Work

A torque balance measurement of anisotropy of the magnetic susceptibility in white matter

Year: 2014

Type: article

Abstract: PURPOSE: Recent MRI studies have suggested that the magnetic susceptibility of white matter (WM) in the human brain is anisotropic, providing a new contrast mechanism for the visualization of fiber bundles and allowing the extraction of cellular compartment-specific information. This study provides an independent confirmation and quantification of this anisotropy. METHODS: Anisotropic magnetic susceptibility results in a torque exerted on WM when placed in a uniform magnetic field, tending to align the WM fibers with the field. To quantify the effect, excised spinal cord samples were placed in a torque balance inside the magnet of a 7 T MRI system and the magnetic torque was measured as function of orientation. RESULTS: All tissue samples (n = 5) showed orienting effects, confirming the presence of anisotropic susceptibility. Analysis of the magnetic torque resulted in reproducible values for the WM volume anisotropy that ranged from 13.6 to 19.2 ppb. CONCLUSION: The independently determined anisotropy values confirm estimates inferred from MRI experiments and validate the use of anisotropy to extract novel information about brain fiber structure and myelination.

Source: Magnetic Resonance in Medicine

DOI: 10.1002/mrm.25524

Authors: Peter van Gelderen, Hendrik Mandelkow, Jacco A. de Zwart, Jeff H. Duyn

Institutions: National Institutes of Health, National Institute of Neurological Disorders and Stroke

Language: English

Topic: Advanced Neuroimaging Techniques and Applications

Subfield: Radiology, Nuclear Medicine and Imaging

Field: Medicine

Domain: Health Sciences

Open Access status: bronze

Funder: National Institutes of Health

Award: G4988861893