A system and method for registering three-dimensional images with two-dimensional intra-operative images includes segmenting (24) a tubular structured organ in a three-dimensional image of the organ, and projecting (26) the three-dimensional image of the organ into two-dimensional space to provide a projected image. A medical instrument depicted in a two-dimensional image of the medical instrument is segmented (28). A similarity score is computed between the projected image and a shape of the medical instrument depicted in the two-dimensional image to determine a best match. The projected image is registered (30) to the two-dimensional image based on the best match.