METHOD AND APPARATUS FOR MAKING AN IMAGE OF A LUMEN OR OTHER BODY CAVITY AND ITS SURROUNDING TISSUE
 Inventors: E. I. Cespedes, Folsom, Calif.; C. L.
de Korte, Driebergen-Rijsenburg; A. F. W. van der Steen, Rotterdam, both of Netherlands
 Assignee: EndoSonics Corporation, Rancho Cordova, Calif.
 Appl. No.: 09/166,016
 Filed: Oct. 5, 1998
 Foreign Application Priority Data
Oct. 6, 1997 [EP] European Pat. Off 97203072
 Int. CI. A61B 8/12
 U.S. CI 600/463
 Field of Search 600/437, 443,
600/449, 455-456; 128/916
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U.S. PATENT DOCUMENTS 5,125,410 6/1992 Misono et al. .
5,195,521 3/1993 Melton, Jr. et al 600/456
5,622,174 4/1997 Yamazobi 600/455 X
5,800,356 9/1998 Criton et al 600/455 X
FOREIGN PATENT DOCUMENTS
WO 94/23652 10/1994 WIPO .
C. L. de Korte et al., "Intravascular Elasticity Imaging Using Ultrasound: Feasibility Studies In Phantoms," Ultrasound in Medicine and Biology, vol. 23, No. 5, May 1997, USA, pp. 735-746.
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.