A system identifies a stent in an image using luminance density and anatomical information. An X-ray imaging system automatically detects and indicates location of an invasive anatomical device in an image. An interface acquires, data representing X-ray images of patient vessels and data identifying a particular vessel containing a medical device. An image data processor employs a model of anatomical vessels to select a region of interest in a vessel identified by the acquired data and automatically determines a location of the medical device in an acquired image by determining at least a portion of an outline of the medical device by detecting a luminance transition in the acquired image using an image edge detector. A display processor initiates generation of data depicting location of the medical device in the acquired image in response to determining the at least a portion of the outline of the medical device.