Abstract: Method and apparatus for making an image of a lumen and surrounding tissue in a body by inserting a transducer in the cavity and emitting ultrasound signals and collecting and processing echo signals to form an image, where the apparatus includes a signal processor arranged for performing the steps of and the method includes the steps of:a) obtaining echo signals from tissue at a given state of mechanical stress in a chosen direction;b) obtaining similar echo signals after a change of the mechanical stress;c) identifying the lumen-tissue boundary;d) comparing the echo signals to obtain a parameter indicative of tissue stiffness;e) performing similar steps for a number of directions;f) deriving and displaying the conventional echo image of the lumen and surrounding tissue from the echo signals of step a);g) superimposing in said image the tissue stiffness as a coded line along the lumen-tissue boundary.