1. A device for visualizing structure located on the interior of a visually opaque substance relative to a region of interest in a body, the device comprising: a marker member, the marker member composed of a biologically stable material, the marker member capable of permitting non-obstructive visualization of at least one structure located relative to the region of interest, the marker member having an interior, a proximal end, and a distal end, the distal end of the marker member being removably insertable in the visually opaque substance in proximate relationship to a cavity of potential space defined therein; an external access member contiguously connected to the proximal end of the marker member, at least a portion of the external access member extending from the marker member to a location external to the visually opaque substance when the marker member is in removable insertable position in the visually opaque substance; and an imaging material contained relative to the market member in a manner such that the imaging material does not directly contact the substance to be imaged, wherein the imaging material produces a signal detectable external to the visually opaque substance, the imaging material containing at least one radiopharmaceutical material, the radiopharmaceutical material producing an image detectable in at least one of positron emission tomography, and single photon emission computed tomography.