1. An obturator, comprising: a. an elongated shaft comprising a cylindrical wall having a proximal end, a distal end and defining an internal lumen extending to the distal end and an obturator tip secured to the distal end; and b. a detectable element which is in contact with the mating surfaces of the terminal distal end of the cylindrical wall and the obturator tip, said detectable element comprising a material selected from the group consisting of metal, ceramic, metal-filled plastic, a radiopaque material, or a mineral-filled plastic and being configured to produce a significant magnetic resonance image signature.