Researcher(s)
- Emma Zarate, Biomedical Engineering, University of Delaware
Faculty Mentor(s)
- Curtis Johnson, Biomedical Engineering, University of Delaware
Abstract
Magnetic Resonance Elastography (MRE) is a cutting-edge neuroimaging modality that characterizes tissue microstructure through detailed maps of mechanical properties like stiffness and viscosity. Unlike conventional MRI, which primarily provides volumetric measurements, MRE uses small tissue deformations to estimate these properties via inverse solutions of motion equations. MRE has also been instrumental in identifying changes in brain mechanics associated with aging populations, revealing alterations in tissue stiffness and viscosity that correlate with age-related neurodegenerative processes. This study explores MRE’s potential in detecting and monitoring neurodegenerative disease in female Long Evans rats (DiFabio et al., 2022; Schwarb et al., 2017).
Neurodegeneration is observed in rodent models of acute neuroinflammation. We collected MRE scans prior to and at several time points following systemic injection with lipopolysaccharide (LPS), an endotoxin that causes immediate neuroinflammation and, when sustained, causes neurodegeneration (Revuelta et al., 2022)
MRE scans were conducted on anesthetized rats maintained under 1-3% isoflurane in oxygen at 32-36℃. MRE imaging parameters included: TE/TR = 600/4000 ms; FOV = 80×80 mm matrix size; number of slices= 40 slices; slice thickness = 0.5 mm; resolution = 0.25×0.25×0.5 mm. Mechanical properties, such as stiffness and damping ratio, were derived from displacement images using nonlinear inversion methods without boundary conditions (McGarry et al., 2012). A decrease in stiffness between pre-injection and post-injection of LPS was noted from MRE scans from each rat.
This comprehensive approach aims to advance our understanding of how mechanobiological changes can be measured and characterized as biomarkers of neuroinflammation. MRE’s ability to quantify tissue mechanics enhances its relevance in preclinical research, offering insights into disease pathogenesis and treatment efficacy assessment.