A novel target field approach to design of biplanar gradient coils for permanent MRI system

Target Field (TF) method is very important for design of shim and gradient coils. Many works based on TF have been proposed. To restrict the current distribution on a rectangular plane with finite size, the current density is expanded by Fourier series and the unknown coefficients are estimated based on the standard Least Square (LS) with L2 norm regularization (LS-L2). Then the winding pattern of the coils can be obtained by the stream function method. In this paper, the proposed method was employed to design a transverse gradient coil for a magnetic resonance imaging (MRI) system. The size of the two planes is 500 mm × 150 mm, the distance of which is 50 mm, and the region of interest is a cylinder with radius of 4 mm and length of 8 mm. The simulation results demonstrate that the proposed method is practical in biplanar MRI system.