Patent ID: 6165128
Filing Date: 2000-12-26
Classification: A61B

Abstract:
A method for making an image of a lumen or other body cavity and its surrounding tissue in a body wherein a transducer is inserted in the lumen or cavity and ultrasound signals are emitted by said transducer and directed towards a wall of said lumen or cavity, after which echo signals are collected and processed to form an image of the lumen or cavity and its surrounding tissue, whereas from the emitted and collected signals also information is derived concerning the stiffness of the tissue around the lumen or cavity, which information is displayed in the image that has been formed, comprising the steps of:a) obtaining one or more echo signals from tissue in a chosen direction, said tissue being at a given state of mechanical stress;b) obtaining one or more signals from said tissue in said chosen direction, after the given state of mechanical stress has changed;c) determining the extent of the lumen or cavity in said chosen direction in order to identify the lumen-tissue or cavity-tissue boundary;d) comparing the echo signals from steps a) and b) starting at the lumen-tissue or cavity-tissue boundary and for a finite depth in the tissue to obtain a parameter indicative of tissue stiffness of the inner layer of tissue in said chosen direction;e) performing the steps a) to d) for a number of directions;f) deriving and displaying the echo image of the cavity or lumen and its surrounding tissue from the echo signals obtained in step a); andg) presenting in the image obtained in step f) the tissue stiffness as a one-dimensional coded line along the lumen-tissue or cavity-tissue boundary.