Proton Magnetic Resonance Relaxation Times and Biomechanical Properties of Human Vascular Wall

Vinée, P; Meurer, B.; Constantinesco, A.; Kohlberger, Bernd; Kh, Hauenstein; Petkov, Simeon

doi:10.1097/00004424-199207000-00006

Cited by 4 publications

(1 citation statement)

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“…In vivo determination of mechanical properties of vascular tissue components is a challenging problem, which has yet to be solved in a satisfactory way. Existing techniques are based on MR methods [30] and ultrasonic methods [18].…”

Section: In Vivo Applicationmentioning

confidence: 99%

Assessment of Plaque Stability Based on High-Resolution Magnetic Resonance Imaging of Human Atherosclerotic Lesions and Computational Mechanical Analysis

Schulze-Bauer¹,

Stadler²,

Stollberger³

et al. 2004

Computational Bioengineering

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Background-To date there is no efficient diagnostic strategy available for the assessment of plaque stability. The present work proposes a computational methodology to identify high-risk plaques. The proposed model considers eight major tissue components and allows three-dimensional mechanical analyses of plaque stability subject to various factors such as blood pressure and mechanical properties of tissue components. Methods and Results-Morphology of an eccentric low-grade lesion was determined by means of multi-phasic and highresolution magnetic resonance imaging on a 1.5 T whole body system and corresponding histological analyses. Nonlinear anisotropic material models were fitted to experimental data obtained from tensile tests of isolated tissue components. Stress distributions in the lesion were computed using nonlinear finite element analyses. Based on the particular low-grade lesion, the effects of elevated blood pressure were studied, and, additionally, the potential effects of changes in the lipid pool stiffness and the media stiffness, that can be controlled by drug treatment, investigated. Intimal stress distributions are strongly influenced by non-intimal components, and hence suitable modeling of non-intimal and intimal components is equally important. A meaningful stability assessment of individual lesions requires three-dimensional approaches. Conclusions-Realistic three-dimensional "morpho-mechanical" modeling of atherosclerotic lesions provide information and insights important for the assessment and understanding of plaque stability and related drug effects. This information can not be obtained by entirely morphological approaches.

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Section: In Vivo Applicationmentioning

confidence: 99%

Assessment of Plaque Stability Based on High-Resolution Magnetic Resonance Imaging of Human Atherosclerotic Lesions and Computational Mechanical Analysis

Schulze-Bauer¹,

Stadler²,

Stollberger³

et al. 2004

Computational Bioengineering

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MR detection of quantitative and structural changes in human aortic aneurysms

Vinée

Meurer

Constantinesco³

et al. 1993

Magnetic Resonance Imaging

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Collagen is a major component of the extracellular matrix and a determinant of the elastic behavior of the human aorta. To investigate the changes found in aneurysmal degeneration, the authors studied the solid-state hydrogen-1 nuclear magnetic resonance line shape of collagen in aneurysms and normal human aortas. A three-component decomposition of the free induction decay was performed, with collagen characterized by a T2 of about 18 microseconds. The second moment of the collagen line shape was found to be increased in aneurysms (5.3 vs 4.8 G2), while, correspondingly, the T2 of collagen was lower in aneurysms (16.3 vs 17.7 microseconds). This corresponds to a modification of collagen structure and molecular motion. Collagen concentration was lower in nondiseased aortic walls (9.4% vs 7.3%). These results are discussed in reference to the contradictory conclusions in the current literature. The increase in collagen and the modification of its structure and molecular motion are explained by the need to resist an increasing tangential tension due to increased aortic diameter and diminished wall thickness in aneurysms and by intercalation or site binding in the helices or electric dipolar interactions in the less mobile side groups.

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In vitro proton NMR study of collagen in human aortic wall

Vinée¹,

Meurer

Constantinesco³

et al. 1993

Magnetic Resonance in Med

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The authors relate the findings in the 1H solid state line shape (at 60 MHz) of human aortic walls (n = 12) in native state and after histologically controlled selective lysis of collagen and elastin. An analysis of the line shape shows a composite free induction decay (FID) consisting of a low amplitude (3-7%) fast decaying component (T2 approximately 20 microseconds) and a slow decaying one (T2 > 1 ms). The fast component is identified as the protons of the collagen macromolecules. The second moment computed from the experimental fast component of the FID is in agreement with published studies examining the motional characteristics of collagen by multinuclear NMR employing spin labeling. A theoretical second moment is computed for the collagen macromolecular backbone from the atomic positions in the superhelix. Comparison with the observed experimental values allows determination of the step angle (29 degrees) of the fast rotational motion of the collagen strands along their long axis.

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Proton Magnetic Resonance Relaxation Times and Biomechanical Properties of Human Vascular Wall

Cited by 4 publications

References 0 publications

Assessment of Plaque Stability Based on High-Resolution Magnetic Resonance Imaging of Human Atherosclerotic Lesions and Computational Mechanical Analysis

Assessment of Plaque Stability Based on High-Resolution Magnetic Resonance Imaging of Human Atherosclerotic Lesions and Computational Mechanical Analysis

MR detection of quantitative and structural changes in human aortic aneurysms

In vitro proton NMR study of collagen in human aortic wall

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