TY - JOUR
T1 - Noninvasive Vascular Elastography
T2 - Theoretical Framework
AU - Maurice, Roch L.
AU - Ohayon, Jacques
AU - Frétigny, Yves
AU - Bertrand, Michel
AU - Soulez, Gilles
AU - Cloutier, Guy
N1 - Funding Information:
Manuscript received March 12, 2003; revised August 26, 2003. The work of G. Cloutier was supported in part by the Natural Sciences and Engineering Research Council of Canada under Grant 138570–01. The work of J. Ohayon, M. Bertrand, G. Soulez, and G. Cloutier was supported in part by the Valorisation-Recherche Québec structuring group program. The work of M. Bertrand and G. Cloutier was supported in part by the Quebec Ministry of Education FCAR group program. A part of the project upon which this publication is based was performed pursuant to the University of Texas Grant CA64597 (M. Bertrand) with the NIH, PHS. The salaries of G. Soulez and G. Cloutier are supported in part by research scholarship awards from the Fonds de la Recherche en Santé du Québec. The Associate Editor responsible for coordinating the review of this paper and recommending its publication was G. Wang. Asterisk indicates corresponding author.
PY - 2004/2
Y1 - 2004/2
N2 - Changes in vessel wall elasticity may be indicative of vessel pathologies. It is known, for example, that the presence of plaque stiffens the vascular wall, and that the heterogeneity of its composition may lead to plaque rupture and thrombosis. Another domain of application where ultrasound elastography may be of interest is the study of vascular wall elasticity to predict the risk of aneurysmal tissue rupture. In this paper, this technology is introduced as an approach to noninvasively characterize superficial arteries. In such a case, a linear array ultrasound transducer is applied on the skin over the region of interest, and the arterial tissue is dilated by the normal cardiac pulsation. The elastograms, the equivalent elasticity images, are computed from the assessment of the vascular tissue motion. Investigating the forward problem, it is shown that motion parameters might be difficult to interpret; that is because tissue motion occurs radially within the vessel wall while the ultrasound beam propagates axially. As a consequence of that, the elastograms are subjected to hardening and softening artefacts, which are to be counteracted. In this paper, the Von Mises (VM) coefficient is proposed as a new parameter to circumvent such mechanical artefacts and to appropriately characterize the vessel wall. Regarding the motion assessment, the Lagrangian estimator was used; that is because it provides the full two-dimensional strain tensor necessary to compute the VM coefficient. The theoretical model was validated with biomechanical simulations of the vascular wall properties. The results allow believing in the potential of the method to differentiate hard plaques and lipid pools from normal vascular tissue. Potential in vivo implementation of noninvasive vascular elastography to characterize abdominal aneurysms and superficial arteries such as the femoral and the carotid is discussed.
AB - Changes in vessel wall elasticity may be indicative of vessel pathologies. It is known, for example, that the presence of plaque stiffens the vascular wall, and that the heterogeneity of its composition may lead to plaque rupture and thrombosis. Another domain of application where ultrasound elastography may be of interest is the study of vascular wall elasticity to predict the risk of aneurysmal tissue rupture. In this paper, this technology is introduced as an approach to noninvasively characterize superficial arteries. In such a case, a linear array ultrasound transducer is applied on the skin over the region of interest, and the arterial tissue is dilated by the normal cardiac pulsation. The elastograms, the equivalent elasticity images, are computed from the assessment of the vascular tissue motion. Investigating the forward problem, it is shown that motion parameters might be difficult to interpret; that is because tissue motion occurs radially within the vessel wall while the ultrasound beam propagates axially. As a consequence of that, the elastograms are subjected to hardening and softening artefacts, which are to be counteracted. In this paper, the Von Mises (VM) coefficient is proposed as a new parameter to circumvent such mechanical artefacts and to appropriately characterize the vessel wall. Regarding the motion assessment, the Lagrangian estimator was used; that is because it provides the full two-dimensional strain tensor necessary to compute the VM coefficient. The theoretical model was validated with biomechanical simulations of the vascular wall properties. The results allow believing in the potential of the method to differentiate hard plaques and lipid pools from normal vascular tissue. Potential in vivo implementation of noninvasive vascular elastography to characterize abdominal aneurysms and superficial arteries such as the femoral and the carotid is discussed.
KW - Mathematical modeling
KW - Mechanical properties
KW - Noninvasive scanning
KW - Ultrasound elastography
KW - Vascular pathologies
KW - Vascular wall
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U2 - 10.1109/TMI.2003.823066
DO - 10.1109/TMI.2003.823066
M3 - Article
C2 - 14964562
AN - SCOPUS:1342303481
VL - 23
SP - 164
EP - 180
JO - IEEE Transactions on Medical Imaging
JF - IEEE Transactions on Medical Imaging
SN - 0278-0062
IS - 2
ER -