Dissertation Talk: Magnetic Resonance Imaging and Modeling of Brain Magnetic Susceptibility

Seminar | April 25 | 10-11 a.m. | Cory Hall, 490 Swarm Lab, Immersion Room

Speaker/Performer:  Jingjia Chen

Sponsor:  Electrical Engineering and Computer Sciences (EECS)

In MRI, the human body’s magnetic susceptibility causes a slight resonance frequency shift of the nuclear spins. This frequency shift is stored in the phase of MRI signals. By solving a magnetic dipole model using the frequency shift map, we can recover the tissue’s local magnetic susceptibilities using a method called quantitative susceptibility mapping (QSM).

However, the method is inaccurate if non-homogeneous magnetic susceptibility sources exist within one imaging voxel. To address this issue, we developed a compartmentalized tissue signal model named DECOMPOSE-QSM. We used both traditional optimization and deep learning techniques to solve this highly nonlinear model. The resulting parameter solutions are used to construct paramagnetic and diamagnetic component susceptibility maps within a voxel. Using this technique, we discovered anisotropic paramagnetic susceptibilities in the brain, which we believe reflects a microstructural order of oligodendrocyte wrapping around axons.

Event Contact:  jingjia.chen@berkeley.edu

Access Coordinator:  Shirley Salanio,  shirley@eecs.berkeley.edu,  510-643-8347