Probing dynamic myocardial microstructure with cardiac magnetic resonance diffusion tensor imaging

Axel, Leon; Wedeen, Van J.; Ennis, Daniel B.

doi:10.1186/s12968-014-0089-6

Cited by 30 publications

(32 citation statements)

References 33 publications

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“…Therefore, the myocardium constitutive model should include anisotropy in the cross‐cardiomyocyte plane. To simulate wall thickening, we used global fractional shortening values, which may be higher than those reported for individual cardiomyocytes …”

Section: Discussionmentioning

confidence: 99%

“…To simulate wall thickening, we used global fractional shortening values, which may be higher than those reported for individual cardiomyocytes. 42 We intend to further improve our mechanical modeling in the future to incorporate anatomies and motion trajectories of increasing complexity. 43,44 For higher fidelity mapping in our future studies, conducting DT-MRI scanning on a heart in vivo, and subsequently conducting high-resolution DT-MRI on the same heart ex vivo will allow us to employ reverse finite element analysis to map end systolic cardiomyocyte orientation to in vivo DT-MRI data.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

A comparison of two quasi‐static computational models for assessment of intra‐myocardial injection as a therapeutic strategy for heart failure

Fan

Ronan

Teh

et al. 2019

Numer Methods Biomed Eng

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Myocardial infarction, or heart attack, is the leading cause of mortality globally. Although the treatment of myocardial infarct has improved significantly, scar tissue that persists can often lead to increased stress and adverse remodeling of surrounding tissue and ultimately to heart failure. Intra‐myocardial injection of biomaterials represents a potential treatment to attenuate remodeling, mitigate degeneration, and reverse the disease process in the tissue. In vivo experiments on animal models have shown functional benefits of this therapeutic strategy. However, a poor understanding of the optimal injection pattern, volume, and material properties has acted as a barrier to its widespread clinical adoption. In this study, we developed two quasistatic finite element simulations of the left ventricle to investigate the mechanical effect of intra‐myocardial injection. The first model employed an idealized left ventricular geometry with rule‐based cardiomyocyte orientation. The second model employed a subject‐specific left ventricular geometry with cardiomyocyte orientation from diffusion tensor magnetic resonance imaging. Both models predicted cardiac parameters including ejection fraction, systolic wall thickening, and ventricular twist that matched experimentally reported values. All injection simulations showed cardiomyocyte stress attenuation, offering an explanation for the mechanical reinforcement benefit associated with injection. The study also enabled a comparison of injection location and the corresponding effect on cardiac performance at different stages of the cardiac cycle. While the idealized model has lower fidelity, it predicts cardiac function and differentiates the effects of injection location. Both models represent versatile in silico tools to guide optimal strategy in terms of injection number, volume, site, and material properties.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

A comparison of two quasi‐static computational models for assessment of intra‐myocardial injection as a therapeutic strategy for heart failure

Fan

Ronan

Teh

et al. 2019

Numer Methods Biomed Eng

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“…The diffusion time (Δ) in the PGSE experiments is short, and the effects of strain are thus minimal. The STE approach, however, requires a long Δ, during which time the impact of strain is significant and cannot be neglected (2,3,38,42,49).…”

Section: Impact Of Strainmentioning

confidence: 99%

“…The metrics most commonly used to measure the microstructure in the heart include MD, FA, myofiber HA, and the myofiber sheet angle (14,17,20,26,67). Recent studies suggest that two populations of sheet angles exist within the myocardium, and that radial reorientation of the sheets from diastole to systole facilitates radial strain (49,56,57). The superquadric glyph representation of the diffusion tensor has also been used to highlight the helical organization and structure of the myocardium (70,71).…”

Section: Fiber Architecture Of the Heartmentioning

confidence: 99%

Diffusion MRI in the heart

et al. 2015

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Diffusion MRI provides unique information on the structure, organization, and integrity of the myocardium without the need for exogenous contrast agents. Diffusion MRI in the heart, however, has proven technically challenging because of the intrinsic non‐rigid deformation during the cardiac cycle, displacement of the myocardium due to respiratory motion, signal inhomogeneity within the thorax, and short transverse relaxation times. Recently developed accelerated diffusion‐weighted MR acquisition sequences combined with advanced post‐processing techniques have improved the accuracy and efficiency of diffusion MRI in the myocardium. In this review, we describe the solutions and approaches that have been developed to enable diffusion MRI of the heart in vivo, including a dual‐gated stimulated echo approach, a velocity‐ (M 1) or an acceleration‐ (M 2) compensated pulsed gradient spin echo approach, and the use of principal component analysis filtering. The structure of the myocardium and the application of these techniques in ischemic heart disease are also briefly reviewed. The advent of clinical MR systems with stronger gradients will likely facilitate the translation of cardiac diffusion MRI into clinical use. The addition of diffusion MRI to the well‐established set of cardiovascular imaging techniques should lead to new and complementary approaches for the diagnosis and evaluation of patients with heart disease. © 2015 The Authors. NMR in Biomedicine published by John Wiley & Sons Ltd.

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“…Characterization of this complex tissue microarchitecture as a basis for understanding cardiac function is both important and challenging. 1 Diffusion magnetic resonance imaging (MRI) measures the diffusion of water, 2 which is hindered and restricted in the cellular environment, and consequently serves as a marker of cellular structure and organization in biological tissues. 3 Diffusion tensor imaging (DTI) is a rapidly emerging and noninvasive approach 4 for assessing cardiac microstructure.…”

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confidence: 99%

Biomimetic phantom for cardiac diffusion MRI

Teh

Zhou

Cristinacce

et al. 2016

Magnetic Resonance Imaging

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Purpose: Diffusion magnetic resonance imaging (MRI) is increasingly used to characterize cardiac tissue microstructure, necessitating the use of physiologically relevant phantoms for methods development. Existing phantoms are generally simplistic and mostly simulate diffusion in the brain. Thus, there is a need for phantoms mimicking diffusion in cardiac tissue. Materials and Methods: A biomimetic phantom composed of hollow microfibers generated using co-electrospinning was developed to mimic myocardial diffusion properties and fiber and sheet orientations. Diffusion tensor imaging was carried out at monthly intervals over 4 months at 9.4T. 3D fiber tracking was performed using the phantom and compared with fiber tracking in an ex vivo rat heart. Results: The mean apparent diffusion coefficient and fractional anisotropy of the phantom remained stable over the 4-month period, with mean values of 7.53 6 0.16 3 10 -4 mm 2 /s and 0.388 6 0.007, respectively. Fiber tracking of the 1st and 3rd eigenvectors generated analogous results to the fiber and sheet-normal direction respectively, found in the left ventricular myocardium. Conclusion: A biomimetic phantom simulating diffusion in the heart was designed and built. This could aid development and validation of novel diffusion MRI methods for investigating cardiac microstructure, decrease the number of animals and patients needed for methods development, and improve quality control in longitudinal and multicenter cardiac diffusion MRI studies.

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Probing dynamic myocardial microstructure with cardiac magnetic resonance diffusion tensor imaging

Cited by 30 publications

References 33 publications

A comparison of two quasi‐static computational models for assessment of intra‐myocardial injection as a therapeutic strategy for heart failure

A comparison of two quasi‐static computational models for assessment of intra‐myocardial injection as a therapeutic strategy for heart failure

Diffusion MRI in the heart

Biomimetic phantom for cardiac diffusion MRI

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