Investigation of Brain’s Structure-Function Relationship in Glioma Patients using MRE

The effects of brain tumors on brain function are difficult to predict due to the complexity of individual brain networks and the brain's potential for functional reorganization. Invasive and noninvasive brain imaging techniques can help to better understand the effects of brain tumors on brain networks and improve treatment efficacy and levels of control. Studying how tissue biomechanics relate to individual differences in cognitive function has emerged as one of the exciting new directions in magnetic resonance elastography (MRE), a tool for studying biomechanical properties (e.g., viscoelasticity) in the brain [1]. This can lead to implications for the links between brain health and cognitive impairment [2].

Until now, MRE holds great potential for noninvasive in vivo assessment of biomechanical characterization of brain tumors [3,4]. MRE is a phase contrast-based MRI technique that allows the quantification of displacement caused by propagating mechanical waves. From this, material properties of the tissue such as viscoelasticity can be evaluated. Mechanical imaging of the brain using multifrequency MRE confirmed that glioblastomas can be distinguished from healthy reference tissue by their lower viscoelastic behavior, i.e. glioblastomas are generally less viscous and softer than healthy brain parenchyma [5]. More importantly, in a recent study, we investigated fluidity, a material property of biological tissue of braintumors, to better understand the infiltration behavior of glioblastomas as the most aggressive, malignant brain tumors [6], which might improve future diagnosis and treatment strategies of these tumors. The structural and functional integrity of neurons and glial cells is affected by the viscoelasticity of the brain parenchyma and intracranial pressure. Therefore, brain viscoelastic parameters could lead to the prognosis of brain diseases or therapeutic outcomes in brain tumors, trauma, and neurodegenerative diseases [7,8]. However, the relationship between clinical outcomes (e.g., cognitive and functional impairments) and pathology-induced changes in the mechanical properties of neural tissue needs further investigation. Based on the relationship between tissue biomechanical properties and microstructural organization, it has been hypothesized that viscoelasticity is related to brain function, which would make these measurements more interpretable in terms of brain health [9].

The purpose of this study is to develop methods to preoperatively investigate the altered functional relationship between brain structure and functional impairment in patients with brain tumors using local and global biophysical tissue parameters including mechanical properties (e.g. viscoelasticity) by MRE.