Abstract 16874: Unraveling 3D-Myocardial Fiber Architecture by Novel Histological Technique and Correlation With Diffusion-tensor MRI in Normal and Diseased Mice
Introduction: The myocardium has a complex 3-dimensional (3D) microstructure which thought to be perturbed in a range of diseases.
Hypothesis: We present a novel approach to characterize the microstructural response of the myocardium to heart failure (HF), with the use of diffuse tensor magnetic resonance imaging (DT-MRI) and its validation by intact, un-sectioned 3D histology using the technique called CLARITY, which transforms intact tissue into a nanoporous hydrogel-hybridized form that is fully assembled but optically transparent.
Method: Validation of the approach was performed in normal (n=9), ischemic (n=8) and adriamycin-induced non-ischemic HF mouse model (n=9). DT-MRI 3D whole heart fiber tracking in fixed ex-vivo mice hearts was performed, and the hearts were processed with the CLARITY technique. Optical imaging of the intact, un-sectioned final samples was obtained using selective plane illumination microscopy (SPIM), and 3D histology was reconstructed. Fiber orientation quantification was performed on both DT-MRI and 3D histology. Helix angle (HA, indicates reverse remodeling) and mean diffusivity (MD, represents the degree of fibrosis) were calculated, and the DT-MRI findings were compared with 3D histology voxel by voxel.
Results: In DT-MRI, the global MD was significantly increased in ischemics when compared with non-ischemics and controls (1.02±0.12 vs 0.85±0.11 vs 0.51±0.06, p<0.001). The global HA was significantly depressed in both ischemics and non-ischemics compared with controls (-0.79±0.13 vs -0.85±0.08 vs -1.30±0.73, p<0.001). The DT-MRI fiber orientation of each group was correlated with the fiber orientation quantified from the 3D histology.
Conclusion: We demonstrated the capability and the accuracy of the DT-MRI in mapping myocardial fiber orientation in both healthy control and diseased model. DT-MRI is a promising tool for the noninvasive characterization of myocardial fiber architecture.
Author Disclosures: S. Lee: None. C. Nguyen: None. H. Chang: None. J. Yoon: None. S. Kim: None. C. Kim: None. N. Chung: None. D. Li: None.
- © 2016 by American Heart Association, Inc.