Hui Zhang1, Torben Schneider2, Claudia AM Wheeler-Kingshott2, Daniel C. Alexander1
1Department of Computer Science & Centre for Medical Image Computing, University College London, London, United Kingdom; 2NMR Research Unit, Department of Neuroinflammation, UCL Institute of Neurology, University College London, London, United Kingdom
This work proposes neurite orientation dispersion and density imaging (NODDI), a practical diffusion MRI technique for quantifying microstructural complexity of dendrites and axons on clinical scanners. Orientation dispersion and density are two key microstructural features of neurites. ex vivo studies have shown that estimates of these features from diffusion MRI are consistent with independent histological measures. However, existing protocols are impractical for clinical applications. We address this problem by developing NODDI, a novel neurite imaging and analysis framework with clinical feasibility. We demonstrate that NODDI enables for the first time the whole-brain in vivo imaging of neurite characteristics.