title: Principles and implementation of diffusion-weighted and diffusion tensor imaging.
abstract: We review the physiological basis of diffusion-weighted imaging and discuss the implementation of diffusion-weighted imaging pulse sequences and the subsequent postprocessing to yield quantitative estimations of diffusion parameters. We also introduce the concept of directionality of "apparent" diffusion in vivo and the means of assessing such anisotropy quantitatively. This in turn leads to the methodological application of diffusion tensor imaging and the subsequent postprocessing, known as tractography. The following articles deal with the clinical applications enabled by such methodologies.
authors.affiliation: Department of Radiology, The Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine, 324 S. 34th St. and Civic Center Blvd, Philadelphia, PA 19104, USA. robertstim@email.chop.edu
authors.forename: Timothy P L
authors.initials: TP
authors.lastname: Roberts
authors.forename: Erin Simon
authors.initials: ES
authors.lastname: Schwartz
mesh_terms: D016880:Anisotropy; D001921:Brain / Q000473:pathology*; D001931:Brain Mapping / Q000379:methods*; D038524:Diffusion Magnetic Resonance Imaging; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D009413:Nerve Fibers, Myelinated / Q000473:pathology; D009434:Neural Pathways / Q000473:pathology