0
Technical Briefs

Three-Dimensional Geometry of the Human Carotid Artery

[+] Author and Article Information
Alexey V. Kamenskiy

Department of Mechanical and Materials Engineering,  University of Nebraska-Lincoln, Lincoln, NE 68588

Jason N. MacTaggart, Iraklis I. Pipinos

Department of Surgery,  University of Nebraska-Medical Center, Omaha, NE 68198

Jai Bikhchandani

 Creighton University Medical Center, Omaha, NE 68131

Yuris A. Dzenis1

Department of Mechanical and Materials Engineering,  University of Nebraska-Lincoln, Lincoln, NE 68588ydzenis@unl.edu

1

Corresponding author.

J Biomech Eng 134(6), 064502 (Jun 12, 2012) (7 pages) doi:10.1115/1.4006810 History: Received September 14, 2011; Revised March 15, 2012; Posted May 12, 2012; Published June 12, 2012; Online June 12, 2012

Accurate characterization of carotid artery geometry is vital to our understanding of the pathogenesis of atherosclerosis. Three-dimensional computer reconstructions based on medical imaging are now ubiquitous; however, mean carotid artery geometry has not yet been comprehensively characterized. The goal of this work was to build and study such geometry based on data from 16 male patients with severe carotid artery disease. Results of computerized tomography angiography were used to analyze the cross-sectional images implementing a semiautomated segmentation algorithm. Extracted data were used to reconstruct the mean three-dimensional geometry and to determine average values and variability of bifurcation and planarity angles, diameters and cross-sectional areas. Contrary to simplified carotid geometry typically depicted and used, our mean artery was tortuous exhibiting nonplanarity and complex curvature and torsion variations. The bifurcation angle was 36 deg ± 11 deg if measured using arterial centerlines and 15 deg ± 14 deg if measured between the walls of the carotid bifurcation branches. The average planarity angle was 11 deg ± 10 deg. Both bifurcation and planarity angles were substantially smaller than values reported in most studies. Cross sections were elliptical, with an average ratio of semimajor to semiminor axes of 1.2. The cross-sectional area increased twofold in the bulb compared to the proximal common, but then decreased 1.5-fold for the combined area of distal internal and external carotid artery. Inter-patient variability was substantial, especially in the bulb region; however, some common geometrical features were observed in most patients. Obtained quantitative data on the mean carotid artery geometry and its variability among patients with severe carotid artery disease can be used by biomedical engineers and biomechanics vascular modelers in their studies of carotid pathophysiology, and by endovascular device and materials manufacturers interested in the mean geometrical features of the artery to target the broad patient population.

FIGURES IN THIS ARTICLE
<>
Copyright © 2012 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Work flow diagram showing three major steps for geometry characterization: segmentation of arterial contours, generation of 3D mean geometry, and analysis of geometrical features (tangent, normal, and binormal vectors of the arterial centerlines used for calculations of curvature and torsion; and change of lumen equivalent diameter along the length of the artery calculated as =2·cross-sectional area/π for cross sections (in blue) orthogonal to the centerlines)

Grahic Jump Location
Figure 2

Schematic of the mean carotid bifurcation. CCA = common carotid artery, ICA = internal carotid artery, ECA = external carotid artery, L = lateral, M = medial, A = anterior, P = posterior. Arrows show planarity and bifurcation angles measured using two different approaches (as angle formed by branching centerlines and as angle formed between medial wall of the ICA and lateral wall of the ECA). Distance factor was calculated as the ratio of the ICA centerline length (solid bold line) to the shortest distance between two locations: the end of the bulb and point where two centerlines branch (dashed bold line).

Grahic Jump Location
Figure 3

Anterior, lateral, posterior, and medial views of the mean carotid artery reconstructed from the results of CTA studies of 16 patients with carotid artery disease. See conventions of the anterior, lateral, posterior, and medial directions in Fig. 2.

Grahic Jump Location
Figure 4

(a) Centerlines of the mean carotid artery plotted in the posterior and medial planes. Frenet frame at each point of the centerline is defined by tangent, normal, and binormal vectors; (b)–(d) distributions of centerline curvature (b), torsion (c), and combined curvature (d) along the length of the mean artery. Thin vertical lines represent standard deviations, thick vertical lines represent standard errors.

Grahic Jump Location
Figure 5

(a) B/A radio of semimajor to semiminor axes of the elliptical cross sections plotted along the length of the artery; (b) change of cross-sectional area (mm2 ) along the length of the artery. Green dotted line represents cumulative ICA + ECA area. Thin vertical lines represent standard deviations of presented mean data, thick vertical lines represent standard errors.

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In