A convex gradient coil design for vertical field open MRI

We introduce a convex gradient coil that can be used for interventional studies using a vertical field open MRI system. By placing gradient coil wires on two coaxial convex surfaces seeing each other, we can improve the accessibility to the patient during the scan, while maintaining the space for imaging. We have defined convex surfaces on hyperboloids at the prolate spheroidal coordinate. If we take account of accessibility at the figure of merit for the gradient coil performance, the convex gradient coil has better performance than conventional planar gradient coils