Viscoelastic Property of the Brain Assessed With Magnetic Resonance Elastography and Its Association With Glymphatic System in Neurologically Normal Individuals

• Published in: Korean journal of radiology Vol. 24; no. 6; pp. 564 - 573
• Main Authors: Joo, Bio, Won, So Yeon, Sinkus, Ralph, Lee, Seung-Koo
• Format: Journal Article
• Language: English
• Published: Korea (South) The Korean Society of Radiology 01.06.2023; Korean Radiological Society
• Subjects: Age; Alzheimer's disease; Aneurysms; Brain - diagnostic imaging; Brain research; Elasticity Imaging Techniques - methods; Female; Glymphatic System - diagnostic imaging; Humans; Life Sciences; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Male; Neuroimaging and Head & Neck; Prospective Studies; Vibration; Viscoelasticity; Brain; Glymphatic system; Neurodegenerative disease; Magnetic resonance elastography; Viscoelastic property
• ISSN: 1229-6929; 2005-8330; 2005-8330
• DOI: 10.3348/kjr.2022.0992

To investigate the feasibility of assessing the viscoelastic properties of the brain using magnetic resonance elastography (MRE) and a novel MRE transducer to determine the relationship between the viscoelastic properties and glymphatic function in neurologically normal individuals. This prospective study included 47 neurologically normal individuals aged 23-74 years (male-to-female ratio, 21:26). The MRE was acquired using a gravitational transducer based on a rotational eccentric mass as the driving system. The magnitude of the complex shear modulus |G*| and the phase angle ϕ were measured in the centrum semiovale area. To evaluate glymphatic function, the Diffusion Tensor Image Analysis Along the Perivascular Space (DTI-ALPS) method was utilized and the ALPS index was calculated. Univariable and multivariable (variables with < 0.2 from the univariable analysis) linear regression analyses were performed for |G*| and ϕ and included sex, age, normalized white matter hyperintensity (WMH) volume, brain parenchymal volume, and ALPS index as covariates. In the univariable analysis for |G*|, age ( = 0.005), brain parenchymal volume ( = 0.152), normalized WMH volume ( = 0.011), and ALPS index ( = 0.005) were identified as candidates with < 0.2. In the multivariable analysis, only the ALPS index was independently associated with |G*|, showing a positive relationship (β = 0.300, = 0.029). For ϕ, normalized WMH volume ( = 0.128) and ALPS index ( = 0.015) were identified as candidates for multivariable analysis, and only the ALPS index was independently associated with ϕ (β = 0.057, = 0.039). Brain MRE using a gravitational transducer is feasible in neurologically normal individuals over a wide age range. The significant correlation between the viscoelastic properties of the brain and glymphatic function suggests that a more organized or preserved microenvironment of the brain parenchyma is associated with a more unimpeded glymphatic fluid flow.