1. A method for determining a three dimensional representation of a tubular organ, said method comprising the procedures of: registering a three dimensional medical positioning system (MPS) coordinate system with a two dimensional coordinate system; acquiring a plurality of MPS points within said tubular organ, said MPS points are associated with said MPS coordinated system, each of said MPS points is acquired with a respective organ timing signal reading; acquiring at least one two dimensional image of said tubular organ, said at least one two dimensional image is associated with said two dimensional coordinate system, said at least one two dimensional image is acquired from at least one perspective angle, each of said at least one two dimensional image is further acquired with a respective organ timing signal reading; associating each of said MPS points with said at least one two dimensional image according to the organ timing signals thereof; determining a temporal three dimensional representation of a portion of said tubular organ for each MPS point, said procedure of determining a three dimensional representation comprising the sub-procedures of: selecting at least one two dimensional image, said at least one two dimensional image including said tubular organ; projecting the trajectory of said catheter on the selected two dimensional image, said trajectory being determined by said MPS points associated with said selected two dimensional image, thereby defining a centerline of said tubular organ; detecting the border points of tubular organ on said selected two dimensional image; and generating a three dimensional closed curve around each of said MPS points, associated with said selected image.