Takeshi Yatsuo

Three-dimensional optimization of correction iron pieces for open high field MRI system

We have developed a new magnet for open high field (0.7 T) MRI systems. In order to homogenize magnetic fields in the field of view, an optimization method to determine initial configurations of large correction iron pieces was developed. In our method, we combined linear programming (LP) and 3D magnetic FEA and, using analytic formulae for LP, we computed field harmonics due to the volume of magnetized iron.

Shielding stray magnetic fields of open high field MRI magnets

We have developed a new magnet for open high field (0.7 T) MRI systems. Since MRI systems are installed in hospital sites, it is important to reduce stray magnetic fields of the magnets. We studied passive, active and hybrid shielding methods and compared them. In order to study feasibility of active shielding, we considered higher order multipole stray fields. We present details of the calculation method and the results.