A system for a medical procedure that uses at least one instrument, comprising: an imaging head (18, 18c, 18d, 18e, 18f) defining a field of view relative to a patient, the imaging head (18, 18c, 18d, 18e, 18f) including: at least one radio-frequency transmitter that emits at least one signal in the field of view; and at least one radio-frequency receiver that receives at least one reflected radio frequency signal based on at least one electrical property of at least one material in the field of view and the at least one instrument; a workstation (24, 24e) having a control module that determines, based on the at least one reflected radio frequency signal received by the at least one radio-frequency receiver, a location of at least one boundary of the at least one material within the field of view and a location of the at least one instrument in relation to the patient within the field of view; wherein the workstation is configured to determine a type of material associated with the at least one instrument based upon a return time of the at least one reflected radio frequency signal associated with the at least one instrument, a shape or other characteristic of the at least one reflected radio frequency signal, a shape of the at least one signal, a location of the at least one radio frequency transmitter and radio frequency receiver, and at least one electrical property of the material associated with the at least one instrument; and a display device (26, 26e) that displays an image of the location of the at least one boundary and an icon of the at least one instrument on the image. an imaging head (18, 18c, 18d, 18e, 18f) defining a field of view relative to a patient, the imaging head (18, 18c, 18d, 18e, 18f) including: at least one radio-frequency transmitter that emits at least one signal in the field of view; and at least one radio-frequency receiver that receives at least one reflected radio frequency signal based on at least one electrical property of at least one material in the field of view and the at least one instrument; at least one radio-frequency transmitter that emits at least one signal in the field of view; and at least one radio-frequency receiver that receives at least one reflected radio frequency signal based on at least one electrical property of at least one material in the field of view and the at least one instrument; a workstation (24, 24e) having a control module that determines, based on the at least one reflected radio frequency signal received by the at least one radio-frequency receiver, a location of at least one boundary of the at least one material within the field of view and a location of the at least one instrument in relation to the patient within the field of view; wherein the workstation is configured to determine a type of material associated with the at least one instrument based upon a return time of the at least one reflected radio frequency signal associated with the at least one instrument, a shape or other characteristic of the at least one reflected radio frequency signal, a shape of the at least one signal, a location of the at least one radio frequency transmitter and radio frequency receiver, and at least one electrical property of the material associated with the at least one instrument; and a display device (26, 26e) that displays an image of the location of the at least one boundary and an icon of the at least one instrument on the image.