Observation of direction-dependent mechanical properties in the human brain with multi-excitation MR elastography.
J Mech Behav Biomed Mater
; 59: 538-546, 2016 06.
Article
en En
| MEDLINE
| ID: mdl-27032311
ABSTRACT
Magnetic resonance elastography (MRE) has shown promise in noninvasively capturing changes in mechanical properties of the human brain caused by neurodegenerative conditions. MRE involves vibrating the brain to generate shear waves, imaging those waves with MRI, and solving an inverse problem to determine mechanical properties. Despite the known anisotropic nature of brain tissue, the inverse problem in brain MRE is based on an isotropic mechanical model. In this study, distinct wave patterns are generated in the brain through the use of multiple excitation directions in order to characterize the potential impact of anisotropic tissue mechanics on isotropic inversion methods. Isotropic inversions of two unique displacement fields result in mechanical property maps that vary locally in areas of highly aligned white matter. Investigation of the corpus callosum, corona radiata, and superior longitudinal fasciculus, three highly ordered white matter tracts, revealed differences in estimated properties between excitations of up to 33%. Using diffusion tensor imaging to identify dominant fiber orientation of bundles, relationships between estimated isotropic properties and shear asymmetry are revealed. This study has implications for future isotropic and anisotropic MRE studies of white matter tracts in the human brain.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Encéfalo
/
Imagen por Resonancia Magnética
/
Anisotropía
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Diagnóstico por Imagen de Elasticidad
Tipo de estudio:
Diagnostic_studies
Límite:
Humans
Idioma:
En
Revista:
J Mech Behav Biomed Mater
Asunto de la revista:
ENGENHARIA BIOMEDICA
Año:
2016
Tipo del documento:
Article