A method for generating and displaying a 3D visualization of a cardiac-ablation balloon in a region of a living heart within a predefined 3D space, the method using single-plane fluoroscopic images and comprising: (1) placing, inflating and positioning the balloon into the region, the balloon having a radio-opaque location marker and central catheter portion； (2) capturing a burst of first-view digitized 2D images of the region from a fluoroscope positioned at a first angle； (3) capturing a burst of second-view digitized 2D images of the region from the fluoroscope positioned at a second angle different from the first angle； (4) selecting first-view and second-view images from the bursts such that the difference between measures of the cardio-respiratory phases of the selected first-view and second-view images is minimized； (5) identifying the location marker in each of the two selected images； (6) placing first and second orientation markers in the selected first-view and second view images, respectively, where the central catheter portion intersects the projected image of the inflated balloon at a farthest point from the location marker； (7) associating the location marker and the second orientation marker in the selected second-view image with the location marker and first orientation marker in the selected first-view image； (8) determining 3D location and orientation of the balloon in the region using the selected first-view and second-view images； (9) based on the determined location and orientation, inserting a 3D balloon model into the predefined space to generate the 3D visualization； and (10) displaying the 3D visualization on a display device, whereby a user can visualize where cardiac ablation was applied within the region.
