known about the structure-function relationship in the human brain than in any other organ system. The challenge of studying brain structure is that brain networks span multiple spatial scales, from individual neurons all the way to whole-brain systems. Diffusion magnetic resonance imaging (MRI) holds great promise among noninvasive imaging methods for probing cellular structure of any depth and location in the living human brain. Robust methods for in vivo mapping of tissue microstructure by diffusion MRI remain elusive due to the demand for fast and strong diffusion-encoding gradients. I will present an overview of our group’s latest efforts to advance MRI hardware, biophysical modeling, and validation of microstructural metrics derived from diffusion MRI to probe the structure of the human brain across multiple scales. These efforts include the development of the next-generation Connectome MRI scanner, the first ultra-high gradient strength human MRI scanner for mesoscopic imaging of human brain microstructure and connections. I will review current progress and applications of ultra-high gradient diffusion MRI to probe gray and white matter microstructure in studies of learning and plasticity, the normal and aging human brain, and uncovering the substrate of neurological disability in multiple sclerosis.