Andrey Zhdanov1, Jaakko O. Nieminen1, Panu T. Vesanen1, Koos C.J. Zevenhoven1, Juhani Dabek1, Juho Luomahaara2, Juha Simola3, Antti I. Ahonen3, Risto J. Ilmoniemi
1Department of Biomedical Engineering and Computer Science, Aalto University School of Science, Espoo, Finland; 2VTT Technical Research Centre of Finland, Espoo, Finland; 3Elekta Oy, Helsinki, Finland
Ultra-low-field (ULF) MRI using microtesla imaging fields posesses a number of advantages over conventional high-field MRI, such as low cost, better patient safety, higher immunity to imaging field inhomogeneities, silent operation and enhanced T1 contrast. ULF MRI experimental setup at Aalto University contains superconducting components that are placed close to the imaging volume: superconducting niobium shields protecting sensors from the prepolarizing field and superconducting polarizing coil. We estimate the impact of these components on the homogeneity of the imaging field using finite element numerical simulations and devise a strategy for their optimal placement.