Apparatus and methods are described for use with an image of at least one blood vessel (50) of a subject including, using at least one computer processor (28), determining a presence of a device (55) within at least a portion of the blood vessel within the image. The computer processor determines a classification of the device as a given type of device, and, based upon the classification of the device as the given type of device, designates a parameter to be calculated. The computer processor automatically calculates the designated parameter, and generates an output on an output device (40) in response to the calculated parameter. Other applications are also described.
