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Diagnostic significance of speckle motion in echography: An experimental study
ABSTRACTS.
ULTRASONIC IMAGING AND TISSUE
CHARACTERIZATION
SYMPOSIUM
our automated algorithm, integrated backscatter waveforms from a recent study of 10 dogs subjected to acute coronary occlusion and reperfusion. A linear regression analysis comparing the results of the two methods as y = ax yields a = 0.88 ? 0.01 (SE of estimate, r = 0.88, p
DIAGNOSTIC SIGNIFICANCE OF SPECKLE MOTION IN ECHOGRAPHY: AN EXPERIMENTAL STUDY, Jean Meunier, Michel Bertrand, Guy Mailloux and Robert Petitclerc, Ecole Polytechnique, Institut de Genie Biomedical and Institut de Cardiologie, Montreal, Canada. Recently, we proposed a new promising method to appraise tissue motion and deformation with speckle tracking in echography [l]. In this paper, we present an experimental evaluation of this method using clinical data from echocardiography. Our approach is based on the correlation existing between tissue and speckle motion for sufficiently small interframe motion (as expected in echocardiography) [l]. Sequences of 150 consecutive frames are digitized (512 x 512 x 8 bits) from clinical data available on video tape. The same region of interest (ROI) of 64 x 64 pixels in the posterior wall of the left ventricle (short axis view) is then extracted from each image. A speckle tracking algorithm based on optical flow techniques computes a linear 2-D velocity vector field characterizing the interframe speckle motion. This velocity field is then decomposed into meaningful components describing interframe translation, rotation and deformation (expansion and compression). By integrating those interframe motion parameters, we get curves representing the total myocardial translation, rotation and deformation (wall thickness and local myocardial length) as a function of time (frame number). Results are particularly interesting in the case of deformation of parameters which show cyclic variations for the local wall thickness and myocardial length in close agreement with manually calculated values. Out-of-phase behavior of these two parameters also appears with appropriate triggering by QRS occurrences as expected from the known cardiac physiology. Translation exhibits also cyclic behavior related to the heart contraction, while rotation is generally small (max: 5 degrees). From those encouraging results, we believe that this technique will lead to the development of an important diagnostic tool in echography to study local biomechanical deformation of myocardium and other soft tissues (liver, skeletal muscle, breast, etc.). [l] Meunier, J., Bertrand, M., Mailloux, G. and Petitclerc, R., Proc. SPIE 914 (1988) (to be published).
PROGRAM COMMITTEE M. Linzer, Chairman K. Chandrasekaran, Hahnemann University F.L. Lizzi, Riverside Research Institute E.L. Madsen, University of Wisconin J.G. Miller, Washington University J. Ophir, University of Texas, Houston T. Sato, Tokyo Institute of Technology D.J. Skorton, University of Iowa
79
ABSTRACTS,
ULTRASONIC IMAGING AND TISSUE CHARACTERIZATION
SYMPOSIUM
S.W. Smith, Food and Drug Administration J.M. Thijssen, University of Nijmegen
CORPORATE COSPONSOR Hewlett-Packard Andover, The generous acknowledged.
support
of
Acuson
Company MA
(Mountain
View,
CA)
is
also
gratefully
ULTRASONIC IMAGING AND TISSUE
CHARACTERIZATION
SYMPOSIUM
our automated algorithm, integrated backscatter waveforms from a recent study of 10 dogs subjected to acute coronary occlusion and reperfusion. A linear regression analysis comparing the results of the two methods as y = ax yields a = 0.88 ? 0.01 (SE of estimate, r = 0.88, p
DIAGNOSTIC SIGNIFICANCE OF SPECKLE MOTION IN ECHOGRAPHY: AN EXPERIMENTAL STUDY, Jean Meunier, Michel Bertrand, Guy Mailloux and Robert Petitclerc, Ecole Polytechnique, Institut de Genie Biomedical and Institut de Cardiologie, Montreal, Canada. Recently, we proposed a new promising method to appraise tissue motion and deformation with speckle tracking in echography [l]. In this paper, we present an experimental evaluation of this method using clinical data from echocardiography. Our approach is based on the correlation existing between tissue and speckle motion for sufficiently small interframe motion (as expected in echocardiography) [l]. Sequences of 150 consecutive frames are digitized (512 x 512 x 8 bits) from clinical data available on video tape. The same region of interest (ROI) of 64 x 64 pixels in the posterior wall of the left ventricle (short axis view) is then extracted from each image. A speckle tracking algorithm based on optical flow techniques computes a linear 2-D velocity vector field characterizing the interframe speckle motion. This velocity field is then decomposed into meaningful components describing interframe translation, rotation and deformation (expansion and compression). By integrating those interframe motion parameters, we get curves representing the total myocardial translation, rotation and deformation (wall thickness and local myocardial length) as a function of time (frame number). Results are particularly interesting in the case of deformation of parameters which show cyclic variations for the local wall thickness and myocardial length in close agreement with manually calculated values. Out-of-phase behavior of these two parameters also appears with appropriate triggering by QRS occurrences as expected from the known cardiac physiology. Translation exhibits also cyclic behavior related to the heart contraction, while rotation is generally small (max: 5 degrees). From those encouraging results, we believe that this technique will lead to the development of an important diagnostic tool in echography to study local biomechanical deformation of myocardium and other soft tissues (liver, skeletal muscle, breast, etc.). [l] Meunier, J., Bertrand, M., Mailloux, G. and Petitclerc, R., Proc. SPIE 914 (1988) (to be published).
PROGRAM COMMITTEE M. Linzer, Chairman K. Chandrasekaran, Hahnemann University F.L. Lizzi, Riverside Research Institute E.L. Madsen, University of Wisconin J.G. Miller, Washington University J. Ophir, University of Texas, Houston T. Sato, Tokyo Institute of Technology D.J. Skorton, University of Iowa
79
ABSTRACTS,
ULTRASONIC IMAGING AND TISSUE CHARACTERIZATION
SYMPOSIUM
S.W. Smith, Food and Drug Administration J.M. Thijssen, University of Nijmegen
CORPORATE COSPONSOR Hewlett-Packard Andover, The generous acknowledged.
support
of
Acuson
Company MA
(Mountain
View,
CA)
is
also
gratefully