A system for stimulation includes an implantable pulse generator, a lead, and conductors. The lead includes an array body disposed at a distal end of the lead and electrodes concentrically arranged on the array body. A center electrode may also be disposed on the array body. The electrodes may be arranged in more than one concentric ring. A method of using an implantable stimulator includes implanting an implantable stimulator and providing an electrical signal to at least one electrode of the implantable stimulator to stimulate a tissue. The electrical signal may be provided between diametrically opposed electrodes or between electrodes that are not diametrically opposed. If the implantable stimulator has a center electrode, the electrical signal may be provided between the center electrode and at least one concentrically arranged electrode.