Choukri
Mekkaoui1, Sonia Nielles-Vallespin2, Marcel Parolin
Jackowski3, Timothy G. Reese4, Peter David Gatehouse2,
David N. Firmin5, David E. Sosnovik4
1Harvard
Medical School - Massachusetts General Hospital - Athinoula A Martinos center
for Biomedical, Boston, MA, United States; 2CMR Unit, Royal
Brompton Hospital, London, United Kingdom; 3University of So
Paulo, So Paulo, Brazil; 4Harvard Medical School - Massachusetts
General Hospital - Athinoula A Martinos center for Biomedical, Charlestown,
MA, United States; 5CMR Unit, Royal Brompton Hospital, London,
United States
In vivo Diffusion Tensor MRI (DTI) of the human heart
has shown that myofiber architecture is dynamic. However, most
architecture-related indices derived from the diffusion tensor have relied
solely upon information from the principal eigenvector. Here we introduce the
fiber architecture matrix (FAM), which encodes myofiber architecture by the
angles of the projections of all three diffusion tensor eigenvectors onto the
orthogonal planes of the cardiac coordinate system. Angular variations across
the LV wall are seen for all FAM coefficients while the greatest changes
between systole and diastole are seen in the elements of the matrix
describing sheet architecture.
Keywords