Certain embodiments of the present invention provide systems and methods for representing a tool or implant in an image. Certain embodiments provide a user interface system for displaying a representation of a tool or implant with respect to an image. The system includes a processor configured to establish a surface boundary for a region of interest depict in the image and configured to determine a position of the tool or implant with respect to the surface boundary, and a display configured to dynamically display the image and the representation to a user. The processor generates a representation of the tool or implant based on the position with respect to the surface boundary. A portion of the tool or implant inside the surface boundary is depicted in the representation with a degree of transparency compared to a portion of the tool or implant outside the surface boundary.