1. A system for alerting a user to a region of interest within an image of interest, the image of interest being one of a sequence of medical images from a patient, the system being configured for sequentially displaying the sequence of medical images for enabling the user to navigate through the sequence of medical images, and the system comprising: an input for receiving a sequence navigation command from the user for requesting the system to display images from the sequence of medical images as part of pixel data shown on a display, and includes one or more processors; and a signal generator for providing a non-visual sensory signal to the user in separation from the pixel data and which changes in dependence on a difference between a position of a currently displayed image of the sequence of medical images in the sequence and a position of the image of interest in the sequence, and includes the one or more processors.