Abstract: A system and method of producing virtual roadmap image of a patient is described. CT-like image data may be obtained for a patient, with or without a contrast agent, and differenced so as to form a roadmap mask. The roadmap mask is in the form of a 2-dimensional digitally reconstructed radiograph from the same orientation as that of a fluoroscopic X-ray device which takes real-time images of the patient during treatment. The fluoroscopic image may be subtracted from the roadmap mask so as to more clearly visualize the position of a catheter introduced into the patient for treatment. When the orientation of the fluoroscopic image is changed during the course of treatment, the roadmap mask image for the corresponding orientation is used.