2 Introduction to Diffusion Tractography

Intro to Tractography — lecture covering the basics of diffusion MRI and how we reconstruct white-matter pathways. (Note: the first ~20 minutes didnt record audio and were cut).

What’s covered:

Diffusion tensor imaging (DTI): tensors, mean diffusivity (MD) vs apparent diffusion coefficient (ADC), fractional anisotropy (FA), and axial/radial diffusivity
Why MD and FA are sensitive but not specific — examples from oedema, maturation, and degeneration
Noise, resolution, and uncertainty in diffusion data; introduction to probabilistic tractography
Crossing fibres and the need for spherical deconvolution
Multishell acquisitions, diffusion kurtosis imaging, and microstructural models (e.g., NODDI, “standard model”)
Fibre orientation distributions (FOD), hindrance-modulated orientational anisotropy (HMOA), and other advanced metrics
Clinical and research applications: subject-specific anatomy, neurosurgical planning, and links to TMS and cortical excitability
Brief outlook on next-generation head-only high-gradient scanners

Chapters:
00:00 DTI fundamentals
00:08 MD vs ADC, FA explained
00:25 Noise & uncertainty; probabilistic tracking
00:35 Crossing fibres & spherical deconvolution
00:50 Multishell/kurtosis/microstructure models
01:05 Clinical applications & next-gen scanners

Keywords: diffusion MRI, DTI, tractography, FA, MD, ADC, kurtosis, multishell, spherical deconvolution, NODDI, FOD, neurosurgery, TMS, connectome.