Tailoring magnetic fields for magnetic resonance imaging

Within this research project we will test the feasibility of a completely new hardware and software based approach to overcoming errors in the magnetic field of high -field magnetic resonance imaging (MRI) scanners. A high homogeneity (i.e., having the same magnetic field strength within all body parts that are imaged via MRI) is essential for high-quality MRI examination. Via numerical simulations and analytical models, we will predict the feasibility of this new approach for imaging the human brain within the geometrical and hardware limitations that are imposed in typical commercial whole-body MRI scanners. A first, simple prototype will be used to validate the predicated results.

Building on initial results from Mach-Batlle et al. Physics Rev. Lett. 2020, the targeted scientific breakthrough of our proposal was to develop a prototype of a new Magnetic resonance imaging technology to generate more homogeneous static magnetic fields by creating tailored magnetic field distributions inside the human body that would cancel errors in otherwise inaccessible regions in the human body. This would be at first glance contradicting the Earnshaw's theorem (1842), which states that: "There is no static magnetic or electric field without a source that can keep objects in a stable equilibrium." Mach-Batlle et al. Had, however, suggested theoretically and in a simple experiment that metamaterials should be able to provide a solution for this problem and our study's target was to utilize their results for a first proof-of-principle in Magnetic resonance imaging of the brain to overcome long-standing problems in creating truly homogeneous magnetic fields in Magnetic resonance imaging. In our project we have simulated an array of different geometric and material configurations and build a shimming hardware that should be capable of generating the corrective magnetic field predicted via this new approach. However, both simulations and experiments have shown that the obtained effects are too small and cannot extend in a sufficiently large distance to be able to improve Magnetic resonance imaging in a practical setting.