A system for displaying structural information in a body of a living subject, comprising: an ultrasound imaging catheter adapted for introduction into said body, said ultrasound imaging catheter having a field of view and having a position sensor therein; an operative catheter adapted for introduction into said body and for effecting a medical procedure on a target structure of said body, said operative catheter having a position sensor therein; a robotic manipulator operative for maneuvering said ultrasound imaging catheter in said body; a positioning processor linked to said robotic manipulator, said positioning processor being operative responsively to signals from the position sensor of the ultrasound imaging catheter and the position sensor of the operative catheter to determine a position of the operative catheter relative to the ultrasound imagining catheter while effecting the medical procedure, the positioning processor being operative responsively to the current position of the operative catheter to transmit control signals to said robotic manipulator to cause said robotic manipulator to maneuver said ultrasound imaging catheter to maintain a portion of the operative catheter in the field of view; an image processor operative to generate an image of said field of view responsively to image data received from said ultrasound imaging catheter; a display for displaying said image; and characterised in that the system includes an enhanced mode of operation configured to be enabled once a target is in proximity with the operative catheter, in which the positioning processor is operative to instruct the robotic manipulator to include the target in the field of view along with the operative catheter, wherein the target is identified using images developed by the image processor, and displayed on the display in a perspective view. an ultrasound imaging catheter adapted for introduction into said body, said ultrasound imaging catheter having a field of view and having a position sensor therein; an operative catheter adapted for introduction into said body and for effecting a medical procedure on a target structure of said body, said operative catheter having a position sensor therein; a robotic manipulator operative for maneuvering said ultrasound imaging catheter in said body; a positioning processor linked to said robotic manipulator, said positioning processor being operative responsively to signals from the position sensor of the ultrasound imaging catheter and the position sensor of the operative catheter to determine a position of the operative catheter relative to the ultrasound imagining catheter while effecting the medical procedure, the positioning processor being operative responsively to the current position of the operative catheter to transmit control signals to said robotic manipulator to cause said robotic manipulator to maneuver said ultrasound imaging catheter to maintain a portion of the operative catheter in the field of view; an image processor operative to generate an image of said field of view responsively to image data received from said ultrasound imaging catheter; a display for displaying said image; and characterised in that the system includes an enhanced mode of operation configured to be enabled once a target is in proximity with the operative catheter, in which the positioning processor is operative to instruct the robotic manipulator to include the target in the field of view along with the operative catheter, wherein the target is identified using images developed by the image processor, and displayed on the display in a perspective view.