Patent ID: 7382133

Claim:
A method of producing a self-shielded gradient adapted to be disposed within a main magnet field of an MRI scanner, comprising: determining a shield current distribution J s based on current density components φ n on a gradient surface where J s = ∑ n ⁢ ⁢ a n ⁢ ϕ n , by using an optimization technique; and constructing a gradient coil according to the shield current distribution; wherein the current distribution is a predetermined value within a volume defined by a periphery of the gradient coil; wherein the current distribution is substantially zero outside the periphery of the gradient coil; wherein the gradient is oriented along the static field direction; wherein the gradient currents flow in at least one circular loop; and wherein determining a shield current distribution includes determining a current density for a single current loop such that the current density is zero except at a radius of the loop.