The long-term objectives of this research are: (1) to identify geometric features of the vasculature that enhance arterial susceptibility to atherosclerotic disease and can be used for early identification of individuals accordingly at risk, and (2) to understand the role of mechanical factors in the localization and pathobiology of atherosclerosis. To achieve the first objective, relationships are sought between in vivo measurements of the geometric features of human coronary arteries and the pathology of the vessels, with a focus on the early lesion. The second objective is furthered by computing the distribution of fluid dynamic and intramural stresses in selected vessel segments, and seeking correlations between these variables and the thicknesses of the vascular intima and media, as measured in vivo. Clinical biplane coronary cineangiograms of sixty patients at The Ohio State University and Wake Forest University School of Medicine will be processed digitally to reconstruct the three- dimensional (3-D) course of the medial axes of selected segments of the left anterior descending and right coronary artery trees. Quantitative geometric parameters of the segments, including both static and dynamic measures of arterial geometry and measures of vessel kinematics, will be obtained from the axes using objective computer algorithms. Variations in geometry among individuals will be assessed. Intravascular ultrasound (IVUS) records of the same segments will be obtained and processed to yield detailed measurements of vessel morphometry collocated to the vessel axes. Doppler flow data and phasic pressure will also be acquired. Relations will be sought between the geometric variables from the angiograms and morphometric parameters derived from the IVUS records; and analysis will take into account individual variability with respect to the traditional risk factors for atherosclerosis. The dynamic data from the angiograms will be used in model calculations to estimate the effect of vessel motion and bending on the flow fieled and wall stresses. For twelve cases, the angiographic and IVUS records will be used to describe the 3-D lumen and wall of a portion of the vessel in diastole. The flow fieled and wall stresses in this region will be simulated numerically, using the Doppler and pressure data as input; the first flow calculation will be validated experimentally. By comparing the computed distribution of stresses acting on and in the vessel segment against that of intima/media thickness, inferences will be drawn regarding the role of mechanical forces in relation to human atherosclerosis.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
7R01HL058856-03
Application #
6389733
Study Section
Surgery and Bioengineering Study Section (SB)
Program Officer
Wassef, Momtaz K
Project Start
1999-04-01
Project End
2003-03-31
Budget Start
2001-04-01
Budget End
2002-03-31
Support Year
3
Fiscal Year
2001
Total Cost
$399,909
Indirect Cost
Name
Duke University
Department
Biomedical Engineering
Type
Schools of Engineering
DUNS #
071723621
City
Durham
State
NC
Country
United States
Zip Code
27705
Long, David S; Zhu, Hui; Friedman, Morton H (2013) Microscope-based near-infrared stereo-imaging system for quantifying the motion of the murine epicardial coronary arteries in vivo. J Biomed Opt 18:096013
Zhang, Qi; Steinman, David A; Friedman, Morton H (2010) Use of factor analysis to characterize arterial geometry and predict hemodynamic risk: application to the human carotid bifurcation. J Biomech Eng 132:114505
Liang, Yun; Zhu, Hui; Friedman, Morton H (2010) Measurement of the 3D arterial wall strain tensor using intravascular B-mode ultrasound images: a feasibility study. Phys Med Biol 55:6377-94
Friedman, Morton H (2009) Variability of arterial wall shear stress, its dependence on vessel diameter and implications for Murray's Law. Atherosclerosis 203:47-8
Liang, Yun; Zhu, Hui; Friedman, Morton H (2009) The correspondence between coronary arterial wall strain and histology in a porcine model of atherosclerosis. Phys Med Biol 54:5625-41
Zhu, Hui; Ding, Zhaohua; Piana, Robert N et al. (2009) Cataloguing the geometry of the human coronary arteries: a potential tool for predicting risk of coronary artery disease. Int J Cardiol 135:43-52
Zhu, Hui; Zhang, Ji; Shih, Jessica et al. (2009) Differences in aortic arch geometry, hemodynamics, and plaque patterns between C57BL/6 and 129/SvEv mice. J Biomech Eng 131:121005
Liang, Yun; Zhu, Hui; Friedman, Morton H (2008) Estimation of the transverse strain tensor in the arterial wall using IVUS image registration. Ultrasound Med Biol 34:1832-45
Liang, Yun; Zhu, Hui; Gehrig, Thomas et al. (2008) Measurement of the transverse strain tensor in the coronary arterial wall from clinical intravascular ultrasound images. J Biomech 41:2906-11
Gleason Jr, Rudolph L; Humphrey, Jay D (2005) A 2D constrained mixture model for arterial adaptations to large changes in flow, pressure and axial stretch. Math Med Biol 22:347-69

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