The invention relates to a visualization system (10) for visualizing an accuracy of an alignment of a position and shape of an instrument (33), which has been determined by a position and shape determination device (9), with an image of the instrument. The accuracy is determined for different regions of the instrument as defined by the position and shape and of the image, wherein among these regions at least one region is determined, in which the determined accuracy indicates that it is insufficient. A visualization is then generated in which the determined region is indicated on a representation of the position and shape and/or the image. This visualization guides a user's eyes to the region which should not be missed, while deciding whether, for instance, a navigation of the instrument during a subsequent interventional procedure should be based on this alignment, which in turn allows for an improved navigation accuracy.