Bm. Shapo et al., DISPLACEMENT AND STRAIN IMAGING OF CORONARY-ARTERIES WITH INTRALUMINAL ULTRASOUND, IEEE transactions on ultrasonics, ferroelectrics, and frequency control, 43(2), 1996, pp. 234-246
Tissue elasticity can be estimated from displacement and strain images
acquired under controlled deformation, We extend this approach for co
ronary arteries, deformed and imaged by an integrated angioplasty ball
oon and ultrasonic imaging probe. Because the lumen cross section of a
severely occluded artery is not circular, we have also developed a te
chnique to perform all motion computations in the reference frame of t
he lumen's geometric center. This coordinate system is independent of
the imaging catheter and consequently referencing to this frame remove
s artifacts associated with probe motion within the balloon during def
ormation, Displacements and strains estimated by phase-sensitive corre
lation-based speckle tracking were used to distinguish arterial plaque
s in simulated coronary arteries of differing elastic moduli: hard, so
ft, and homogenous. We have also applied these methods to images of a
homogeneous gelatin phantom collected with the integrated probe, The m
aximum phantom displacement was about 40 mu m, and the maximum radial
normal strain was about 4% (absolute value), The spatial dependence of
these quantities shows good agreement with theoretically predicted va
lues.