1. An X-ray imaging system for automatically detecting and indicating location of, an invasive anatomical device in an image, comprising: an interface for acquiring, data representing x-ray images of patient vessels including a particular vessel in which a medical device is located at a position in which the medical device was previously deployed during a previous acquiring of earlier images and data identifying said particular vessel containing said previously deployed medical device, wherein the previously deployed medical device was deployed in said particular vessel before said acquiring data representing images of patient vessels and said acquiring data identifying said particular vessel containing said previously deployed medical device; an image data processor for, employing a model of anatomical vessels to select a region of interest in said particular vessel containing said previously deployed medical device identified by the acquired data identifying said particular vessel containing said previously deployed medical device and automatically determining a location of said medical device in said selected region of interest in response to said data identifying said particular vessel containing said previously deployed medical device by determining at least a portion of an outline of said medical device by detecting a luminance transition in said acquired image using an image edge detector; and a display processor for initiating generation of data depicting location of said medical device in the acquired image in response to determining said at least a portion of said outline of said medical device.