DT-MRI measurement of myolaminar structure: Accuracy and sensitivity to time post-fixation, b-value and number of directions

DT-MRI has been widely used to quantify myocardial fiber and laminar orientations. These structural orientations influence both the spread of excitation and the reorganization of the myocardium during contraction and are altered in disease states. Studies have sought to validate DT-MRI but questions remain about the accuracy of the method and its sensitivity to the time post-fixation and imaging parameters, including b-value, number of diffusion directions and image voxel size. The advent of high-spatial resolution ex vivo MRI and structure tensor (ST) analysis provides a means of direct validation of DT-MRI and assessment of sensitivity to the b-value, the number of diffusion directions and the image voxel size. We find that, with the fixation method we used, structure does not change with time (up to 72 hours). We show that DT-MRI and ST/HR-MRI are markedly similar measures of fiber orientation but DT-MRI and ST are much less similar measures of laminar orientation. DT-MRI performance is not sensitive to the number of directions, with similar structural orientations measured with 6 or 12 directions. Likewise, DT-MRI performance is generally insensitive to b-value, but laminar measurement is moderately more accurate at b = 500 than for higher b-values.

[1]  D L Buckley,et al.  Two‐component diffusion tensor MRI of isolated perfused hearts , 2001, Magnetic resonance in medicine.

[2]  Alan P Benson,et al.  Regional localisation of left ventricular sheet structure: integration with current models of cardiac fibre, sheet and band structure. , 2007, European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery.

[3]  Halina Dobrzynski,et al.  Visualization and quantification of whole rat heart laminar structure using high-spatial resolution contrast-enhanced MRI. , 2012, American journal of physiology. Heart and circulatory physiology.

[4]  J B Bassingthwaighte,et al.  Microvasculature of the dog left ventricular myocardium. , 1974, Microvascular research.

[5]  Bruce H Smaill,et al.  Laminar Arrangement of Ventricular Myocytes Influences Electrical Behavior of the Heart , 2007, Circulation research.

[6]  J. Zhang,et al.  Reconstruction of Cardiac Ventricular Geometry and Fiber Orientation Using Magnetic Resonance Imaging , 2000, Annals of Biomedical Engineering.

[7]  David Gavaghan,et al.  Progressive changes in T1, T2 and left‐ventricular histo‐architecture in the fixed and embedded rat heart , 2011, NMR in biomedicine.

[8]  Mirza Faisal Beg,et al.  Measuring and Mapping Cardiac Fiber and Laminar Architecture Using Diffusion Tensor MR Imaging , 2005, Annals of the New York Academy of Sciences.

[9]  Gregory B. Sands,et al.  A framework for myoarchitecture analysis of high resolution cardiac MRI and comparison with diffusion Tensor MRI , 2012, 2012 Annual International Conference of the IEEE Engineering in Medicine and Biology Society.

[10]  Arun V. Holden,et al.  Reconstruction and Quantification of Diffusion Tensor Imaging-Derived Cardiac Fibre and Sheet Structure in Ventricular Regions used in Studies of Excitation Propagation , 2008 .

[11]  Gregory B. Sands,et al.  Three-dimensional transmural organization of perimysial collagen in the heart , 2008, American journal of physiology. Heart and circulatory physiology.

[12]  N. Trayanova.  Whole-heart modeling: applications to cardiac electrophysiology and electromechanics. , 2011, Circulation research.

[13]  Susumu Mori,et al.  Effects of b-value and echo time on magnetic resonance diffusion tensor imaging-derived parameters at 1.5 t: A voxel-wise study , 2013 .

[14]  Andrew D McCulloch,et al.  Laminar fiber architecture and three-dimensional systolic mechanics in canine ventricular myocardium. , 1999, American journal of physiology. Heart and circulatory physiology.

[15]  C. Henriquez,et al.  Magnetic resonance myocardial fiber-orientation mapping with direct histological correlation. , 1998, American journal of physiology. Heart and circulatory physiology.

[16]  Stefan Skare,et al.  The presence of two local myocardial sheet populations confirmed by diffusion tensor MRI and histological validation , 2011, Journal of magnetic resonance imaging : JMRI.

[17]  David Benoist,et al.  Inhomogeneity in the response to mechanical stimulation: cardiac muscle function and gene expression. , 2008, Progress in biophysics and molecular biology.

[18]  D L Buckley,et al.  MR imaging measurement of compartmental water diffusion in perfused heart slices. , 2001, American journal of physiology. Heart and circulatory physiology.

[19]  Michael I. Miller,et al.  Image-Based Estimation of Ventricular Fiber Orientations for Personalized Modeling of Cardiac Electrophysiology , 2012, IEEE Transactions on Medical Imaging.

[20]  Bruce H. Smaill,et al.  Measurement of Myocardial Structure: 3D Structure Tensor Analysis of High Resolution MRI Quantitatively Compared to DT-MRI , 2012, STACOM.