Discrete design method of transverse gradient coils for MRI

A method is presented for designing transverse gradient coils for magnetic resonance imaging. This method is based on the set of Z intercepts of the coils' current patterns with the z axis in the unfolded z‐arc plane. We show that the set of Z intercepts combined with a description of the coil topology, as defined by the necessary azimuthal harmonics, the axial symmetry and the directions of the current flow, is sufficient for designing a practical gradient coil. The theory and design of transverse coils with Z intercepts is illustrated with examples of a symmetric unshielded insert gradient coil for small animal imaging, a human head unshielded symmetric insert gradient coil with shoulder cutouts, and a self‐shielded short whole‐body gradient coil. The Z‐intercept method has also been extended to design higher‐order transverse shims. This is illustrated with the design of a ZX shim. Additional design capabilities of the Z‐intercepts method are also discussed.