A method and apparatus for providing a high-quality representation of a volume having a real-time 3-D reconstruction therein of movement of an object, wherein the real-time movement of the object is determined using a lower-quality representation of only a portion of the volume. Movement of the object is detected in a 2-D X-ray fluoroscopy image and is reconstructed in a 3-D angiography (X-ray) reconstruction. Using a common C-arm and X-ray geometry advantageously, the 2-D and 3-D data representative of vascular structures of a patient is acquired, thereby facilitating the merger of the real-time 2-D fluoroscopic images with the 3-D reconstructed vascular structures in a common 3-D-visualization framework. Also described is a technique for 3-D reconstruction of a catheter from real-time 2-D fluoroscopic images and stored 3-D angiography data, so as to present the 3-D reconstructed catheter in the common coordinate frame. The merger of 3-D angiography image representations acquired with other modalities, such as MR or CT, is also disclosed.