White matter integrity, fiber count, and other fallacies: The do's and don'ts of diffusion MRI

• DOI: 10.1016/j.neuroimage.2012.06.081
• Publication Date: 2012-07-23T20:32:22Z
• Authors: Derek K. Jones; Thomas R. Knösche; Robert Turner
• Keywords: 0301 basic medicine; Brain Mapping; Models, Statistical; Brain; Cell Count; Signal-To-Noise Ratio; 03 medical and health sciences; Diffusion Magnetic Resonance Imaging; Diffusion Tensor Imaging; Nerve Fibers; Data Interpretation, Statistical; Neural Pathways; Image Processing, Computer-Assisted; Humans

Diffusion-weighted MRI (DW-MRI) has been increasingly used in imaging neuroscience over the last decade. An early form of this technique, diffusion tensor imaging (DTI) was rapidly implemented by major MRI scanner companies as a scanner selling point. Due to the ease of use of such implementations, and the plausibility of some of their results, DTI was leapt on by imaging neuroscientists who saw it as a powerful and unique new tool for exploring the structural connectivity of human brain. However, DTI is a rather approximate technique, and its results have frequently been given implausible interpretations that have escaped proper critique and have appeared misleadingly in journals of high reputation. In order to encourage the use of improved DW-MRI methods, which have a better chance of characterizing the actual fiber structure of white matter, and to warn against the misuse and misinterpretation of DTI, we review the physics of DW-MRI, indicate currently preferred methodology, and explain the limits of interpretation of its results. We conclude with a list of 'Do's and Don'ts' which define good practice in this expanding area of imaging neuroscience.