BACKGROUND: Knowledge of the three-dimensional (3D) @entity1188 and fiber orientation remodeling is essential for complete understanding of @entity1188 pathophysiology and post- @entity1188 electromechanical functioning of the heart. Accurate imaging of @entity1188 microstructure necessitates imaging techniques that produce high image spatial resolution and high signal-to-noise ratio (SNR). The aim of this study is to provide detailed reconstruction of 3D chronic @entity1188 in order to characterize the @entity1188 microstructural remodeling in porcine and @entity1 hearts. METHODS: We employed a customized diffusion  tensor imaging (DTI) technique in conjunction with late @entity2287 enhancement (LGE) cardiovascular magnetic resonance (CMR) on a 3T clinical scanner to image, at submillimeter resolution, myofiber orientation and scar structure in eight chronically @entity1188 porcine hearts ex vivo. Systematic quantification of local microstructure was performed and the chronic @entity1188 remodeling was characterized at different levels of wall thickness and scar transmurality. Further, a @entity1 heart with @entity583 was imaged using the same DTI sequence. RESULTS: The SNR of non-diffusion-weighted images was >100 in the @entity1188 and control hearts. Mean diffusivity and fractional anisotropy (FA) demonstrated a 43% increase, and a 35% decrease respectively, inside the scar tissue. Despite this, the majority of the scar showed anisotropic structure with FA higher than an isotropic liquid. The analysis revealed that the primary eigenvector orientation at the @entity1188 wall on average followed the pattern of original fiber orientation (imbrication angle mean: 1.96        11.03   vs. 0.84        1.47  , p   =   0.61, and inclination angle range: 111.0        10.7   vs. 112.5        6.8  , p   =   0.61, @entity1188 /control wall), but at a higher transmural gradient of inclination angle that increased with scar transmurality (r   =   0.36) and the inverse of wall thickness (r   =   0.59). Further, the @entity1188 wall exhibited a significant increase in both the proportion of left-handed epicardial eigenvectors, and in the angle incoherency. The @entity1188 @entity1 heart demonstrated preservation of primary eigenvector orientation at the thinned region of @entity1188 , consistent with the findings in the porcine hearts. CONCLUSIONS: The application of high-resolution DTI and LGE-CMR revealed the detailed organization of anisotropic @entity1188 at a chronic state. This information enhances our understanding of chronic post- @entity1188 remodeling in large animal and @entity1 hearts.

Submillimeter diffusion tensor imaging and late @entity2287 enhancement cardiovascular magnetic resonance of chronic XXXX .

@entity1 :: ('9606', 'Species') :: ['human'] @entity583 :: ('MESH:D009203', 'Disease') :: ['myocardial infarction'] @entity2287 :: ('MESH:D005682', 'Chemical') :: ['gadolinium'] @entity1188 :: ('MESH:D007238', 'Disease') :: ['infarcted', 'infarct structure', 'infarcts', 'infarct', 'infarction']
@entity583 :: (MESH:D009203,Disease) :: ['myocardial infarction']
