Irvin Teh1, Henrik Lundell2, Hannah J Whittington1, Tim Bjørn Dyrby2, and Jürgen E Schneider1
1Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom, 2Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital Hvidovre, Copenhagen, Denmark
Diffusion tensor imaging
(DTI) is widely used for structural characterization of the heart. However, the
measured fractional anisotropy (FA) is influenced by diffusion anisotropy as
well as orientation dispersion. In the heart, orientation dispersion is
ubiquitous and stems from the transmural variation in cardiomyocyte orientation
and regions where multiple cell populations intersect. We propose microscopic
FA (µFA) as a more robust measure of intrinsic diffusion anisotropy that is
insensitive to orientation dispersion, and demonstrate this with simulations
and ex vivo MRI.
