Effects of Residual Stress, Axial Stretch, and Circumferential Shrinkage on Coronary Plaque Stress and Strain Calculations: A Modeling Study Using IVUS-Based Near-Idealized Geometries.
Accurate stress and strain calculations are important for plaque progression and vulnerability assessment. Models based on in vivo data often need to form geometries with zero-stress/strain conditions. The goal of this paper is to use IVUS-based near-idealized geometries and introduce a three-step model construction process to include residual stress, axial shrinkage, and circumferential shrinkage and investigate their impacts on stress and strain calculations. In Vivo intravascular ultrasound (IVUS) data of human coronary were acquired for model construction. In Vivo IVUS movie data were acquired and used to determine patient-specific material parameter values. A three-step modeling procedure was used to make our model: (a) wrap the zero-stress vessel sector to obtain the residual stress; (b) stretch the vessel axially to its length in vivo; and (c) pressurize the vessel to recover its in vivo geometry. Eight models were constructed for our investigation. Wrapping led to reduced lumen and cap stress and increased out boundary stress. The model with axial stretch, circumferential shrink, but no wrapping overestimated lumen and cap stress by 182% and 448%, respectively. The model with wrapping, circumferential shrink, but no axial stretch predicted average lumen stress and cap stress as 0.76 kPa and -15 kPa. The same model with 10% axial stretch had 42.53 kPa lumen stress and 29.0 kPa cap stress, respectively. Skipping circumferential shrinkage leads to overexpansion of the vessel and incorrect stress/strain calculations. Vessel stiffness increase (100%) leads to 75% lumen stress increase and 102% cap stress increase.
Mathematical Sciences Department, Worcester Polytechnic Institute, Worcester, MA 01609.
Liang
L
Wang
Department of Cardiology, Zhongda Hospital, Southeast University, Nanjing 210009, China.
Jian
J
Zhu
Department of Medicine, Emory University School of Medicine, Atlanta, GA 30307.
Habib
H
Samady
Department of Medicine, Emory University School of Medicine, Atlanta, GA 30307.
David
D
Monoly
Mallinckrodt Institute of Radiology, Washington University, St. Louis, MO 63110.
Jie
J
Zheng
Department of Mathematics, Southeast University, Nanjing 210096, China.
Xiaoya
X
Guo
The Cardiovascular Research Foundation, Columbia University, New York, NY 10022.
Akiko
A
Maehara
Network Technology Research Institute, China United Network Communications Co., Ltd., Beijing 100140, China.
Chun
C
Yang
Department of Cardiology, Zhongda Hospital, Southeast University, Nanjing 210009, China.
Genshan
G
Ma
The Cardiovascular Research Foundation, Columbia University, New York, NY 10022.
Gary S
GS
Mintz
Mathematical Sciences Department, Worcester Polytechnic Institute, Worcester, MA 01609;Department of Mathematics, Southeast University, Nanjing 210096, China.
Dalin
D
Tang
D019245:Compressive Strength; D003198:Computer Simulation; D003324:Coronary Artery Disease / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology*; D055119:Elastic Modulus; D054459:Elasticity Imaging Techniques / Q000379:methods; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology*; D033081:Shear Strength; D013314:Stress, Mechanical; D013718:Tensile Strength; D018084:Ultrasonography, Interventional / Q000379:methods*; D014783:Viscosity