Intravoxel Fibre Structure of the Left Ventricular Free Wall and Posterior Left-Right Ventricular Insertion Site in Canine Myocardium Using Q-Ball Imaging

Q-ball imaging (QBI) is an established high-angular resolution diffusion MRI technique enabling to resolve intravoxel fibre structure. Here, we present a detailed study of myocardial fibre orientation using QBI. We compare standard diffusion tensor MRI (DTI) versus QBI in the canine left ventricular free wall (LVFW) and posterior left-right ventricular insertion site. Most voxels within the LVFW show high fractional anisotropy (FA), Gaussian diffusion profiles, and a single population of aligned fibres. In these, the difference between fibre helix angles estimated by DTI and QBI is below 5 degrees. However, we show that reduced FA near the anterior papillary muscle in the LVFW and in most of the left-right ventricular fusion site correlates with non-Gaussian diffusion. The QBI orientation distribution functions (ODF) in these regions reveal complex intravoxel fibrous structure, which cannot be inferred using DTI. Extensive ODF maps of myocardial fibre orientation are presented and discussed for the first time to our knowledge.

[1]  José Jalife,et al.  Minimal principle for rotor filaments , 2002, Proceedings of the National Academy of Sciences of the United States of America.

[2]  Pratik Mukherjee,et al.  Development and initial evaluation of 7-T q-ball imaging of the human brain. , 2008, Magnetic resonance imaging.

[3]  Robert H. Anderson,et al.  The three‐dimensional arrangement of the myocytes in the ventricular walls , 2009, Clinical anatomy.

[4]  H. Verschelde,et al.  A geometric theory for scroll wave filaments in anisotropic excitable media , 2009 .

[5]  P. Basser,et al.  MR diffusion tensor spectroscopy and imaging. , 1994, Biophysical journal.

[6]  V. Wedeen,et al.  Reduction of eddy‐current‐induced distortion in diffusion MRI using a twice‐refocused spin echo , 2003, Magnetic resonance in medicine.

[7]  L. Frank.  Anisotropy in high angular resolution diffusion‐weighted MRI , 2001, Magnetic resonance in medicine.

[8]  Covariant stringlike dynamics of scroll wave filaments in anisotropic cardiac tissue. , 2007, Physical review letters.

[9]  F. Fenton,et al.  Vortex dynamics in three-dimensional continuous myocardium with fiber rotation: Filament instability and fibrillation. , 1998, Chaos.

[10]  D. Tuch.  Q‐ball imaging , 2004, Magnetic resonance in medicine.

[11]  A Garfinkel,et al.  Role of papillary muscle in the generation and maintenance of reentry during ventricular tachycardia and fibrillation in isolated swine right ventricle. , 1999, Circulation.

[12]  J. E. Tanner,et al.  Spin diffusion measurements : spin echoes in the presence of a time-dependent field gradient , 1965 .

[13]  Sheng-Kwei Song,et al.  Regional ventricular wall thickening reflects changes in cardiac fiber and sheet structure during contraction: quantification with diffusion tensor MRI. , 2005, American journal of physiology. Heart and circulatory physiology.

[14]  L. Clerc.  Directional differences of impulse spread in trabecular muscle from mammalian heart. , 1976, The Journal of physiology.

[15]  P. Basser,et al.  Microstructural and physiological features of tissues elucidated by quantitative-diffusion-tensor MRI. 1996. , 1996, Journal of magnetic resonance.

[16]  T. Arts,et al.  Characterization of the normal cardiac myofiber field in goat measured with MR-diffusion tensor imaging. , 2002, American journal of physiology. Heart and circulatory physiology.

[17]  Chun-Hung Yeh,et al.  Resolving crossing fibres using constrained spherical deconvolution: Validation using diffusion-weighted imaging phantom data , 2008, NeuroImage.