title: Determining mean fractional anisotropy using DDCOSY: preliminary results in biological tissues.
abstract: Complex materials are ubiquitous in science, engineering and nature. One important parameter for characterising their morphology is the degree of anisotropy. Magnetic resonance imaging offers non-invasive methods for quantitative measurements of the materials anisotropy, most commonly via diffusion tensor imaging and the subsequent extraction of the spatially resolved fractional anisotropy (FA) value. Here, we propose an alternative way of determining the FA as a sample average for cases where spatially resolved methods are not needed or not applicable. It is based on a particular diffusion-diffusion correlation spectroscopy protocol, allowing for the extraction of the mean (i.e. sample averaged) FA value. We demonstrate that mean FA values obtained from three anisotropic biological tissues are consistent with those extracted using diffusion tensor imaging. Moreover, we show that differences of mean FA values in healthy and tumour-bearing mouse brains allow to distinguish these tissue types. We anticipate that the proposed method will be beneficial in the wider context of medical and material science. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington, New Zealand.
authors.forename: Fangrong
authors.initials: F
authors.lastname: Zong
authors.affiliation: Malaghan Institute of Medical Research, Wellington, New Zealand.|Maurice Wilkins Centre, Auckland, New Zealand.
authors.forename: Lindsay R
authors.initials: LR
authors.lastname: Ancelet
authors.affiliation: Malaghan Institute of Medical Research, Wellington, New Zealand.|Maurice Wilkins Centre, Auckland, New Zealand.|School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand.
authors.forename: Ian F
authors.initials: IF
authors.lastname: Hermans
authors.affiliation: MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington, New Zealand.
authors.forename: Petrik
authors.initials: P
authors.lastname: Galvosas
mesh_terms: D000818:Animals; D016880:Anisotropy; D001921:Brain / Q000000981:diagnostic imaging; D001932:Brain Neoplasms / Q000000981:diagnostic imaging; D045744:Cell Line, Tumor; D003198:Computer Simulation; D018552:Daucus carota; D004058:Diffusion; D056324:Diffusion Tensor Imaging; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D051379:Mice
keywords: 1H NMR; diffusion tensor imaging; diffusion-diffusion correlation spectroscopy; fractional anisotropy